CN120519139A - Composite synergistic system for shale gas old well and production increasing process of fixed tubular column - Google Patents
Composite synergistic system for shale gas old well and production increasing process of fixed tubular columnInfo
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- CN120519139A CN120519139A CN202510670419.6A CN202510670419A CN120519139A CN 120519139 A CN120519139 A CN 120519139A CN 202510670419 A CN202510670419 A CN 202510670419A CN 120519139 A CN120519139 A CN 120519139A
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Abstract
本发明提供了一种用于页岩气老井的复合增效体系及不动管柱增产工艺，该复合增效体系主要包括以下物质：10%‑12%润湿改善剂；4%‑6%除垢剂；2%‑3%阻垢分散剂；5%‑10%降阻助排剂；15%‑20%协同促进剂；所述湿润改善剂为烷基多糖苷、阴离子表面活性剂十二烷基苯磺酸钠和去离子水的混合，所述湿润改善剂中烷基多糖苷为5%‑10%，所述阴离子表面活性剂十二烷基苯磺酸钠为15%‑18%；所述除垢剂为α‑烯基磺酸钠和壬基酚聚氧乙烯醚硫酸铵盐的混合，所述除垢剂中α‑烯基磺酸钠和壬基酚聚氧乙烯醚硫酸铵盐的质量比为2:1‑3:1。本发明的复合增效体系通过不同物料以及不同剂量之间的组合复用，从而研发出一种集振动、渗透和分散作用的多功能复合增效体系，从而实现页岩气老井的不动管柱增产施工。
The present invention provides a composite synergistic system for old shale gas wells and a production enhancement process without a fixed tubing string. The composite synergistic system mainly comprises the following substances: 10%-12% wetting improver; 4%-6% descaling agent; 2%-3% scale inhibitor and dispersant; 5%-10% drag reducing and drainage aid; and 15%-20% synergistic promoter. The wetting improver is a mixture of an alkyl polysaccharide, an anionic surfactant, sodium dodecylbenzenesulfonate, and deionized water, wherein the alkyl polysaccharide accounts for 5%-10% and the anionic surfactant, sodium dodecylbenzenesulfonate, accounts for 15%-18%. The descaling agent is a mixture of sodium α-olefin sulfonate and ammonium sulfate of polyoxyethylene nonylphenol ether, wherein the mass ratio of sodium α-olefin sulfonate to ammonium sulfate of polyoxyethylene nonylphenol ether is 2:1-3:1. The composite synergistic system of the present invention is developed into a multifunctional composite synergistic system integrating vibration, penetration and dispersion by combining and reusing different materials and different dosages, thereby realizing the production increase construction of old shale gas wells without moving the tubing.
Description
Technical Field
The invention relates to the technical field of petroleum and natural gas exploitation, in particular to a compound synergy system for a shale gas old well and a production increase process of an immobile tubular column.
Background
At present, unconventional oil gas exploitation of shale oil gas, deep coal rock gas and the like in China becomes development emphasis and new growth points of oil field companies, but as shale gas production time passes, the formation pressure of shale gas wells gradually decreases, the gas yield gradually decreases, well bore effusion and blockage are serious, the pressure and yield decrease is obvious, and old well measure yield increasing technology is attracting more and more attention.
With the progress of shale gas well production, stratum particulate migration, proppant backflow fine sand, soluble bridge plug dissolvent residues, inorganic scale, well drilling, fracturing and other well entering fluids or materials returning, iron oxides and the like caused by bacterial metabolites are likely to block stratum cracks and wellbore channels, most of blockage is a result of daily accumulation, blockage is subjected to processes of starting, aggravating, blocking and the like, the existing dredging means are mainly realized through chemical reagents, the removal of blocking materials of a pipeline is realized, but the existing chemical reagents are mainly only aiming at single types, multi-effect synergy is difficult to realize, the pipe column is required to be continuously moved in the process of application of the traditional chemical reagents, so that the dredging effect can be optimized, and the operation safety is ensured, a series of problems can be generated in the process of moving the pipe column, such as secondary damage to the stratum can be caused by moving the pipe column, the sediment can be stirred in the process of moving the pipe column, and the bottom of the well can be caused by sediment, so that fine particles enter the stratum cracks are caused, and the permeability is reduced.
In view of this, the present invention has been made.
Disclosure of Invention
The first aim of the invention is to provide a composite synergistic system for shale gas old well, which can treat various plugs simultaneously through the compound use of various substances, thereby remarkably improving the plug removal effect, well overcoming the defect that a pipe column needs to be frequently moved in the traditional chemical dredging agent, and having the characteristics of safety, high efficiency and environmental friendliness.
The second aim of the invention is to provide a shale gas old well fixed string production increasing construction process, which adopts the composite synergistic system, and omits the operation of continuously moving oil pipes by pumping the composite synergistic system without moving a string, so that the action effect of the composite synergistic system is optimized to a great extent, and the composite synergistic system can be soaked in a blocking area for a long time to fully dissolve the blocking objects.
In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:
the composite synergistic system for the shale gas old well mainly comprises the following substances in percentage by mass:
10% -12% of a wetting improver;
4% -6% of a descaling agent;
2% -3% of scale inhibition dispersing agent;
5-10% of resistance-reducing and drainage-assisting agent;
15% -20% of synergistic accelerator;
The wetting improver is a mixture of alkyl polyglucoside, anionic surfactant sodium dodecyl benzene sulfonate and deionized water, wherein the alkyl polyglucoside in the wetting improver is 5-10%, and the anionic surfactant sodium dodecyl benzene sulfonate is 15-18%;
the scale remover is a mixture of alpha-sodium alkenyl sulfonate and nonylphenol polyoxyethylene ether ammonium sulfate, and the mass ratio of the alpha-sodium alkenyl sulfonate to the nonylphenol polyoxyethylene ether ammonium sulfate in the scale remover is 2:1-3:1.
Preferably, as a further specific embodiment,
12% Wetting improver;
5% of a detergent;
3% of scale inhibition dispersant;
8% of resistance-reducing and drainage-assisting agent;
19% of a synergistic accelerator;
The alkyl polyglucoside in the wetting improver is 8%, and the anionic surfactant sodium dodecyl benzene sulfonate is 16%;
The mass ratio of the alpha-sodium alkenyl sulfonate to the nonylphenol polyoxyethylene ether ammonium sulfate salt in the scale remover is 2.5:1.
In the invention, through the combined use of the wetting improver, the scale remover, the scale reducing dispersant, the resistance reducing and cleanup additive and the synergistic accelerator, a supermolecule multifunctional composite synergistic system is developed, the supermolecule multifunctional composite synergistic system shows remarkable technical advantages through unique molecular recognition and dynamic assembly capability, compared with the traditional chemical dredging agent, the composite synergistic system provided by the invention can be more efficiently contacted with various plugs and can reduce secondary damage to stratum, and meanwhile, the composite synergistic system provided by the invention has the characteristics of spectral adaptability and selective dissolution, can realize efficient blocking removal under mild conditions, avoid corrosion of strong acid and alkali to tubular columns and stratum, and simultaneously has the functions of blocking removal, descaling, water removal lock, cleanup and the like.
In the present invention, the wetness improver is an alkyl polyglycoside, According to the invention, a compound system of alkyl polyglucoside and anionic surfactant sodium dodecyl benzene sulfonate is adopted to be used as a high-efficiency wetting improver, wherein the two compounds can obviously reduce the surface tension of an aqueous solution, the spreading capacity of liquid on the rock surface is enhanced, so that the wetting performance is improved, simultaneously, hydroxyl in the alkyl polyglucoside and sulfonic acid groups in the anionic surfactant sodium dodecyl benzene sulfonate act together, so that the solution is more easily adsorbed on the shale surface covered by organic matters or oil films, water phase permeation is promoted, simultaneously, hydroxyl in the alkyl polyglucoside can be adsorbed on the rock surface through hydrogen bond, so that the oil wetting performance is converted to water wetting performance, and the strong group in the anionic surfactant sodium dodecyl benzene sulfonate can further strengthen the effect of changing the wetting performance of the rock, so that the efficiency of a compound system is improved, the water-phase polysaccharide is improved, the alkyl polyglucoside has good effect on the organic polyglucoside, the high-activity sodium dodecyl polyglucoside can be stably treated under the conditions of high-level, and the high-efficiency sodium dodecyl polygluconate can be stably treated under the conditions of the high-level environment, and the high-efficiency polysaccharide is still realized, according to the invention, the anionic surfactant sodium dodecyl benzene sulfonate and the alkyl polysaccharide glycoside are multiplexed to serve as a high-efficiency wetting improver, and for the invention, the dosage between the alkyl polyglucoside and the anionic surfactant sodium dodecyl benzene sulfonate in the wetting improver is limited to a certain extent, when the alkyl polyglucoside is 5% -10%, the anionic surfactant sodium dodecyl benzene sulfonate is 15% -18%, preferably 8%, the chemical composite synergistic system prepared by the anionic surfactant sodium dodecyl benzene sulfonate is 16%, the effect of the chemical composite synergistic system is excellent because the dosage proportion of the alkyl polyglucoside and the anionic surfactant sodium dodecyl benzene sulfonate in the system compounded to serve as the wetting improver can obviously influence the wetting improving effect of the system, the reasonable proportion between the alkyl polyglucoside and the anionic surfactant sodium dodecyl benzene sulfonate can better exert the synergistic effect, the improper proportion between the alkyl polyglucoside and the anionic surfactant can lead to the performance reduction of the wetting improver even the antagonistic effect, wherein if the dosage of the alkyl polyglucoside is too small and the anionic surfactant sodium dodecyl benzene sulfonate is 15% -18%, the effect of the prepared composite synergistic system is excellent, the ionic sodium dodecyl benzene sulfonate can not cause the poor in the solubilizing effect of the surface of the system, and the poor in the solubility of the ionic polysaccharide can not cause the poor in the effect of the surface stability of the organic sodium dodecyl benzene sulfonate.
According to the invention, the alpha-alkenyl sodium sulfonate and the nonylphenol polyoxyethylene ether ammonium sulfate salt are mixed to be used as a scale remover, so that the blocking removal effect is remarkably improved, the limitation of a single surfactant is overcome, the alpha-alkenyl sodium sulfonate has excellent capability of reducing the surface tension, so that the surface of rock can be quickly wetted, the scale remover is promoted to enter microcracks and pores of shale gas old wells, and polyoxyethylene chains in the nonylphenol polyoxyethylene ether ammonium sulfate salt can enhance the molecular extensibility and act synergistically with the alpha-alkenyl sodium sulfonate to form a more stable micelle structure, so that the permeability and the spreading capability of the scale remover are further improved; meanwhile, the alpha-alkenyl sulfonic acid can still keep activity at high mineralization degree and high temperature through compounding the alpha-alkenyl sulfonic acid and the alpha-alkenyl sulfonic acid, if the alpha-alkenyl sulfonic acid is singly used, the alpha-alkenyl sulfonic acid can be invalid due to precipitation of calcium and magnesium ions, the EO chain of the ammonium salt of the polyoxyethylene nonyl phenyl ether sulfate can endow the ammonium salt of the polyoxyethylene nonyl phenyl ether sulfate with hard water resistance, the divalent ions can be chelated to protect the ammonium salt of the polyoxyethylene nonyl phenyl ether sulfate from being influenced by the calcium and magnesium ions, the tolerance is obviously improved through compounding the ammonium salt of the polyoxyethylene nonyl phenyl ether sulfate, and simultaneously, the organic blockage and the inorganic blockage can be treated, when the mass ratio of the alpha-sodium alkenyl sulfonate to the nonylphenol polyoxyethylene ether ammonium sulfate salt in the scale remover is 2:1-3:1, preferably the mass ratio of the alpha-sodium alkenyl sulfonate to the nonylphenol polyoxyethylene ether ammonium sulfate salt is 2.5:1, the prepared composite synergistic system has excellent effect, because the mass ratio between the alpha-sodium alkenyl sulfonate and the nonylphenol polyoxyethylene ether ammonium sulfate salt can obviously influence the performance of the composite synergistic system. The surface activity, the emulsifying capacity and the salt resistance stability can be optimized through synergistic effect, but different proportions can generate differential effect, wherein if the dosage of the alpha-alkenyl sodium sulfonate is too large, the hard water resistance of the prepared composite synergistic system is weaker, the solubilizing capacity of the composite synergistic system for heavy organic matters is limited, and if the dosage of the nonylphenol polyoxyethylene ether ammonium sulfate salt is too large, the biodegradability of the prepared composite synergistic system is poorer.
Preferably, as a further specific embodiment, the scale inhibition and dispersion agent is a mixture of hydroxyethylidene diphosphonic acid, sodium hexametaphosphate and deionized water, wherein the mass percentage of hydroxyethylidene diphosphonic acid is 10% -15%, and the mass percentage of sodium hexametaphosphate is 2% -5%;
preferably, the mass percentage of the hydroxyethylidene diphosphonic acid is 12%, and the mass percentage of the sodium hexametaphosphate is 3%.
According to the invention, by adopting the mixture of the hydroxyethylidene diphosphonic acid, the sodium hexametaphosphate and the deionized water as the scale inhibition and dispersion agent, the inhibition and removal effects on inorganic scales can be obviously improved, and the formation compatibility and the operation economy are simultaneously considered, wherein the hydroxyethylidene diphosphonic acid can form stable chelates with a plurality of metal ions through chelation, so that scale crystal nuclei are formed, and can be adsorbed on the surface of crystals to inhibit scale crystal growth, and meanwhile, the sodium hexametaphosphate can disperse formed micro-scale particles through electrostatic repulsion to prevent aggregation and precipitation, the dispersion capability on iron oxide and silicon scale is outstanding, meanwhile, the hydroxyethylidene diphosphonic acid is more effective in scale removal under the high-temperature and high-pH environment, the sodium hexametaphosphate is better in performance under the low-temperature and high-salinity conditions, and the two compound systems can permeate into a scale layer, and the two compound systems can chelate the metal ions in the scale, the sodium hexametaphosphate and the sodium hexametaphosphate, so that the micro-scale particles are decomposed to promote the disintegration and the back-flow into micro-scale particles; wherein for the invention, the dosage ratio between the two is also limited, wherein the mass percent of the hydroxyethylidene diphosphonic acid is 10% -15%, the mass percent of the sodium hexametaphosphate is 2% -5%, preferably the mass percent of the hydroxyethylidene diphosphonic acid is 12%, and the mass percent of the sodium hexametaphosphate is 3%, the prepared compound synergistic system has excellent effect because the dosage ratio between the two directly influences the effect of the scale inhibition dispersing agent, the composite synergistic system prepared by the method has insufficient chelating ability on compact scales such as calcium carbonate when the dosage of the hydroxyethylidene diphosphonic acid is small, meanwhile, sodium hexametaphosphate is easy to be hydrolyzed and invalid at high temperature without the assistance of the hydroxyethylidene diphosphonic acid, and if the dosage of the hydroxyethylidene diphosphonic acid is high, the dispersing effect of the composite synergistic system on suspended particles is weaker than that of sodium hexametaphosphate, so that the overall dispersing effect of the composite synergistic system is poor.
Preferably, as a further specific embodiment, the group-reducing cleanup additive is a mixture of cocamidopropyl amine oxide, dodecyl dimethyl hydroxysulfobetaine and deionized water;
The mass percentage of the cocoamidopropyl amine oxide is 8-12%, and the mass percentage of the dodecyl dimethyl hydroxysulfobetaine is 7-9%;
preferably, the mass percentage of the cocamidopropyl amine oxide is 10%, and the mass percentage of the dodecyl dimethyl hydroxysulfobetaine is 8%.
According to the invention, the cocoamidopropyl amine oxide, the dodecyl dimethyl hydroxysulfobetaine and deionized water are mixed to be used as a resistance-reducing discharge assistant, so that the fluid friction resistance can be remarkably reduced, the flowback efficiency is improved and the reservoir protection is considered, wherein the cocoamidopropyl amine oxide is used as a zwitterionic surfactant, a hydration layer can be formed on the pipe wall through adsorption, so that the friction between the fluid and a pipe column is reduced, the friction coefficient is reduced, the unique sliding resistance effect of the cocoamidopropyl amine oxide can promote the fluid turbulence to be converted into laminar flow, the strong hydrophilic sulfonic acid group of the sulfobetaine can enhance the fluid lubricity, the fluid state can be further optimized in cooperation with the cocoamidopropyl amine oxide, meanwhile, the shear stability is excellent, in addition, the complex use between the cocoamidopropyl amine oxide can reduce the surface tension, so that the capillary resistance is reduced, the flowback of a fracturing fluid is promoted, the wettability of the dodecyl dimethyl hydroxysulfobetaine is changed in cooperation with the amide groups of the cocoamidopropyl amine oxide, the water locking injury is reduced, and the residual oil phase and the organic blocking effect of the cocoamidopropyl amine oxide can be reduced, and the residual oil phase and the drain-back flow can be blocked on the surface of the amine oxide can be reduced; and for the present invention, the amount of the two is very important for the performance of the compound synergistic system prepared by the present invention, when the mass percentage of cocamidopropyl amine oxide is 8% -12%, the mass percentage of dodecyl dimethyl hydroxysulfobetaine is 7% -9%, preferably the mass percentage of cocamidopropyl amine oxide is 10%, when the mass percentage of the dodecyl dimethyl hydroxysulfobetaine is 8%, the prepared compound synergistic system has excellent effect, because the dosage ratio of the cocoamidopropyl amine oxide to the dodecyl dimethyl hydroxysulfobetaine can obviously influence the comprehensive performance of the resistance-reducing and drainage-assisting agent in the fracturing or dredging operation of the old shale gas well. The friction resistance, the flowback efficiency and the reservoir compatibility of the fluid can be optimized through the synergistic effect, but different proportions can generate a differentiation effect, wherein if the consumption of the cocamidopropyl amine oxide is excessive, the discharge assisting effect of the prepared compound synergistic system is weaker, more foam can be generated, and therefore, an additional defoaming agent is needed to be added, and if the consumption of the cocamidopropyl amine oxide is less, the resistance reducing capability of the prepared compound synergistic system is weaker, and part of the cocamidopropyl amine oxide can be partially invalid at a high temperature.
Preferably, as a further specific embodiment, the synergistic accelerator is an inorganic salt, nonylphenol polyoxyethylene ether, a polyhydric organic alcohol, and deionized water;
wherein the mass percentage of the inorganic salt is 1-2%, the mass percentage of the nonylphenol polyoxyethylene ether is 15-18%, and the mass percentage of the polyhydric organic alcohol is 4-6%;
preferably, the mass percentage of the inorganic salt is 1.5%, the mass percentage of the nonylphenol polyoxyethylene ether is 16%, and the mass percentage of the polyhydric organic alcohol is 5%.
In the invention, the inorganic salt, the polyoxyethylene nonylphenol ether, the polyhydric organic alcohol and the deionized water are mixed to be used as a synergistic accelerator, so that the permeability, the stability and the reservoir adaptability of a composite synergistic system can be obviously improved, wherein the polyoxyethylene nonylphenol ether can further reduce the surface tension, so that the composite synergistic system is promoted to enter microcracks and pores, meanwhile, the hydrophilic-lipophilic balance of the polyoxyethylene nonylphenol ether can be adapted to different wettability reservoirs, the polyhydric organic alcohol can be combined with water molecules through the action of hydrogen bonds, so that the liquid viscosity is reduced, the fluidity is improved, the polyoxyethylene nonylphenol ether can be assisted to solubilize organic plugs, meanwhile, the inorganic salt can also compress an electric double layer, the clay expansion is reduced, the ionic strength can also be regulated, so that the stability of the micelle of the polyoxyethylene nonylphenol ether is enhanced, in addition, the polyoxyethylene nonylphenol ether is easy to separate out under the condition of high salt, however, the polyol can be used as a cosolvent to maintain the solubility of the inorganic salt, the inorganic salt can also delay the cloud point phenomenon of the polyoxyethylene nonylphenol ether at high temperature, and the polyol can buffer the pH value so as to avoid the severe reaction of the inorganic salt and stratum minerals, wherein for the purposes of the invention, the inorganic salt accounts for 1-2 percent by mass, the polyoxyethylene nonylphenol ether accounts for 15-18 percent by mass, the polyol accounts for 4-6 percent by mass, preferably the inorganic salt accounts for 1.5 percent by mass, the polyoxyethylene nonylphenol ether accounts for 16 percent by mass, and the polyol accounts for 5 percent by mass, the prepared composite synergistic system has excellent effect because the proper dosage proportion can obviously influence the osmotic agent, the stabilizer and the reservoir compatibility of the synergistic accelerator, and if the polyoxyethylene nonylphenol ether is excessively high in dosage, the nonylphenol polyoxyethylene ether is easy to lose efficacy in a high-salt environment, so that the nonylphenol polyoxyethylene ether is buffered by increasing the ratio of the polyol, if the consumption of the polyol is too high, the viscosity reducing effect is too strong, so that the sand carrying capacity is reduced, and if the consumption of the inorganic salt is too high, the overall salinity of the composite synergistic system is increased, and the nonylphenol polyoxyethylene ether is likely to be separated out under the high salt, so that scaling can be caused.
Preferably, as a further specific embodiment, the composition further comprises 15% -20% of chelating dispersant, 3% -5% of penetrating agent, 0.1% -0.2% of sterilizing agent and 23.8% -45.9% of deionized water;
Wherein the chelating dispersant is a mixture of polyepoxysuccinic acid, polyphosphate and organic alcohol;
the penetrating agent is one or more of trideceth and sodium dioctyl sulfosuccinate;
The sterilizing agent is a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one.
In the invention, the performance of the compound synergistic system is further improved by adding the chelating dispersant, the penetrating agent and the sterilizing agent, wherein the chelating dispersant is the mixture of polyepoxysuccinic acid, polyphosphate and organic alcohol, the problems of inorganic scale precipitation, clay expansion and fluidity can be effectively solved by the compound system of the polyepoxysuccinic acid, the clay expansion and the fluidity can be simultaneously considered, the environment-friendly and economical efficiency can be simultaneously considered, the polyepoxysuccinic acid can inhibit the formation of compact scales such as calcium carbonate and the like by chelating metal ions such as calcium ions, magnesium ions and the like, the unique threshold effect of the polyepoxysuccinic acid is adsorbed on the surfaces of scale crystals, the crystal growth is prevented, the polyphosphate can disperse the formed microcrystal particles through electrostatic repulsion, the aggregation deposition of the microcrystal particles is prevented, the dispersing effect of the polyphosphate on iron scale and the silicon scale is obvious, the organic alcohol can reduce the viscosity of liquid, the permeability of the medicament in cracks is improved, the compatibility of the polyepoxysuccinic acid and the polyphosphate is enhanced as a cosolvent, thereby the precipitation under high salt is prevented, and in addition, the compound synergistic system can simultaneously treat the hardness scale, the colloid scale and the organic-inorganic compound scale; meanwhile, the invention can obviously improve the wetting agent, the permeation efficiency and the reservoir compatibility of the medicament by adding the penetrating agent, wherein the tridecyl alcohol polyoxyethylene ether can further reduce the surface tension of the solution and obviously reduce the capillary resistance, thereby promoting the medicament to enter the vitamin nano-pores, the lengths of the hydrophobic chain and the hydrophilic chain are adjustable so as to adapt to different wettability reservoirs, the strong hydrophilic sulfonic acid group in the sodium dioctyl sulfosuccinate can change the surface of the rock from oil wet to water wet, reduce the damage of water lock, the emulsion efficiency to light oil and organic scale is high, and meanwhile, the addition of the sterilizing agent can play a role in long-acting sterilization and bacterial metabolite dissolution, so that a series of problems caused by microbial activity lock are effectively solved.
The invention also provides a shale gas old well fixed tubular column yield increasing process, which is applied to the composite synergistic system for the shale gas old well and comprises the following steps of:
Carrying out data collection and analysis on the periphery of the shale gas old well, then designing a measure scheme and building a shale gas old well immobile tubular column construction environment;
selecting proper injection measures according to the characteristics of the old shale gas well body structure, the gas production well head and the well completion pipe string, and injecting the injection measures into the composite synergistic system for blowout after well soaking;
The injection measure comprises any one or two of oil pipe injection, sleeve injection and oil sleeve co-injection, wherein the oil pipe injection is blocked or throttled for an oil pipe, the sleeve injection is blocked or throttled for the sleeve annulus of the old shale gas well, and the oil sleeve co-injection is blocked or throttled for the old shale gas well near oil pipe shoes, horizontal wells or near wells or water locks of reservoirs caused by adjacent well channeling;
The formula for calculating the specific dosage of the compound synergistic system is as follows:
Wherein:
q total amount of composite synergistic system (m 3)
Crack complexity correction coefficient (1.2-2.0)
Substrate inhomogeneity coefficient (0.8-1.5)
Fracture volume (m 3)
Fracture porosity (0.3-0.6)
Substrate volume (m 3)
Substrate porosity (0.3-0.6)
Target compound synergistic system concentration (5-10 wt%)
Saturation of gas (0.3-0.7)
Reaction time of braised well (h)
Effective action time (h) of composite synergistic system
Measure treatment target radius (m)
Radius of action (m) of composite synergistic system
R is the residual coefficient of the composite synergistic system (generally 0.1-0.3).
Preferably, as a further specific implementation manner, a nitrogen oil pipe is adopted to push the compound synergistic system in the oil pipe injection process, wherein the pushing construction displacement of the nitrogen is 600-800Nm 3/h, the pushing time is 1-2h, and the well-stewing time is 24-48h.
Preferably, as a further specific implementation manner, nitrogen is adopted to push the compound synergistic system in the injection process of the sleeve, wherein the pushing construction displacement of the nitrogen is 600-1200Nm 3/h, the pushing time is 2-4h, and the well stewing time is 24-72h.
Preferably, as a further specific implementation mode, nitrogen is adopted to respectively inject the oil pipe and the sleeve into the composite synergistic system for pushing, wherein the pushing construction displacement of the nitrogen is 1000-1200Nm 3/h, the pushing time is 6-8h, and the well-stewing time is 48-72h.
In the invention, the composite synergistic system can be filled by adopting the nitrogen to fill the composite synergistic system in the pipe column, namely, the nitrogen with different construction displacement can be adopted to push the composite synergistic system in the whole time period when the nitrogen is adopted to fill the pipe column, so that the composite synergistic system can spread over a larger range, the effect is better, and compared with the filling mode of adopting one nitrogen pushing construction displacement in the whole time, the filling mode of adopting the variable displacement disturbance type has higher yield increase multiple.
According to the invention, the production increasing process of the fixed pipe column suitable for the shale gas old well is provided, the geological condition, the engineering condition, the dynamic condition and the economic condition of the shale gas old well are integrated to perform optimization of the target well, and a novel environment-friendly supermolecule multifunctional composite synergistic system is matched, so that the injection, pushing and blocking removal and reproduction of the fixed pipe column are realized, and compared with the traditional chemical injection mode, the fixed pipe column construction mode provided by the invention does not need to drop a pipe column or disassemble wellhead equipment, greatly reduces the operation time, and the operation mode of the movable pipe column always needs to balance the pressure of well-killing liquid, so that reservoir damage is easily caused, the injection of the fixed pipe column can keep the pressure balance of a shaft well, and secondary damage is avoided; according to the fixed pipe string production increasing process, a composite synergistic system is accurately put in a blocking area of a shale gas old well selectively, meanwhile, the using amount of the synergistic system is accurately established through a series of creative labor and a formula sought by an inventor, so that damage to a fracture network and excessive use of chemical reagents caused by mechanical operation to the shale gas old well are reduced, meanwhile, the traditional filling mode is difficult to accurately control an action range, leakage of effective medicaments is easy to cause, the fixed pipe string construction mode provided by the invention is more suitable for the shale gas old well with sleeve deformation and poor shaft integrity, the traditional filling process can not be implemented due to shaft obstruction of the shale gas old well, multiple functions can be synchronously integrated, and meanwhile, the flow back amount generated by the fixed pipe string process can be reduced by 40% -60%.
The oil pipe injection composite synergistic system has multiple advantages, can obviously improve the operation efficiency and the reservoir protection effect, can directly convey the composite synergistic system to a target interval, avoids invalid diffusion of the composite synergistic system in a sleeve annulus, thereby greatly improving the medicament utilization rate, and simultaneously realizes layering treatment by sleeving and combining sealing treatment with the oil pipe, and can well control the flow and pressure by injecting the oil pipe, thereby avoiding the composite synergistic system from entering a non-target layer and greatly saving the dosage of the composite synergistic system.
The sleeve injection composite synergistic system has unique advantages, and the sleeve injection type efficient scheme for treating scenes such as full-parallel section uniform blockage, oil pipe limitation and the like in the sleeve injection type fixed pipe column process can fully exert the advantages of large discharge capacity and wide coverage through the matching temporary blocking technology and real-time monitoring.
Compared with the prior art, the invention has the beneficial effects that:
(1) The invention provides a composite synergistic system for shale gas old wells, which can treat various plugs simultaneously through the compound use of various substances, thereby remarkably improving the plug removal effect, well overcoming the defect that a pipe column needs to be frequently moved in the traditional chemical dredging agent, and having the characteristics of safety, high efficiency and environmental friendliness.
(2) The invention provides a shale gas old well fixed tubular column production increasing process, which adopts the composite synergistic system, and omits continuous oil pipe moving operation by pumping the composite synergistic system without moving the tubular column, so that the action effect of the composite synergistic system is optimized to a great extent, and the composite synergistic system can be soaked in a blocking area for a long time to fully dissolve a blocking object.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures.
FIG. 1 is a process flow diagram of tubing injection;
FIG. 2 is a process flow diagram of a cannula injection;
FIG. 3 is a process flow diagram of oil jacket co-injection;
FIG. 4 is a specific data diagram of variable displacement in mode one;
FIG. 5 is a specific data diagram of variable displacement in mode two;
FIG. 6 is a specific data diagram of variable displacement in mode three;
fig. 7 is a specific data diagram of variable displacement in mode four.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and detailed description, but it will be understood by those skilled in the art that the examples described below are some, but not all, examples of the present invention, and are intended to be illustrative of the present invention only and should not be construed as limiting the scope of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In order to more clearly illustrate the technical scheme of the invention, the following description is given by way of specific examples.
Example 1
The invention relates to a composite synergistic system for shale gas old wells, which comprises the following specific substances in percentage by weight:
10% of a wetting improver;
4% of a scale remover;
2% of scale inhibition dispersant;
5% of resistance-reducing and drainage-assisting agent;
15% of a synergistic accelerator;
15% chelating dispersant;
3% penetrant;
0.1% sterilant;
45.9 deionized water;
Wherein the wetting improver is 5% alkyl polyglucoside, 15% sodium dodecyl benzene sulfonate and 80% deionized water;
the scale remover is alpha-sodium alkenyl sulfonate and nonylphenol polyoxyethylene ether ammonium sulfate with the mass ratio of 2:1;
the scale inhibition and dispersion agent is 10 percent of hydroxyethylidene diphosphonic acid, 2 percent of sodium hexametaphosphate and 88 percent of deionized water;
The resistance-reducing and drainage-assisting agent is a mixture of 8% of cocamidopropyl amine oxide, 7% of dodecyl dimethyl hydroxysulfobetaine and 85% of deionized water;
the synergistic accelerator is 1% of inorganic salt, 15% of polyoxyethylene nonylphenol ether, 4% of polyhydric organic alcohol and 80% of deionized water;
The chelating dispersant is a mixture of 33% polyepoxysuccinic acid, 14% polyphosphate and 53% organic alcohol;
The penetrating agent is tridecyl alcohol polyoxyethylene ether;
the sterilizing agent is a mixture of 50% of 5-chloro-2-methyl-4-isothiazolin-3-one and 50% of 2-methyl-4-isothiazolin-3-one;
the invention relates to a shale gas old well immobile tubular column yield increasing process, which mainly comprises the following steps:
firstly, data collection and analysis are carried out on the periphery of a shale gas old well, wherein the specific collection and analysis require the following processes:
(1) Analysis of target well preferences
For old shale gas wells, four aspects of geological conditions, engineering conditions, dynamic conditions and economic conditions need to be analyzed and evaluated, and the method specifically comprises the following steps:
reservoir geological conditions (track passing conditions, EUR, test yield, accumulated yield and the like), well structure (casing and oil pipe sizes, running depth, pipe column structure) analysis, well track (data of sounding, well inclination, azimuth angle, well type and the like) analysis, perforation and bridge plug drilling and grinding through well depth parameters (perforation positions, bridge plug drilling and grinding conditions, through well depth and the like) analysis, stratum return (gas component content, stratum water component, return foreign matter scale sample component) component analysis, production dynamic data (yield fluctuation condition, water yield, shut-in pressure recovery, working fluid level and the like) analysis, early measure condition (measure effect analysis of gas lift, foam drainage, unblocking and the like) analysis and the like, and guiding the optimization of medicament formulas, dosage, injection process, yield increasing process and parameters;
1.1 formulation of selection principles
According to analysis and optimization of a target well, a well selection 'five-selection five-non-selection' principle of shale gas old well yield increasing measures is formulated, the measure priority is determined, and the measure pertinence and effect are improved:
1.2 preference for high pressure injection device
To meet the process construction requirements of shale gas old well measures, the injection pump is required to bear high enough injection pressure, and the high-pressure injection equipment mainly comprises two types of mobile vehicle-mounted injection equipment and skid-mounted continuous injection equipment. The following requirements need to be met:
the discharge capacity of the high-pressure injection device is 1400-2000L/H and needs to meet the injection requirement of 2-15 prescription of the medicine dosage for site construction;
the high-pressure injection equipment and accessories meet the site standardization requirements of the natural gas well, meet various safety requirements of the oil and gas field and meet night construction requirements;
The provided on-site high-pressure injection equipment and accessories must meet the installation requirements of the oil and gas field equipment;
The provided on-site high-pressure injection equipment and accessories meet the on-site standardized requirements, meet various safety requirements of oil and gas fields and meet night construction requirements;
Qualified equipment requirement pressure test, and pipeline pressure test more than 20 MPa;
(1) Building a shale gas old well immobile tubular column construction environment;
(2) Selecting a proper pouring mode;
The flow chart of oil pipe injection is shown in figure 1, and the oil pipe injection mode is selected according to the characteristics of the old shale gas well structure, the gas production well head and the well completion pipe string, so that the oil pipe injection flow is optimized for the situation that a throttle well is blocked, firstly, 2000kg of a compound synergistic system is introduced into the pipe string, then 600Nm 3/h of nitrogen is introduced to push the medicament to the target depth, the pushing time is 1h, and the well soaking time is 24h.
Example 2
The invention relates to a composite synergistic system for shale gas old wells, which comprises the following specific substances in percentage by weight:
12% of a moisturizing and improving agent;
6% of a descaling agent;
3% of scale inhibition dispersant;
10% of resistance-reducing and drainage-assisting agent;
20% of a synergistic accelerator;
20% chelating dispersant;
5% penetrant;
0.2% sterilant;
23.8% deionized water;
wherein the wetting improver is 10% alkyl polyglucoside, 18% sodium dodecyl benzene sulfonate and 72% deionized water;
the scale remover is alpha-sodium alkenyl sulfonate and nonylphenol polyoxyethylene ether ammonium sulfate with the mass ratio of 3:1;
The scale inhibition and dispersion agent is 15% of hydroxyethylidene diphosphonic acid, 5% of sodium hexametaphosphate and 80% of deionized water;
the resistance-reducing and cleanup additive is a mixture of 12% of cocamidopropyl amine oxide, 9% of dodecyl dimethyl hydroxysulfobetaine and 79% of deionized water;
the synergistic accelerator is 2% of inorganic salt, 18% of polyoxyethylene nonylphenol ether, 6% of polyhydric organic alcohol and 74% of deionized water
The chelating dispersant is a mixture of 33% polyepoxysuccinic acid, 14% polyphosphate and 53% organic alcohol;
The penetrating agent is tridecyl alcohol polyoxyethylene ether;
the sterilizing agent is a mixture of 50% of 5-chloro-2-methyl-4-isothiazolin-3-one and 50% of 2-methyl-4-isothiazolin-3-one;
the invention relates to a shale gas old well immobile tubular column yield increasing process, which mainly comprises the following steps:
firstly, data collection and analysis are carried out on the periphery of a shale gas old well, wherein the specific collection and analysis require the following processes:
(1) Analysis of target well preferences
For old shale gas wells, four aspects of geological conditions, engineering conditions, dynamic conditions and economic conditions need to be analyzed and evaluated, and the method specifically comprises the following steps:
reservoir geological conditions (track passing conditions, EUR, test yield, accumulated yield and the like), well structure (casing and oil pipe sizes, running depth, pipe column structure) analysis, well track (data of sounding, well inclination, azimuth angle, well type and the like) analysis, perforation and bridge plug drilling and grinding through well depth parameters (perforation positions, bridge plug drilling and grinding conditions, through well depth and the like) analysis, stratum return (gas component content, stratum water component, return foreign matter scale sample component) component analysis, production dynamic data (yield fluctuation condition, water yield, shut-in pressure recovery, working fluid level and the like) analysis, early measure condition (measure effect analysis of gas lift, foam drainage, unblocking and the like) analysis and the like, and guiding the optimization of medicament formulas, dosage, injection process, yield increasing process and parameters;
1.1 formulation of selection principles
According to analysis and optimization of a target well, a well selection 'five-selection five-non-selection' principle of shale gas old well yield increasing measures is formulated, the measure priority is determined, and the measure pertinence and effect are improved:
1.2 preference for high pressure injection device
To meet the process construction requirements of shale gas old well measures, the injection pump is required to bear high enough injection pressure, and the high-pressure injection equipment mainly comprises two types of mobile vehicle-mounted injection equipment and skid-mounted continuous injection equipment. The following requirements need to be met:
the discharge capacity of the high-pressure injection device is 1400-2000L/H and needs to meet the injection requirement of 2-15 prescription of the medicine dosage for site construction.
The high-pressure injection equipment and accessories meet the site standardization requirements of the natural gas well, meet various safety requirements of the oil and gas field and meet night construction requirements;
the field high pressure injection equipment and accessories provided must meet field installation requirements.
The provided on-site high-pressure injection equipment and accessories meet the on-site standardized requirements, meet various safety requirements of oil and gas fields and meet night construction requirements.
Qualified equipment requirement pressure test, and pipeline pressure test more than 20 MPa;
(1) Building a shale gas old well immobile tubular column construction environment;
(2) Selecting a proper pouring mode;
The flow chart of the casing injection is shown in fig. 2, a casing injection mode is selected according to the characteristics of the shale gas old well structure, the gas production wellhead and the well completion pipe string, and for the situation that the annulus of the shale gas old well casing is blocked or throttled, 2000kg of a compound synergistic system is firstly introduced into the pipe string, then 600Nm 3/h of nitrogen is introduced to push the medicament to the target depth, the pushing time is 2h, and the well soaking time is 24h.
Example 3
The invention relates to a composite synergistic system for shale gas old wells, which comprises the following specific substances in percentage by weight:
12% of a wetting improver;
5% of a detergent;
3% of scale inhibition dispersant;
8% of resistance-reducing and drainage-assisting agent;
19% of a synergistic accelerator;
20% chelating dispersant;
5% penetrant;
0.2% sterilant;
27.8% deionized water;
Wherein the wetting improver is 8% alkyl polyglucoside, 16% sodium dodecyl benzene sulfonate and 76% deionized water;
the scale remover is alpha-sodium alkenyl sulfonate and nonylphenol polyoxyethylene ether ammonium sulfate with the mass ratio of 2.5:1;
The scale inhibition and dispersion agent is 12% of hydroxyethylidene diphosphonic acid, 3% of sodium hexametaphosphate and 85% of deionized water;
the resistance-reducing and cleanup additive is a mixture of 10% cocoamidopropyl amine oxide, 8% dodecyl dimethyl hydroxysulfobetaine and 82% deionized water;
The synergistic accelerator is 1.5% of inorganic salt, 16% of nonylphenol polyoxyethylene ether, 5% of polyhydric organic alcohol and 77.5% of deionized water;
The chelating dispersant is a mixture of 33% polyepoxysuccinic acid, 14% polyphosphate and 53% organic alcohol;
The penetrating agent is tridecyl alcohol polyoxyethylene ether;
the sterilizing agent is a mixture of 50% of 5-chloro-2-methyl-4-isothiazolin-3-one and 50% of 2-methyl-4-isothiazolin-3-one;
the invention relates to a shale gas old well immobile tubular column yield increasing process, which mainly comprises the following steps:
firstly, data collection and analysis are carried out on the periphery of a shale gas old well, wherein the specific collection and analysis require the following processes:
(1) Analysis of target well preferences
For old shale gas wells, four aspects of geological conditions, engineering conditions, dynamic conditions and economic conditions need to be analyzed and evaluated, and the method specifically comprises the following steps:
reservoir geological conditions (track passing conditions, EUR, test yield, accumulated yield and the like), well structure (casing and oil pipe sizes, running depth, pipe column structure) analysis, well track (data of sounding, well inclination, azimuth angle, well type and the like) analysis, perforation and bridge plug drilling and grinding through well depth parameters (perforation positions, bridge plug drilling and grinding conditions, through well depth and the like) analysis, stratum return (gas component content, stratum water component, return foreign matter scale sample component) component analysis, production dynamic data (yield fluctuation condition, water yield, shut-in pressure recovery, working fluid level and the like) analysis, early measure condition (measure effect analysis of gas lift, foam drainage, unblocking and the like) analysis and the like, and guiding the optimization of medicament formulas, dosage, injection process, yield increasing process and parameters;
1.1 formulation of selection principles
According to analysis and optimization of a target well, a well selection 'five-selection five-non-selection' principle of shale gas old well yield increasing measures is formulated, the measure priority is determined, and the measure pertinence and effect are improved:
1.2 preference for high pressure injection device
To meet the process construction requirements of shale gas old well measures, the injection pump is required to bear high enough injection pressure, and the high-pressure injection equipment mainly comprises two types of mobile vehicle-mounted injection equipment and skid-mounted continuous injection equipment. The following requirements need to be met:
the discharge capacity of the high-pressure injection device is 1400-2000L/H and needs to meet the injection requirement of 2-15 prescription of the medicine dosage for site construction.
The high-pressure injection equipment and accessories meet the site standardization requirements of the natural gas well, meet various safety requirements of the oil and gas field and meet night construction requirements;
the field high pressure injection equipment and accessories provided must meet field installation requirements.
The provided on-site high-pressure injection equipment and accessories meet the on-site standardized requirements, meet various safety requirements of oil and gas fields and meet night construction requirements.
Qualified equipment requirement pressure test, and pipeline pressure test more than 20 MPa;
(1) Building a shale gas old well immobile tubular column construction environment;
(2) Selecting a proper pouring mode;
the injection flow chart of the oil jacket simultaneous injection is shown in fig. 3, a sleeve sleeving mode is selected according to the characteristics of the well body structure of the shale gas old well, the gas production well mouth and the well completion pipe string, and for the situation that the annulus of the shale gas old well sleeve is blocked or throttled, 2000kg of a composite synergistic system is firstly introduced into the pipe string, then 1000Nm 3/h of nitrogen is introduced to push the medicament to the target depth, the pushing time is 6h, and the well stewing time is 48h.
Example 4
The specific implementation was identical to example 3, except that the weight percent of alkyl polyglycoside in the wetting improver was 1%, the weight percent of sodium dodecylbenzenesulfonate was unchanged, and the weight percent of deionized water was 83%.
Example 5
The specific implementation was identical to example 3, except that the weight percent of alkyl polyglycoside in the wetting improver was 20%, the weight percent of sodium dodecylbenzenesulfonate was unchanged, and the weight percent of deionized water was 64%.
Example 6
The specific implementation is the same as example 3, except that the weight percentage of sodium dodecyl benzene sulfonate in the wetting improver is 5%, the weight percentage of alkyl polyglucoside is unchanged, and the weight percentage of deionized water is 87%.
Example 7
The specific implementation is the same as example 3, except that the weight percentage of sodium dodecyl benzene sulfonate in the wetting improver is 30%, the weight percentage of alkyl polyglucoside is unchanged, and the weight percentage of deionized water is 62%.
Example 8
The specific implementation process is the same as that of example 3, except that the mass ratio of alpha-alkenyl sodium sulfonate to nonylphenol polyoxyethylene ether ammonium sulfate salt in the scale remover is changed to be 0.5:1.
Example 9
The specific implementation process is the same as that of example 3, except that the mass ratio of the alpha-alkenyl sodium sulfonate to the nonylphenol polyoxyethylene ether ammonium sulfate salt in the scale remover is changed to be 5:1.
Example 10
The specific implementation process is the same as that of example 3, except that the mass percentage of the hydroxyethylidene diphosphonic acid in the scale inhibition dispersing agent is 5%, the mass percentage of the sodium hexametaphosphate is unchanged, and the mass percentage of the deionized water is 92%.
Example 11
The specific implementation process is the same as that of example 3, except that the mass percentage of the hydroxyethylidene diphosphonic acid in the scale inhibition dispersing agent is 30%, the mass percentage of the sodium hexametaphosphate is unchanged, and the mass percentage of the deionized water is 67%.
Example 12
The specific implementation process is the same as that of example 3, except that the mass percentage of sodium hexametaphosphate in the scale inhibition and dispersion agent is 0.5%, the mass percentage of hydroxyethylidene diphosphonic acid is unchanged, and the mass percentage of deionized water is 87.5%.
Example 13
The specific implementation process is the same as that of example 3, except that the mass percentage of sodium hexametaphosphate in the scale inhibition and dispersion agent is 10%, the mass percentage of hydroxyethylidene diphosphonic acid is unchanged, and the mass percentage of deionized water is 78%.
Example 14
The specific implementation process is the same as that of example 3, except that the mass percentage of cocamidopropyl amine oxide in the resistance-reducing and drainage-assisting agent is 1%, the mass percentage of dodecyl dimethyl hydroxysulfobetaine is unchanged, and the mass percentage of deionized water is 91%.
Example 15
The specific implementation process is the same as that of example 3, except that the mass percentage of cocamidopropyl amine oxide in the resistance-reducing and drainage-assisting agent is 20%, the mass percentage of dodecyl dimethyl hydroxysulfobetaine is unchanged, and the mass percentage of deionized water is 72%.
Example 16
The specific implementation process is the same as that of example 3, except that the mass percentage of dodecyl dimethyl hydroxysulfobetaine in the resistance-reducing and drainage-assisting agent is 1%, the mass percentage of cocamidopropyl amine oxide is unchanged, and the mass percentage of deionized water is 89%.
Example 17
The specific implementation process is the same as that of example 3, except that the mass percentage of dodecyl dimethyl hydroxysulfobetaine in the resistance-reducing and drainage-assisting agent is 20%, the mass percentage of cocamidopropyl amine oxide is unchanged, and the mass percentage of deionized water is 70%.
Example 18
The specific implementation process is the same as that of example 3, except that the mass percentage of inorganic salt in the synergistic accelerator is 0.2%, the mass percentage of nonylphenol polyoxyethylene ether and polyhydric organic alcohol is unchanged, and the mass percentage of deionized water is 78.8%.
Example 19
The specific implementation process is the same as that of example 3, except that the mass percentage of inorganic salt in the synergistic accelerator is 10%, the mass percentage of nonylphenol polyoxyethylene ether and polyhydric organic alcohol is unchanged, and the mass percentage of deionized water is 69%.
Example 20
The specific implementation process is the same as that of example 3, except that the mass percentage of the nonylphenol polyoxyethylene ether in the synergistic accelerator is 5%, the mass percentage of the inorganic salt and the polyhydric organic alcohol is unchanged, and the mass percentage of the deionized water is 88.5%.
Example 21
The specific implementation process is the same as that of example 3, and the difference is that the mass percentage of the nonylphenol polyoxyethylene ether in the synergistic accelerator is 30%, the mass percentage of the inorganic salt and the polyhydric organic alcohol are unchanged, and the mass percentage of the deionized water is 63.5%.
Example 22
The specific implementation process is the same as that of example 3, except that the mass percentage of the polyhydric organic alcohol in the synergistic accelerator is 1%, the mass percentages of the inorganic salt and the nonylphenol polyoxyethylene ether are unchanged, and the mass percentage of the deionized water is 81.5%.
Example 23
The specific implementation process is the same as that of example 3, except that the mass percentage of the polyhydric organic alcohol in the synergistic accelerator is 15%, the mass percentage of the inorganic salt and the nonylphenol polyoxyethylene ether are unchanged, and the mass percentage of the deionized water is 67.5%.
Experimental example 1 determination of the Performance of a Complex synergistic System
Performance tests are carried out on the composite synergistic system in the examples 1-23, wherein the examples 1-23 are experimental groups 1-23, and a control group is a common dredging agent for dredging old pipelines in the market;
the specific experimental steps are as follows:
1.1 Collecting plugs, namely collecting plug samples in the selected target shale gas old well, weighing, uniformly dividing into 24 groups, and crushing;
1.2 Mixing the composite synergistic system prepared in the examples 1-23 and the dredging agent of the control group with the same mass respectively with the blocking materials, and placing the mixture in a reaction kettle;
1.3 Setting reaction conditions, namely setting the reaction temperature to 120 ℃, setting the pressure to 15MPa, and carrying out constant-temperature reaction for 20 hours;
1.4 Filtering residual solids after the reaction is finished, drying and weighing, and calculating the dissolution rate;
The specific test results are shown in table 1 below:
TABLE 1 dissolution rate results
。
As can be seen from the above experimental data, the raw material consumption in the wetting improver is changed and the performance of the wetting improver for the compound synergistic system is also changed by comparing the experimental groups 1-5, wherein the content of the alkyl polyglycoside in the experimental group 4 is smaller and is far lower than 5% -10% of that provided by the invention, so that the prepared surfactant is unbalanced, the compound synergistic system is difficult to effectively adsorb on the hydrophobic surface due to the too low alkyl polyglycoside, the rock wettability of the surface of the old well of shale gas is changed insufficiently, the dissolution rate is reduced to 89.3%, the alkyl polyglycoside in the experimental group 5 is up to 20%, exceeds the preferred range, competitive adsorption is generated with sodium dodecyl benzene sulfonate, the effective coverage rate is reduced, meanwhile, the viscosity of the solution is increased due to too much hydroxyl groups, the permeability is reduced, the dissolution rate is 86.7%, and the sodium dodecyl benzene sulfonate in the experimental group 6 is only 5%, the less than the preferred value is 15% -18%, so that the dispersion capability of inorganic scale is seriously affected. Insufficient sulfonic acid groups lead to weakening of electrostatic repulsion, and inorganic particles cannot be dispersed effectively, and the dissolution rate is 88.1%. The experimental group 7 sodium dodecyl benzene sulfonate is up to 30%, precipitation is easy to generate under the high-temperature and high-salt environment, meanwhile, excessive anionic surfactant can compress an electric double layer, aggregation of particles is promoted, and the dissolution rate is reduced to 85.4%;
As can be seen by comparing the experimental groups 8-9, the change of the raw material dosage in the detergent has a certain influence on the performance of the compound synergistic system, wherein the proportion of the alpha-sodium alkenyl sulfonate and the ammonium salt of the polyoxyethylene nonylphenol ether sulfate in the experimental group 8 is 0.5:1, and the former is seriously insufficient. The hard water resistance of the system is obviously reduced, the partial failure of the scale remover is caused by calcium and magnesium ions, the dissolution rate is 83.6%, the ratio of experiment group 9 is 5:1, the latter is insufficient, the solubilization capacity of heavy organics is insufficient due to the too low EO chain content, the biodegradability is poor, and the dissolution rate is 87.2%;
As can be seen from comparison of experimental groups 10-13, the change of the raw material dosage in the scale inhibition and dispersion agent affects the performance of the compound synergistic system, wherein when the dosage of the hydroxyethylidene diphosphonic acid in the experimental group 10 is only 5%, the chelating site is easily caused to be seriously insufficient, the formation of compact scale such as calcium carbonate cannot be effectively inhibited, so that the dissolution rate is reduced to 82.9%, while when the dosage of the hydroxyethylidene diphosphonic acid in the experimental group 11 is as high as 30%, although the chelating capacity is strong, the dispersing effect is not as high as that of sodium hexametaphosphate, and excessive use can cause excessive chelation of metal ions to affect the stability of stratum minerals, so that the dissolution rate is reduced to 84.5%, and meanwhile, when the dosage of the sodium hexametaphosphate in the experimental group 12 is only 0.5%, the effect of the sodium hexametaphosphate cannot be provided with enough electrostatic repulsion to disperse formed microcrystal particles, especially the effect on iron scale and silicon scale is poor, so that the dissolution rate is reduced to 81.7%, and when the dosage of the sodium hexametaphosphate in the experimental group 13 is as high as 10%, the dosage of the sodium hexametaphosphate is high as possible to be hydrolyzed to generate orthophosphate at high temperature, so that the dissolution rate is easily lost, and the dispersing effect is reduced to form and the new precipitation rate is reduced to 86.3%.
As can be seen from comparison of experimental groups 14-17, when the raw material consumption in the resistance-reducing cleanup additive is changed, the raw material consumption in the resistance-reducing cleanup additive has a certain influence on the performance of a compound synergistic system, wherein the cocoamidopropyl amine oxide in the experimental group 14 is only 1%, so that a complete hydration layer cannot be formed to reduce friction resistance, the resistance-reducing effect of the compound synergistic system is poor, the dissolution rate is reduced to 80.5%, when the consumption of the cocoamidopropyl amine oxide in the experimental group 15 is up to 20%, the resistance-reducing effect is good, excessive foam is generated, an additional antifoaming agent is required, the backflow efficiency is possibly influenced, the consumption of the dodecyl dimethyl hydroxysulfobetaine in the experimental group 16 is only 1%, the lubricity is reduced due to insufficient sulfonic acid groups, the capillary resistance is increased, the dissolution rate is reduced to 83.2%, and when the consumption of the dodecyl dimethyl hydroxysulfobetaine in the experimental group 17 is up to 20%, the strong groups of the dodecyl dimethyl hydroxysulfobetaine possibly causes excessive rock wettability, and on the contrary, water lock is caused, the cost is remarkably increased, and the dissolution rate is reduced to 87.6%;
As can be seen from comparison of experimental groups 18-23, the performance of the composite synergistic system is affected when the amount of each raw material in the synergistic accelerator is changed, wherein when the amount of inorganic salt in the experimental group 18 is only 0.2%, the composite synergistic system is easy to cause that the double electric layer cannot be effectively compressed to control the clay expansion, the ionic strength is not enough to adjust, and the dissolution rate is reduced to 88.4%; the inorganic salt in experiment group 19 may cause the system to have too high salinity and precipitate nonylphenol polyoxyethylene ether, while aggravating the scaling risk, and further reducing the dissolution rate to 82.3%, while the nonylphenol polyoxyethylene ether in experiment group 20 has only 5% and is liable to cause insufficient surface tension, and is difficult to enter the nanoscale pores of the plugs, and further causes the dissolution rate to be reduced to 84.8%, while the nonylphenol polyoxyethylene ether in experiment group 21 has the amount of up to 30%, and the nonylphenol polyoxyethylene ether is liable to fail after exceeding the cloud point temperature, and EO chains may be too much adsorbed on the rock surface and difficult to elute, while the multielement organic alcohol in experiment group 22 has the amount of only 1%, and the compound synergy system is liable to be incapable of effectively reducing the liquid viscosity, and causes insufficient hydrogen bonding water molecule capacity, and the dissolution rate to be reduced to 81.5%, and the multielement organic alcohol in experiment group 23 has the amount of up to 15%, and although the viscosity reducing effect is liable to further cause insufficient drug carrying capacity, and may affect the stability, and thus the dissolution rate to be reduced to 85.7%.
Experimental example 2 exploration of variable Displacement modes in a stationary pipe string
The Weiyuan shale gas field of China oil and southwest oil and gas field division is positioned at the south of Sichuan basin, is an demonstration area of national shale gas which is built earliest in China, the longest production period of old shale gas wells exceeds 10 years, the number of old shale gas wells produced at present exceeds 500, the annual shale gas produced by Weiyuan shale gas fields exceeds 20 hundred million cubic meters, and the old shale well measure and yield increasing technology has become a key technology for stable production of shale gas wells. The depth of a reservoir of Weiyuan shale gas and gas fields is 3000-4000 m, the highest stratum temperature is 140 ℃, the stratum pressure coefficient is 1.5-2.0, the Young modulus is 25-40 GPa, the Poisson's ratio is 0.18-0.25, and the development is mainly carried out by adopting a horizontal well staged fracturing technology.
1.1 Variable Displacement disturbance type push mode optimization
The first mode of variable construction displacement is shown as the accompanying figures 4-7 of the specification, wherein the composite synergistic system adopted in the experimental example is the composite synergistic system prepared in the embodiment 3, according to the measure process requirements of the old shale gas well, the 3 different injection flows, namely oil pipe injection, casing injection and oil jacket co-injection, are combined, and the passive random injection is changed into active slug disturbance by optimizing the pushing modes of different nitrogen displacement disturbance, so that the medicament sweep range and the action depth are enlarged, and the effect of the old well measure on increasing production is improved;
1.2 dose optimization
According to the geological and other parameter characteristics of different wells, the following calculation formula is optimized to optimize the dosage of the agent of the on-site single well yield increasing measure:
Wherein:
q total amount of composite synergistic system (m 3)
Crack complexity correction coefficient (1.2-2.0)
Substrate inhomogeneity coefficient (0.8-1.5)
Fracture volume (m 3)
Fracture porosity (0.3-0.6)
Substrate volume (m 3)
Substrate porosity (0.3-0.6)
Target compound synergistic system concentration (5-10 wt%)
Saturation of gas (0.3-0.7)
Reaction time of braised well (h)
Effective action time (h) of composite synergistic system
Measure treatment target radius (m)
Radius of action (m) of composite synergistic system
R, the residual coefficient of the composite synergistic system (generally 0.1-0.3)
The filling amount of the composite synergistic system is comprehensively considered according to reservoir temperature, gas saturation, crack volume, crack and matrix porosity, permeability, soaking reaction time, composite synergistic system action radius, composite synergistic system action time and the like of different shale gas wells, under the general condition, the soaking time T kou of the old shale gas well and the composite synergistic system action effective time T kou are optimized to 48 hours, the average crack porosity is 3 percent, the permeability is 1.8mD, the composite synergistic system treatment radius is calculated according to 30-50m, the balance of the composite synergistic system is considered according to 10-15 percent, and the composite synergistic system amount is calculated to 2000-8000Kg;
Aiming at the Weiyuan shale gas field old well yield increase measure process, the optimized supermolecule multifunctional composite synergistic system comprises the composite synergistic system prepared in the embodiment 3;
The consumption of the composite synergistic system of the block fixed-pipe column production increasing process measure is 2000-5000Kg, the soaking time is optimized to 38-72h, the effective period after the measure is 65-87d, the measure production increasing multiple is 4.7-10.5 times, and the better production increasing and stabilizing effects are achieved, wherein the specific results are shown in the following table 2.
Statistical table of effect of old shale gas well stimulation in oil and southwest oil and gas field Weiyuan in table 2
。
As can be seen from the data in table 2, the invention also provides a method for changing the flux of the composite synergistic system in the whole filling time when the composite synergistic system is filled with nitrogen, so that the yield increasing efficiency of the old shale gas well is further improved.
According to the experimental example 1-2, the composite synergy system and the immobile pipe column production increasing process are provided, the geological conditions, engineering conditions, dynamic conditions and economic conditions of the shale gas old well are integrated to perform optimization of a target well, the novel environment-friendly supermolecule multifunctional composite synergy system is matched, the functions of blocking removal, descaling, water lock removal, drainage assistance and the like are achieved, the immobile pipe column injection, pushing and unblocking and production recovery are achieved, compared with the traditional chemical injection mode, the immobile pipe column construction mode provided by the invention does not need to be used for lowering pipe columns or disassembling wellhead equipment, construction cost and operation time are greatly shortened, and the operation mode of a movable pipe column always needs to balance pressure of well fluid, so that reservoir damage is easily caused, the filling of the immobile pipe column can keep the pressure balance of a well shaft, secondary damage is avoided, the immobile pipe column process can accurately put in the composite system in a blocking area of the shale gas well through selectivity, damage of mechanical operation to a crack network is reduced, meanwhile, compared with the traditional chemical injection mode, the traditional chemical injection mode is effectively controlled to be used for reducing the problem that the traditional chemical injection mode is difficult to be solved, and the invention can be more difficult to simultaneously, and the well casing can be deformed due to the fact that the traditional chemical injection mode is more than 60% is difficult, and the traditional chemical injection mode can not be used, and the well casing can be simultaneously integrated, and the well casing can be easily and can be deformed.
It should be noted that the above embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.
Claims (10)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510670419.6A CN120519139A (en) | 2025-05-23 | 2025-05-23 | Composite synergistic system for shale gas old well and production increasing process of fixed tubular column |
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