CN102492527B

CN102492527B - High-temperature thread grease for oil-casing joints with metal sealing structure and its preparation process

Info

Publication number: CN102492527B
Application number: CN201110361044.3A
Authority: CN
Inventors: 苏忠贵; 贾广民; 李芙蓉
Original assignee: YANAN JIASHENG PETROLEUM MACHINERY CO Ltd
Current assignee: YANAN JIASHENG PETROLEUM MACHINERY CO Ltd
Priority date: 2011-11-15
Filing date: 2011-11-15
Publication date: 2014-01-15
Anticipated expiration: 2031-11-15
Also published as: CN102492527A

Abstract

A high-temperature thread grease for oil-casing joints with a metal-sealed structure and a preparation process thereof, comprising the following components: perfluoropolyether; dimethyl silicone oil; molybdenum disulfide powder; compound calcium sulfonate. The method for realizing the above-mentioned thread grease includes the following steps : First add perfluoropolyether into the reaction kettle, then add dimethyl silicone oil and complex calcium sulfonate, and stir evenly; then add molybdenum disulfide powder into the system, continue stirring, and then it can be packaged and used. It has the characteristics of good lubricity, good sealing effect and simple process.

Description

High temperature thread sealant for metal sealed oil casing joint and preparation technology thereof

Technical field

The invention belongs to oil and gas exploitation technical field, relate to high temperature thread sealant for metal sealed oil casing joint and preparation technology thereof, increase the sealing reliability of downhole oil sleeve pipe tubing string.

Background technology

The oil pipe using in petroleum exploration and development process is all linked to be long string by threaded connector by each single pipe, in order to reduce between screw thread and to adhere as much as possible, improve the sealing property of screw thread, before upper button, all can apply appropriate thread compound in thread surface, to play lubrication assistant and sealing function.Along with deepening continuously of petroleum natural gas exploration, the high-pressure gas well with complex working condition is on the increase, as High Temperature High Pressure, deep & ultra-deep well, orientation well, horizontal well, extended reach well etc. require to improve gradually to the performance reliability of tubing and casing tubing string, the tubing and casing special joint application with shape metallic leak-proof structure is more and more.Using comparatively general thread compound is at present API oil base fat thread compound, the type thread compound is owing to having emphasized to fill the effect that thread pitch increases sealing, therefore except containing part basis fat and base oil, also has a large amount of heavy metal fillers, as lead powder, zinc powder, copper powder etc., require particle diameter to be less than 0.27mm, allow 10% particle diameter to be greater than 0.075mm, maximum 70% particle diameter is greater than 0.045mm.Practical application shows that API thread compound can cause when having the special joint of shape metallic leak-proof structure occurring reducing sealing reliability by micro-damage on metallic sealing section, and tubing and casing tubing string just leaks after in the time of one section of down-hole application.In standard A PI RP 5A3-2003 " the thread compound recommend method of sleeve pipe, oil pipe and line pipe ", also explicitly point out, API thread compound can not guarantee to have the use properties of the oil sleeve joint of metal construction.Reason is lead powder, the soft metals such as copper powder, although there is good spreadability, effectively reduce the tendency that adhesion occurs, but to because these metallic particles particle diameters are in about 0.04mm, much larger than metal covering roughness (the about 0.003mm of Ra), be filled in and between metallic sealing section, increased the local contact pressure between trim simultaneously, on trim, there is micro-damage, and basic fat and the base oil of more continuous distribution between these larger particles, have been filled, down-hole hot conditions makes these greases volatilize very soon or be extruded by internal gas pressure, thereby form gas leakage passage.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the object of the present invention is to provide a kind of high temperature thread sealant for metal sealed oil casing joint and preparation technology thereof, this thread compound is different from traditional API thread compound, do not contain metallic particles, environmentally friendly, can not pollute site environment, main lubricate in button process on threaded connector, between the metallic sealing section of Interference contact, forming thin film can increase the sealing property of joint, under the hot conditions of 250 ℃ of Qie down-holes, still can keep good grease state, avoid the leakage accident of metallic seal special joint, there is oilness good, the simple feature of good sealing effect and technique.

To achieve these goals, the technical solution used in the present invention is: high temperature thread sealant for metal sealed oil casing joint, do not contain any metal, and comprise following component (by weight percentage):

PFPE 55～68%; Dimethyl silicone oil 14～26%; Molybdenum disulphide powder 10～22%; Complex calcium sulfonate, 7～18%;

Composition ingredient requirement: the grain size of molybdenum disulphide powder should be not more than 0.01mm, 80% particle diameter is less than 0.006mm; Comparatively common raw material on other raw materials Jun Shi market, it is convenient to buy;

The preparation method of high temperature thread sealant for metal sealed oil casing joint, comprises the following steps: first to the PFPE that adds 55～68% in reactor, and then add 14～26% dimethyl silicone oil and 7～18% complex calcium sulfonate, after stirring; To the molybdenum disulphide powder that adds 10～22% in this system, continue to stir after 1 hour again, can encapsulate use.

Beneficial effect of the present invention:

Traditional API thread compound that contains the metallic particles such as copper powder, lead powder has very large harm to environment; next these metallic particles that are embedded between metallic sealing section also can increase the possibility of trim generation micro-damage, after basic grease volatilization, between metallic particles, also may form gas leakage passage.The tubing and casing special joint with shape metallic leak-proof structure of the present invention is different from traditional API thread compound with high temperature lubricating thread compound, the thread compound of not containing metal particle of the present invention, in the thread compound of preparing according to above composition and engineering, do not contain metal, there is good environment-friendly type and coating, can guarantee that threaded connector is at the upper good lubrication linking in termination process, the particle diameter of composition can fill up the uneven surface of the metal of processing substantially, can not form support effect to the metallic sealing section of interference, guaranteed the sealing reliability of joint, prevent joint generation thread gluing damage, breakseal,

Preparation technology of the present invention is simple, good reliability, the high temperature thread compound of preparing according to above-mentioned technique, there is good environmental-protecting performance and good lubricated and sealing property, it is especially applicable to being applied to shackle on metallic seal oil sleeve joint for the high-pressure gas wells such as the harsher high temperature of underground working, deep-well applicable to having the oil pipe of special sealed structure, the thread connecting joint of sleeve pipe.

Accompanying drawing explanation

Fig. 1 API thread compound particle diameter, metallic sealing section and thread compound grain size of the present invention be schematic diagram relatively, wherein Fig. 1 (a) is API thread compound particle diameter schematic diagram, Fig. 1 (b) screw thread and trim surfaceness schematic diagram, Fig. 1 (c) thread compound particle diameter of the present invention schematic diagram.

Fig. 2 API thread compound form between metallic sealing section.

Fig. 3 screw thread of the present invention form between metallic sealing section.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in further detail.

embodiment 1

High temperature thread sealant for metal sealed oil casing joint, does not contain any metal, comprises following component (by weight percentage):

PFPE 62%; Dimethyl silicone oil 16%; Molybdenum disulphide powder 12%; Complex calcium sulfonate 10%,

Composition ingredient requirement: the grain size of molybdenum disulphide powder is 0.008mm, and 80% particle diameter is less than 0.007mm; Comparatively common raw material on other raw materials Jun Shi market, it is convenient to buy.

The thread compound of not containing metal particle of the present invention, there is good environment-friendly type and coating, can guarantee that threaded connector is at the upper good lubrication linking in termination process, the particle diameter of composition can fill up the uneven surface of the metal of processing, can not form support effect to the metallic sealing section of interference, guarantee the sealing reliability of joint, prevented joint generation thread gluing damage, breakseal.

embodiment 2

PFPE 60%; Dimethyl silicone oil 14%; Molybdenum disulphide powder 13%; Complex calcium sulfonate 13%,

Composition ingredient requirement: the grain size of molybdenum disulphide powder should be not more than 0.010mm, 80% particle diameter is less than 0.005mm; Comparatively common raw material on other raw materials Jun Shi market, it is convenient to buy.

embodiment 3

PFPE 58%; Dimethyl silicone oil 14%; Molybdenum disulphide powder 10%; Complex calcium sulfonate 18%,

Composition ingredient requirement: the grain size of molybdenum disulphide powder should be not more than 0.01mm, 80% particle diameter is less than 0.006mm; Comparatively common raw material on other raw materials Jun Shi market, it is convenient to buy.

embodiment 4

The preparation method of high temperature thread sealant for metal sealed oil casing joint, comprises the following steps: first to the PFPE that adds 62% in reactor, and then add 16% dimethyl silicone oil and 10% complex calcium sulfonate, after stirring; To the molybdenum disulphide powder that adds 12% in this system, continue to stir 1 hour again, can encapsulate use.

embodiment 5

The preparation method of high temperature thread sealant for metal sealed oil casing joint, comprises the following steps: first to the PFPE that adds 60% in reactor, and then add 14% dimethyl silicone oil and 13% complex calcium sulfonate, after stirring; To the molybdenum disulphide powder that adds 13% in this system, continue to stir 1 hour again, can encapsulate use.

embodiment 6

The preparation method of high temperature thread sealant for metal sealed oil casing joint, comprises the following steps: first to the PFPE that adds 58% in reactor, and then add 14% dimethyl silicone oil and 18% complex calcium sulfonate, after stirring; To the molybdenum disulphide powder that adds 10% in this system, continue to stir 1 hour again, can encapsulate use.

Referring to Fig. 1, Fig. 1 (a) is API thread compound particle diameter schematic diagram, API thread compound particle diameter 1 is generally 0.045mm left and right, i.e. 0.040～0.05mm, its particle diameter is greater than thread compound particle diameter 0.006mm of the present invention in Fig. 1 (c), and Fig. 1 (b) is metallic sealing section 4 surfacenesses, its surface irregularity, the highest burr 3 length are no longer than 0.0032mm, and the scantling length of metallic sealing section 4 is 0.6～1.2mm.

Referring to Fig. 2, API thread compound is form between metallic sealing section 4, and Fig. 2 shows that grain diameter of grease 1 volume of the API thread compound between metallic sealing section 4 is larger, and its larger volume is volatile and extruded by pressure, can cause oilness and stopping property to reduce.

Referring to Fig. 3, invention thread compound particle diameter 2 is form between screw thread and metallic sealing section 4, if the lubricant component particle diameter volume between Fig. 3 explanation metallic sealing section 4 is little, just not volatile and be extruded away, can guarantee stopping property and oilness between metallic sealing section 4.

Claims

1. High-temperature thread grease for oil-casing joints with metal seal structure, characterized in that it consists of the following components (by weight percentage):

Perfluoropolyether 55-68%; Dimethicone 14-26%; Molybdenum disulfide powder 10-22%; Composite calcium sulfonate, 7-18%;

The particle size of the molybdenum disulfide powder should not be greater than 0.01mm, and 80% of the particle diameters should be less than 0.006mm.

2. The high-temperature thread grease for metal-sealed structure oil-casing joints according to claim 1, characterized in that it consists of the following components (by weight percentage):

Perfluoropolyether 60%; Dimethicone 14%; Molybdenum disulfide powder 13%; Composite calcium sulfonate 13%,

Component raw material requirements: The particle size of molybdenum disulfide powder should not be greater than 0.010mm, and 80% of the particle diameters should be less than 0.005mm.

3. The high-temperature thread grease for metal-sealed structure oil-casing joints according to claim 1, characterized in that it consists of the following components (by weight percentage):

Perfluoropolyether 58%; Dimethicone 14%; Molybdenum disulfide powder 10%; Composite calcium sulfonate 18%,

Component raw material requirements: The particle size of molybdenum disulfide powder should not be greater than 0.01mm, and 80% of the particle diameters should be less than 0.006mm.

4. A method for preparing high-temperature thread grease for oil-casing joints with metal-sealed structures according to claim 1, comprising the following steps: first adding 55-68% perfluoropolyether to the reaction kettle, and then adding 14-68% Mix 26% simethicone oil and 7-18% calcium sulfonate compound evenly; then add 10-22% molybdenum disulfide powder to the system, continue stirring for 1 hour, and then package and use.

5. The method for preparing high-temperature thread grease for metal-sealed oil-casing joints according to claim 4, comprising the following steps: first adding 60% perfluoropolyether to the reaction kettle, and then adding 14 % of simethicone oil and 13% of calcium sulfonate compound, stir evenly; then add 13% of molybdenum disulfide powder to the system, the particle size of molybdenum disulfide powder should not be greater than 0.010mm, 80% of If the particle diameter is less than 0.005mm, continue to stir for 1 hour, then it can be packaged and used.

6. The preparation method of high-temperature thread grease for oil-casing joints with metal sealing structure according to claim 4, characterized in that, comprising the following steps: first adding 58% perfluoropolyether to the reaction kettle, and then adding 14 % of simethicone oil and 18% of calcium sulfonate compound, stir evenly; then add 10% of molybdenum disulfide powder to the system, the particle size of molybdenum disulfide powder should not be greater than 0.01mm, 80% of If the diameter of the particles is less than 0.006mm, continue to stir for 1 hour, then it can be packaged and used.