BRPI0502151B1 - APPARATUS FOR DETERMINING CHARACTERISTICS OF A UNDERGROUND GEOLOGICAL TRAINING, AND METHOD FOR DETERMINING CHARACTERISTICS OF A SUBTERRANEUS TRAINING - Google Patents

Description

APPARATUS FOR DETERMINING CHARACTERISTICS OF AN UNDERGROUND GEOLOGICAL FORMATION AND METHOD FOR DETERMINING

FEATURES OF UNDERGROUND TRAINING

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to the in-depth investigation of underground geological formations. More particularly, the present invention relates to the determination of characteristics of a formation located below the earth surface by means of a sampling operation performed by drilling in a perforated hole that penetrates the formation. 2. Prior Art Historically, boreholes (also known as wellbores, or simply as wells) have been drilled for formations located below the earth's surface (also known as inland wells) that contain very high fluids. such as oil, gas or water. A drill hole is drilled with a drill rig that can be located on dry land or over water bodies, and the drill hole itself extends into a well interior in the direction of the formations located below the earth's surface. The drilled hole may remain 'open' after drilling (ie not lined with a sheath), or may be equipped with a sheath (in other cases referred to as a lining), forming a 'sheathed' drilled hole. A coated drilled hole is created by inserting a plurality of interconnected tubular steel coating sections (i.e. joints) into an open drilled hole, and pumping cement into the well through the center of the coating. Cement flows out through the bottom portion of the liner and returns toward the surface through a portion of the perforated hole which is located between the liner and the wall of the perforated hole known as the annulus. Cement is thus employed on the outside of the coating to maintain the coating in a fixed arrangement and to provide a certain degree of structural integrity and a seal between the formation and the coating.

Various techniques for performing formation assessment (i.e. research and analysis of the surrounding formation regions with respect to the hole for the presence of oil and gas) in open, uncoated boreholes have been described, for example. , U.S. Patent Nos. 4,860,581 and 4,936,139, both of which are assigned to the assignee of the present invention. Figures 1A and 1B illustrate a formation test apparatus known in the art according to the teachings of these patents. Apparatus A of Figures 1A and 1B has a modular construction, although a unitary tool may also have utility. Apparatus A is a downhole tool that can be lowered into the wellbore (not shown) by a wireline (not shown) for evaluation tests of geological formations. Connections for tool A drill cable coupling as well as for power supply and for communications related electronic components are not illustrated for the sake of clarity of the present description. Power and communication lines extending the full length of the tool are generally illustrated with numeral 8. These power and communication components are well known to those skilled in the art and already were in commercial use in the past. Control equipment of this type would normally be installed at the upper end of the tool, adjacent to the drill cable connection with the tool, with power lines arranged through the tool and connected to the various components.

As shown in the configuration of Figure 1A, apparatus A has a hydraulic power module C, a packer P, and a probe E module. Probe E is illustrated with a probe assembly 10 that can be used for permeability testing or for sampling fluid (s). When the tool is used for anisotropic permeability determination and the vertical structure of the deposit according to known techniques, a multiple probe module F may be added to the probe module E as shown in Figure 1A. The multiple probe module F has a sink probe assembly 14, and a horizontal probe assembly 12. Alternatively, a dual plug obturator module P is normally combined with probe module E for vertical probe testing. permeability.

The hydraulic power module C includes a pump 16, a reservoir 18, and a motor 20 for controlling the operation of pump 16. A low oil level switch 22 provides a low oil level warning to the tool operator. , and as such is used to regulate pump operation 16.

The hydraulic fluid line 24 is connected to the discharge side of the pump 16 and is disposed through the hydraulic power module C, following to adjacent modules to be used as a hydraulic power source. In the configuration illustrated in Figure 1A, the hydraulic fluid line 24 extends through the hydraulic power module C into the probe modules E and / or F depending on which configuration will be used. The hydraulic loop is closed via the hydraulic fluid return line 26, which in Figure 1A extends from probe module E returning to the hydraulic power module C where it terminates in reservoir 18.

The discharge pumping module M, shown in Figure 1B, may be used for disposal of undesirable samples by pumping fluid from flow line 54 into the borehole, or may be used for pumping fluid from the hole drilled into the flow line 54 for straddle packer inflation 28 and 30. In addition, the discharge pumping module M can be used to withdraw formation fluid from the wellbore through the probe E or F, or the packer P, with subsequent pumping of the forming fluid into the sampling chamber module S against a buffer fluid therein. This process will be further described below.

The bi-directional piston pump 92, powered by hydraulic fluid from pump 91, may be aligned to withdraw from flow line 54 and discard an unwanted sample through flow line 95, or may be aligned to pump fluid from the drilled hole. (through flow line 95) to flow line 54. The discharge pumping module can also be configured at the point where flow line 95 connects to flow line 54 such that fluid can be drawn from the downstream of the flow line 54 and the fluid may be pumped upstream or vice versa. The discharge pumping module M has the necessary control devices to regulate the piston pump 92 and align the flow line 54 with the flow line 95 to perform the discharge pumping procedure. It should be noted in this case that the piston pump 92 may be used for pumping samples into sampling chamber module (s) S, including overpressurizing such samples as desired as well as pumping samples out of the sampling chamber module (s) using the discharge pumping module M. The discharge pumping module M may also be used to obtain constant rate or constant pressure injection if required. With sufficient energy, the discharge pumping module M can be used for fluid injection at sufficiently high rates to allow the creation of micro-fractures for formation stress measurements.

Alternatively, the straddle packers 28 and 30 shown in Figure 1A may be inflated and emptied with borehole fluid using the piston pump 92. As can be readily observed, selective actuation of the feeder module. discharge pumping M to activate piston pump 92, in combination with selective operation of control valve 96 and inflation and deflating of valves I may result in inflation or selective deflating of packers 28 and 30. Packers 28 and 30 are mounted on the outer periphery 32 of apparatus A, and may be constructed of a resilient material compatible with well bore fluids and temperatures. Packers 28 and 30 have a cavity therein. When the piston pump is operational and inflation valves I are properly adjusted, flow line fluid 54 passes through inflation / drain valves I and through flow line 38 to packers 28. and 30.

As also shown in Figure 1A, probe module E has a probe assembly 10 which is selectively movable relative to apparatus A. Movement of probe assembly 10 is initiated by operation of a probe actuator 40, which aligns hydraulic flow lines 24 and 26 with flow lines 42 and 44. Probe 26 is mounted on a frame 48 which is movable relative to apparatus A, and probe 46 is movable relative to structure 48. These movements Relative signals are initiated when a controlling device 40 sends fluid from flow lines 24 and 26 selectively to flow lines 42, 44, resulting in an initial displacement of structure 48 outwardly in contact with the borehole wall. well (not shown). The extension of the frame 48 brings the probe 46 into the vicinity of the wellbore wall and compresses over an elastomeric ring (designated as a "packer") against the wellbore wall, thereby creating a seal between the drilled hole and the probe 46. To the extent that an objective is to obtain a correct reading of the formation pressure, where this pressure is reflected in the probe 46, it will be desirable to further insert the probe 46 through the accumulated mud cake, contacting the formation. Thus, alignment of hydraulic flow line 24 with flow line 44 results in a relative displacement of probe 46 into the formation by relative movement of probe 46 with respect to frame 48. Operation of probes 12 and 14 is similar to probe 10, and will not be described separately.

Following inflation of packers 28 and 30 and / or the placement of probe 10 and / or probes 12 and 14, the test fluid withdrawal operation may begin. Sampling flow line 54 extends from probe 46 in probe module E downwardly to outer periphery 32 at a point between packers 28 and 30 through adjacent modules and entering the module modules. The vertical probe 10 and the depth probe 14 thus allow formation fluids to enter the sample flow line 54 through one or more of a resistivity measuring cell 56, a pressure measuring device 58, and a pretest mechanism 59, according to the desired configuration. In addition, flow line 64 allows formation fluids to enter into sample flow line 54. When module E is used, or when multiple modules E and F are used, inflation valve 62 is downstream of the resistivity sensor 56. In the closed position, the inflation valve 62 limits the internal volume of the flow line, improving the accuracy of the dynamic measurements made by the pressure measuring instrument 58. After initial pressure tests are made , the inflation valve 62 may be opened to allow flow to the other modules through flow line 54.

In initial sampling, there is a strong likelihood that the initially obtained forming fluid will be contaminated by mud cake and filtered. It is desirable to purge these contaminants from the sample stream prior to sample collection (s). In this way, the discharge pumping module M is used to initially purge from the apparatus A specimens of forming fluid collected through the access port 64 of the straddle packers 28, 30, or the vertical probe 10, or from depth probe 14 into flow line 54.

Fluid analysis module D includes an optical fluid analysis device 99 which is particularly suitable for the purpose of indicating whether or not fluid in the flow line 54 is acceptable for collecting a sample of fluid. high quality. Optical fluid analysis device 99 is equipped with means for discriminating between various oils, gas and water. U.S. Patent Nos. 4,994,671; No. 5,166,747; No. 5,939,717; and 5,956,132 as well as other known patents, all under assignment to Schlumberger, describe in detail the analyzer device 99, and this description will not be repeated herein.

While contaminants are removed and disposed of apparatus A, the formation fluid may continue to flow through the sampling flow line 54 extending through adjacent modules such as fluid analysis module D, discharge pumping Μ, the flow control module N, and any number of sampling chamber modules S which may be coupled as shown in Figure 1B. Those skilled in the art will appreciate that by configuring a sampling flow line 54 arranged along the length of the various modules, it becomes possible to stack a plurality of sampling chamber modules S without necessarily increasing the overall tool diameter. . Alternatively, as explained below, a single sampling module S may be equipped with a plurality of small diameter sampling chambers, for example by locating such chambers side by side and equidistant from the axis of the sampling module. The tool can therefore take more samples before it has to be recovered to the surface, and can be used in smaller holes.

Referring again to Figures 1A and 1B, flow control module N includes a flow sensor 66, a flow controller 68, a piston 71, reservoirs 72, 73, and 74, and a selectively restrained device. such as a valve 70. A predetermined sample size can be obtained at a specific flow rate using the equipment described above.

Sampling chamber module S can then be employed to take a sample of the fluid supplied through flow line 54. If a multiple sampling module is used, the sampling rate may be regulated by the flow control module. N, which is a benefit but not indispensable for fluid sampling. Referring to the upper sampling chamber module S in Figure 1B, a valve 80 is opened and one of valves 62 or 62A, 62B is opened (regardless of the control valve for the sampling module) and the forming fluid is sent through the sampling module into flow line 54 and into sample collection cavity 84C in chamber 84 of sampling chamber module S, and thereafter valve 80 is closed to isolate the sample , and the sampling module control valve is closed to isolate flow line 54. Chamber 84 has a sample collection cavity 84C and a compensation / pressurization cavity 84p. The tool may then be moved to a different location and the process may be repeated. Additional samples taken may be stored in any number of additional sampling chamber modules S that can be coupled by proper valve alignment. For example, there are two sampling chambers S illustrated in Figure 1B. After filling the upper chamber by operation of the isolation valve 80, a subsequent sample may be stored in the lower sampling chamber module S by opening the isolation valve 88 coupled to the sample collection cavity 90C of chamber 90. Chamber 90 has one 90C sample collection well and one 90p compensation / pressurization well. It should be noted that each sampling chamber module has its own control set, illustrated in Figure 1B with numerals 100 and 94. Any number of sampling chamber modules S, or even no sampling chamber module, may be used. specific tool configurations, depending on the nature of the test to be performed. In addition, sampling module S may consist of a multiple sampling module housing a plurality of sampling chambers as mentioned above.

It should also be noted that a buffer fluid in the form of full pressure borehole fluid may be applied to the rear sides of the pistons in chambers 84 and 90 for further control of the fluid pressure. For this purpose, valves 81 and 83 are opened, and the discharge pump module M piston pump 92 must pump fluid in flow line 54 at a pressure greater than the borehole. It has been found that this action has the effect of damping or reducing the pressure pulse or "shock" experienced during drawdown. This low shock level sampling method has been used with particular advantage in obtaining fluid samples from unconsolidated formations, in addition to allowing overpressurization of the fluid sample by means of the piston pump 92.

It is known that various configurations of apparatus A may be employed depending on the purpose to be fulfilled. For basic sampling, hydraulic power module C can be used in combination with electrical power module L, probe module E and a plurality of sampling chamber modules S. For field pressure determination, the hydraulic power module C can be used with electrical power module L and probe module E. For sampling without contamination in deposit conditions, hydraulic power module C can be used with electrical power module L, and probe module E in combination with fluid analysis module D, discharge pumping module M and a plurality of sampling chamber modules S. A simulated Drill Column Test type test may be performed. Test (DST) by combining the L power module with the P packer module and the S sampling chamber modules. possible and the arrangement of these settings also depends on the objectives to be achieved with the tool. The tool can be either unitary or modular in construction, however modular construction allows for greater flexibility and lower costs for users when not all attributes are required.

The individual modules of apparatus A are designed to be quickly coupled to one another. Flush connections may be used between modules instead of male / female connections to avoid points where contaminants that are normally encountered in a well location environment may be trapped.

Flow control during sampling allows the use of different flow rates. In situations of low permeability, flow control is very useful in preventing the withdrawal pressure of fluid samples from the formation from being below their bubbling point or asphaltene precipitation point.

Thus, when the tool contacts the wellbore wall, fluid communication is established between the formation and the wellbore tool. Various testing and sampling operations can then be performed. Typically, a pretest is performed by withdrawing fluid into the flow line by selectively activating a pretest piston. The pretest piston is retracted such that fluid flows into a portion of the in-pit tool flow line. Piston cycles in an extraction phase and an accumulation phase provide a pressure indication that is analyzed for evaluation of the formation pressure within the well to determine whether the packer has established a proper seal, and to determine if fluid flow is adequate to obtain a diagnostic specimen.

It follows from the above discussion that pressure measurement and fluid sampling operations from formations penetrated by open drilled holes are well known in the relevant art. After a liner has been installed in the drilled hole, however, the possibility of performing these tests is limited. There are hundreds of wells that are considered to be abandoned each year in North America, and these wells add to the thousands of wells that are already inactive. These wells have been abandoned due to the fact that they no longer produce oil and gas in the quantities required to be economically profitable. However, most of these wells were drilled in the late 1960s and during the 1970s and were profiled using techniques considered primitive by current standards. Thus, recent research has revealed that many of these abandoned wells contain large amounts of recoverable natural gas and oil (perhaps as much as 100 to 200 trillion cubic feet) (from 2,831 trillion to 5,662 trillion cubic meters) that have not been tapped by conventional production techniques. Due to the fact that most of the costs of developing production fields, such as drilling, coating and cementing costs, have already been spent on these wells, it may be proven that the exploration of these wells to produce oil resources and natural gas would be an inexpensive undertaking that would increase the production of hydrocarbons and gas. It is therefore desirable to perform further testing on such coated drilled holes.

In order to conduct various tests on a coated drilled hole to determine if the well is a good candidate for production, it is often necessary to drill the coating to investigate formation around the drilled hole. One such commercially used drilling technique employs a tool that can be lowered on a wireline to a coated section of a drilled hole, wherein the tool includes a shaped explosive charge intended to pierce the coating, and devices. testing and sampling for measuring the hydraulic parameters of the environment behind the liner and / or collecting fluid samples from the environment.

Various techniques have been developed for drilling in coated drilled holes, such as drilling techniques and tools which are described, for example, in U.S. Patent Nos. 5,195,588; No. 5,692,565; No. 5,746,279; No. 5,779,085; No. 5,687,806; and No. 6,119,782, all under assignment to the assignee of the present invention.

The '588 patent issued to Dave discloses an interior well formation test tool that can reseal a hole or bore in a wall of a coated drilled hole. The '565 patent issued to McDougall et al. Discloses a single-drill well interior tool arranged on a flexible shaft for drilling, sampling, and subsequently sealing a plurality of holes drilled into a coated drilled hole. Havlinek et al. Patent 279 discloses an apparatus and method for overcoming drill life limitations by carrying multiple drills, each of which is employed to drill only one hole. The '806 patent issued to Salwasser et al. Discloses a technique for adding the weight-over-drill supplied to the flexible shaft drill using a hydraulic piston.

Another drilling technique is described in U.S. Patent No. 6,167,968 issued to Penetrators Canada. The '968 patent discloses a somewhat complex drilling system involving the use of a machining drill for steel cladding drilling and a rock drill mounted on a flexible shaft to drill through the formation and the cemented layer.

Despite these advances in drilling and formation assessment systems, there remains a need to provide an interior well tool that is capable of drilling the sidewall of a wellbore and performing the desired formation assessment processes. Such a system will also preferably be equipped with a probe / plug system capable of supporting the drilling tool and / or fluid withdrawal pumping capabilities into the interior well tool. It is equally desirable that this combined drilling and forming evaluation system be provided with a drill system capable of long term regular use, and adaptable to work in a variety of wellbore conditions, such as coated wellbores or open hole. It is also desirable for such a system to provide a probe / plug assembly that is less subject to the differential locking problems of the tool body with the drilled hole wall, and to reduce the risk of damage to the probe assembly while moving the tool. It is further desirable that such a system can drill through a selective distance within the formation sufficient to reach a point beyond a zone located immediately around the drilled hole and whose permeability may have been altered, reduced or damaged due to the effects of drilling (well) drilling of the drilled hole, including pumping and invasion of drilling fluids.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides apparatus for determining features of a formation located below the earth surface, including a tool body adapted for routing within a perforated hole that penetrates the underground formation. A probe assembly is carried by the tool body to seal and insulate a region of the drilled hole wall. The term "probe assembly" will hereinafter be used herein to describe the present invention to encompass the use of probes (pickup or sensing devices), packers, and a combination thereof. An actuator is employed to move the probe assembly between a retracted position for routing the tool body during maneuvering and an operating position for sealing and isolating a region of the drilled hole wall. A perforating device is employed to penetrate a portion of the sealed contact region of the drilled hole wall.

In a specific embodiment, the apparatus according to the invention further includes a flow line that extends through a part of the tool body and is arranged in fluid communication with at least one of the punching device, actuator, flow assembly. probe, and a combination thereof, to admit forming fluid into the body of the tool. A pump is also carried within the tool body to extract formation fluid into the tool body through the flow line. A sampling chamber may additionally be carried within the tool body to receive pump forming fluid. Additionally, an instrument may be carried within the tool body to analyze forming fluid drawn into the tool body via the flow line and the pump.

The tool body of the apparatus according to the invention is adapted for movement within a drilled hole by using a wireline in the same manner as conventional forming test devices, or by of a drill string for use during drilling interruption (well) periods in very directional holes (wells) or in situations where interlocking is a substantial probability.

The probe assembly includes, in a specific configuration, a pair of individually inflatable rings carried around axially separated portions of the tool body and adapted for sealing contact with axially separated annular regions of the drilled hole wall. The actuator includes a hydraulic system to selectively inflate and deflate packer rings.

In another embodiment of the apparatus according to the invention, the probe assembly is adapted for establishing sealing contact with a well hole wall region adjacent one side of the tool body. Thus, this configuration further includes an anchor system for supporting the tool body against a well hole wall region located opposite that side of the tool body. The probe assembly of the present embodiment preferably includes a substantially rigid plate and a compressible plug member mounted on the plate. The actuator of the present embodiment preferably includes a plurality of pistons coupled to the probe plate for moving the probe assembly between retracted and operational positions, and a controllable power supply for piston power supply. The controllable power source preferably includes a hydraulic system.

In a particular embodiment of the apparatus according to the invention, the drilling device includes at least one drilling shaft having a drill bit coupled to one end thereof to penetrate a portion of the sealed and insulated region of the drill hole wall. well, and a drilling motor assembly for applying torque and driving force to the drilling shaft. The shaft (s) may be flexible / rigid or rigid depending on the specific application. Thus, for example, if extensive lateral drilling is required, a rigid shaft may not be adequate as the length of a rigid shaft will be constrained by the diameter of the tool body. It will be preferred that the drilling device of the present embodiment additionally includes a tubular guide for orienting the drilling axis translation path for achieving a substantially perpendicular penetration path through the drill bit through the borehole wall.

In one particular embodiment, the tubular guide is flexible and is attached at one end to the drill motor assembly and is attached at the other end to the probe assembly. Alternatively, the tubular guide is defined by a conduit extending through a part of the tool body. In the alternative embodiment, the tubular guide may include a laterally protruding part of the tool body through which a conduit portion extends, or it may include a substantially rigid tubular portion of the probe assembly that is concentric with a conduit portion.

In various embodiments of the apparatus according to the invention, the piercing device includes at least one of an explosive charge, a hydraulic punch, a coring bit, and a combination thereof.

In another aspect, the present invention relates to a method for determining characteristics of a formation located beneath the earth's surface, including the steps of sealing and insulating a region of a perforated hole wall that penetrates the surface. forming, and drilling a portion of the sealed and insulated region of the wellbore wall to facilitate formation testing.

The method according to the invention preferably includes the steps of collecting a sample from the formation through the perforated portion of the well bore wall, and analyzing the sample taken from the formation fluid.

In another aspect, the present invention relates to an apparatus for drilling a coated drilled hole that penetrates an underground formation, including a tool body adapted for movement within the coated drilled hole. A first drill shaft has a first drill bit coupled to one end thereof to drill a portion of the liner that lines the wellbore wall, and a second drill shaft has a second drill bit coupled to an end thereof to extend through the drill hole in the casing and drill a portion of the wellbore wall. A drill motor assembly is employed for applying torque and travel force to the first and second drilling axes, and a coupling assembly is employed for selectively coupling the drilling motor assembly to the first drilling axis to the second drilling axis. drilling, or a combination thereof.

An anchoring system is preferably carried by the tool body to support the tool body within the drilled hole. The anchoring system is preferably displaceable for disposal in an operating position by, for example, a hydraulic system.

In a particular embodiment, the coupling assembly includes a gear assembly operably coupled to both the first and second drilling axes. At least one of the drill shafts of this configuration is selectively operably coupled to the gear assembly.

In another embodiment, the second drilling axis has a defined drilling path, and the coupling assembly includes a drill coupling coupled to one end of the first drilling axis at a location opposite that of the first drilling drill, and a means for selectively moving the first drilling axis between a hold position and a drilling position. The drilling position is located in the drilling path of the second drilling axis, thereby allowing the second drilling drill to contact the drill coupling and drive the first drilling shaft. The movement means may displace the first drilling axis in a pivoting movement or a translational movement.

In an additional configuration, the first and second drilling axes have respective defined drilling paths, and the coupling assembly includes a drill coupling coupled to one end of the first drilling axis as opposed to the first drilling drill, and means for selectively moving the second drilling axis from its drilling path to the drilling path of the first drilling axis, thereby allowing the second drill bit to contact the drill coupling and drive the first drilling shaft.

A further aspect of the present invention relates to a method for drilling a coated drilled hole that penetrates an underground formation, including the step of drilling a portion of the coating that lines the wellbore wall using a drill motor assembly and a first drill spindle having a first drill bit coupled to one end thereof, and extending a second drill spindle by drilling through the liner using the drill motor assembly. The second drill shaft has a second drill bit coupled to one end thereof to penetrate the formation. A portion of the wellbore wall is then drilled using the drill motor assembly and the second drill shaft with the second drill bit. The first and second drill axes are selectively coupled to the drill motor assembly to perform drilling and extension steps.

BRIEF DESCRIPTION OF DRAWINGS

In order to make possible a detailed understanding of the features and advantages of the present invention as referred to above, a more specific description of the invention will be given which has been briefly summarized above with reference to the embodiments thereof which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only typical embodiments of the invention and should therefore not be construed as limiting the scope of the invention, as the invention may allow other equally effective embodiments.

Figures 1A-1B are schematic illustrations of a prior art forming test device for use in open hole environments.

Figure 2 is a schematic illustration of a prior art forming test device for use in coated hole environments.

Figure 3 is a schematic illustration of an improved formation test device for use in open hole or coated hole environments in accordance with the present invention.

Figures 4A-4B are detailed sequential, partially cross-sectional illustrations of a configuration of a displaceable probe assembly for disposition in an operating position in accordance with an aspect of the present invention.

Figures 5A-5B are detailed, partially cross-sectional, sequential detailed illustrations of a second configuration of the displaceable probe assembly for placement in an operating position.

[00050] Figures 6A-6B are detailed, partially cross-sectional, sequential detailed illustrations of a third configuration of the displaceable probe assembly for placement in an operating position.

[00051] Figure 7 is a detailed, partially cross-sectional illustration of a fourth configuration of the displaceable probe assembly for placement in an operating position.

Figure 8 is a schematic illustration of an improved formation test device employing dual inflatable packers in accordance with another aspect of the present invention.

Figures 9A, 9B, and 9C are detailed sequential illustrations, partially in cross section, of an embodiment of a double drill configuration for drilling the walls of a coated hole in accordance with another aspect of the present invention.

Figures 10A, 10B, and 10C are detailed sequential illustrations, partially in cross section, of a second embodiment of the double drill configuration for drilling the walls of a coated hole.

Figures 11A, 11B, and 11C are detailed sequential illustrations, partially in cross section, of a third embodiment of the double drill configuration for drilling the walls of a coated hole.

Figures 12A, 12B, and 12C are detailed sequential illustrations, partially in cross section, of a second embodiment of the double drill configuration for drilling the walls of a coated hole.

DETAILED DESCRIPTION OF THE INVENTION

[00057] Figure 2 illustrates a drilling tool 212 for formation evaluation. Tool 212 is suspended on a cable 213 within a steel sheath 211. This steel sheath coats or lines the drilled hole 210 and is supported with cement 210b. The drilled bore 210 is typically filled with a completion fluid or water. The length of the handle substantially determines the depths to which the tool 212 may be lowered into the drilled hole. Depth gauges can determine the cable offset over a support mechanism (eg a pulley) by determining the specific depth of the profiling tool 212. The length of the cable is controlled by a suitable known means on the surface such as a mechanism. drum / reel and winch (not shown). Depth can also be determined by electrical, nuclear, or other sensors that correlate depth with previous measurements made in the well or in relation to the well casing. In addition, surface-mounted (not shown) electronic circuits represent processing, communications, and control circuits for the 212 profiling tool. The circuits may be of a known type and need not have new characteristics.

The tool 212 of Figure 2 is illustrated with a generally cylindrical body 217 equipped with a longitudinal cavity 228 surrounding an inner housing 214 and electronic components. Anchor Pistons 215 force the tool-shutter assembly 217b against the liner 211 to form a pressure tight seal between the tool and the liner that serves to keep the tool stationary.

Internal housing 214 contains the drilling means, the testing and sampling means and the closing means. This inner housing is moved along the tool axis (vertically) through cavity 228 by the housing translation piston 216 attached to a body portion 207 but also disposed within cavity 228. This movement of the inner housing 214 positions the respective lower and upper positions, the perforation and plugging means components in lateral alignment with the side opening of the body 212a within the packer 217b. Opening 212a communicates with cavity 228 through an opening 228a into the cavity.

A flexible shaft 218 is located within the inner housing and is routed through a tubular guide conduit 214b extending through the housing 214 from the drive motor 220 to a side opening 214a in the housing. A drill bit 219 is rotated through the flexible shaft 218 by the drive motor 220. This motor is held in the inner housing by a motor holder 221, which is itself coupled to a translation motor 222. The translation motor drives the drive motor 220 by rotating a threaded shaft 223 within a locknut located on the motor holder 221. The flexible shaft translation motor thus provides a downward force on the drive motor 220 and the shaft 218 during drilling, thereby controlling penetration. This drilling system allows you to drill holes substantially deeper than the tool diameter, but alternative technology (not shown) may be employed to produce holes a bit smaller than the tool diameter if necessary.

For the purpose of obtaining measurements and samples, a flow line 224 is also contained in the inner housing 214. The flow line is coupled at one end to cavity 228 - which is opened for formation pressure during perforation - and is otherwise coupled via an isolation valve (not shown) to the main tool flow line (not shown) passing along the tool extension allowing the tool to be coupled to sampling chambers.

A magazine of shutter elements (or alternatively a revolver) 226 is also contained in the inner housing 214. After the formation pressure has been measured and samples taken, the housing translation piston 216 moves the inner housing 214 for moving the shutter drum 226 into position by aligning a shutter member positioning piston 225 with apertures 228a, 212a and the drilled bore. The sealing member positioning piston 225 then forces a drum sealing member into the liner, thereby resealing the drilled hole. The integrity of the plug element seal may be tested by monitoring the pressure through the flow line during the actuation of a drawdown piston. The resulting pressure should fall and subsequently remain constant at the reduced value. A leakage of a plug element will be indicated by a return of pressure to the formation pressure value after actuation of the extraction piston. It should be noted that this same test method is also used for checking the integrity of the tool-plug seal prior to the start of drilling. The sequence of events ends by loosening the tool anchors. The tool is then ready to repeat the sequence.

[00063] Figure 3 illustrates a well interior formation assessment tool 300 positioned in an open hole well bore. The tool includes a body 301 adapted for movement within a perforated hole 316 which penetrates underground formation 305. Tool body 301 is well adapted for movement within a perforated hole by means of a drill cable W thereof the same as conventional formation test devices, but is equally adaptable for movement within a drill string (ie being routed during the well drilling operation). The apparatus is anchored and / or supported against the borehole wall side 312 located opposite to a probe assembly 307 by actuation of anchor pistons 311.

Probe assembly (also simply referred to as "probe") 307 is carried by tool body 301 to seal and isolate a region 314 from wellbore wall 312. A piston actuator 316 is employed to move the assembly 307 between a retracted position (not shown in Figure 3) for tool body transport, and an installed position ready for commissioning (shown in Figure 3) for sealing and isolating the well hole wall region 314 The actuator of this configuration preferably includes a plurality of pistons coupled to probe assembly 307 for moving the probe between retracted and installed positions, and a controllable power source (preferably a hydraulic system) for supplying power to the pistons. Probe assembly 307 preferably includes a compressible plug 324 mounted on a piston installed plate 326 for creating the seal between wellbore wall 312 and the formation of interest 305.

A drilling device, including a flexible drill shaft 309 equipped with a drill bit 308 and driven by a motor assembly 302, is employed to penetrate a portion of the sealed and insulated region 314 of the limited borehole wall 312. by the packer 324. The flexible shaft 309 transmits rotational and translational force to the drill bit 308 from the drive motor 302. The action of the punch device results in a hole or side bore 310 extending partially through formation 305.

The tool 301 further includes a flow line 318 extending through a part of the tool and establishing fluid communication with forming 305 through bore 310 via the punch path 320 and path 322 defined by the tool. actuator and plug (both paths are considered as flow line extension components 318) for forming fluid inlet into tool body 301. A pretest piston 315 is also coupled to flow line 320 for pre-tests.

A pump 303 is also carried within the tool body for extracting formation fluid into the tool body via flow line 318. A sampling chamber 321 is additionally ported within the tool body 301. for receiving forming fluid from the pump 303. In addition, instruments may be carried within the tool body 301 for pressure measurement, and for analysis of forming fluid drawn into the tool body (e.g., as optical fluid analysis device 99 of Figure 1) through flow line 318 and pump 303.

After drilling / boreholes or bore (s) 310 has been created, flow line 318 can freely communicate forming fluid to these components for evaluation and / or storage within the borehole. well. Pump 303 is not essential, but is quite useful for controlling formation fluid flow through flow line 318. Sampling and evaluation of formation can occur at a multiplicity of bore penetration depths by additional drilling into the interior of the formation. Preferably, such a bore extends through the damaged zone surrounding perforated bore 306 and into the syngeneic fluid zone of formation 305.

Referring now to Figures 4A-4B, an alternative formation assessment tool 400 is illustrated therein. Figure 4A illustrates probe assembly 407 in the retracted position for tool movement 400. Figure 4B illustrates probe assembly 407 moving to the extended position to seal and insulate a wellbore wall region 412. The tool 400 employs a drilling device that includes at least one flexible drilling shaft 409 equipped with a drill bit 408 at one end thereof to penetrate a portion of the sealed and insulated region 414 of wellbore wall 412 (and a casing and a cement mass if present). It is preferred that the drill bit 408 of this configuration is made of diamond for open hole use, but it will preferably employ other materials (eg tungsten carbide) for use in coated holes (as will be described in detail below), thus a formation penetration capability 405 is improved to a desired lateral depth. A drilling motor assembly 402 is provided for applying torque and travel force to the drilling spindle 409. The drilling device of this configuration further includes a semi-rigid tubular guide 420 to guide the travel path of the flexible drilling spindle 409, to perform a substantially perpendicular penetration path of the drill bit through wellbore wall 412.

As illustrated by the sequence formed by Figures 4A-4B, the tubular guide 420 is semi-flexible, allowing flexing and movement with the start-up of probe assembly 407. The hydraulically induced force by pistons 416 makes it operational and compresses the plug member 424 against the wall 412 of the drilled hole 405. The tubular guide 420 is coupled at one end to the drill motor assembly 402, and is coupled at the other end to the probe assembly 407. The tubular guide 420 complies with two purposes. Firstly, it provides sufficient stiffness to impose a reaction force on the flexible shaft 409 allowing the shaft to move under the force provided by the drive motor 402. Secondly, the tubular guide 420 engages a flow line ( 4A-4B) in apparatus 400 to probe plate 426, and thus acts as an extension of the tool flow line.

Figures 5A-5B illustrate another alternative moving formation evaluation tool 500 within a perforated hole penetrating a formation 505. Figure 5A illustrates probe assembly 507 in the retracted position. Figure 5B illustrates probe assembly 507 moving to the extended position to contact the wellbore wall. The tool includes a tubular guide 520 defined by a conduit extending through a part of the tool body 501. In this alternative embodiment, the tubular guide includes a laterally protruding part 530 of the tool body 501 through which a part of the tool extends. guide definition conduit. In this manner, the drill 508 at the end of the flexible drill shaft 509 is guided through the central opening in the probe assembly 507 toward the well bore wall 512. A bellows 535 is used for fluid coupling of the tubular guide 520 (which functions as part of a flow line within the tool) in the tool body 500 to probe assembly 507 when the probe assembly is brought into operation by the action of hydraulic pistons 516 on probe plate 526, giving a compression to the plug element 524 and forcing it against wall 512 of formation 505 to seal and insulate region 514.

In Figure 6A-6B an additional alternative formation evaluation tool 600 is shown being carried within a drilled hole penetrating a formation 605. Figure 6A illustrates a probe assembly 607 in the retracted position as shown in FIG. whereas Figure 6B illustrates probe assembly 607 moving to the extended position to contact wellbore wall 612. Pistons 616 are provided for extension and retraction of probe assembly 607. A tubular guide 620 includes a substantially rigid tubular portion 632 of probe assembly 607 which is concentric with a conduit portion 621 that substantially defines tubular guide 620. The tubular portion 632 may be used to fluidly couple the tool body 601 (more particularly the tubular guide 620) to the probe assembly 607. Thus, when the pistons 616 install the probe plate 626 toward the wall 612 of the drilled hole for imposing a compressive force on the plug element 624 and sealing a region 614 (see Figure 6B) the perforations (not shown) formed by the flexible shaft 609 and the drill bit 608 drive fluid from the formation 605 to the tool 600. tubular portion 632 is preferably flexible to deflect when probe assembly 607 is put into operation, and such that tubular portion 632 maintains physical contact with the side projecting portion 630 of the tool body 601, thereby maintaining fluid communication with the tool body 601. The addition of a spherical joint (not shown) between the sliding tubular part 632 and the mounting plate. probe 626 may reduce preference for the flexible character of the sliding tubular portion 632.

Figure 7 illustrates another alternative forming evaluation tool 700 including a tool body 701 carried within a drilled hole penetrating a formation 705. This alternative is similar to that of Figures 6A-6B in that a tubular guide 720 includes a substantially rigid tubular portion 732 of a probe assembly 707 which is concentric with a conduit portion 721 that substantially defines tubular guide 720. The main differences in this case lie in that the probe plate 726 is relatively narrow. , and the rigid tubular part 732 of probe assembly 707 also functions as an actuator piston (see annular protrusion 734 within hydraulically pressurized annular space 736). Figure 7 also illustrates an anchor system 711 for positioning and holding tool 700 within the drilled hole. An additional difference lies in the use of a separate flow line 780 which is coupled at one end thereof to a cavity 770 into which the probe portion 732 reciprocates. Flow line 780 is otherwise coupled via an isolating valve (not shown) to the main tool flow line (not shown) disposed along the tool extension, which allows coupling of the tool with sampling chambers. Thus, in this embodiment, the tubular guide 720 is not a means for sampling of forming fluid (although the tubular guide may experience a forming pressure).

Figure 8 illustrates another alternative formation assessment tool 800 disposed in a drilled hole 812 that penetrates a formation 805. In this configuration, the probe assembly 807 includes a pair of inflatable shutters 824 individually carried around axially portions. 808. The shutters 824 are well adapted to sealably seal axially separated annular regions of the wellbore wall 812. In this configuration, the actuator for assembly 800 includes a hydraulic system (not shown) for inflation and selective emptying of shutters 824.

Figure 8 further illustrates an alternative punch device useful in the present invention. Thus, an explosive charge 809 is useful for creating a bore 810 in formation 805. Other suitable boring means include a hydraulic punch and a core drill, any of which are useful for creating boreholes through the borehole wall. Thus, the illustrated configuration is effective for inflating forming fluid into the flow line 818 for collection into a sampling chamber 811 with the aid of a pump 803.

Figures 9-12 illustrate alternative versions of a dual drill bit assembly that can be used in drilling tools, such as the drilling tools of Figures 2 and 3. As shown in Figure 9A, the set of double drill can be used to penetrate the wall 912 of a perforated hole 906 that penetrates an underground formation 905. the perforated hole 906 can be equipped with a 936 concrete cladding casing column 9 that fills the annular space between the casing and the wall well borehole. An anchor system 911 is carried by tool 900 to support the tool within the perforated coated hole 906, or more particularly within the casing column 936.

In Figures 9A-9C there is illustrated a configuration of the double drill drilling assembly 970 including a tool body 900 adapted for transport within a drilled hole such as the coated drilled hole 906 having a wall of well hole 912. Figure 9A illustrates the double drill system in the retracted position for maneuvering within a drilled hole. Figure 9B illustrates the system in a first drilling configuration. Figure 9C illustrates the system in a second drilling configuration. This apparatus utilizes a dual drill system to drill successive co-linear holes through sidewall 912 of the drilled hole and through (essentially rock) formation together with coating and cement if present. A first drill shaft 909a has a first drill bit 908a coupled to one end thereof. The first drill bit is preferably suitable for drilling a portion of the steel casing 936 that lines the wellbore wall 912. A second drill shaft 909b, which is flexible, has a second drill bit 908b coupled to one end thereof. The second drill bit is preferably tailored to be extended through a hole formed in the liner 936 and to pierce the concrete layer 938 and a portion of the formation 905. A drilling motor assembly (not shown) is employed for torque application and translation force to the first and second drilling axes 909a, 909b.

A mechanism, in the form of a coupling assembly 950, provides a means by which both drilling axes 909a, 909b can be driven from a single motor drive device. The coupling assembly includes a coupled spur gear assembly 940, 942, an idler shaft 944, and a right angle gear box 946. The coupling assembly is useful for selectively coupling the drill motor assembly to the first and second drilling axes. The second drilling shaft 909b is selectively operably coupled to the gear assembly and thus a torsion applied to the second drilling shaft 909b by the drilling motor assembly is preferably not transferred through the coupling gear assembly 950 to the first drilling axis. 909a unless the second drill spindle 909b is sufficiently retracted to dispose the second drill bit 908b in contact with spur gear 942.

Thus, for example, for drilling through the steel casing, the second (flexible) drill shaft 909b may be retracted within the tubular guide 920 until the second drill bit 908b contacts the spur gear 942 as shown in Figure 9B. This contact induces a rotation of the intermediate rotary shaft 944. This rotary shaft in turn drives the first drill shaft 909a via the right angle gear mechanism 946. The first drill shaft 909a is mechanically coupled to the first drill bit 908a. , which preferably consists of a carbide drill bit suitable for steel drilling. A hydraulic piston (not shown) may be employed with a thrust bearing to provide an increase in the drill weight to a level required to pierce the steel liner 936.

After the casing has been drilled, concrete layer 938 and formation 905 are drilled by reversing the direction of the travel motor to retract the first drilling shaft 909a and / or by retracting the hydraulic piston (if provided). This retraction step creates sufficient space for insertion of the second (flexible) drilling shaft 909b through the hole in casing 936 as shown in Figure 9C. The flexible shaft then proceeds to drill through the cement layer 938 and the steel liner 936 using the torsional drive force provided by the drive motor system.

Figures 10A-10C illustrate another embodiment of the dual drill drilling system 1070. Figure 10A illustrates the dual drill system in the retracted position for transport within a drilled hole. Figure 10B illustrates the system in a first drilling configuration. Figure 10C illustrates the system in a second drilling configuration. In these figures, the second drill shaft 1009b has a defined drill path which is defined by the tubular guide 1020b, and the coupling assembly includes a drill coupling 1008c coupled to an end of the first drill shaft 1009a opposite the end of the first. drill bit 1008a. A means is provided for selectively moving the first drilling shaft 1009a between a holding position on the tubular guide 1020a (see Figures 10A and 10C) and a drilling position on the tubular guide 1020b (see Figure 10B). The drilling position is located in the drilling path (i.e., tubular guide 1020b) of the second drilling shaft 1009b, thereby allowing the second drilling drill 1008b (which is specially designed for contacting) to contact the drill coupling. drill 1008c and drive the first drilling shaft 1009a.

The movement means may move the first drilling axis in a pivoting movement as illustrated by the double drill drilling system 1070 of Figures 10A-10C or in a translational movement as illustrated by the drilling system double drill bit 1170 of Figures 11A-11C. A hydraulic piston assist mechanism, as mentioned above, may also be used here to provide the appropriate weight-over-drill for the liner drilling operation, and may additionally be used as a means of movement. Thus, the hydraulic mechanism may be used to retract (by pivoting or translating) the first drilling spindle assembly 1109a back into the tool body 1103, and out of the path 1120b of the second drilling spindle 1109b and back. to hold position 1120a. Then, the second drill shaft 1109b and the second drill bit 1108b are free to perform translation and rotation through the pathway 1120b for drilling through the formation rock.

Figures 12A-12C illustrate another dual drill drilling system 1270 including a tool body 1203. In these figures, the first and second drilling axes 1209a, 1209b individually have respective defined drilling paths 1220a, 1220b. In this case, the coupling assembly includes a drill coupling 1208c coupled to an end of the first drill bit 1209a opposite the end of the first drill bit 1208b, and a means including a whipstock 1250 for displacing it. selectively the second drilling axis 1209b from its drilling path 1220b to the drilling path 1220a of the first drilling axis 1209a. This has the effect of positioning the second drill bit 1208b in an arrangement for engaging with the drill coupling 1208c, and thereby the second drilling shaft 1209b drives the first drilling shaft 1209a. In other words, the specially designed rock drill located at the end of the flexible shaft 1209b interfaces with the drill coupling 1208c at the end of the casing drill shaft 1209a. Thus, a rotational movement of the coating bit 1208a is applied by rotating the second (flexible) drilling shaft 1209b.

The casing drill shaft 1209a is preferably mechanically coupled to a hydraulic assist mechanism (not shown). The power assist mechanism provides the weight-over-drill required for coating drilling operations, and retracts the coating drill assembly back into the tool body 1200 when required. During drilling of the steel sheathing, tool 1200 performs a downward translation (see Figure 12B) to ensure entry of the second drilling shaft into the first drilling path through the whipstock 1250, with proper elevation. When drilling through the formation rock, tool 1200 performs an upward translation (see Figure 12C) to ensure entry of the second drilling axis into the second drilling path 1220b at a suitable elevation, and at that time the second drilling axis. 1209b and the second drill bit 1208b are free to begin rock drilling through drilling path 1220b.

The dual drill configurations described above may require additional mechanical operation to position the steel drill bit 1208a in the down position (Figure 12B) for steel drilling and to move the first drilling shaft 1209a upward and downward. off course (Figure 12C) for formation drilling. This mechanical operation can be accomplished by adding selected hydraulic components - for example, additional solenoid elements and hydraulic lines added to existing systems - which are at the normal technical level in the relevant technical area.

It should be understood from the foregoing description that various modifications and changes may be made to the preferred and alternative embodiments of the present invention without departing from its true spirit.

[00087] This description is for illustrative purposes only and should not be construed in a limiting sense. The scope of the present invention should be determined solely by the language of the following claims. The term "comprising" in the claims is intended to mean "including at least" such that the list of elements cited in a claim constitutes an open group. "One", "one" and other terms used in the singular are intended to include the plural forms thereof unless such exclusion is specifically stated. - CLAIMS -

Claims (17)

1. Apparatus for determining the characteristics of an underground geological formation, comprising: a tool body (301) adapted to be moved within a perforated hole penetrating the underground formation; a probe assembly (307) carried by the tool body (301) for sealing and isolating a region of the wellbore wall; an actuator (316) for moving the probe assembly (307) between a retracted position for tool body transportation (301) and an operating position for sealing and isolating a wellbore wall region; a piercing device (322) extending through the probe assembly (307) to penetrate a portion of the sealed and insulated region of the wellbore wall, with the piercing device (322) penetrating at least one of a consolidated formation. , coating and cement; a power source disposed on the tool body (301) and operatively connected to the punch device (322) to operate the punch device (322); and a flow line (224) extending through a portion of the tool body (301) and fluidly in communication with at least one of the perforating device (322), actuator (316), probe assembly (307), and a combination thereof for inlet formation fluid into the tool body (301). Apparatus according to claim 1, further comprising: a pump carried within the tool body to draw forming fluid into the tool body through the flow line. Apparatus according to claim 2, characterized in that it further comprises: a sampling chamber (321) carried within the tool body (301) and intended to receive forming fluid sent by the pump. Apparatus according to claim 2, further comprising: an instrument carried within the tool body and intended for analyzing forming fluid drawn into the tool body (301) through the flow line (224). ) and the pump. Apparatus according to Claim 1, characterized in that the probe assembly (307) comprises a pair of inflatable plug rings (28) individually carried around axially separated portions of the tool body (301) and adapted to contact them. sealable and insulated axially separated annular regions of the wellbore wall. Apparatus according to Claim 5, characterized in that the actuator (316) comprises a hydraulic system for selectively inflating and emptying the plug rings (28). Apparatus according to claim 1, characterized in that it further comprises: an anchor system (9011) for supporting the tool body (301) against a region of the wellbore wall located opposite to one side of the tool body (301). Apparatus according to claim 1, characterized in that the probe assembly (307) comprises: a substantially rigid plate (426); and a compressible shutter member (424) mounted on the plate (426). Apparatus according to claim 8, characterized in that the actuator (316) comprises: a plurality of pistons coupled to the probe plate (426) for moving the probe assembly (307) between retracted and operational positions; and a controllable power source for piston power supply. Apparatus according to claim 1, characterized in that the drilling device (322) comprises: at least one flexible drilling spindle (309) having a drill bit (308) coupled to one end thereof to penetrate a portion of the spindle. sealed and insulated region of the wellbore wall; and a drilling motor assembly (402) for applying torque and driving force to the drilling shaft (309). Apparatus according to claim 10, characterized in that the perforating device (322) further comprises: a tubular guide (420) for orienting the translation path of the drilling axis (309) for achieving a substantially perpendicular penetration path. through the drill bit (308) through the wellbore wall. Apparatus according to claim 11, characterized in that the tubular guide (420) is flexible and is coupled at one end to the drill motor assembly (402) and coupled at the other end to the probe assembly (307). Apparatus according to claim 11, characterized in that the tubular guide (420) is defined by a conduit extending through a part of the tool body (301). Apparatus according to claim 1, characterized in that the piercing device (322) comprises at least one of an explosive charge (809), a hydraulic punch, a core bit, and a combination thereof. METHOD FOR DETERMINING CHARACTERISTICS OF AN UNDERGROUND FORMATION, characterized by the steps of: sealing to isolate a region of a wall from an open perforated hole that penetrates the formation; moving a probe assembly (307) from a retracted position to an operational position for sealing a perforated hole wall region; extending at least one flexible drill shaft (309) having a drill bit (308) connected to one end thereof through the probe assembly (307) for creating a drill through a portion of the sealed and insulated region of the drill wall. borehole, wherein the bore extends beyond a damaged zone located around the borehole, with the borehole device (322) penetrating at least one of a consolidated formation, coating and cement; and test the formation. A method according to claim 15, further comprising the step of collecting a fluid sample from the formation through drilling. The method of claim 16 further comprising the step of analyzing the fluid sample taken from the formation.