Hydraulic sand blasting perforation method for plugging fallen fishes in old well of gas storage

Abstract

According to the hydraulic sand blasting perforation method for blocking the fallen fishes in the old well of the gas storage, the old well of the gas storage with the fallen fishes serves as a construction well, a rescue well is dug in one side of the construction well, the rescue well and the construction well are accompanied, and fish touching is conducted in a preset layer section to achieve fish attaching accompanying; in the rescue well, a cementing fluid channel is established towards the construction well through hydraulic sand blasting directional perforation, and solid particles are accelerated by a high-speed fluid carrier and impact a sleeve and rock at a high speed; and in the rescue well, cement is squeezed and injected from the perforated holes through a cement injection tool to plug the water holes, and plugging of the old well of the fish-falling gas storage is completed. The method has good applicability to plugging of the underground fish hole.

Description

Technical Field

[0001] The present invention relates to the technical field of gas storage reservoir plugging construction operations, and particularly to a hydraulic sandblasting perforation method for plugging a fish left in an old well of a gas storage reservoir. Background Art

[0002] A gas storage reservoir is a gas storage facility that compresses natural gas through a compressor and then injects it into depleted gas (oil) reservoirs, underground salt cavern solution cavities or other geological structures for storage, and extracts it during the peak consumption period to meet the demand of the natural gas market. At present, the main types of gas storage reservoirs in China are depleted oil and gas reservoir type gas storage reservoirs, which are mainly formed by using depleted and abandoned gas reservoirs that have been exploited, retired gas reservoirs exploited to a certain extent, and depleted and abandoned oil reservoirs or oil reservoir gas caps with a high degree of oil recovery. Its advantages are good sealing, high safety and reliability, high utilization rate of injected gas, and short construction period. However, there are still difficulties in building depleted oil and gas reservoir type gas storage reservoirs. The main problem is the high requirement for sealing. The service life of old depleted oil and gas wells is relatively long. Affected by factors such as casing corrosion and wear, well testing perforation, etc., the quality, strength of the casing and the quality of cement bonding outside the pipe have all decreased to varying degrees, and the plugging difficulty is great. Especially for abandoned accident old wells, there are still fish left in the well such as drill bits and drill pipes. There are fluid channels on the fish left in the well, which are more likely to cause leakage of the gas in the gas storage reservoir and result in safety accidents. Therefore, safe and effective plugging has become an important link in the transformation and construction of old wells.

[0003] At present, the plugging treatment of old wells in domestic gas storage reservoirs follows the treatment principle of "from the ground to the underground, from the wellhead to the wellbore, and first test then plug". The main plugging technologies and processes include the technology of squeezing and plugging with a released and scrapped packer, the casing section milling technology, the technology of injecting cement slurry to plug the production layer and wellbore of old wells, and the plugging process of old wells in gas storage reservoirs of "multiple-stage plugging, step-by-step pressure testing, and waiting for setting under pressure", etc. Among them, the technology of squeezing and plugging with a released and scrapped packer mainly separates the gas layer by applying a packer in the perforated interval to achieve stratification of the gas layer and waiting for setting under pressure; the casing section milling technology uses special milling and reaming tools to mill and ream the casing and cement sheath in the well section with unqualified cementing quality, and reshape the caprock; the technology of injecting cement slurry to plug the production layer and wellbore of old wells is mainly applied to low-porosity and low-permeability reservoirs, and generally uses ultra-fine cement slurry to effectively plug the reservoir. When the above technologies and processes are applied in a wellbore with fish left in the well, generally, the fish left at the bottom of the well needs to be salvaged to expose the layer to be plugged. Although the above technologies and processes are already mature, their plugging bases are all established on the basis of the integrity of the old wellbore, and they are not applicable to abandoned accident old wells with an incomplete wellbore and fish left in the well. Therefore, how to effectively plug the water holes of the fish left in the well has become a key problem in the transformation of abandoned accident old wells into gas storage reservoirs.

[0004] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] During the construction of gas storage caverns, there are serious sealing problems in abandoned accident wells. The wellbore data of abandoned accident wells is missing, the wellbore is incomplete, and there are fishing tools such as drill bits and drill pipes in the well. There are fluid channels on the fishing tools, which are likely to cause leakage of gas in the gas storage cavern and result in safety accidents. Therefore, how to safely and effectively block the fluid channels has become an important issue in the construction of gas storage caverns. In view of the above problems, a hydraulic sandblasting perforation well sealing method for plugging fishing tools in old wells of gas storage caverns is proposed. This method provides a new way for plugging the underground fluid channels of abandoned accident wells, speeds up the construction speed of gas storage caverns, and reduces the construction cost.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A hydraulic sandblasting perforation method for plugging fishing tools in old wells of gas storage caverns of the present invention includes:

[0008] Taking the old well of the gas storage cavern with fishing tools as the construction well, drilling a relief well on one side of the construction well. The relief well runs parallel to the construction well, and fish touching is carried out in a predetermined interval to achieve running parallel while in contact with the fish.

[0009] In the relief well, hydraulic sandblasting directional perforation is used to establish a cement injection fluid channel towards the construction well. Solid particles are accelerated by a high-speed fluid carrier and impact the casing and rock at high speed.

[0010] In the relief well, a cement injection tool is used to squeeze cement through the perforation holes to plug the water holes, and the plugging of the old well of the gas storage cavern with fishing tools is completed.

[0011] In the described hydraulic sandblasting perforation method for plugging fishing tools in old wells of gas storage caverns, passive magnetic guidance is used to achieve the parallel running of the relief well and the construction well.

[0012] In the described hydraulic sandblasting perforation method for plugging fishing tools in old wells of gas storage caverns, the predetermined interval is the interval where the top of the fishing tool in the construction well is located.

[0013] In the described hydraulic sandblasting perforation method for plugging fishing tools in old wells of gas storage caverns, the drilling start position and wellbore structure of the relief well are determined according to the wellbore structure of the construction well.

[0014] In the described hydraulic sandblasting perforation method for plugging fishing tools in old wells of gas storage caverns, the jetting depth and direction of the hydraulic sandblasting directional perforation are determined based on the orientation and depth of the fishing tool, and running parallel while in contact with the fish is achieved at the perforation interval.

[0015] In the described hydraulic sandblasting perforation method for plugging fishing tools in old wells of gas storage caverns, the relief well is equipped with a hydraulic sandblasting perforation tool for hydraulic sandblasting directional perforation and a construction string.

[0016] In the described hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, according to the wellbore structure of the relief well, the size of the hydraulic sandblasting directional perforation, the hydraulic parameters, and the structural parameters of the construction string are determined to install the construction string and the hydraulic sandblasting perforation tool in the relief well.

[0017] In the described hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, a gyroscope is lowered into the relief well to check the lowering depth and the jetting azimuth of the hydraulic sandblasting perforation tool.

[0018] In the described hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, establishing a cement injection fluid channel by the hydraulic sandblasting directional perforation towards the construction well includes

[0019] Pressurizing the construction string of the relief well;

[0020] Assembling and lowering the hydraulic sandblasting perforation tool;

[0021] Determining the jetting azimuth;

[0022] Circulating and cleaning the construction string;

[0023] Conducting a ball dropping pressure test;

[0024] Performing a jetting operation;

[0025] Pulling out the construction string.

[0026] In the described hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, after the jetting operation is completed, a cement injection tool is lowered to squeeze and inject cement to plug the water holes of the sunken fish.

[0027] In the above technical solution, the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir provided by the present invention has the following beneficial effects: Through long-distance directional perforation, multiple layers and multiple holes can be shot open at one time to form a regular and good fluid channel. Cooperating with the subsequent cement injection process, it has good applicability to plugging the hole eyes of the sunken fish in the well. Compared with the prior art, it has the technical characteristics of safety, high efficiency, and repeatability, providing an economically feasible technical means for shooting open multiple layers and multiple holes at one time and realizing multiple hole opening and plugging. It can not only meet the standards and requirements for plugging old wells in gas storage reservoirs, but more importantly, it provides a new method for plugging abandoned accident old wells with incomplete wellbores and sunken fish, solves the problem of plugging during the construction of abandoned accident wells for building gas storage reservoirs, and promotes the construction of related old well renovations in gas storage reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0029] Figure 1 This is a schematic structural diagram of a hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir provided by an embodiment of the present invention.

[0030] Figure 2 This is a schematic structural diagram of a hydraulic sandblasting perforation tool for a hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir provided by an embodiment of the present invention.

[0031] Figure 3 is Figure 2 a schematic cross-sectional structural diagram of the hydraulic sandblasting perforation tool. Detailed implementation manners

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that: like reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0037] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "coupled", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0039] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] See Figures 1-3 As shown, in one embodiment, a hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to the present invention includes

[0041] The old well of the gas storage reservoir with the sunken fish is used as the construction well 1, a relief well 2 is drilled on one side of the construction well 1, the relief well 2 runs parallel to the construction well 1, and fish touching is carried out in a predetermined interval to achieve fish touching and parallel running.

[0042] In the relief well 2, hydraulic sandblasting directional perforation is used to establish a cement injection fluid channel towards the construction well 1, and solid particles are accelerated by a high-speed fluid carrier and impact the casing and rock at high speed.

[0043] In the relief well 2, a cement injection tool is used to squeeze cement from the perforation holes to plug the water holes, thereby completing the plugging of the old well of the gas storage reservoir with the sunken fish.

[0044] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, a passive magnetic guidance is used to enable the relief well 2 to run parallel to the construction well 1.

[0045] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, the predetermined interval is the interval where the top of the sunken fish drill string 3 in the construction well 1 is located.

[0046] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, the drilling start position and wellbore structure of the relief well 2 are determined according to the wellbore structure of the construction well 1.

[0047] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, the jetting depth and azimuth of the hydraulic sandblasting directional perforation are determined based on the azimuth and depth of the sunken fish drill string 3, and running parallel while sticking to the fish is achieved at the perforated interval.

[0048] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, the relief well 2 is provided with a hydraulic sandblasting perforation tool 4 for hydraulic sandblasting directional perforation and a construction string 5.

[0049] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, according to the wellbore structure of the relief well 2, the size, hydraulic parameters of the hydraulic sandblasting directional perforation and the structural parameters of the construction string 5 are determined to install the construction string 5 and the hydraulic sandblasting perforation tool 4 in the relief well 2.

[0050] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, a gyroscope is lowered into the relief well 2 to check the lowering depth and jetting azimuth of the hydraulic sandblasting perforation tool 4.

[0051] In the preferred embodiment of the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, establishing a cement injection fluid channel from the hydraulic sandblasting directional perforation towards the construction well 1 includes,

[0052] Pressurizing the construction string 5 of the relief well 2;

[0053] Assembling and lowering the hydraulic sandblasting perforation tool 4;

[0054] Determining the jetting azimuth;

[0055] Circulating and cleaning the construction string 5;

[0056] Ball dropping and pressurizing test;

[0057] Jetting operation;

[0058] Pulling out the construction string 5.

[0059] In a preferred embodiment of the described hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, after the jetting operation is completed, a cement injection tool is lowered to squeeze and inject cement to plug the water holes of the sunken fish.

[0060] In one embodiment, the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir is a downhole sunken fish hole plugging technology that integrates drilling a relief well 2, hydraulic sandblasting directional perforation, and cement injection. Through long-distance directional perforation, multiple layers and multiple holes can be shot open at one time to form a well-shaped fluid channel. Combined with the subsequent cement injection process, it has good applicability for plugging the downhole sunken fish holes. First, drill a relief well 2 on one side of the construction well 1, use the passive magnetic guidance technology to make the relief well 2 run parallel to the construction well 1, and touch the fish at a suitable interval to achieve running parallel while sticking to the fish; then use hydraulic sandblasting directional perforation to establish a cement injection fluid channel. According to the hydrodynamic momentum-impulse principle, solid particles are accelerated by the high-speed fluid carrier and impact the casing and rock at high speed; finally, use the cement injection tool to squeeze and inject cement from the perforation holes to plug the water holes.

[0061] In one embodiment, the hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir includes the following steps:

[0062] (1) According to the wellbore structure of the construction well 1, select a suitable location to drill the relief well 2 and reasonably design the wellbore structure of the relief well 2;

[0063] (2) Combine with the passive magnetic guidance device to gradually bring the relief well 2 closer to the construction well 1, achieve running parallel while sticking to the fish at the perforation interval, and touch the fish at a suitable location to determine the orientation and depth of the sunken fish drill string 3, providing the jetting depth and orientation for subsequent sandblasting perforation;

[0064] (3) According to the wellbore structure of the relief well 2, reasonably design the size of the hydraulic sandblasting perforation tool 4, and combine with the construction string 5, the wellbore structure of the relief well 2 and carry out hydraulic parameter calculation to design and calculate reasonable construction hydraulic parameters;

[0065] (4) Design and calculate the structure of the construction string 5, assemble and lower the hydraulic sandblasting perforation tool 4;

[0066] (5) Lower the gyroscope to check the lowering depth and jetting orientation to ensure that the jetting orientation of the nozzle is within the reasonable range of the designed orientation;

[0067] (6) Carry out hydraulic sandblasting perforation operation, and the operation process includes: 1. Pressure test the drilling string; 2. Assemble and lower the hydraulic sandblasting perforation tool 4; 3. Determine the jetting orientation; 4. Circulate and clean the string; 5. Drop a ball for pressure test; 6. Jetting operation; 7. Pull out the construction string 5 and evaluate the construction effect.

[0068] (7) After the jetting operation is completed, lower the cement injection tool to squeeze and inject cement to plug the water holes of the sunken fish.

[0069] The embodiments described above are only a part of the embodiments of this application, rather than all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative efforts belong to the scope protected by this application.

[0070] Only some exemplary embodiments of the present invention have been described by way of illustration above. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir, characterized in that, it includes, using the old well of the gas storage reservoir with the sunken fish as the construction well, drilling a relief well on one side of the construction well, the relief well running parallel to the construction well, and achieving fish contact and parallel running at a predetermined interval; adopting hydraulic sandblasting directional perforation in the relief well to establish a cement injection fluid channel towards the construction well, with solid particles accelerated by a high-speed fluid carrier and impacting the casing and rock at high speed; using a cement injection tool in the relief well to squeeze cement through the perforation holes to plug the water holes, completing the plugging of the old well of the gas storage reservoir with the sunken fish.

2. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, using passive magnetic guidance to achieve parallel running of the relief well and the construction well.

3. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, the predetermined interval is the interval where the top of the sunken fish drill string in the construction well is located.

4. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, determining the drilling position and wellbore structure of the relief well according to the wellbore structure of the construction well.

5. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, determining the jetting depth and azimuth of the hydraulic sandblasting directional perforation based on the azimuth and depth of the sunken fish drill string, and achieving fish contact and parallel running at the perforated interval.

6. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, the relief well is provided with a hydraulic sandblasting perforation tool for hydraulic sandblasting directional perforation and a construction string.

7. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 6, characterized in that, determining the size, hydraulic parameters of the hydraulic sandblasting directional perforation and the structural parameters of the construction string according to the wellbore structure of the relief well to install the construction string and the hydraulic sandblasting perforation tool in the relief well.

8. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 6, characterized in that, lowering a gyroscope into the relief well to check the lowering depth and jetting azimuth of the hydraulic sandblasting perforation tool.

9. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, the establishment of the cement injection fluid channel towards the construction well by the hydraulic sandblasting directional perforation includes, pressurizing the construction string in the relief well; assembling and lowering the hydraulic sandblasting perforation tool; determining the jetting azimuth; circulating and cleaning the construction string; performing a ball-seating pressure test; jetting operation; lifting the construction string.

10. The hydraulic sandblasting perforation method for plugging a sunken fish in an old well of a gas storage reservoir according to claim 1, characterized in that, after the jetting operation is completed, lowering a cement injection tool and squeezing cement to plug the water holes of the sunken fish.

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