Efficient composite method for re-production of shale gas horizontal well affected by channeling

Abstract

The present application relates to the technical field of shale oil and gas exploration and development, and particularly relates to a high-efficiency production recovery and combination method for a shale gas horizontal well with channeling, comprising stage division and production recovery and combination. The stage division is to divide the production stages of the shale gas horizontal well with channeling. The production recovery and combination is to select a forward-looking coiled tubing deepening operation, an electric drive circulating gas lifting forced drainage operation or a ground wellhead system pressurization operation according to the stage division result and aiming at different production stages of the shale gas horizontal well. The technical scheme integrates the forward-looking coiled tubing deepening, the electric drive circulating gas lifting forced drainage and the ground wellhead system pressurization into one to form a production recovery and combination process system for the shale gas well with channeling. The production recovery process can be optimized according to different production stages of the shale gas horizontal well with channeling. The limitations of a single process are solved. The production recovery and combination process has strong pertinence and high production recovery efficiency, and provides an effective technical means for further improving the productivity of the shale gas well.

Description

Technical Field

[0001] This invention relates to the field of shale oil and gas exploration and development technology, and in particular to a high-efficiency composite method for the recovery of production from horizontal wells of shale gas that have been suppressed and channeled. Background Technology

[0002] my country is rich in shale gas resources, and its proven reserves account for an increasingly large proportion of unconventional resources. The efficient development of shale gas is of great significance for improving my country's future energy structure. However, with the continuous increase in well density and the extended production time of adjacent wells, shale gas wells are frequently experiencing cross-contamination and interconnection. Once an older well experiences cross-contamination, its production immediately drops sharply, and the wellhead pressure rises, posing challenges to continuous, stable, and safe production. To address the problems of cross-contamination during fracturing operations, water flooding of older wells, and limited well production capacity, existing technologies offer some solutions, such as:

[0003] Chinese patent document CN114382455A discloses a method for repeated fracturing of shale gas horizontal wells. The key technical points include the following steps: S1, preparing a repeated fracturing casing with packers at both ends of the repeated fracturing section; S2, running the repeated fracturing casing into the wellbore; S3, plugging by circulating temporary plugging fluid to temporarily plug the initial fracturing, followed by sealing the packers to complete the reconstruction of the repeated fracturing wellbore; S4, performing repeated fracturing to generate new fractures in the repeated fracturing section. This invention improves the sealing performance of the initial perforation hole and utilizes the repeated fracturing casing to reconstruct the shale gas production wellbore, increasing the fracturing success rate. Furthermore, the individual treatment of fractures in each repeated fracturing section enhances the effectiveness and accuracy of repeated fracturing stimulation, allowing for more precise prediction of fracturing fluid flow direction, control of fracture propagation, and maximizing reservoir stimulation volume.

[0004] Chinese patent document CN110924918A discloses a composite temporary plugging and re-fracturing method suitable for long horizontal shale gas wells, comprising the following steps: performing injection to replenish energy in the pressure-depleted zone of the old well; performing multi-stage re-fracturing to first clear the old fractures; using a temporary plugging ball to seal some of the initial fracturing orifices; then using fracturing fluid for proppant fracturing to modify the under-modified areas of the initial fracturing; using fracturing fluid to carry an in-fracture re-directing agent to induce fracture re-direction and increase fracture complexity; after the in-fracture re-directing agent reaches the formation, continuing proppant fracturing to further modify the under-modified and unmodified areas of the initial fracturing. This invention eliminates the need for running and dragging tubing, making it highly operable in the field, significantly shortening the construction cycle, and reducing costs. It can improve the utilization rate of the horizontal section of shale gas wells, enabling shale gas wells to recover or increase production capacity, meeting the requirements for low-cost re-fracturing modification of long horizontal shale gas wells, and improving the economic benefits of shale gas fields.

[0005] The above-mentioned technical solutions all rely on a single production recovery measure, and different measures are difficult to effectively replace each other. Once a gas well is subjected to pressure surge, its production will decrease rapidly, the affected days will be long, the recovery rate will be low, and the production loss will be significant. In general, the existing single production recovery technology is difficult to maintain the efficient and stable production capacity of gas wells. Summary of the Invention

[0006] This invention aims to address the deficiencies and shortcomings of existing technologies by providing a highly efficient composite method for the recovery of horizontal shale gas wells that have experienced compression and channeling. This method establishes a comprehensive recovery process system integrating forward-looking coiled tubing deepening technology, electric-driven circulating gas lift forced drainage technology, and surface wellhead system pressurization technology. Furthermore, it utilizes field data on the recovery processes of compression and channeling wells to generate empirical parameters for the highly efficient composite process of recovering horizontal shale gas wells. This technology optimizes the recovery process based on different production stages during the compression and channeling of shale gas horizontal wells, employing a targeted and highly efficient composite process to increase production, providing an effective technical means to further enhance the productivity of shale gas wells.

[0007] This invention is achieved by adopting the following technical solution:

[0008] A method for efficient recovery and regeneration of horizontal wells affected by pressure-induced shale gas leakage includes stage division and combined recovery and regeneration. Stage division involves establishing a model for different production stages of horizontal wells affected by pressure-induced shale gas leakage based on the recovery level, casing pressure, oil pressure, and gas-liquid ratio of the wells in the block. The production stages of the horizontal wells are then divided based on this model. The model for different production stages of horizontal wells affected by pressure-induced shale gas leakage refers to a set of production stage division standards for shale gas horizontal wells obtained through statistical analysis based on existing inter-well pressure-induced leakage case data. Combined recovery and regeneration involves selecting appropriate operations for different production stages of the shale gas horizontal wells based on the stage division results: forward-looking coiled tubing deepening operation, electric-driven circulating gas lift forced drainage operation, or surface wellhead system pressurization operation.

[0009] Preferably, the criteria for dividing the production stages of the shale gas well include:

[0010] When the recovery rate of the shale gas well under pressure is (0, 0.1], and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0.7, 1), and the gas-liquid ratio is (10000, +∞), the shale gas well under pressure is in the non-intervention production stage.

[0011] When the recovery rate of the shale gas well under pressure is (0.1, 0.15], and the ratio of wellhead casing pressure to test stable casing pressure is (0.4, 0.7], and the gas-liquid ratio is (1000, 10000], the shale gas well under pressure is in the production stage that requires forward-looking tubing deepening.

[0012] When the recovery rate of the shale gas well under pressure is (0.15, 0.2], and the ratio of wellhead casing pressure to test stable casing pressure is (0.1, 0.4], the ratio of wellhead oil pressure to oil pressure during production in tubing is (0.6, 1), and the gas-liquid ratio is (0, 1000], the shale gas well under pressure is in the production stage that requires electric-driven circulating gas lift forced drainage.

[0013] When the recovery rate of the shale gas well under pressure is (0.15, +∞), and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0, 0.1], the ratio of the wellhead oil pressure to the oil pressure during production in the tubing is (0, 0.6], and the gas-liquid ratio is (0, 1000], the shale gas well under pressure is in the production stage that requires pressurization by the surface wellhead system.

[0014] Preferably, during the forward-looking coiled tubing deepening process, when the inclination angle of point B in the horizontal well of the suppressed shale gas is greater than 90 degrees, the depth of the coiled tubing is the same as the depth of point A in the horizontal well of the suppressed shale gas; when the inclination angle of point B in the horizontal well of the suppressed shale gas is less than or equal to 90 degrees, the depth of the coiled tubing is determined according to the production status of the horizontal well of the suppressed shale gas; wherein, point A is the heel end of the horizontal well, i.e., the starting point of the horizontal section; point B is the toe end of the horizontal well, i.e., the ending point of the horizontal section.

[0015] Preferably, when the inclination angle of point B in the horizontal well of the shale gas being compressed is less than or equal to 90 degrees, the criteria for determining the depth of the coiled tubing are as follows: when the recovery rate of the shale gas well is (0.1, 0.125], and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0.4, 0.5], and the gas-liquid ratio is (1000, 5000], the depth of the coiled tubing is distributed at 60% to 80% of the horizontal section of the shale gas well; when the recovery rate of the shale gas well is (0.125, 0.15], and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0.5, 0.7], and the gas-liquid ratio is (5000, 10000], the depth of the coiled tubing is distributed at 40% to 60% of the horizontal section of the shale gas well.

[0016] Preferably, the electrically driven circulating gas lift forced drainage includes the following steps: deploying a compressor on the production platform; the gas source for the compressor inlet is natural gas produced within the production platform or pipeline-transported natural gas; the compressor outlet is connected to the production tree casing end of the suppressed shale gas well via a gas injection main line and a tee; a regulating valve is connected to the gas injection line between the tee and the production tree casing end of the suppressed shale gas well; during forward lift operation, the gas tree tubing injection end of the suppressed shale gas well is opened, and the gas injection parameters are controlled by the regulating valve to achieve drainage operation from the tubing into the casing; during reverse lift operation, the gas tree casing injection end of the suppressed shale gas well is opened, and the gas injection parameters are controlled by the regulating valve to achieve drainage operation from the casing into the tubing.

[0017] Preferably, during the deployment of the compressor, when it is necessary to perform electric-driven circulating gas lift forced drainage operations on multiple shale gas wells that have been subjected to compression and displacement, an injection branch pipe is added to the main pipeline at the compressor outlet according to the number of shale gas wells subjected to compression and displacement, so as to connect all the shale gas wells subjected to compression and displacement to the compressor. Each injection branch pipe is equipped with a gas-liquid flow meter, a single-flow valve and a gas volume regulating valve.

[0018] Preferably, the process of forced drainage using electric-driven circulating gas lift further includes determining the gas injection parameters, namely: when the recovery rate of the suppressed shale gas well is (0.15, 0.175], and the ratio of wellhead casing pressure to the tested stable casing pressure is (0.2, 0.4], the ratio of wellhead oil pressure to the oil pressure during tubing production is (0.8, 1), and the gas-liquid ratio is (500, 1000], the gas injection parameters for forced drainage using electric-driven circulating gas lift are 10,000 to 20,000 cubic meters per day; when the recovery rate of the suppressed shale gas well is (0.175, 0.2], and the ratio of wellhead casing pressure to the tested stable casing pressure is (0.1, 0.2], the ratio of wellhead oil pressure to the oil pressure during tubing production is (0.6, 0.8), and the gas-liquid ratio is (0, 500], the gas injection parameters for forced drainage using electric-driven circulating gas lift are 20,000 to 50,000 cubic meters per day.

[0019] Preferably, the pressurization of the surface wellhead system includes setting empirical parameters, namely: when the recovery rate of the suppressed shale gas well is (0.15, 0.18), and the ratio of wellhead casing pressure to the tested stable casing pressure is (0.05, 0.1], the ratio of wellhead oil pressure to the oil pressure during tubing production is (0.3, 0.6], and the gas-liquid ratio is (500, 1000], the air intake pressure of the surface wellhead system is set to 1~3MPa; when the recovery rate of the suppressed shale gas well is [0.18, +∞), and the ratio of wellhead casing pressure to the tested stable casing pressure is (0, 0.05], the ratio of wellhead oil pressure to the oil pressure during tubing production is (0, 0.3], and the gas-liquid ratio is (0, 500], the air intake pressure of the surface wellhead pressurization system is set to 0.5~1.0MPa.

[0020] The beneficial technical effects of this invention are as follows:

[0021] 1. This technical solution proposes for the first time to establish a standard for classifying different production stages of horizontal wells subjected to pressure channeling based on actual field pressure channeling data. Based on this standard, the production stages of the horizontal wells subjected to pressure channeling are divided. Then, according to the production stage of the wells, adaptive composite regeneration operations are performed. Compared with existing technologies, this technical solution integrates forward-looking coiled tubing deepening, electric-driven circulating gas lift forced drainage, and surface wellhead system pressurization into a composite regeneration process system for shale gas wells subjected to pressure channeling. This organically combines forward-looking coiled tubing deepening, electric-driven circulating gas lift forced drainage, and surface wellhead system pressurization, providing a new and feasible technical means to promote the efficient development of shale gas reservoirs and maximize well production capacity. Specifically, it allows for the optimization of regeneration processes based on the different production stages of the shale gas horizontal wells when they are subjected to pressure channeling, overcoming the limitations of single processes. By adopting a targeted and highly efficient composite process to increase production, it provides an effective technical means to further enhance the production capacity of shale gas wells.

[0022] 2. This technical solution provides a complete standard for dividing the production stages of shale gas wells. The application field has implemented the process data for the recovery of wells with suppressed cross-flow, and formed a composite process experience parameter for the efficient recovery of horizontal wells with suppressed cross-flow. It has strong applicability, the results are easy to judge, and it is particularly suitable for rapid on-site judgment and application. Attached Figure Description

[0023] Figure 1 This is a basic implementation flowchart of the technical solution. Detailed Implementation

[0024] To make the purpose, technical solution and advantages of the invention clearer, the technical solution of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the invention, but not all embodiments.

[0025] Therefore, the following detailed description of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] Example 1

[0027] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes: stage division and recovery and composite production.

[0028] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure-induced cross-flow is established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure-induced cross-flow are divided based on this judgment model. The judgment model for different production stages of horizontal wells under pressure-induced cross-flow refers to a set of production stage division standards for shale gas horizontal wells obtained using statistical analysis methods based on existing inter-well pressure-induced cross-flow case data. These shale gas well production stage division standards include:

[0029] When the recovery rate of the shale gas well under pressure is (0, 0.1], and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0.7, 1), and the gas-liquid ratio is (10000, +∞), the shale gas well under pressure is in the non-intervention production stage.

[0030] When the recovery rate of the shale gas well under pressure is (0.1, 0.15], and the ratio of wellhead casing pressure to test stable casing pressure is (0.4, 0.7], and the gas-liquid ratio is (1000, 10000], the shale gas well under pressure is in the production stage that requires forward-looking tubing deepening.

[0031] When the recovery rate of the shale gas well under pressure is (0.15, 0.2], and the ratio of wellhead casing pressure to test stable casing pressure is (0.1, 0.4], the ratio of wellhead oil pressure to oil pressure during production in tubing is (0.6, 1), and the gas-liquid ratio is (0, 1000], the shale gas well under pressure is in the production stage that requires electric-driven circulating gas lift forced drainage.

[0032] When the recovery rate of the shale gas well under pressure is (0.15, +∞), and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0, 0.1], the ratio of the wellhead oil pressure to the oil pressure during production in the tubing is (0, 0.6], and the gas-liquid ratio is (0, 1000], the shale gas well under pressure is in the production stage that requires pressurization by the surface wellhead system.

[0033] Reproduction synergy refers to the selection of operations—such as forward-looking coiled tubing deepening, electric-driven circulating gas lift forced drainage, or surface wellhead system pressurization—based on the stage classification results and targeting different production stages of shale gas horizontal wells. Specifically, if the shale gas well being squeezed belongs to the production stage requiring forward-looking tubing deepening, then forward-looking coiled tubing deepening is performed; if it belongs to the production stage requiring electric-driven circulating gas lift forced drainage, then electric-driven circulating gas lift forced drainage is performed; and if it belongs to the production stage requiring surface wellhead system pressurization, then surface wellhead system pressurization is performed.

[0034] Example 2

[0035] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes stage division and recovery and composite production.

[0036] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure and displacement was established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure and displacement were divided based on this judgment model. Among them, when the recovery level of the horizontal well under pressure and displacement is (0.1, 0.15], the ratio of wellhead casing pressure to the tested stable casing pressure is (0.4, 0.7], and the gas-liquid ratio is (1000, 10000], the horizontal well under pressure and displacement belongs to the production stage that requires forward-looking tubing deepening.

[0037] Reproduction Combination: For wells with suppressed or channeled shale gas, a forward-looking tubing deepening operation is performed. During this process, when the inclination angle at point B of the suppressed or channeled shale gas horizontal well is greater than 90 degrees, the depth of the coiled tubing is the same as the depth at point A of the suppressed or channeled shale gas horizontal well. When the inclination angle at point B of the suppressed or channeled shale gas horizontal well is less than or equal to 90 degrees, the depth of the coiled tubing is determined based on the production status of the suppressed or channeled shale gas horizontal well. Point A is the heel of the horizontal well, i.e., the starting point of the horizontal section, generally the entry point for geological steering; point B is the toe of the horizontal well, i.e., the ending point of the horizontal section, generally the exit point for geological steering.

[0038] Example 3

[0039] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes stage division and recovery and composite production.

[0040] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure and displacement was established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure and displacement were divided based on this judgment model. Among them, when the recovery level of the horizontal well under pressure and displacement is (0.1, 0.15], the ratio of wellhead casing pressure to the tested stable casing pressure is (0.4, 0.7], and the gas-liquid ratio is (1000, 10000], the horizontal well under pressure and displacement belongs to the production stage that requires forward-looking tubing deepening.

[0041] Reproduction Combination: For wells with suppressed and channeled shale gas, a forward-looking tubing deepening operation is performed. During the forward-looking coiled tubing deepening process, when the inclination angle of point B in the suppressed and channeled shale gas horizontal well is greater than 90 degrees, the depth of the coiled tubing is the same as the depth of point A in the suppressed and channeled shale gas horizontal well; when the inclination angle of point B in the suppressed and channeled shale gas horizontal well is less than or equal to 90 degrees, the depth of the coiled tubing is determined according to the production status of the suppressed and channeled shale gas horizontal well.

[0042] Furthermore, when the inclination angle of point B in the horizontal well of the shale gas being channeled is less than or equal to 90 degrees, the standard for determining the depth of the coiled tubing is as follows:

[0043] When the recovery rate of the shale gas well under pressure is (0.1, 0.125], and the ratio of wellhead casing pressure to test stable casing pressure is (0.4, 0.5], and the gas-liquid ratio is (1000, 5000], the depth of the coiled tubing is distributed at 60% to 80% of the horizontal section of the shale gas well under pressure.

[0044] When the recovery rate of the shale gas well under pressure is (0.125, 0.15], and the ratio of wellhead casing pressure to test stable casing pressure is (0.5, 0.7], and the gas-liquid ratio is (5000, 10000], the depth of the coiled tubing is distributed at 40% to 60% of the horizontal section of the shale gas well under pressure.

[0045] Example 4

[0046] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes stage division and recovery and composite production.

[0047] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure and displacement was established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure and displacement were divided based on this judgment model. Among them, when the recovery level of the horizontal well under pressure and displacement is (0.15, 0.2], the ratio of wellhead casing pressure to the tested stable casing pressure is (0.1, 0.4], the ratio of wellhead oil pressure to the oil pressure during production with tubing is (0.6, 1), and the gas-liquid ratio is (0, 1000], the horizontal well under pressure and displacement belongs to the production stage that requires electric-driven circulating gas lift forced drainage.

[0048] Reproduction Resumption: This involves performing an electrically driven circulating gas lift forced drainage operation on the suppressed shale gas well. The electrically driven circulating gas lift forced drainage includes the following steps:

[0049] A compressor is deployed on the production platform (shale gas wells are usually managed as platforms, i.e., 6 to 8 wellheads are concentrated in an 85m*115m area on the ground, which is called the production platform). The gas source for the compressor inlet is natural gas produced within the production platform or pipeline natural gas. The compressor outlet is connected to the gas production tree and casing end of the shale gas well being compressed through the main gas injection line via a tee. A regulating valve is connected to the gas injection line between the tee and the gas production tree and casing end of the shale gas well being compressed.

[0050] During the lifting operation, the injection end of the production tree tubing of the shale gas well that has been compressed and eroded is opened, and the injection parameters are controlled by the regulating valve to realize the production and drainage operation from the tubing to the casing.

[0051] During the reverse lift operation, the gas production tree casing injection end of the shale gas well that has been compressed and eroded is opened, and the gas injection parameters are controlled by the regulating valve to achieve the production and drainage operation from the casing into the tubing.

[0052] Example 5

[0053] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes stage division and recovery and composite production.

[0054] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure and displacement was established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure and displacement were divided based on this judgment model. Among them, when the recovery level of the horizontal well under pressure and displacement is (0.15, 0.2], the ratio of wellhead casing pressure to the tested stable casing pressure is (0.1, 0.4], the ratio of wellhead oil pressure to the oil pressure during production with tubing is (0.6, 1), and the gas-liquid ratio is (0, 1000], the horizontal well under pressure and displacement belongs to the production stage that requires electric-driven circulating gas lift forced drainage.

[0055] Reproduction Resumption: This involves performing an electrically driven circulating gas lift forced drainage operation on the suppressed shale gas well. The electrically driven circulating gas lift forced drainage includes the following steps:

[0056] A compressor is deployed on the production platform. The air source for the compressor inlet is natural gas produced within the production platform or pipeline natural gas. The compressor outlet is connected to the gas production tree and casing end of the shale gas well being compressed and ventilated via the main gas injection line and a tee. A regulating valve is connected on the gas injection line between the tee and the gas production tree and casing end of the shale gas well being compressed and ventilated, which is mainly used to control the gas injection parameters.

[0057] During the lifting operation, the injection end of the production tree tubing of the shale gas well that has been compressed and eroded is opened, and the injection parameters are controlled by the regulating valve to realize the production and drainage operation from the tubing to the casing.

[0058] During the reverse lift operation, the gas production tree casing injection end of the shale gas well that has been compressed and eroded is opened, and the gas injection parameters are controlled by the regulating valve to achieve the production and drainage operation from the casing into the tubing.

[0059] Furthermore, during the deployment of the compressor, when it is necessary to meet the electric-driven circulating gas lift forced drainage operation of multiple shale gas wells under pressure, an injection branch pipe is added to the main pipeline at the compressor outlet according to the number of shale gas wells under pressure, so as to connect all the shale gas wells under pressure to the compressor. Each injection branch pipe is equipped with a gas-liquid flow meter, a single-flow valve and a gas volume regulating valve.

[0060] Example 6

[0061] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes stage division and recovery and composite production.

[0062] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure and displacement was established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure and displacement were divided based on this judgment model. Among them, when the recovery level of the horizontal well under pressure and displacement is (0.15, 0.2], the ratio of wellhead casing pressure to the tested stable casing pressure is (0.1, 0.4], the ratio of wellhead oil pressure to the oil pressure during production with tubing is (0.6, 1), and the gas-liquid ratio is (0, 1000], the horizontal well under pressure and displacement belongs to the production stage that requires electric-driven circulating gas lift forced drainage.

[0063] Reproduction Resumption: This involves performing an electrically driven circulating gas lift forced drainage operation on the suppressed shale gas well. The electrically driven circulating gas lift forced drainage includes the following steps:

[0064] A compressor is deployed on the production platform. The air source for the compressor inlet is natural gas produced within the production platform or pipeline natural gas. The compressor outlet is connected to the gas production tree and casing end of the shale gas well being compressed and ventilated via the main gas injection line and a tee. A regulating valve is connected on the gas injection line between the tee and the gas production tree and casing end of the shale gas well being compressed and ventilated, which is mainly used to control the gas injection parameters.

[0065] During the lifting operation, the injection end of the production tree tubing of the shale gas well that is being squeezed and displaced is opened, and the injection parameters are controlled by the regulating valve to achieve the production and drainage operation from the tubing to the casing.

[0066] During the reverse lift operation, the gas production tree casing injection end of the shale gas well that has been compressed and eroded is opened, and the gas injection parameters are controlled by the regulating valve to realize the production and drainage operation from the casing to the tubing.

[0067] Furthermore, during the deployment of the compressor, when it is necessary to meet the electric-driven circulating gas lift forced drainage operation of multiple shale gas wells under pressure, an injection branch pipe is added to the main pipeline at the compressor outlet according to the number of shale gas wells under pressure, so as to connect all the shale gas wells under pressure to the compressor. Each injection branch pipe is equipped with a gas-liquid flow meter, a single-flow valve and a gas volume regulating valve.

[0068] Furthermore, the electric-driven circulating air lift forced drainage process also includes determining the air injection parameters, namely:

[0069] When the recovery rate of the shale gas well under pressure is (0.15, 0.175], and the ratio of wellhead casing pressure to test stable casing pressure is (0.2, 0.4], the ratio of wellhead oil pressure to oil pressure during tubing production is (0.8, 1), and the gas-liquid ratio is (500, 1000], the gas injection parameters for electric-driven circulating gas lift forced drainage are 10,000 to 20,000 cubic meters per day.

[0070] When the recovery rate of the shale gas well under pressure is (0.175, 0.2], and the ratio of wellhead casing pressure to test stable casing pressure is (0.1, 0.2], the ratio of wellhead oil pressure to oil pressure during tubing production is (0.6, 0.8), and the gas-liquid ratio is (0, 500], the injection parameters for electric-driven circulating gas lift forced drainage are 20,000 to 50,000 cubic meters of gas per day.

[0071] The technical solution achieves the optimal daily gas injection rate, which meets the minimum requirements for fluid carrying in the wellbore while minimizing the pressure loss of gas-water flow in the wellbore and fully utilizes the continuous gas production of the formation, thus maximizing the gas injection utilization rate.

[0072] Example 7

[0073] This embodiment discloses a method for efficient recovery and composite production of horizontal wells with suppressed and channeled shale gas. As a preferred embodiment of the present invention, it includes stage division and recovery and composite production.

[0074] Stage Division: A judgment model for different production stages of horizontal shale gas wells under pressure and cross-contamination was established based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of the horizontal wells under pressure and cross-contamination were divided based on this judgment model. Among them, when the recovery level of the horizontal well under pressure and cross-contamination is (0.15, +∞), the ratio of wellhead casing pressure to the tested stable casing pressure is (0, 0.1], the ratio of wellhead oil pressure to the oil pressure during production with tubing is (0, 0.6], and the gas-liquid ratio is (0, 1000], the horizontal well under pressure and cross-contamination belongs to the production stage that requires pressurization by the surface wellhead system.

[0075] Reproduction Combination: This involves pressurizing the surface wellhead system of a suppressed shale gas well. The surface wellhead system pressurization includes setting empirical parameters, namely:

[0076] When the recovery rate of the shale gas well under pressure is (0.15, 0.18), and the ratio of wellhead casing pressure to test stable casing pressure is (0.05, 0.1], the ratio of wellhead oil pressure to oil pressure during tubing production is (0.3, 0.6], and the gas-liquid ratio is (500, 1000], the gas inlet pressure of the surface wellhead system is set to 1~3MPa;

[0077] When the recovery rate of the shale gas well under pressure is [0.18, +∞), and the ratio of wellhead casing pressure to test stable casing pressure is (0, 0.05], the ratio of wellhead oil pressure to oil pressure during tubing production is (0, 0.3], and the gas-liquid ratio is (0, 500], the inlet pressure of the surface wellhead booster system is set to 0.5~1.0MPa.

[0078] The inlet pressure is the same as the wellhead pressure. The inlet pressure set in this technical solution meets the requirements for continuous and stable seepage in the formation, while also meeting the minimum fluid carrying requirements and minimizing the flow pressure loss in the wellbore.

Claims

1. A method for efficient recovery of production in a horizontal well of suppressed shale gas, characterized in that: This includes phased division and resumption of production; The aforementioned stage division involves establishing a judgment model for different production stages of horizontal shale gas wells subject to cross-flow based on the recovery level, wellhead casing pressure, wellhead oil pressure, and gas-liquid ratio of the horizontal wells in the block. Then, the production stages of these horizontal wells are divided based on this judgment model. The judgment model for different production stages of horizontal wells subject to cross-flow refers to a set of standards for dividing the production stages of shale gas horizontal wells, obtained using statistical analysis methods based on existing inter-well cross-flow case data. These standards include: When the recovery rate of the shale gas well under pressure is (0, 0.1], and the ratio of the wellhead casing pressure to the tested stable casing pressure is (0.7, 1), and the gas-liquid ratio is (10000, +∞), the shale gas well under pressure is in the non-intervention production stage. When the recovery rate of the shale gas well under pressure is (0.1, 0.15], and the ratio of wellhead casing pressure to test stable casing pressure is (0.4, 0.7], and the gas-liquid ratio is (1000, 10000], the shale gas well under pressure is in the production stage that requires forward-looking tubing deepening. When the recovery rate of the shale gas well under pressure is (0.15, 0.2], and the ratio of wellhead casing pressure to test stable casing pressure is (0.1, 0.4], the ratio of wellhead oil pressure to oil pressure during production in tubing is (0.6, 1), and the gas-liquid ratio is (0, 1000], the shale gas well under pressure is in the production stage that requires electric-driven circulating gas lift forced drainage. When the recovery rate of the shale gas well under pressure is (0.15, +∞), and the ratio of wellhead casing pressure to test stable casing pressure is (0, 0.1], the ratio of wellhead oil pressure to oil pressure during production in tubing is (0, 0.6], and the gas-liquid ratio is (0, 1000], the shale gas well under pressure is in the production stage that requires pressurization by the surface wellhead system. The aforementioned production recovery and integration refers to selecting, based on the stage division results, forward-looking coiled tubing deepening operation, electric-driven circulating gas lift forced drainage operation, or surface wellhead system pressurization operation for different shale gas horizontal well production stages.

2. The method for efficient recovery of compressed and channeled shale gas horizontal wells as described in claim 1, characterized in that: During the forward-looking coiled tubing deepening process, when the inclination angle of point B in the horizontal well of the suppressed shale gas is greater than 90 degrees, the depth of the coiled tubing is the same as the depth of point A in the horizontal well of the suppressed shale gas; when the inclination angle of point B in the horizontal well of the suppressed shale gas is less than or equal to 90 degrees, the depth of the coiled tubing is determined according to the production status of the horizontal well of the suppressed shale gas; where point A is the heel end of the horizontal well, i.e., the starting point of the horizontal section; and point B is the toe end of the horizontal well, i.e., the ending point of the horizontal section.

3. The method for efficient recovery of compressed and channeled shale gas horizontal wells as described in claim 2, characterized in that, When the inclination angle of point B in a horizontal well subjected to shale gas compression is less than or equal to 90 degrees, the standard for determining the depth of the coiled tubing is as follows: When the recovery rate of the shale gas well under pressure is (0.1, 0.125], and the ratio of wellhead casing pressure to test stable casing pressure is (0.4, 0.5], and the gas-liquid ratio is (1000, 5000], the depth of the coiled tubing is distributed at 60% to 80% of the horizontal section of the shale gas well under pressure. When the recovery rate of the shale gas well under pressure is (0.125, 0.15], and the ratio of wellhead casing pressure to test stable casing pressure is (0.5, 0.7], and the gas-liquid ratio is (5000, 10000], the depth of the coiled tubing is distributed at 40% to 60% of the horizontal section of the shale gas well under pressure.

4. The method for efficient recovery of compressed and channeled shale gas horizontal wells as described in claim 1, characterized in that: The electrically driven circulating air-lift forced drainage includes the following steps: A compressor is deployed on the production platform. The air source for the compressor inlet is natural gas produced within the production platform or pipeline natural gas. The compressor outlet is connected to the gas production tree oil casing end of the shale gas well that is being suppressed through the main gas injection line via a tee. A regulating valve is connected to the gas injection line between the tee and the gas production tree oil casing end of the shale gas well that is being suppressed. During the lifting operation, the injection end of the production tree tubing of the shale gas well that has been compressed and eroded is opened, and the injection parameters are controlled by the regulating valve to realize the production and drainage operation from the tubing to the casing. During the reverse lift operation, the gas production tree casing injection end of the shale gas well that has been compressed and eroded is opened, and the gas injection parameters are controlled by the regulating valve to achieve the production and drainage operation from the casing into the tubing.

5. The method for efficient recovery of compressed and channeled shale gas horizontal wells as described in claim 4, characterized in that: During the deployment of the compressor, when it is necessary to perform electric-driven circulating gas lift forced drainage operations on multiple shale gas wells that have been subjected to compression and displacement, an injection branch pipe is added to the main pipeline at the compressor outlet according to the number of shale gas wells subjected to compression and displacement, so that all the shale gas wells subjected to compression and displacement can be connected to the compressor. Each injection branch pipe is equipped with a gas-liquid flow meter, a single-flow valve and a gas volume regulating valve.

6. The method for efficient recovery of compressed and channeled shale gas horizontal wells as described in claim 1, characterized in that: The electric-driven circulating air lift forced drainage process also includes determining the air injection parameters, namely: When the recovery rate of the shale gas well under pressure is (0.15, 0.175], and the ratio of wellhead casing pressure to test stable casing pressure is (0.2, 0.4], the ratio of wellhead oil pressure to oil pressure during tubing production is (0.8, 1), and the gas-liquid ratio is (500, 1000], the gas injection parameters for electric-driven circulating gas lift forced drainage are 10,000 to 20,000 cubic meters per day. When the recovery rate of the shale gas well under pressure is (0.175, 0.2], and the ratio of wellhead casing pressure to test stable casing pressure is (0.1, 0.2], the ratio of wellhead oil pressure to oil pressure during tubing production is (0.6, 0.8), and the gas-liquid ratio is (0, 500], the injection parameters for electric-driven circulating gas lift forced drainage are 20,000 to 50,000 cubic meters of gas per day.

7. The method for efficient recovery of production in a horizontal well of compressed shale gas as described in claim 1, characterized in that, The pressurization of the surface wellhead system includes setting empirical parameters, namely: When the recovery rate of the shale gas well under pressure is (0.15, 0.18), and the ratio of wellhead casing pressure to test stable casing pressure is (0.05, 0.1], the ratio of wellhead oil pressure to oil pressure during tubing production is (0.3, 0.6], and the gas-liquid ratio is (500, 1000], the gas inlet pressure of the surface wellhead system is set to 1~3MPa; When the recovery rate of the shale gas well under pressure is [0.18, +∞), and the ratio of wellhead casing pressure to test stable casing pressure is (0, 0.05], the ratio of wellhead oil pressure to oil pressure during tubing production is (0, 0.3], and the gas-liquid ratio is (0, 500], the inlet pressure of the surface wellhead booster system is set to 0.5~1.0MPa.

Images