A method and device for determining a gas field water reinjection horizon and reinjection well
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
Smart Images
Figure CN122106578A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of gas field water reinjection technology, and in particular to a method and apparatus for determining the gas field water reinjection layer and reinjection well. Background Technology
[0002] Currently, enhanced oil recovery technologies for water-bearing gas reservoirs are relatively limited, primarily relying on drainage. Furthermore, due to the ever-increasing demand for natural gas, natural gas production is rising annually, leading to a continuous increase in produced water from gas fields. Therefore, the importance of gas field water treatment has reached unprecedented levels. Currently, existing technologies for gas field water treatment include: evaporation in drying ponds after the produced water meets environmental standards, but this method is expensive; and reinjecting the produced water into the ground to ensure smooth production, but the current increase in water production has resulted in a large reinjection gap. The commonly used method is gas field water reinjection, but the following problems exist in the gas field water reinjection process:
[0003] 1. The seismic data of non-target layers is relatively poor, the well logging data is incomplete, and there is no core sampling data. This will increase the uncertainty of the underground geological structure, making it impossible to accurately identify and locate suitable reinjection layers, thus affecting the reinjection effect.
[0004] 2. When the target area is large, the number of wells is large, the depth span is large, and the formation and water absorption and storage conditions are difficult to determine, it is difficult to accurately determine the optimal reinjection point and reinjection depth. This may result in water being injected into an undesirable formation, which may not be able to effectively store or absorb the injected water, thereby reducing reinjection efficiency.
[0005] 3. The presence of regional fault development, fractured subsurface layers, and significant issues with sealing and wellbore integrity contributes to the complexity of these geological conditions. These factors lead to unstable water flow paths during reinjection, potentially causing leakage or blockage and resulting in poor reinjection performance. Furthermore, wellbore integrity issues increase the risk of water leakage, further reducing reinjection efficiency and effectiveness.
[0006] The above three problems lead to poor water reinjection results in gas fields, so there is an urgent need for a method that can accurately locate the water reinjection layers and reinjection wells in gas fields.
[0007] This section is intended to provide background or context for the embodiments of this application set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section. Summary of the Invention
[0008] This application provides a method and apparatus for determining the water reinjection zone and reinjection well in a gas field, so as to at least solve the problems of high difficulty in water reinjection and difficulty in selecting the reinjection zone in a gas field.
[0009] According to one aspect of this application, a method for determining the water reinjection layer and reinjection well in a gas field is provided, comprising:
[0010] Identify the reservoir types of oil and gas; oil and gas reservoir types include non-production-oriented reservoirs and production-oriented reservoirs.
[0011] The type of reinjection well is determined based on the reservoir type of the oil and gas. When the reservoir type of the oil and gas is a non-production target layer, existing wells are mainly used as reinjection wells. When the reservoir type of the oil and gas is a production target layer, new wells are mainly used as reinjection wells.
[0012] Determine the gas field water reinjection layer based on the properties of the reinjection well.
[0013] In one embodiment, determining the gas field water reinjection layer based on the properties of the reinjection well includes:
[0014] When existing wells are used as the main reinjection wells, based on the static logging data of the existing wells, the layers with a thickness exceeding the preset value and dominated by sandstone are selected from the existing wells as the reinjection layers.
[0015] When new wells are mainly used as reinjection wells, the reinjection layers are determined by conducting trial production and injection tests on existing wells at the edge of the gas reservoir.
[0016] In one embodiment, when using existing wells as the main reinjection wells, based on the static logging data of the existing wells, a sandstone-dominated section with a thickness exceeding a preset value is selected from the existing well cuttings data as the reinjection layer, including:
[0017] Obtain the main logging curves from the existing well static logging data and determine the main sand bodies in the area;
[0018] Based on the main logging curves and the main sand bodies in the region, predict the distribution range of the main sand bodies and establish a geological model of the main sand bodies in the region;
[0019] The reinjection wells and reinjection layers are determined based on the geological model.
[0020] In one embodiment, the main logging curves are obtained from existing well static logging data, and the main sand bodies in the area are determined, including:
[0021] The main logging curves are obtained by analyzing the static logging data of existing wells. The main logging curves include gamma logging curves, resistivity logging curves and sonic logging curves.
[0022] The sand bodies in the low-gamma and low-resistivity zones are determined based on the main logging curves.
[0023] Single-well comparisons were conducted on sand bodies in low-gamma and low-resistivity zones to identify the dominant sand bodies within the region.
[0024] In one embodiment, based on the main logging curves and the main sand bodies in the region, the distribution range of the main sand bodies is predicted and a geological model of the main sand bodies in the region is established, including:
[0025] The sedimentary characteristics of the main sand bodies are obtained based on their lithology and logging curves.
[0026] Based on the sedimentary characteristics of the main sand bodies, the distribution range of the main sand bodies is predicted by seismic waveform inversion.
[0027] The percentage of mudstone within the vertical fault displacement range is obtained from the distribution range of the main sand bodies. The percentage of mudstone within the vertical fault displacement range is used to determine the lateral sealing property of the regional faults, and a geological model of the main sand bodies in the region is established.
[0028] In one embodiment, determining the reinjection zone by conducting trial production and injection at existing wells at the edge of the gas reservoir includes:
[0029] A large geological model, including the marginal water layer, was established using geological data from the edge of the gas reservoir.
[0030] The production and test data obtained from the trial production are input into the large geological model to determine the theoretical reinjection layer;
[0031] The location of new wells will be determined by testing existing wells at the edge of the gas reservoir;
[0032] The actual reinjection layer is determined by trial injection of the theoretical reinjection layer.
[0033] According to another aspect of this application, an apparatus for determining the water reinjection zone and reinjection well in a gas field is also provided, comprising:
[0034] The reservoir type determination unit is used to determine the reservoir type of oil and gas; the reservoir types of oil and gas include non-production target reservoirs and production target reservoirs.
[0035] The reinjection well type determination unit is used to determine the type of reinjection well based on the reservoir type of oil and gas;
[0036] The non-production target layer module is used when the oil and gas reservoir type is a non-production target layer, and existing wells are mainly used as injection wells.
[0037] The production target layer module is used when the oil and gas reservoir type is a production target layer, with new wells as the main injection wells.
[0038] The reinjection layer determination unit is used to determine the gas field water reinjection layer based on the properties of the reinjection well.
[0039] In one embodiment, the reinjection layer determination unit includes:
[0040] The first selection module is used to select, when existing wells are the main reinjection wells, the layer with a thickness exceeding the preset value and dominated by sandstone from the existing well cuttings data as the reinjection layer.
[0041] The second selection module is used to determine the reinjection layer by conducting trial production and injection tests on existing wells at the edge of the gas reservoir when new wells are the main reinjection wells.
[0042] In one embodiment, the non-production target layer module includes:
[0043] The main sand body identification module is used to obtain the main logging curves from the static logging data of existing wells and identify the main sand bodies in the area.
[0044] The geological model building module is used to predict the distribution range of the main sand bodies and establish a geological model of the main sand bodies in the region based on the main logging curves and the main sand bodies in the region.
[0045] The reinjection location determination module is used to determine the reinjection well and reinjection layer based on the geological model.
[0046] In one embodiment, the main sand body determination module includes:
[0047] The main logging curve acquisition module is used to analyze the static logging data of existing wells to obtain the main logging curves, which include gamma logging curves, resistivity logging curves and sonic logging curves.
[0048] The target sand body determination module is used to determine sand bodies in low-gamma and low-resistivity intervals based on the main logging curves.
[0049] The main sand body locking module is used to identify the main sand bodies in a region by comparing sand bodies in low gamma and low resistivity zones with a single well.
[0050] In one embodiment, the geological model building module includes:
[0051] The sedimentary characteristics acquisition module is used to acquire the sedimentary characteristics of the main sand bodies based on their lithology and logging curves.
[0052] The sand body size prediction module is used to predict the distribution range of the main sand bodies based on their sedimentary characteristics and using seismic waveform inversion.
[0053] The geological model building module is used to obtain the percentage of mudstone within the vertical fault range from the distribution range of the main sand bodies, use the percentage of mudstone within the vertical fault range to determine the lateral sealing of regional faults, and build a geological model of the main sand bodies in the region.
[0054] In one embodiment, the second selection module includes:
[0055] The large geological model building module is used to build a large geological model, including the marginal water layer, using geological data from the edge of the gas reservoir.
[0056] The reinjection layer determination module is used to input production data and test data obtained from pilot production into the large geological model to determine the reinjection layer;
[0057] The test production module is used to determine the location of new wells by testing existing wells at the edge of the gas reservoir;
[0058] The trial injection module is used to perform trial injections on the theoretical back injection layer to determine the actual back injection layer.
[0059] This application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-mentioned method for determining the gas field water reinjection layer and reinjection well.
[0060] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for determining the gas field water reinjection layer and reinjection well.
[0061] This application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-mentioned method for determining the gas field water reinjection layer and reinjection well.
[0062] Compared with existing technologies, this application prioritizes shallow rather than deep non-target layers as reinjection layers (shallow layers typically have easier access to geological and seismic data, and processing and reinjection costs are relatively low). It fully utilizes limited data, combining well logging and seismic analysis to address sand body size prediction, and further integrates geological engineering to address sealing and wellbore integrity issues. Specifically, the methods for addressing sealing and wellbore integrity include: combining geological and seismic studies to determine that in areas with shallow mudstone development, mudstone can form a natural vertical sealing layer, effectively preventing vertical water leakage; and considering the distribution of sand bodies, lateral mudstone sealing is achieved from isolated sand bodies. A model is established to evaluate changes in formation pressure, predicting increases in formation pressure to assess wellbore integrity and sealing effectiveness. The model predicts increases in formation pressure, and this method is used to assess the wellbore integrity of adjacent wells. The water storage capacity V = πr for every 1 MPa increase in formation pressure is calculated. 2 ×h×Φ×(C f +C w ), where r is the radius; h is the effective thickness; Φ is the porosity; C f C is the rock compressibility coefficient. w Formation water compressibility coefficient (e.g.) Figure 13 (As shown).
[0063] A method system for optimizing reinjection layers and wells was established to achieve the goal of well exploration in different zones. At the same time, a large model was built in the deep target layer, and reinjection was carried out in the target layer at the edge of the gas reservoir, thus providing a good reference for the optimization of water reinjection layers and wells in similar gas reservoirs. Attached Figure Description
[0064] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0065] Figure 1 A flowchart illustrating a method for determining water reinjection zones and reinjection wells in a gas field, as provided in this application.
[0066] Figure 2 This is a flowchart illustrating the process of determining the type of reinjection well based on the reservoir type of oil and gas in this embodiment of the application.
[0067] Figure 3 This is a flowchart illustrating the process of determining the gas field water reinjection layer based on the attributes of the reinjection well in this embodiment of the application.
[0068] Figure 4 This is a flowchart illustrating how, in this embodiment of the application, a layer composed mainly of sandstone and with a thickness exceeding a preset value is selected from existing well cuttings data as a reinjection layer.
[0069] Figure 5 This is a flowchart illustrating the determination of the main sand bodies within the region in this application embodiment.
[0070] Figure 6 This is a flowchart illustrating the prediction of the distribution range of the main sand bodies and the establishment of a geological model of the main sand bodies within the region, as described in this application embodiment.
[0071] Figure 7 This is a flowchart illustrating the method for determining the reinjection layer in an embodiment of this application.
[0072] Figures 8 to 18 This is one specific embodiment listed in this application.
[0073] Figure 19 A structural block diagram of a device for determining the water reinjection layer and reinjection well in a gas field, provided in this application.
[0074] Figure 20 This is a structural block diagram of the reinjection layer determination unit in an embodiment of this application.
[0075] Figure 21This is a structural block diagram of the non-production target layer module in the embodiments of this application.
[0076] Figure 22 This is a structural block diagram of the main sand body determination module in the embodiments of this application.
[0077] Figure 23 This is a structural block diagram of the geological model construction module in the embodiments of this application.
[0078] Figure 24 This is a structural block diagram of the second selection module in the embodiments of this application.
[0079] Figure 25 This is a specific implementation of an electronic device provided in the embodiments of this application. Detailed Implementation
[0080] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of this application are used to explain this application, but are not intended to limit this application.
[0081] Currently, the technology for enhancing oil recovery in water-bearing gas reservoirs is relatively simple, mainly relying on drainage. Furthermore, due to the continuous increase in natural gas energy demand and annual increases in natural gas production, the amount of produced water in gas fields is also constantly increasing. Therefore, the importance of gas field water treatment has reached an unprecedented level. The commonly used method is gas field water reinjection. However, due to the current increase in water production, a large reinjection gap has emerged, making it urgent to find reinjection layers and wells to solve the gas field water reinjection problem. Currently, gas field water treatment options include: evaporation in a drying pond after the produced gas field water meets environmental standards, but this method is expensive; reinjecting the produced water underground to ensure smooth production, but this method has the following problems: 1. Seismic data for non-target layers is relatively poor, well logging data is incomplete, and core testing data is lacking; 2. The search target area is large, with many wells, a wide depth range, and difficulties in determining the layers and water absorption / storage; 3. There are regional fault developments, fractured bottom layers, and significant issues with sealing and wellbore integrity.
[0082] The selection of gas field water reinjection sites and wells is a crucial method for gas field water treatment and plays a vital role in supporting the efficient development of gas fields. Based on this, this application provides a method for determining gas field water reinjection sites and wells, such as... Figure 1 As shown, it includes:
[0083] S101: Determine the reservoir type of oil and gas; the reservoir types of oil and gas include non-production target reservoirs and production target reservoirs;
[0084] S102: Determine the type of reinjection well based on the reservoir type of oil and gas;
[0085] S103: Determine the gas field water reinjection layer based on the properties of the reinjection well.
[0086] First, it is necessary to classify the reservoirs in the oil and gas field. Reservoir types are generally divided into two main categories: non-production-oriented reservoirs and production-oriented reservoirs. Non-production-oriented reservoirs typically refer to those layers with geological characteristics that are not directly used for production, such as caprocks or water-bearing formations. Production-oriented reservoirs are oil or gas reservoirs directly used for oil and gas extraction. After the reservoir type is determined, the next step is to select a suitable reinjection well type based on the reservoir characteristics. In a specific embodiment of this application, when the oil and gas reservoir type is a non-production-oriented reservoir, existing wells are mainly used as reinjection wells; when the oil and gas reservoir type is a production-oriented reservoir, new wells are mainly used as reinjection wells. After determining the type of reinjection well, the next step is to select the specific reinjection layer.
[0087] In one embodiment, the type of reinjection well is determined based on the reservoir type of the oil and gas, such as... Figure 2 As shown, it includes:
[0088] S201: When the reservoir type of oil and gas is a non-production target layer, existing wells should be used as the main injection wells.
[0089] S202: When the reservoir type of oil and gas is a production target layer, new wells are mainly used as injection wells.
[0090] In one embodiment, such as Figure 3 As shown, determining the gas field water reinjection layer based on the properties of the reinjection well includes:
[0091] S301: When existing wells are used as the main reinjection wells, based on the static logging data of the existing wells, select the sandstone-dominated section from the cuttings data of the existing wells as the reinjection layer.
[0092] S302: When new wells are mainly used as reinjection wells, the reinjection layer is determined by conducting trial production and injection on existing wells (target layer transit wells) at the edge of the gas reservoir.
[0093] In one embodiment, when existing wells are primarily used as reinjection wells, based on the static logging data of the existing wells, a sandstone-dominated section with a thickness exceeding a preset value is selected from the cuttings data of the existing wells as the reinjection layer, such as... Figure 4 As shown, it includes:
[0094] S401: Obtain the main logging curves from the existing well static logging data and determine the main sand bodies in the area;
[0095] S402: Based on the main logging curves and the main sand bodies in the region, predict the distribution range of the main sand bodies and establish a geological model of the main sand bodies in the region;
[0096] S403: Determine the reinjection wells and reinjection layers based on the geological model.
[0097] Static logging data includes various downhole physical measurements such as natural gamma ray, sonic transit time, and resistivity. This data helps identify the primary reservoir lithology, particularly sandstone formations. Key logging curves are crucial curves used during the assessment process to identify major sand bodies and other geological features. These curves help determine which intervals have the required petrophysical properties for reservoirs or reinjection layers. Using the obtained key sand body information, geological modeling is performed, including using geological and geophysical methods to predict the spatial distribution of sand bodies. The geological model relies on multi-well data and possible surface geophysical exploration data to generate detailed information on how sand bodies are distributed within the region. This model helps assess the optimal location of reinjection wells within the sand bodies to ensure reinjection efficiency and sand body acceptability.
[0098] In one embodiment, the dominant logging curves are obtained from existing well static logging data, and the dominant sand bodies in the area are determined, such as... Figure 5 As shown, it includes:
[0099] S501: Analyze the static logging data of existing wells to obtain the main logging curves, which include gamma logging curves, resistivity logging curves and sonic logging curves;
[0100] S502: Determine the sand bodies in low-gamma and low-resistivity zones based on the main logging curves;
[0101] S503: Single-well comparison of sand bodies in low gamma and low resistivity zones to determine the main sand bodies in the area.
[0102] In one embodiment, based on the main logging curves and the main sand bodies in the region, the distribution range of the main sand bodies is predicted and a geological model of the main sand bodies in the region is established, such as... Figure 6 As shown, it includes:
[0103] S601: Obtain the sedimentary characteristics of the main sand bodies based on their lithology and logging curves.
[0104] S602: Based on the sedimentary characteristics of the main sand bodies, the distribution range of the main sand bodies is predicted using seismic waveform inversion;
[0105] S603: Obtain the percentage of mudstone within the vertical fault displacement range from the distribution range of the main sand bodies, use the percentage of mudstone within the vertical fault displacement range to determine the lateral sealing property of the regional fault, and establish a geological model of the main sand bodies in the region.
[0106] Static logging data (such as resistivity, sonic transit time, and natural gamma) are used to identify the main characteristics of sandstone layers. These logging curves help reveal sedimentary features such as sandstone texture, grain size, and ordering, which are key to understanding how sand bodies formed in paleoenvironments. By analyzing this data, the sedimentary environment of the sand bodies can be inferred. After obtaining the basic sedimentary characteristics of the sand bodies, the next step is to use seismic waveform inversion technology to predict the spatial distribution of the sand bodies. The final step is to analyze the mudstone content in the sand bodies, especially within the vertical displacement range associated with regional faults. The percentage of mudstone is an important factor in determining whether a fault has good lateral sealing properties. Specifically, the development of shallow mudstone in the entire area can be used to determine the vertical sealing of the reservoir. Current technologies rely on conventional judgments based on experience, while this application can demonstrate lateral sealing on a site-specific basis, establish models to evaluate pressure changes, and clarify formation sealing properties and wellbore integrity.
[0107] The sealing performance of faults affects the migration path and range of fluids (such as water, oil, and gas) within formations. High mudstone content typically implies strong sealing capabilities, which is crucial for determining safe and effective reinjection sites. Based on this, a comprehensive geological model incorporating the characteristics of sand bodies and surrounding rock formations is constructed to accurately determine the most suitable reinjection wells.
[0108] In one embodiment, the reinjection layer is determined by conducting trial production and injection at new wells on the edge of the gas reservoir, such as... Figure 7 As shown, it includes:
[0109] S701: Establish a large geological model, including the marginal water layer, using geological data from the edge of the gas reservoir;
[0110] S702: Input the production data and test data obtained from the trial production into the large geological model to determine the theoretical reinjection layer;
[0111] S703: Determine the location of new wells by conducting trial production on existing wells at the edge of the gas reservoir;
[0112] S704: Conduct trial injections on the theoretical reinjection layer to determine the actual reinjection layer.
[0113] First, geological data from the reservoir periphery needs to be collected and analyzed, including seismic data, drilling records, and well logging data, to construct a detailed geological model. This model includes various strata at the reservoir periphery. After establishing the preliminary geological model, test production is conducted at the reservoir periphery to collect data on well production performance, such as water production and pressure changes. This data is then input into the geological model, and simulation analysis is used to evaluate the potential effectiveness and possible problems of different strata as reinjection layers. The technical effect it can achieve is to identify the strata most suitable as reinjection layers under ideal conditions.
[0114] More targeted test production can be conducted on existing wells at the edge of the gas reservoir. The technical effect of this is to verify the accuracy of the geological model and the actual performance of the production data, thereby more accurately determining the optimal location for new wells.
[0115] Actual injection tests are conducted on the ideal reinjection layer to verify its reinjection capacity and safety under realistic conditions, including observation of reinjection pressure, fluid diffusion, and the response of surrounding rock formations. The test results will determine whether this layer should be used as the final reinjection layer, or whether the reinjection strategy and target layer need to be adjusted.
[0116] In one specific embodiment, the formation of the gas field is differentiated. In the shallow Jidik Formation, which is not the production target layer, existing wells are mainly used as reinjection wells. First, the layers with a thickness greater than 5m and dominated by sandstone in the existing well cuttings data are selected to determine the reinjection layers. Then, combined with the static logging data of the wells, the main logging curves such as gamma, resistivity, and sonic logging are identified to lock in the sand bodies in the low gamma and low resistivity layers. The high sonic logging curve value greater than 50 is used to assist in judging the reservoir space and permeability of the sand bodies, such as porosity and permeability, to improve the accuracy of layer selection. Single wells that have locked in the sand bodies are selected for precise regional comparison to determine the main sand bodies in the region. Based on the lithology of the main sand bodies... The study comprehensively assesses the sedimentary characteristics of the main sand bodies using features such as well logging curves; controls the distribution range of sedimentary facies by combining geological and geophysical exploration with seismic waveform inversion to predict sand body size, determine the distribution range of the main sand bodies, and ensure the persistence of water injection; uses the percentage of mudstone (SGR) within the vertical fault displacement range to determine the lateral sealing capability of regional faults according to local conditions; when SGR≦20%, the fault is laterally opened, and when SGR>20%, the fault is laterally sealed; establishes a geological model of the main sand body region's structure → lithofacies → porosity and permeability; evaluates regional pressure changes based on measured pressure from single wells and pressure values at different depths calculated from regional pressure gradients, and clarifies the reinjection potential of the main sand bodies. The optimal process involves: multi-well cuttings lithology screening, vertical sand body search → sand body comparison, horizontal selection of main sand bodies → determining sedimentary facies based solely on the characteristics of the main sand bodies → seismic attributes, macroscopic prediction of sand body distribution → combining with engineering to determine the final well location.
[0117] In one specific embodiment, at a relatively deep location within the Bashkichik Formation, the target production layer, new wells are primarily used as injection wells. Firstly, test production and injection are conducted using water wells at the reservoir periphery to determine the injection potential of this layer. The test production yield per unit pressure differential is greater than 100 m³ / s. 3 / MPa, the injection and reinjection volume is greater than 400m³. 3 / d. A large geological model, including the marginal water layer, is then established using seismic, tectonic, drilling, and logging data. Production and testing data are then input into the geological model for numerical simulation studies. The pressure and saturation fields of the gas reservoir are well-fitted and consistent with actual measurements, indicating model reliability. Based on this, water injection into the adjacent large water body is demonstrated. A comparison is made of the impact of daily water injection of 5000 cubic meters and reinjection over 10 years on gas field development in the A2 gas reservoir. The formation pressure increases by 0.06 MPa, and the water intrusion increases by 1.74 million cubic meters, accounting for 0.9% of the cumulative water intrusion, which is essentially negligible and can be considered a reinjection layer. The thickness and water storage capacity of the caprock and reservoir are analyzed, combined with the injection test results. For specific well selection, the shallow seismic profile shows continuous phase axes, good data quality, and a stable target layer, with no large faults connecting the target layer to the surface.
[0118] In a specific embodiment, taking the actual A area of Tarim as an example for analysis, firstly, for the shallower non-target layers, 1. Research is carried out using the old well K9 (e.g. Figure 8 As shown), sand bodies were identified using natural gamma and resistivity curves (GR < 70, Rt < 5), and sonic curves were used to assist in judging physical properties (AC > 65), selecting three favorable sand bodies; 2. Regional studies were conducted combining geological and geophysical exploration, using phase control correlation to locate sand bodies, waveform inversion to define boundaries, confirming sand body scale, ensuring water injection persistence, and using phase control and waveform indication inversion for the first time in shallow layers (e.g. Figure 9 , Figure 10 As shown), accurately depict the distribution range of the sand body (e.g. Figure 11 As shown in Table 1, calculate the water storage capacity of the main sand body at the bottom of the Jidike Formation in this area.
[0119] Table 1. Prediction of Reinjection Volume of Main Sand Bottom Body in Area A, Jidike Formation
[0120]
[0121] Lateral sealing should be demonstrated according to local conditions. Vertical sealing is formed by the development of shallow mudstone throughout the area. Lateral sealing is considered from fault lateral sealing in contiguous sand bodies, and lateral sealing from mudstone lateral sealing in isolated sand bodies (e.g.) Figure 12 As shown in the figure, the reinjection area is clearly well-sealed, and the injected water will not leak to the surface. A method for predicting formation pressure increases is proposed (e.g., Figure 13 As shown),
[0122] The water storage capacity V = πr increases by 1 MPa 2 ×h×Φ×(Cf+Cw)
[0123] The water storage capacity of the reinjection wells was determined. Based on the regional feasibility study results, existing wells and new wells were selected for reinjection. Existing wells were utilized, and water injection was improved in conjunction with engineering feasibility studies.
[0124] For the production stratum in area A, the deep Bashkichik Formation is used for reinjection site verification. The main production stratum of the A2 gas reservoir is the Bashkichik Formation, and the adjacent water structure is the A3 structure. First, the oil testing results of the old well S3 within the A3 structure are considered (e.g., ...). Figure 14 (As shown), one section of the perforation is 71m long, with a daily water production of 662m³. 3 The production pressure differential is 3.22 MPa. Analysis shows that the formation has good physical properties and great reinjection potential. Well S6 in this area has begun trial injection into the Cretaceous Bashkichik and Basi Formations (e.g., Figure 15 As shown), the pump pressure is 24.7–32.2 MPa, and the daily reinjection volume is 562–1411 cubic meters per day (e.g.). Figure 16 (As shown). This further clarifies the region's great potential.
[0125] The following analysis examines whether the reinjection in area A3 affects the development of the A2 gas reservoir in that area. A large-scale model of the A2 gas reservoir plus the surrounding water bodies (A1 and A3) is established for the first time (e.g., Figure 17 As shown in the figure, the model is reliable because it fits the historical saturation and pressure changes, planar pressure field, etc. of the A2 gas reservoir and the historical water layer pressure changes of a single well in the A3 block. Then, the model is validated by designing reinjection wells in the A3 block's water layer. Through numerical simulation, comparing the impact of a daily water injection of 5000 cubic meters and reinjection over 10 years on the development of the A2 gas field in the A3 block, the formation pressure of the A2 gas reservoir increases by 0.06 MPa, and the water intrusion increases by 1.74 million cubic meters, accounting for 0.9% of the cumulative water intrusion (e.g., ...). Figure 18 (As shown in Table 2). The reinjection of Block A3 has virtually no impact on the development of the A2 gas field.
[0126] Table 2. Development Prediction Results for Gas Reservoir A2 (with and without water injection in Block A3)
[0127]
[0128] Using this technology, four old wells and one new well have been reinjected into the non-target layer, Jidike Formation, and two old wells and three new wells have been reinjected into the target layer, Bashkichik Formation, with a daily reinjection capacity of 5,000 cubic meters, demonstrating significant results.
[0129] This application also provides a device for determining the gas field water reinjection layer and reinjection well, as described in the following embodiments. Since the principle behind this device is similar to the method for determining the gas field water reinjection layer and reinjection well, its implementation can be referenced in the implementation of the method for determining the gas field water reinjection layer and reinjection well; repeated details will not be elaborated further.
[0130] This application provides a device for determining the water reinjection layer and reinjection well in a gas field, such as... Figure 19 As shown, it includes:
[0131] The reservoir type determination unit 1901 is used to determine the reservoir type of oil and gas; the reservoir types of oil and gas include non-production target layers and production target layers.
[0132] The reinjection well type determination unit 1902 is used to determine the type of reinjection well based on the reservoir type of oil and gas;
[0133] The non-production target layer module 1903 is used when the oil and gas reservoir type is a non-production target layer, and existing wells are mainly used as injection wells.
[0134] Production Target Layer Module 1904 is used when the oil and gas reservoir type is a production target layer, with new wells as the main injection wells.
[0135] The reinjection layer determination unit 1905 is used to determine the gas field water reinjection layer based on the properties of the reinjection well.
[0136] In one embodiment, such as Figure 20 As shown, the reinjection layer determination unit 1905 includes:
[0137] The first selection module 2001 is used to select, when existing wells are the main reinjection wells, a layer with a thickness exceeding a preset value and dominated by sandstone from the existing well cuttings data as the reinjection layer.
[0138] The second selection module 2002 is used to determine the reinjection layer by conducting trial production and trial injection on existing wells at the edge of the gas reservoir when new wells are mainly used as reinjection wells.
[0139] In one embodiment, such as Figure 21 As shown, the non-production destination layer module 1903 includes:
[0140] The main sand body determination module 2101 is used to obtain the main logging curve from the static logging data of existing wells and determine the main sand bodies in the area;
[0141] The geological model construction module 2102 is used to predict the distribution range of the main sand bodies and establish a geological model of the main sand bodies in the region based on the main logging curves and the main sand bodies in the region.
[0142] The reinjection location determination module 2103 is used to determine the reinjection well and reinjection layer based on the geological model.
[0143] In one embodiment, such as Figure 22 As shown, the main sand body determination module 2101 includes:
[0144] The main logging curve acquisition module 2201 is used to analyze the static logging data of existing wells to obtain the main logging curves, which include gamma logging curves, resistivity logging curves and sonic logging curves.
[0145] The target sand body determination module 2202 is used to determine sand bodies in low-gamma and low-resistivity intervals based on the main logging curves.
[0146] The main sand body locking module 2203 is used to determine the main sand body in the area by single-well comparison of sand bodies in low gamma and low resistivity sections.
[0147] In one embodiment, such as Figure 23 As shown, the geological model construction module 2102 includes:
[0148] The sedimentary characteristics acquisition module 2301 is used to acquire the sedimentary characteristics of the main sand bodies based on their lithology and logging curves.
[0149] The sand body size prediction module 2302 is used to predict the distribution range of the main sand bodies based on the sedimentary characteristics of the main sand bodies and by using seismic waveform inversion.
[0150] The geological model building module 2303 is used to obtain the percentage of mudstone within the vertical fault range from the distribution range of the main sand bodies, use the percentage of mudstone within the vertical fault range to determine the lateral sealing of the regional fault, and build a geological model of the main sand bodies in the region.
[0151] In one embodiment, such as Figure 24 As shown, the second selection module 2002 includes:
[0152] Large geological model building module 2401 is used to build a large geological model, including the edge water layer, using geological data of the gas reservoir edge.
[0153] The reinjection layer determination module 2402 is used to input the production data and test data obtained from the trial production into the large geological model to determine the reinjection layer;
[0154] The test production module 2403 is used to determine the location of new wells by testing existing wells at the edge of the gas reservoir;
[0155] The trial injection module 2404 is used to perform trial injections on the theoretical back injection layer to determine the actual back injection layer.
[0156] This application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-mentioned method for determining the gas field water reinjection layer and reinjection well.
[0157] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for determining the gas field water reinjection layer and reinjection well.
[0158] This application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-mentioned method for determining the gas field water reinjection layer and reinjection well.
[0159] Compared with existing technologies, this application optimizes shallow non-target layers, makes full use of limited data, combines well logging and seismic monitoring to solve the problem of sand body size prediction, and combines geological engineering to solve the problems of sealing and wellbore integrity. It establishes a method system for optimizing reinjection layers and reinjection wells to achieve the goal of zonal well finding. At the same time, it establishes a large model in deep target layers and conducts reinjection in target layers at the edge of the gas reservoir, thus providing a good reference for the optimization of water reinjection layers and reinjection wells in similar gas reservoirs.
[0160] Figure 25 This is a schematic diagram of the physical structure of the electronic device provided in the embodiments of this application, such as... Figure 25 As shown, the electronic device includes: a processor 2501, a memory 2502, and a bus 2503.
[0161] The processor 2501 and the memory 2502 communicate with each other via the bus 2503.
[0162] The processor 2501 is used to call program instructions in the memory 2502 to execute the methods provided in the above-described method embodiments.
[0163] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0164] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0165] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0166] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0167] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A method for determining the water reinjection layer and reinjection well in a gas field, characterized in that, include: Determine the reservoir type of oil and gas; The oil and gas reservoir types include non-production-oriented reservoirs and production-oriented reservoirs; The type of reinjection well is determined based on the reservoir type of the oil and gas. When the reservoir type of the oil and gas is a non-production target layer, existing wells are mainly used as reinjection wells. When the reservoir type of the oil and gas is a production target layer, new wells are mainly used as reinjection wells. The gas field water reinjection layer is determined based on the properties of the reinjection well.
2. The method for determining the gas field water reinjection layer and reinjection well according to claim 1, characterized in that, Determining the gas field water reinjection layer based on the properties of the reinjection well includes: When existing wells are used as the main reinjection wells, based on the static logging data of the existing wells, the layers with a thickness exceeding the preset value and dominated by sandstone are selected from the existing wells as the reinjection layers. When new wells are mainly used as reinjection wells, the reinjection layers are determined by conducting trial production and injection tests on existing wells at the edge of the gas reservoir.
3. The method for determining the gas field water reinjection layer and reinjection well according to claim 2, characterized in that, When existing wells are primarily used as reinjection wells, based on the static logging data of the existing wells, a sandstone-dominated section with a thickness exceeding a preset value is selected from the existing well cuttings data as the reinjection layer, including: Obtain the main logging curves from the existing well static logging data and determine the main sand bodies in the area; Based on the main logging curves and the main sand bodies in the region, predict the distribution range of the main sand bodies and establish a geological model of the main sand bodies in the region. The reinjection wells and reinjection layers were determined based on the geological model.
4. The method for determining the gas field water reinjection layer and reinjection well according to claim 3, characterized in that, The step of obtaining the main logging curves from the existing well's static logging data and determining the main sand bodies in the area includes: The static logging data of the existing wells are analyzed to obtain the main logging curves, which include gamma logging curves, resistivity logging curves and sonic logging curves. The sand bodies in the low-gamma and low-resistivity intervals were determined based on the main logging curves. The main sand bodies in the region are determined by single-well comparison of the sand bodies in the low gamma and low resistivity sections.
5. The method for determining the gas field water reinjection layer and reinjection well according to claim 3, characterized in that, The step of predicting the distribution range of the main sand bodies and establishing a geological model of the main sand bodies in the region based on the main logging curves and the main sand bodies in the region includes: The sedimentary characteristics of the main sand bodies are obtained based on the lithology of the main sand bodies and the main logging curves. Based on the sedimentary characteristics of the main sand bodies, the distribution range of the main sand bodies is predicted using seismic waveform inversion. The percentage of mudstone within the vertical fault displacement range is obtained from the distribution range of the main sandstone body. The percentage of mudstone within the vertical fault displacement range is used to determine the lateral sealing property of the regional fault and to establish a geological model of the main sandstone body in the region.
6. The method for determining the gas field water reinjection layer and reinjection well according to claim 2, characterized in that, The process of determining the reinjection zone by conducting trial production and injection tests on existing wells at the edge of the gas reservoir includes: A large geological model, including the marginal water layer, was established using geological data from the edge of the gas reservoir. The production and test data obtained from the trial production are input into the large geological model to determine the theoretical reinjection layer; The location of new wells will be determined by testing existing wells at the edge of the gas reservoir; The actual reinjection layer is determined by trial injection of the theoretical reinjection layer.
7. A device for determining the water reinjection layer and reinjection well in a gas field, characterized in that, include: Reservoir type determination unit, used to determine the reservoir type of oil and gas; The oil and gas reservoir types include non-production-oriented reservoirs and production-oriented reservoirs; The reinjection well type determination unit is used to determine the type of reinjection well based on the reservoir type of the oil and gas. The non-production target layer module is used to primarily use existing wells as injection wells when the oil and gas reservoir type is a non-production target layer. The production target layer module is used to primarily use new wells as injection wells when the reservoir type of the oil and gas is a production target layer. The reinjection layer determination unit is used to determine the gas field water reinjection layer based on the properties of the reinjection well.
8. The apparatus for determining the gas field water reinjection layer and reinjection well according to claim 7, characterized in that, The reinjection layer determination unit includes: The first selection module is used to select, when existing wells are the main reinjection wells, the layer with a thickness exceeding the preset value and dominated by sandstone from the existing well cuttings data as the reinjection layer. The second selection module is used to determine the reinjection layer by conducting trial production and injection tests on existing wells at the edge of the gas reservoir when new wells are the main reinjection wells.
9. The apparatus for determining the gas field water reinjection layer and reinjection well according to claim 7, characterized in that, The non-production-target layer module includes: The main sand body determination module is used to obtain the main logging curve from the static logging data of the existing wells and determine the main sand bodies in the area; The geological model construction module is used to predict the distribution range of the main sand bodies and establish a geological model of the main sand bodies in the region based on the main logging curves and the main sand bodies in the region. The reinjection location determination module is used to determine the reinjection well and reinjection layer based on the geological model.
10. The apparatus for determining the gas field water reinjection layer and reinjection well according to claim 9, characterized in that, The main sand body determination module includes: The main logging curve acquisition module is used to analyze the static logging data of the existing wells to obtain the main logging curves, which include gamma logging curves, resistivity logging curves and sonic logging curves. The target sand body determination module is used to determine sand bodies in low-gamma and low-resistivity intervals based on the main logging curves. The main sand body locking module is used to determine the main sand body in the area by single-well comparison of the sand bodies in the low gamma and low resistivity sections.
11. The apparatus for determining the gas field water reinjection layer and reinjection well according to claim 9, characterized in that, The geological model construction module includes: A sedimentary feature acquisition module is used to acquire the sedimentary features of the main sand body based on the lithology of the main sand body and the main logging curve. The sand body size prediction module is used to predict the distribution range of the main sand body based on its sedimentary characteristics and using seismic waveform inversion. The geological model building module is used to obtain the percentage of mudstone within the vertical fault range from the distribution range of the main sand body, use the percentage of mudstone within the vertical fault range to determine the lateral sealing of the fault in the region, and build a geological model of the main sand body in the region.
12. The apparatus for determining the gas field water reinjection layer and reinjection well according to claim 8, characterized in that, The second selection module includes: The large geological model building module is used to build a large geological model, including the marginal water layer, using geological data from the edge of the gas reservoir. The reinjection layer determination module is used to input the production data and test data obtained from the trial production into the large geological model to determine the reinjection layer; The test production module is used to determine the location of new wells by testing existing wells at the edge of the gas reservoir; The trial injection module is used to perform trial injections on the theoretical back injection layer to determine the actual back injection layer.
13. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 6.
14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.
15. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 6.