A method, apparatus, and equipment for constructing a calibration model for the development effect of horizontal wells.

Abstract

This invention discloses a method, apparatus, and equipment for constructing a horizontal well development effect calibration model. The method includes: dissecting the reservoir space of the target study area to determine the sand body distribution characteristics; classifying the spatial structure model of the gas field reservoir in the target study area based on the sand body distribution characteristics to determine the reservoir structure pattern; the reservoir structure pattern includes: a blocky concentrated development pattern, a medium-thin layer superimposed pattern, and a thin-layer isolated pattern; calibrating the reservoir structure pattern based on the static indicators of the reservoirs encountered by known horizontal wells in the target study area, and constructing a quantitative classification calibration model for horizontal wells after determining the reservoir quality corresponding to the reservoir structure pattern. Compared to the homogeneous and ideal reservoir models assumed in laboratory simulations, this method is more geologically adaptable and practically applicable to tight sandstone gas reservoirs; compared to the analogy method, it is more targeted and scientific, and can better support and guide production.

Description

Technical Field

[0001] This invention relates to the field of oil and gas development technology, and in particular to a method, apparatus and equipment for constructing a calibration model for the development effect of horizontal wells. Background Technology

[0002] During gas field development, horizontal wells need to go through four stages: "initial exploration," "large-scale production," "rapid development," and "stable development." As geological understanding deepens and horizontal well technology matures, the overall development effect will gradually improve. However, due to the differences in reservoir quality and structural characteristics in different blocks and development layers, the implementation effect of horizontal wells varies greatly. At the same time, given the reality that the quality of remaining gas fields gradually deteriorates as the best development is carried out in the enriched areas, the development effect of horizontal wells needs to be evaluated more thoroughly. Summary of the Invention

[0003] The inventors discovered that, based on a large amount of static and dynamic data from operational horizontal wells, and focusing on the detailed geological analysis and combined analysis of dynamic and static parameters of operational horizontal wells, they conducted an in-depth study of the differences in development index characteristics and development effects of horizontal wells encountered in reservoirs of different qualities. By establishing quantitative identification and classification standards, they were able to provide technical support for the "large-scale production and efficient development" of gas fields and provide guidance and reference for the development of horizontal wells in similar gas reservoirs.

[0004] In view of the above problems, the present invention is proposed to provide a method, apparatus and equipment for constructing a horizontal well development effect calibration model to overcome or at least partially solve the above problems.

[0005] In a first aspect, embodiments of the present invention provide a method for constructing a horizontal well development effect calibration model, which may include:

[0006] The reservoir space in the target study area is dissected to determine the sand body distribution characteristics of the reservoir.

[0007] Based on the aforementioned sand body distribution characteristics, a spatial structure model of the gas field reservoir in the target study area is delineated to determine the reservoir structure pattern; the reservoir structure pattern includes: blocky concentrated development pattern, medium and thin layer superposition pattern, and thin layer isolated pattern;

[0008] Based on the static indices of the reservoirs encountered by known horizontal wells in the target study area, the reservoir structure pattern is calibrated to determine the reservoir quality corresponding to the reservoir structure pattern and then a quantitative classification calibration model for horizontal wells is constructed.

[0009] Optionally, the method may further include: constructing a quantitative classification and calibration model of horizontal wells corresponding to reservoir structure patterns of different qualities based on the known production and decline characteristics of horizontal wells in the target study area, so as to simulate the development effect of horizontal wells.

[0010] Optionally, the step of constructing a quantitative classification and calibration model for horizontal wells corresponding to different reservoir structure patterns based on known production and decline characteristics of horizontal wells within the target study area includes:

[0011] Based on the production data of known horizontal wells in the target study area, the dynamic reserves and well-controlled area of ​​the encountered horizontal wells corresponding to different reservoir structure models are determined by using the production instability analysis method or the flow material balance method.

[0012] Based on the corrected isochronous well test results of known horizontal wells in the target study area, and using the production test results of horizontal wells encountered in reservoirs of different qualities, the empirical parameters of horizontal wells encountered in reservoirs are determined; and based on the production capacity and bottom hole flow pressure of the horizontal wells and the empirical parameters of horizontal wells encountered in reservoirs, the unobstructed flow rate is determined.

[0013] Based on the Arps production decline analysis method, the gas reservoir decline characteristics of known horizontal wells in the study area are analyzed to determine the initial annual decline rate of the horizontal wells encountered in the reservoir.

[0014] Based on the dynamic reserves, the well-controlled area, the empirical parameters of horizontal wells encountered in the reservoir, the unobstructed flow rate, the initial production rate, and the initial annual decline rate, a quantitative classification and calibration model for horizontal wells corresponding to different reservoir structure patterns is constructed.

[0015] Optionally, the productivity of the horizontal well encountered in the reservoir can be determined based on empirical parameters of the horizontal well encountered in the reservoir, which can be expressed by the following formula:

[0016]

[0017]

[0018] in, P R P represents formation pressure, in MPa; wf q represents the bottom hole flowing pressure, in MPa; g For the gas production at ground level, 10 4 m 3 / d;P D q is a dimensionless pressure, which is dimensionless. D q represents dimensionless output, which is dimensionless. AOF For unobstructed flow, 10 4 m 3 / d.

[0019] Optionally, the dissection of the reservoir space in the target study area to determine the sand body distribution characteristics of the reservoir may include:

[0020] Based on the sand body dissection results, interference test results, gas well logging interpretation results, and cuttings records of the target study area, the reservoir space of the target study area is dissected to determine the sand body distribution characteristics of the reservoir.

[0021] Optionally, the calibration of the reservoir structure pattern based on static indices of known horizontal wells encountered in the target study area may include:

[0022] Based on the known effective sand body length, sand body encounter rate, effective sand body encounter rate and effective thickness of the reservoir encountered by horizontal wells in the target study area, the reservoir structure model is calibrated.

[0023] Secondly, embodiments of the present invention provide a method for evaluating the development effect of horizontal wells, which may include:

[0024] The deployed horizontal wells are incorporated into a pre-constructed quantitative classification and calibration model for horizontal wells to predict their development performance.

[0025] The horizontal well quantitative classification and calibration model is constructed based on the method described in the first aspect.

[0026] Thirdly, embodiments of the present invention provide a horizontal well development effect calibration model construction device, which may include:

[0027] The dissection module is used to dissect the reservoir space in the target study area to determine the sand body distribution characteristics of the reservoir.

[0028] The segmentation module is used to segment the spatial structure model of the gas field reservoir based on the distribution characteristics of the sand bodies, so as to determine the reservoir structure pattern; the reservoir structure pattern includes: blocky concentrated development pattern, medium and thin layer superposition pattern, and thin layer isolated pattern;

[0029] The construction module is used to calibrate the reservoir structure pattern based on the static indicators of the reservoirs encountered by known horizontal wells in the target study area, and to construct a quantitative classification calibration model for horizontal wells after determining the reservoir quality corresponding to the reservoir structure pattern.

[0030] Fourthly, embodiments of the present invention provide a horizontal well development effect evaluation device, which may include:

[0031] The prediction module is used to input the deployed horizontal wells into a pre-built quantitative classification and calibration model of horizontal wells in order to predict the development effect of the horizontal wells.

[0032] The horizontal well quantitative classification and calibration model is constructed based on the method described in the first aspect.

[0033] Fifthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the horizontal well development effect calibration model construction method as described in the first aspect, or the horizontal well development effect evaluation method as described in the second aspect.

[0034] In a sixth aspect, embodiments of the present invention provide 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 program, it implements the horizontal well development effect calibration model construction method as described in the first aspect, or the horizontal well development effect evaluation method as described in the second aspect.

[0035] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0036] This invention provides a method, apparatus, and equipment for constructing a horizontal well development effect calibration model. The method may include: determining the sand body distribution characteristics of the reservoir based on the idea of ​​dissecting the reservoir space of the target study area, focusing on reservoirs of different qualities; then dividing the spatial structure model of the gas field reservoir according to the sand body distribution characteristics; finally, calibrating the development effect parameters based on a large amount of reliable development data during the gas field development process, which has high accuracy. Compared with the homogeneous and ideal reservoir model assumed by laboratory simulation, it is more geologically adaptable and practically applicable to tight sandstone gas reservoirs; compared with the analogy method, it is more targeted and scientific, and can play a more supporting and guiding role in production.

[0037] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0038] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0039] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0040] Figure 1 This is a flowchart of the method for constructing the horizontal well development effect calibration model provided in Embodiment 1 of the present invention;

[0041] Figure 2 This is a typical profile of a horizontal well with a blocky, concentrated development pattern, as provided in Embodiment 1 of the present invention.

[0042] Figure 3 This is a typical profile of a horizontal well drilling reservoir using the medium-thin layer stacking mode provided in Embodiment 1 of the present invention;

[0043] Figure 4 This is a typical profile of a horizontal well drilling reservoir in the thin-layer isolated mode provided in Embodiment 1 of the present invention;

[0044] Figure 5 This is a schematic diagram illustrating the intersection of the effective thickness and effective length of the sand body in Embodiment 1 of the present invention.

[0045] Figure 6 This is a schematic diagram illustrating the intersection of sand body drilling rate and effective sand body drilling rate provided in Embodiment 1 of the present invention;

[0046] Figure 7 This is a schematic diagram showing the lateral layout of the three reservoir structure modes provided in Embodiment 1 of the present invention;

[0047] Figure 8 This is a schematic diagram of the specific process for step S14;

[0048] Figure 9 This is a schematic diagram of the dimensionless pressure and pressure derivative curves of the multi-stage fracturing horizontal well provided in Embodiment 1 of the present invention;

[0049] Figure 10 This is a schematic diagram illustrating the intersection of well control area and dynamic reserves provided in one embodiment of the present invention;

[0050] Figure 11 The sample well α value and unobstructed flow rate statistics provided in Embodiment 1 of the present invention;

[0051] Figure 12 This is a schematic diagram illustrating the intersection of initial output and unobstructed flow rate provided in Embodiment 1 of the present invention;

[0052] Figure 13 This is a comparison chart of horizontal well production rates for the three reservoir structure models provided in Embodiment 1 of the present invention;

[0053] Figure 14 This is a comparison chart of horizontal well pressures for the three reservoir structure models provided in Embodiment 1 of the present invention;

[0054] Figure 15 This is a historical fitting curve of the production and cumulative production of horizontal wells encountered in the blocky concentrated development pattern provided in Embodiment 1 of the present invention;

[0055] Figure 16 This is the historical fitting curve of production and cumulative production of horizontal wells encountered in the medium-thin layer superposition mode provided in Embodiment 1 of the present invention;

[0056] Figure 17The historical fitting curves of production and cumulative production of horizontal wells encountered in the thin-layer isolated mode provided in Embodiment 1 of the present invention are shown.

[0057] Figure 18 This is a comparison chart of the annual production decline rate curves of horizontal wells in three types of reservoirs provided in Embodiment 1 of the present invention;

[0058] Figure 19 This is a schematic diagram of the structure of the device for constructing the horizontal well development effect calibration model provided in Embodiment 1 of the present invention. Detailed Implementation

[0059] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0060] Example 1

[0061] Embodiment 1 of this invention provides a method for constructing a calibration model for the development effect of horizontal wells. This method quantitatively classifies the development effect of horizontal wells with different reservoir qualities in tight sandstone gas fields to construct a calibration model. After constructing the calibration model, the development effect of future deployed horizontal wells can be evaluated to support the optimized deployment of future horizontal wells.

[0062] Reference Figure 1 As shown, the method may include the following steps:

[0063] Step S11: Dissect the reservoir space in the target study area to determine the sand body distribution characteristics of the reservoir.

[0064] Step S12: Based on the distribution characteristics of sand bodies, divide the spatial structure model of gas field reservoirs in the target study area to determine the reservoir structure pattern; the reservoir structure pattern may include: blocky concentrated development pattern, medium and thin layer superposition pattern and thin layer isolated pattern.

[0065] Step S13: Based on the static indicators of the reservoirs encountered by known horizontal wells in the target study area, the reservoir structure pattern is calibrated, and a quantitative classification calibration model for horizontal wells is constructed after determining the reservoir quality corresponding to the reservoir structure pattern.

[0066] Step S14: Based on the known production and decline characteristics of horizontal wells in the target study area, construct a quantitative classification and calibration model of horizontal wells corresponding to reservoir structure patterns of different qualities to simulate the development effect of horizontal wells.

[0067] The method provided in this embodiment of the invention is based on the idea of ​​dissecting the reservoir space of the target study area, focusing on the dissection of reservoirs of different qualities, and determining the sand body distribution characteristics of the reservoir. Then, the spatial structure model of the gas field reservoir is divided according to the sand body distribution characteristics. Finally, the development effect parameters are calibrated based on the massive amount of reliable development data in the gas field development process. The accuracy is high. Compared with the homogeneous and ideal model of the reservoir assumed by laboratory simulation, it is more geologically adaptable and practical in the field for tight sandstone gas reservoirs. Compared with the analogy method, it is more targeted and scientific, and can play a more supporting and guiding role in production.

[0068] In an optional embodiment, the above step S11, which involves dissecting the reservoir space in the target study area to determine the sand body distribution characteristics of the reservoir, may include: dissecting the reservoir space in the target study area based on the sand body dissection results, interference well test results, gas well logging interpretation results, and cuttings records to determine the sand body distribution characteristics of the reservoir.

[0069] In this step, the detailed dissection results of sand bodies in the study area, the results of interference well tests, the interpretation results of gas well logging, and the cuttings records are used as basic data. Based on this basic data, the reservoir space in the target study area is dissected to determine the sand body distribution characteristics of the reservoir.

[0070] In another alternative embodiment, the reservoir structure pattern may include a blocky, concentrated development pattern, a medium-thin layer stacked pattern, and a thin-layer isolated pattern. The characteristics of each pattern are detailed below:

[0071] Among them, the blocky concentrated development pattern is mainly distributed in the main part of the braided river system superimposed zone, where the hydrodynamic conditions are the strongest, referring to Figure 2 As shown, typical reservoir profiles from horizontal well drilling show that the reservoir has developed thick single-layered massive effective sand bodies with good lateral continuity, relatively concentrated geological reserves, and a prominent main layer. The lithology is relatively pure medium-coarse sandstone, and the average drilling rate of effective sand bodies is 63.6%.

[0072] The medium-thin layer superposition model is mainly distributed on the flanks or transition zones of braided river systems, with moderate water conditions, referring to... Figure 3 As shown, typical reservoir profiles encountered by horizontal wells indicate that the sandstone stacks are generally about 10 meters thick, with multiple effective sand bodies of varying thicknesses. Lateral continuity is generally poor, and the sandstone is finer than blocky. Sometimes, there are obvious sandstone-mudstone interbedded features. The average encounter rate of effective sand bodies is between 50% and 60%.

[0073] Thin-layer isolated models are mainly distributed between braided river system zones, where water conditions are weakest, channel phases are distinct, and lateral continuity is poor. (Refer to...) Figure 4As shown in the typical reservoir profile encountered by horizontal wells, the reservoir exhibits a clear interbedded sandstone and mudstone structure, with thin, isolated effective sand bodies, typically numbering 1 to 3. The reservoir has a fine grain size, high clay content, and an effective sand body encounter rate of less than 40%.

[0074] In another optional embodiment, calibrating the reservoir structure pattern based on static indices of known horizontal well-drilled reservoirs within the target study area may include:

[0075] Based on the effective sand body length, sand body encounter rate, effective sand body encounter rate, and effective thickness of the reservoir encountered by known horizontal wells in the target study area, the reservoir structure model is calibrated. In this embodiment of the invention, the reservoir structure models of 300 known horizontal wells in the target study area are calibrated. Most horizontal wells can conform to the above three reservoir structure models, as shown in Table 1.

[0076] Table 1

[0077]

[0078] Reference Figure 5 and Figure 6 As shown, based on the spatial structure analysis of reservoirs encountered in nearly 300 horizontal wells, a graphical cross-section was performed using static indicators such as effective sand body length, sand body encounter rate, and effective thickness.

[0079] Reference Figure 7 As shown, the effective reservoir quality grading standards from actual horizontal well drilling reveal significant differences in static indicators among the three types of reservoir lateral distribution patterns (A is the blocky concentrated development pattern, B is the medium-thin layer superimposed pattern, and C is the thin-layer isolated pattern), indicating significant differences in the adaptability of horizontal well deployment. With the deepening of gas field development, the high-energy superimposed channel zone located in the main part of the braided river system superimposed zone has been fully utilized, and development targets are gradually shifting towards the lateral flanks and transition zones of the channel. Horizontal well development practice shows that fracturing horizontal wells in this target study area generally do not have a clear stable production period; production is high and declines rapidly in the early stages, and low and declines slowly in the middle and late stages. However, the production characteristics and decline patterns of horizontal wells encountered in reservoirs of different quality vary considerably. Studying the decline characteristics and differences of horizontal wells encountered in reservoirs of different quality and establishing quantitative grading standards will help predict the development effects of future newly drilled horizontal wells.

[0080] In another alternative embodiment, refer to Figure 8 As shown, step S14 above may specifically include:

[0081] Step S81: Based on the production data of known horizontal wells in the target study area, determine the dynamic reserves and well-controlled area of ​​the encountered horizontal wells corresponding to different reservoir structure models using the production instability analysis method or the flow material balance method.

[0082] Due to their poor reservoir properties and high heterogeneity, tight sandstone gas reservoirs require staged fracturing after horizontal well completion to achieve higher production capacity and well-controlled reserves. After staged fracturing, a composite reservoir is formed, consisting of a high-permeability fractured zone near the wellbore and a tight, untreated zone further away from the wellbore. Figure 9 This study illustrates several typical flow states experienced by a segmented fractured horizontal well from start-up production to gradual stabilization. In the early stages of production, formation fluids at the fracture surface begin supplying gas to the fractures, flowing into the wellbore along the fractures, exhibiting a bilinear flow (BLF). As the flow within the fractures reaches a quasi-steady state, the pressure decreases at the same rate throughout the fractures, and the formation fluid stably supplies gas to the fractures, exhibiting a formation linear flow (FLF). As the pressure sweep area expands within the formation, individual fractures enter a quasi-radial flow stage (FRF), with no interference between fractures. When the interference between fractures intensifies, the overall flow within the fracture spacing exhibits quasi-steady-state production characteristics, entering the second linear flow stage (SLF). As the pressure sweep area continues to increase, the overall flow pattern of the horizontal well approximates the effect of a single wide fracture, i.e., the second radial flow (SRF) stage, at which point the fractured horizontal well reaches a relatively stable state. In the mid-to-late stages of production, the well-controlled area reaches the well-controlled flow boundary, entering the final quasi-steady-state stage, where the rate of production decline gradually slows down.

[0083] Based on two commonly used dynamic reserve control analysis methods for fractured horizontal wells in tight sandstone gas reservoirs: the production instability analysis model and the flow material balance method, this study investigates the dynamic reserves and well-controlled area of ​​horizontal wells drilled in reservoirs of different qualities. The production instability analysis method uses production data fitted to a dimensionless production decline curve to analyze the dynamic controlled reserves and well-controlled area (discharge range). (Refer to...) Figure 10 The fluid mass balance is determined by the linear relationship of regression formula (1). A rectangular coordinate graph is plotted with Y = qg / [Pp(pi) - Pp(pwf)] as the ordinate and X = qgta / {cti[Pp(pi) - Pp(pwf)]} as the abscissa. The intercept is 1 / bpss, and the slope is 1 / (Gibpss). The dynamic controlled reserves can then be calculated using the slope. In this embodiment of the invention, nearly 300 horizontal wells that have been in production for more than 3 years in the target study area are analyzed as samples. The results are as follows: For Class I quality reservoirs, the dynamic reserves encountered by horizontal wells are >80 million cubic meters, and the well-controlled area is >1.2 km². 2 The dynamic reserves of horizontal wells encountered in Class II quality reservoirs are 40-80 million cubic meters, with a well-controlled area of ​​0.7-1.2 km². 2 The dynamic reserves of horizontal wells encountered in Class II quality reservoirs are <40 million cubic meters, and the well-controlled area is <0.7 km². 2 .

[0084]

[0085]

[0086] Where: b pss A time-independent constant (MPa × d / m) 3 ) -1 ;p i The original formation pressure is MPa; μ gi P represents the initial viscosity of the gas, in mPa·s; p The simulated pressure is measured in MPa; Z gi G is the gas deviation factor under the original formation pressure, dimensionless; i Natural gas geological reserves, 10 8 m 3 .

[0087] Step S82: Based on the corrected isochronous well test results of known horizontal wells in the target study area, determine the empirical parameters of horizontal wells encountered in reservoirs of different quality using the production test results of horizontal wells encountered in reservoirs; and determine the unobstructed flow rate based on the production capacity and bottom hole flow pressure of the horizontal wells and the empirical parameters of horizontal wells encountered in reservoirs.

[0088] To determine the decisive unobstructed flow rate of a gas well, a modified isochronous well test is required, which is time-consuming, especially for tight sandstone gas reservoirs where formation pressure remains unstable for extended periods, rendering the test results unsatisfactory. To avoid these drawbacks, this invention uses a large number of reliable and stable production well test results from horizontal wells drilled in reservoirs of different qualities as a basis to determine the empirical parameter α value for horizontal wells drilled in reservoirs, thus obtaining the corresponding empirical production formula.

[0089] The productivity of horizontal wells encountered in reservoirs can be determined based on empirical parameters, which can be expressed by the following formula:

[0090]

[0091]

[0092] in, P R P represents formation pressure, in MPa; wf q represents the bottom hole flowing pressure, in MPa; g For the gas production at ground level, 10 4 m 3 / d;P D q is a dimensionless pressure, which is dimensionless. D q represents dimensionless output, which is dimensionless. AOF For unobstructed flow, 10 4 m 3 / d.

[0093] Once the value of α is determined, the unrestricted flow rate can be calculated based on the gas well test data, stable production rate, and corresponding stable bottomhole flowing pressure. (Refer to...) Figure 11 As shown, in this embodiment of the invention, the α value and open flow rate are determined based on corrected isochronous well test data from 24 horizontal wells drilled in three types of reservoirs in the target study area. The analysis results show that the α value for horizontal wells drilled in Type I reservoirs is 0.9115, and the open flow rate is greater than 30 × 10⁻⁶. 4 m 3 / d; The α value of horizontal wells encountered in Class II quality reservoirs is 0.8756, and the unobstructed flow rate is 15~30×10 4 m 3 / d; The α value of horizontal wells encountered in Class III quality reservoirs is 0.8432, and the unobstructed flow rate is less than 15×10 4 m 3 / d.

[0094] Figure 12 Schematic diagram of the intersection of initial output and unobstructed flow rate.

[0095] Step S83: Based on the Arps production decline analysis method, analyze the gas reservoir decline characteristics of known horizontal wells in the study area to determine the initial annual decline rate of horizontal wells encountered in the reservoir.

[0096] Arps decline analysis is characterized by its low data requirements and ease of operation. However, achieving a quasi-steady state in gas well flow is crucial for its application. This invention sampled nearly 300 horizontal wells that had been in production for over three years to analyze the decline characteristics and differences in horizontal wells within reservoirs of varying quality. Specific conditions included: 1. Production time greater than 900 days; 2. Well opening rate greater than 85%; 3. Casing pressure drop rate less than 0.02 MPa / d.

[0097] Reference Figure 13 and Figure 14 As shown, gas wells drilled into reservoirs of different qualities exhibit continuous production capacity with pressure drop rates within a reasonable range at their respective production levels. Both production and pressure show a consistent trend: a rapid decrease in the first year, followed by a gradual slowdown in subsequent years. However, the decline characteristics of gas wells differ across reservoir qualities. The relationship between production and decline rate is as follows:

[0098]

[0099] in, Q represents the output at any time during the decreasing phase, 10 4 m 3 / d;Q i For the initial output during the decline phase, 10 4 m3 / d;D i 1 / d is the initial instantaneous decrease rate when the decrease begins; D is the instantaneous decrease rate, 1 / d; n is the decrease exponent.

[0100] In actual field operations, due to the instability of the operating regime and the large variations in well production after production wells in tight sandstone gas reservoirs are put into operation, directly calculating the decline rate using the actual production curve will result in noise and even negative values. Therefore, when calculating the decline rate, curve fitting is performed using the theoretical formula for production decline, referring to... Figures 15-17 As shown, the fitted gas well production decline curve is smoother, and the decline rate calculated based on it is more accurate.

[0101] Reference Figure 18 As shown, in the early stages of decline, the initial decline rate in stage A varies, mainly due to differences in the reserves utilized in the near-wellbore zone and around the fractured fractures during the initial production phase; 2) The predicted well life and cumulative gas production also differ. The main reason for this difference is the variation in reserve replenishment in the reservoir surrounding the fractures as the production pressure differential of the gas well increases, the near-wellbore zone pressure gradually decreases, and the production rate gradually stabilizes in the later stages of production, maintaining stable production at a relatively low level for a considerable period.

[0102] Step S84: Based on dynamic reserves, well-controlled area, empirical parameters of horizontal wells encountered in reservoir drilling, unobstructed flow rate, initial production rate and initial annual decline rate, construct a quantitative classification and calibration model for horizontal wells corresponding to different reservoir structure patterns.

[0103] Based on the development effects and differences of horizontal wells encountered in reservoirs of different qualities, a set of quantitative identification and evaluation standards for the development effects of horizontal wells in gas fields of different qualities in this target study area was established, as shown in Table 2 below. Clear quantitative limits were proposed for key parameters reflecting the development effects of horizontal wells, such as initial annual decline rate, initial production, unobstructed flow rate, and dynamic reserves. This standard can systematically analyze and evaluate the development effects of already-produced horizontal wells in the tight gas reservoirs of this study area, and can also play a predictive role in the development effects of future-produced horizontal wells.

[0104] Table 2

[0105]

[0106] The embodiments of this invention adopt the idea of ​​focusing on the analysis of reservoirs of different qualities. Based on the massive amount of reliable development data in the gas field development process, the development effect parameters are calibrated with high accuracy. Compared with the homogeneous and ideal models of reservoirs assumed by laboratory simulation, it is more geologically adaptable and practical in the field for tight sandstone gas reservoirs. Compared with the analogy method, it is more targeted and scientific, and can play a more supporting and guiding role in production.

[0107] Based on the same inventive concept, this invention also provides a horizontal well development effect calibration model construction device, referring to... Figure 19 As shown, the device may include: an anatomy module 11, a segmentation module 12, and a construction module 13; its working principle is as follows:

[0108] The dissection module 11 is used to dissect the reservoir space in the target study area to determine the sand body distribution characteristics of the reservoir.

[0109] The partitioning module 12 is used to partition the spatial structure model of the gas field reservoir based on the sand body distribution characteristics, so as to determine the reservoir structure pattern; the reservoir structure pattern includes: blocky concentrated development pattern, medium and thin layer superposition pattern and thin layer isolated pattern.

[0110] Module 13 is used to calibrate the reservoir structure pattern based on the static indicators of the reservoirs encountered by known horizontal wells in the target study area, and to construct a quantitative classification calibration model for horizontal wells after determining the reservoir quality corresponding to the reservoir structure pattern.

[0111] Specifically, module 13 constructs a quantitative classification and calibration model of horizontal wells corresponding to reservoir structure patterns of different qualities based on the known production and decline characteristics of horizontal wells in the target study area, in order to simulate the development effect of horizontal wells.

[0112] In an optional embodiment, the above-described building module 13 is specifically used for:

[0113] Based on the production data of known horizontal wells in the target study area, the dynamic reserves and well-controlled area of ​​the encountered horizontal wells corresponding to different reservoir structure models are determined by using the production instability analysis method or the flow material balance method.

[0114] Based on the corrected isochronous well test results of known horizontal wells in the target study area, and using the production test results of horizontal wells encountered in reservoirs of different qualities, the empirical parameters of horizontal wells encountered in reservoirs are determined; and based on the production capacity and bottom hole flow pressure of the horizontal wells and the empirical parameters of horizontal wells encountered in reservoirs, the unobstructed flow rate is determined.

[0115] Based on the Arps production decline analysis method, the gas reservoir decline characteristics of known horizontal wells in the study area are analyzed to determine the initial annual decline rate of the horizontal wells encountered in the reservoir.

[0116] Based on the dynamic reserves, the well-controlled area, the empirical parameters of horizontal wells encountered in the reservoir, the unobstructed flow rate, the initial production rate, and the initial annual decline rate, a quantitative classification and calibration model for horizontal wells corresponding to different reservoir structure patterns is constructed.

[0117] In another alternative embodiment, the construction module 13 determines the productivity of the reservoir-drilled horizontal well based on empirical parameters of the reservoir-drilled horizontal well, which can be expressed by the following formula:

[0118]

[0119]

[0120] in, P R P represents formation pressure, in MPa; wf q represents the bottom hole flowing pressure, in MPa; g For the gas production at ground level, 10 4 m 3 / d;P D q is a dimensionless pressure, which is dimensionless. D q represents dimensionless output, which is dimensionless. AOF For unobstructed flow, 10 4 m 3 / d.

[0121] In an optional embodiment, the dissection module 11 is specifically used to: dissect the reservoir space of the target study area based on the sand body dissection results, interference test results, gas well logging interpretation results, and cuttings records, so as to determine the sand body distribution characteristics of the reservoir.

[0122] In an optional embodiment, the partitioning module 12 is specifically used to: calibrate the reservoir structure pattern based on the effective sand body length, sand body encounter rate, effective sand body encounter rate and effective thickness of the reservoir encountered by known horizontal wells in the target study area.

[0123] Based on the same inventive concept, this embodiment of the invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for constructing a horizontal well development effect calibration model.

[0124] Based on the same inventive concept, this embodiment of the invention 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 program, it implements the horizontal well development effect calibration model construction method described above.

[0125] The principles by which the above-mentioned devices, media, and related equipment in the embodiments of the present invention solve the problem are similar to those of the aforementioned methods. Therefore, their implementation can refer to the implementation of the aforementioned methods, and repeated details will not be repeated.

[0126] Example 2

[0127] Based on the same inventive concept, Embodiment 2 of the present invention provides a method for evaluating the development effect of horizontal wells, which may include:

[0128] The deployed horizontal wells are incorporated into a pre-constructed quantitative classification and calibration model for horizontal wells to predict their development performance.

[0129] The horizontal well quantitative classification and calibration model is constructed according to the method described in Example 1.

[0130] In this embodiment of the invention, after determining the effective reservoir quality classification standard of the gas field horizontal well drilling in Table 1 to identify the reservoir quality, we can find the corresponding Class I, II, and III reservoir predictions in Table 2. After drilling a horizontal well in this reservoir, we can then predict the future development effect parameters of the horizontal well.

[0131] Based on the same inventive concept, this invention also provides a horizontal well development effect evaluation device, which may include:

[0132] The prediction module is used to input the deployed horizontal wells into a pre-built quantitative classification and calibration model of horizontal wells in order to predict the development effect of the horizontal wells.

[0133] The horizontal well quantitative classification and calibration model was constructed according to the method described in Example 1.

[0134] Based on the same inventive concept, this embodiment of the invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for evaluating the development effect of horizontal wells.

[0135] Based on the same inventive concept, this embodiment of the invention 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 program, it implements the horizontal well development effect evaluation method described above.

[0136] The principles by which the above-mentioned devices, media, and related equipment in the embodiments of the present invention solve the problem are similar to those of the aforementioned methods. Therefore, their implementation can refer to the implementation of the aforementioned methods, and repeated details will not be repeated.

[0137] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention 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 and optical storage) containing computer-usable program code.

[0138] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. 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 illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0139] 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.

[0140] 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.

[0141] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for constructing a calibration model for the development effect of horizontal wells, characterized in that, include: The reservoir space in the target study area is dissected to determine the sand body distribution characteristics of the reservoir. Based on the sand body distribution characteristics, a spatial structure model of the gas field reservoir in the target study area is divided to determine the reservoir structure pattern. The reservoir structure patterns include: blocky concentrated development pattern, medium and thin layer superposition pattern, and thin layer isolated pattern; Based on the static indices of the reservoirs encountered by known horizontal wells in the target study area, the reservoir structure pattern is calibrated to determine the reservoir quality corresponding to the reservoir structure pattern. Based on the production data of known horizontal wells in the target study area, the dynamic reserves and well-controlled area of ​​the encountered horizontal wells corresponding to different reservoir structure models are determined by using the production instability analysis method or the flow material balance method. Based on the corrected isochronous well test results of known horizontal wells in the target study area, and using the production test results of horizontal wells encountered in reservoirs of different qualities, the empirical parameters of horizontal wells encountered in reservoirs are determined; and based on the production capacity and bottom hole flow pressure of the horizontal wells and the empirical parameters of horizontal wells encountered in reservoirs, the unobstructed flow rate is determined. Based on the Arps production decline analysis method, the gas reservoir decline characteristics of known horizontal wells in the study area are analyzed to determine the initial annual decline rate of the horizontal wells encountered in the reservoir. Based on the dynamic reserves, the well-controlled area, the empirical parameters of horizontal wells encountered in the reservoir, the unobstructed flow rate, the initial production rate, and the initial annual decline rate, a quantitative classification and calibration model for horizontal wells corresponding to different reservoir structure patterns is constructed to simulate the development effect of horizontal wells.

2. The method according to claim 1, characterized in that, The productivity of the horizontal wells encountered in the reservoir is determined based on the empirical parameters of the wells, expressed by the following formula: ； ； in, , α is an empirical parameter for horizontal wells encountered in the reservoir; P R P represents formation pressure, in MPa; wf q represents the bottom hole flowing pressure, in MPa; g For the gas production at ground level, 10 4 m 3 / d;P D q is a dimensionless pressure, which is dimensionless. D Dimensionless output, without dimensions; For unobstructed flow, 10 4 m 3 / d.

3. The method according to any one of claims 1 to 2, characterized in that, The process of dissecting the reservoir space in the target study area to determine the sand body distribution characteristics includes: Based on the sand body dissection results, interference test results, gas well logging interpretation results, and cuttings records of the target study area, the reservoir space of the target study area is dissected to determine the sand body distribution characteristics of the reservoir.

4. The method according to any one of claims 1 to 2, characterized in that, The calibration of the reservoir structure pattern based on static indices of known horizontal well-drilled reservoirs within the target study area includes: Based on the effective sand body length, sand body encounter rate, effective sand body encounter rate and effective thickness of the reservoir encountered by known horizontal wells in the target study area, the reservoir structure model is calibrated.

5. A method for evaluating the development effect of horizontal wells, characterized in that, include: The deployed horizontal wells are incorporated into a pre-constructed quantitative classification and calibration model for horizontal wells to predict their development performance. The horizontal well quantitative classification and calibration model is constructed using the method described in any one of claims 1 to 4.

6. A device for constructing a calibration model for horizontal well development effects, characterized in that, include: The dissection module is used to dissect the reservoir space in the target study area to determine the sand body distribution characteristics of the reservoir. The segmentation module is used to segment the spatial structure model of the gas field reservoir based on the sand body distribution characteristics, so as to determine the reservoir structure pattern. The reservoir structure patterns include: blocky concentrated development pattern, medium and thin layer superposition pattern, and thin layer isolated pattern; The module is used to calibrate the reservoir structure pattern based on the static indicators of the reservoirs encountered by known horizontal wells in the target study area, thereby determining the reservoir quality corresponding to the reservoir structure pattern; based on the production data of known horizontal wells in the target study area, using the production instability analysis method or the flow mass balance method, to determine the dynamic reserves and well-controlled area of ​​the encountered horizontal wells corresponding to reservoir structure patterns of different qualities; and based on the corrected isochronous well tests of known horizontal wells in the target study area, using the production capacity well test results of horizontal wells encountered in reservoirs of different qualities, to determine the empirical parameters of horizontal wells encountered in reservoirs. The study analyzes the gas reservoir decline characteristics of known horizontal wells in the study area based on the production capacity and bottom-hole flowing pressure of the horizontal wells, as well as the empirical parameters of horizontal wells encountered in the reservoir. It also analyzes the initial annual decline rate of horizontal wells encountered in the reservoir based on the Arps production decline analysis method. Finally, it constructs quantitative classification and calibration models for horizontal wells corresponding to different reservoir structure patterns based on the dynamic reserves, well-controlled area, empirical parameters of horizontal wells encountered in the reservoir, the unobstructed flow rate, initial production, and initial annual decline rate to simulate the development effect of horizontal wells.

7. A device for evaluating the development effect of horizontal wells, characterized in that, include: The prediction module is used to input the deployed horizontal wells into a pre-built quantitative classification and calibration model of horizontal wells in order to predict the development effect of the horizontal wells. The horizontal well quantitative classification and calibration model is constructed using the method described in any one of claims 1 to 4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the horizontal well development effect calibration model construction method as described in any one of claims 1 to 4, or the horizontal well development effect evaluation method as described in claim 5.

9. 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 program, it implements the horizontal well development effect calibration model construction method as described in any one of claims 1 to 4, or the horizontal well development effect evaluation method as described in claim 5.

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