Method and device for predicting gas production rate of shale gas single well

Abstract

The invention discloses a method and device for predicting the gas production rate of a shale gas single well. The method comprises the following steps: acquiring fracturing section lengths, original daily gas production rates and original pressure data of a plurality of shale gas wells put into production in a target block; respectively constructing a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, the original daily gas production and the original pressure data; and determining a to-be-predicted shale gas well in the target block, and determining the target predicted daily gas production of the to-be-predicted shale gas well based on the daily gas production reference curve and the pressure data reference curve. The problem that the geological reserve prediction accuracy of the shale gas well is low is solved, and the beneficial effect of improving the geological reserve prediction accuracy of the shale gas well is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of shale gas exploration and development, and in particular to a method and device for predicting the gas production of a single shale gas well. Background Art

[0002] At present, conventional dynamic analysis methods and analogy methods are usually used to predict the future production scale and annual deployment workload of shale gas reservoirs. For wells that have been put into production, "gas reservoir engineering theory" and "dynamic analysis procedures" are usually used as the basis, integrating gas reservoir description, gas reservoir production dynamic analysis, gas reservoir engineering method calculation and production capacity evaluation. The algorithms for predicting gas well production mainly include analytical model method, production decline method, material balance method and probability method. The analogy method is usually used to predict the wells that have been drilled but not put into production and planned to be deployed. The prediction of shale gas reservoir production scale and annual deployment involves the continuous updating of data in multiple dimensions, including the continuous updating of production history data of wells that have been put into production, the change of drilling attributes in wells that have been drilled but not put into production to completed and fractured wells, and the change of fractured well attributes to produced wells.

[0003] The existing methods for predicting the production scale and annual deployment of shale gas reservoirs have the following limitations: (1) During the prediction stage, the production history of the wells in the gas reservoir is constantly updated. The production prediction methods based on conventional gas reservoir dynamic analysis and other methods have a huge workload and a relatively long prediction cycle. (2) During the development of the gas reservoir, the attributes of the wells that have been drilled but not put into production are constantly changing to the attributes of the wells in production. The number of wells in production, wells being drilled, wells completed, and wells being fractured in the target block changes dynamically, making it difficult to adjust in real time and resulting in a low accuracy rate in production prediction. (3) The attributes of the wells being drilled in the wells that have been drilled but not put into production are constantly changing to the attributes of the wells that have been completed or fractured. The horizontal section length and fracture section length of the wells that have been completed and fractured need to be constantly updated, making it impossible to accurately predict the production of the wells that have been completed and fractured. Summary of the invention

[0004] The present invention provides a method and device for predicting the gas production of a single shale gas well, so as to solve the problem of low accuracy in predicting the gas production of a single shale gas well.

[0005] According to one aspect of the present invention, a method for predicting the gas production of a single shale gas well is provided, and the method for predicting the gas production of a single shale gas well comprises:

[0006] Obtain the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in production in the target block;

[0007] Based on the fracturing section length, the original daily gas production and the original pressure data, a daily gas production reference curve and a pressure data reference curve are respectively constructed;

[0008] The shale gas wells to be predicted in the target block are determined, and the target predicted daily gas production of the shale gas wells to be predicted is determined based on the daily gas production reference curve and the pressure data reference curve.

[0009] According to another aspect of the present invention, a device for predicting gas production of a single shale gas well is provided, and the device for predicting gas production of a single shale gas well comprises:

[0010] A data acquisition module is used to obtain the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells that have been put into production in the target block;

[0011] A curve construction module, used to respectively construct a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, the original daily gas production and the original pressure data;

[0012] The gas production prediction module is used to determine the shale gas well to be predicted in the target block, and determine the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve.

[0013] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0014] at least one processor; and

[0015] a memory communicatively connected to the at least one processor; wherein,

[0016] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the gas production prediction method for a single shale gas well described in any embodiment of the present invention.

[0017] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the method for predicting the gas production of a single shale gas well described in any embodiment of the present invention when executed.

[0018] The technical solution of the embodiment of the present invention obtains the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in the target block that have been put into production; accurately obtains the associated data of the shale gas wells that have been put into production; then, based on the fracturing section length, original daily gas production and original pressure data, respectively constructs a daily gas production reference curve and a pressure data reference curve; based on the associated data of the shale gas wells that have been put into production, the daily gas production reference curve and the pressure data reference curve can be accurately constructed; finally, the shale gas wells to be predicted in the target block are determined, and the target predicted daily gas production of the shale gas wells to be predicted is determined based on the daily gas production reference curve and the pressure data reference curve, thereby solving the problem of low accuracy in geological reserve prediction of shale gas wells and achieving the beneficial effect of improving the accuracy in geological reserve prediction of shale gas wells.

[0019] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a flow chart of a method for predicting gas production of a single shale gas well provided in accordance with Embodiment 1 of the present invention;

[0022] Figure 2a This is a flow chart of a method for predicting gas production of a single shale gas well provided in accordance with the second embodiment of the present invention;

[0023] Figure 2b is a flow chart of an optional example of a method for predicting gas production of a single shale gas well provided in accordance with the second embodiment of the present invention;

[0024] Figure 2c It is a sample schematic diagram of a daily gas production reference curve of an optional example of a method for predicting gas production of a single shale gas well provided in Embodiment 2 of the present invention;

[0025] Figure 2d This is a sample schematic diagram of a pressure data reference curve of an optional example of a method for predicting gas production of a single shale gas well provided in Embodiment 2 of the present invention;

[0026] Figure 3 This is a schematic structural diagram of a shale gas single well gas production prediction device provided in accordance with Embodiment 3 of the present invention;

[0027] Figure 4 It is a schematic diagram of the structure of an electronic device for implementing the method for predicting the gas production of a single shale gas well according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] Embodiment 1

[0031] Figure 1 A flowchart of a method for predicting the gas production of a single shale gas well is provided for the first embodiment of the present invention. This embodiment is applicable to shale gas exploration and development. The method can be performed by a device for predicting the gas production of a single shale gas well. The device for predicting the gas production of a single shale gas well can be implemented in the form of hardware and / or software. The device for predicting the gas production of a single shale gas well can be configured in an electronic device. Figure 1 As shown, the method includes:

[0032] S110, obtaining data on the length of the fracturing section, the original daily gas production, and the original pressure of multiple shale gas wells in production in the target block.

[0033] Among them, shale gas can be understood as natural gas in a reservoir rock system dominated by organic-rich shale. Production shale gas wells can be understood as shale gas wells that have been put into production. Fracturing section length can be understood as the length of the shale gas well that has been fractured after the shale gas well is fractured. Daily gas production can be understood as the amount of shale gas produced by the shale gas well every day. It can be understood that pressure data is correlated with daily gas production.

[0034] Specifically, the horizontal section length, fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in production in the target block are obtained. Among them, the horizontal section length and fracturing section length of a single well are static data, and the original daily gas production and original pressure data are dynamic data. The horizontal section length can be understood as the length of the horizontal section of a horizontal gas well, which can be the length from the point where the predetermined gas formation is drilled and the well inclination reaches a basic level to the completed drilling depth.

[0035] S120, constructing a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, the original daily gas production and the original pressure data.

[0036] The daily gas production reference curve can be understood as a fitting curve in the coordinate system of daily gas production per unit fracturing section length and production time. The pressure data reference curve can be understood as a fitting curve in the coordinate system of casing pressure and production time.

[0037] Specifically, curve fitting and extrapolation are performed on the acquired fracturing section length, original daily gas production and original pressure data, and finally a continuous and smooth reference curve of daily gas production per unit fracturing section length and a reference curve of pressure data are obtained for the target block. It can be understood that the reference curve of daily gas production includes the known original daily gas production and the predicted daily gas production; the reference curve of pressure data includes the known original pressure data and the predicted pressure data.

[0038] S130, determining the shale gas wells to be predicted in the target block, and determining the target predicted daily gas production of the shale gas wells to be predicted based on the daily gas production reference curve and the pressure data reference curve.

[0039] The shale gas well to be predicted is the shale gas well whose daily gas production is to be predicted. The target predicted daily gas production can be understood as the predicted daily gas production of the shale gas well at the target prediction time point.

[0040] Specifically, the shale gas wells to be predicted in the target block can be determined by a preset selection method, and the daily gas production of the shale gas wells to be predicted corresponding to the target prediction time point can be determined based on the daily gas production reference curve and the pressure data reference curve. The preset selection method can be preset by experience, for example: manual selection or automatic selection by the system according to the type of shale gas well, whether it is put into production or the length of time it is put into production, which is not limited in this embodiment.

[0041] Optionally, the target predicted daily gas production of the shale gas well to be predicted is determined based on the daily gas production reference curve and the pressure data reference curve, including: when the shale gas well to be predicted is the shale gas well that has been put into production, determining the first predicted time point and the production time corresponding to the shale gas well that has been put into production; when the production time reaches a preset production time threshold, determining the actual cumulative daily gas production corresponding to the production time, and determining the actual cumulative daily gas production corresponding to the production time according to the actual casing pressure data of the shale gas well that has been put into production. actual pressure drop-time integral; determine the reference cumulative daily gas production corresponding to the produced time and the first predicted daily gas production corresponding to the predicted time point based on the daily gas production reference curve, and determine the reference pressure drop-time integral corresponding to the produced time based on the pressure data reference curve; determine the second predicted daily gas production of the produced shale gas well at the first predicted time point based on the first predicted daily gas production, the actual cumulative daily gas production, the reference cumulative daily gas production, the actual pressure drop-time integral and the reference pressure drop-time integral.

[0042] Among them, the production time can be understood as the number of days produced. The preset production time threshold can be pre-set based on experience, such as 90 days, and this embodiment does not limit it. The actual cumulative daily gas production can be understood as the sum of the daily gas production from the first day of the shale gas well production to the current number of days. For example, if the shale gas well is put into production for 30 days, the actual cumulative daily gas production is the sum of the daily gas production for 30 days. The casing pressure can be understood as the casing pressure, which is the residual pressure after the flow pressure lifts the oil and gas from the bottom of the well through the annular space between the oil and casing to the wellhead. The reference cumulative daily gas production can be understood as the sum of all daily gas production within the production time on the daily gas production reference curve. The first predicted daily gas production can be understood as the daily gas production corresponding to the future predicted time point on the daily gas production reference curve. The first predicted time point can be understood as the time point for predicting the gas production of the shale gas well within the future time range based on the current time point. The second predicted daily gas production can be understood as the daily gas production that the shale gas well may produce at the first predicted time point.

[0043] Exemplarily, when the production time reaches the preset production time threshold, the sum of the daily gas production of the production days is determined as the actual cumulative daily gas production corresponding to the production days; it is expressed by the following formula:

[0044]

[0045] Among them, Q i (n) is the cumulative gas production of the i-th well in production, corresponding to the production time n, in m 3 ;q i (t) is the daily gas production of the i-th well that has been put into production corresponding to the actual production time t;

[0046] The actual pressure drop-time integral corresponding to the production time is determined according to the actual casing pressure data of the shale gas well that has been put into production, and is expressed by the following formula:

[0047] S i (n) = ∫1 n P i (t)dt-∫1 n P i (n)dt

[0048] Among them, S i (n) is the actual pressure drop-time integral corresponding to the production time n of the i-th production well, in MPa·d; P i (t) is the pressure corresponding to the different production time of the i-th well, MPa; P i (n) is the average pressure level corresponding to the production time n of the i-th well, in MPa.

[0049] It is worth noting that since the corresponding pressure of the production well has been in production for n hours, it may have abnormal values ​​due to shut-in or other measures. We extend a data point forward and take all the data points (P i (n-a+1), P i (n-a+2), P i (n-a+1)……P i (n-2), P i (n-1), P i (n)), the M50 statistical method is used to determine the average pressure level corresponding to the actual production time n. For example, if n is 100, the M50 statistical method is used to delete the first 25 values ​​and the last 25 values, and only the remaining 50 middle values ​​are retained for summing and averaging. Wherein, a is the total number of forward extended data, and the value range of a can be set according to experience, such as 6 to 10, and this embodiment does not limit it.

[0050] Specifically, based on the daily gas production reference curve, the reference cumulative daily gas production corresponding to the production time and the first predicted daily gas production corresponding to the predicted time point on the daily gas production reference curve are determined; wherein the calculation formula of the reference cumulative daily gas production corresponding to the production time is as follows:

[0051]

[0052] Among them, Q s (n) is the reference cumulative daily gas production corresponding to the production time n; n is the production time; q s (t) is the daily gas production per unit fracturing section length corresponding to the actual production time t of the well that has been put into production.

[0053] The reference pressure drop-time integral corresponding to the production time is determined based on the pressure data reference curve. The calculation formula of the reference pressure drop-time integral corresponding to the production time is as follows:

[0054] S D (n) = ∫1 n P D (t)dt-∫1 n P D (n)dt

[0055] Among them, S D (n) is the reference pressure drop-time integral when the production time is n, the unit is MPa·d; P D (n) is the pressure value on the corresponding pressure data curve when the production time is n, in MPa.

[0056] Optionally, the product obtained by multiplying the first predicted daily gas production, the first ratio of the actual cumulative daily gas production to the reference cumulative daily gas production, and the second ratio of the actual pressure drop-time integral to the reference pressure drop-time integral and the fracturing section length is used as the second predicted daily gas production of the put into production shale gas well at the predicted time point. The specific calculation formula is as follows:

[0057]

[0058] Among them, q i (n+k) is the daily gas production of the ith well that has been put into production for predicted production time n+k; the unit is m 3 / d; k is the predicted time point in the future time range, k = (1, 2, 3...); q S (n+k) is the daily gas production corresponding to the production time n+k in the daily gas production reference curve, in m 3 / (d·m); is the length of the fracturing section of the i-th well that has been put into production.

[0059] Optionally, after determining the production time of the shale gas well that has been put into production based on the first predicted time point corresponding to the shale gas well that has been put into production, it also includes: when the production time is shorter than a preset production time threshold, determining the second predicted daily gas production of the shale gas well that has been put into production at the first predicted time point based on the length of the fracturing section of the shale gas well that has been put into production and the first predicted daily gas production.

[0060] For example, if the preset production time threshold is 90 days, when the production time is less than 90 days, the daily gas production of the shale gas well decreases rapidly and fluctuates greatly in the initial stage of production. The future daily gas production can be directly predicted using the reference curve of the fracturing section length of the well in production and the daily gas production per unit fracturing section length. The calculation formula is as follows:

[0061]

[0062] Among them, q i (n+k) is the predicted daily gas production of shale gas wells with a production time of less than 90 days, in m 3 / d;q S (n+k) is the daily gas production corresponding to the production time n+k in the daily gas production reference curve, in m 3 / (d·m); It is the length of the fracturing section of the gas well with production time n less than 90 days for the i-th well, in meters.

[0063] Optionally, determining the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve includes: when the shale gas well to be predicted is a drilled but unproduced shale gas well, determining the target well type corresponding to the drilled but unproduced shale gas well and the second predicted time point corresponding to the drilled but unproduced shale gas well, wherein the target well type is a drilling well, a completed well or a fracturing well; determining the third predicted daily gas production of the drilled but unproduced shale gas well corresponding to the second predicted time point based on the daily gas production reference curve; determining the single well horizontal section length of the drilled but unproduced shale gas well based on the target well type, and determining the cumulative fracturing section length and the cumulative horizontal section length of the produced shale gas wells in the target block; determining the fourth predicted daily gas production of the drilled but unproduced shale gas well based on the third predicted daily gas production, the single well horizontal section length, the cumulative fracturing section length and the cumulative horizontal section length.

[0064] The third predicted daily gas production can be understood as the predicted daily gas production of the well being drilled, and the fourth predicted daily gas production can be understood as the predicted daily gas production of the completed well or the fractured well.

[0065] Specifically, when it is determined that the shale gas well to be predicted is a shale gas well that has been drilled but not put into production, the target well type to which the shale gas well to be predicted belongs is determined, and based on different target well types, its predicted daily gas production is determined in different ways.

[0066] In an embodiment of the present invention, when the shale gas well to be predicted is a drilled but not yet put into production shale gas well, the target well type corresponding to the shale gas well to be predicted is determined, and the corresponding calculation method is determined according to the target well type, so as to accurately calculate the predicted daily gas production of the shale gas well to be predicted, thereby improving the accuracy of the daily gas production prediction.

[0067] Optionally, determining the single-well horizontal section length of the drilled but unproduced shale gas well based on the target well type includes: when the target well type is the drilling well, obtaining the preset horizontal section length of the drilling well as the single-well horizontal section length of the drilled but unproduced shale gas well; when the target well type is the completed well or the fractured well, obtaining the actual completed horizontal section length of the completed well or the fractured well as the single-well horizontal section length of the drilled but unproduced shale gas well.

[0068] Specifically, when the target well type is the drilling well, since the gas well has not been completed, the actual length when the drilling is completed cannot be accurately obtained. Therefore, the pre-set drilling horizontal section length is used as the single well horizontal section length; when the target well type is a completed well or a fracturing well, the actual completed horizontal section length of the completed well or the fracturing well is obtained as the single well horizontal section length of the drilled but unproduced shale gas well.

[0069] For example, the predicted daily gas production of the well being drilled is determined based on the designed horizontal section length of the well being drilled, the cumulative fracturing section length of the wells that have been put into production, and the cumulative horizontal section length of the wells that have been put into production in the target block. Assuming there are j wells that have been drilled but not put into production:

[0070]

[0071] Among them, q Drilling (t) is the predicted daily gas production of the well being drilled, in m 3 / d; L is the daily gas production per unit fracturing stage length corresponding to the actual production time t of the i-th well in production; LD Design the horizontal section length for the well being drilled; is the cumulative length of the fracturing stages of the wells in production in the target block, in meters; It is the cumulative horizontal length of the wells that have been put into production in the target block, in meters.

[0072] Production forecast for completed wells and fractured wells is made using the actual completed horizontal section length and horizontal section length fracture utilization rate:

[0073]

[0074] q rest (t) is the daily gas production of completed wells and fractured wells, in m 3 / d;L LA The actual length of the horizontal section of the completed well or fractured well, m. is the cumulative length of the fracturing stages of the wells in production in the target block, in meters; It is the cumulative horizontal length of the wells that have been put into production in the target block, in meters.

[0075] Optionally, determining the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve includes: in the case where the shale gas well to be predicted is a planned deployment well, determining the fifth predicted daily gas production corresponding to the planned deployment well at a third prediction time point based on the daily gas production reference curve; determining the cumulative fracturing section length and the cumulative horizontal section length of all the shale gas wells that have been put into production in the target block, and determining the horizontal level section length corresponding to the planned deployment well based on the actual completed horizontal section length of the shale gas wells that have been put into production; and determining the sixth predicted daily gas production of the planned deployment well based on the fifth predicted daily gas production, the horizontal level section length, the cumulative fracturing section length and the cumulative horizontal section length.

[0076] Among them, the sixth predicted daily gas production can be understood as the predicted daily gas production of the wells deployed in the block.

[0077] For example, assuming that w wells need to be deployed in the block in the next year, the single well production is predicted based on the average completed horizontal section length and the average horizontal section length fracturing utilization rate of the block. The specific calculation formula is as follows:

[0078]

[0079] Among them, q Deploy (t) The predicted daily gas production of the planned wells, in m 3 / d; is the daily gas production per unit fracturing stage length corresponding to the actual production time t of the i-th well that has been put into production; w is the number of planned deployment wells; is the cumulative horizontal length of the wells in production in the target block, in meters; It is the cumulative length of the fracturing sections of the wells that have been put into production in the target block, in meters.

[0080] The technical solution of the embodiment of the present invention obtains the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in the target block that have been put into production; accurately obtains the associated data of the shale gas wells that have been put into production; then, based on the fracturing section length, original daily gas production and original pressure data, respectively constructs a daily gas production reference curve and a pressure data reference curve; based on the associated data of the shale gas wells that have been put into production, the daily gas production reference curve and the pressure data reference curve can be accurately constructed; finally, the shale gas wells to be predicted in the target block are determined, and the target predicted daily gas production of the shale gas wells to be predicted is determined based on the daily gas production reference curve and the pressure data reference curve, thereby solving the problem of low accuracy in geological reserve prediction of shale gas wells and achieving the beneficial effect of improving the accuracy in geological reserve prediction of shale gas wells.

[0081] Embodiment 2

[0082] Figure 2aA flow chart of a method for predicting the gas production of a single shale gas well provided in Example 2 of the present invention is a further refinement of how to construct a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, original daily gas production and original pressure data in this embodiment and the above-mentioned embodiment. Optionally, the daily gas production reference curve and the pressure data reference curve are respectively constructed based on the fracturing section length, the original daily gas production and the original pressure data, including: determining the target daily gas production and target pressure data of the shale gas well in production based on the original daily gas production and the original pressure data corresponding to the shale gas well in production; for each shale gas well in production, determining the daily gas production per unit fracturing section based on the target daily gas production and the fracturing section length; for each production time point, determining the reference daily gas production corresponding to the production time point based on at least part of the daily gas production per unit fracturing section corresponding to multiple shale gas wells in production, and constructing a daily gas production reference curve based on the reference daily gas production corresponding to multiple production time points; determining the reference pressure data corresponding to the production time point based on at least part of the target pressure data corresponding to multiple shale gas wells in production, and constructing a pressure data reference curve based on the reference pressure data corresponding to multiple production time points.

[0083] like Figure 2a As shown, the method includes:

[0084] S210, obtaining the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in production in the target block.

[0085] S220. Determine the target daily gas production and target pressure data of the shale gas well that has been put into production based on the original daily gas production and the original pressure data corresponding to the shale gas well that has been put into production.

[0086] The target daily gas production can be understood as valid daily gas production data, and the target pressure data can be understood as valid pressure data.

[0087] Specifically, based on all original daily gas production and original pressure data corresponding to the shale gas wells that have been put into production, effective daily gas production data and effective pressure data are screened out.

[0088] Optionally, the target daily gas production and target pressure data of the shale gas well that has been put into production are determined based on the original daily gas production and the original pressure data corresponding to the shale gas well that has been put into production, including: taking the original daily gas production of the shale gas well that has been put into production as a benchmark, eliminating the data that is zero in the original daily gas production, and obtaining the target daily gas production of the shale gas well that has been put into production; eliminating the original pressure data corresponding to the eliminated original daily gas production, and obtaining the target pressure data of the shale gas well that has been put into production.

[0089] Specifically, taking the daily gas production data of shale gas wells as a benchmark, the data with zero daily gas production are eliminated to form the continuous daily gas production and pressure data of each shale gas well, and the data are sorted in sequence and recorded as the production time. The production time is marked as 1, 2, 3..., and the unit of the production time is day.

[0090] In the embodiment of the present invention, by eliminating the data with zero daily gas production, it is avoided that the data with zero daily gas production due to well shut-in or other conditions affects the accuracy of daily gas production prediction, thereby improving the accuracy of gas production prediction.

[0091] S230: For each of the shale gas wells in production, determine the daily gas production per unit fracturing stage based on the target daily gas production and the length of the fracturing stage.

[0092] Specifically, based on the continuous daily gas production data of each shale gas well and the specific fracturing section length, the daily gas production data corresponding to the unit fracturing section length of each well is obtained. For example, assuming that m wells have been put into production in the target block:

[0093]

[0094] in, is the daily gas production per unit fracturing section length corresponding to the actual production time t of the i-th well in production, m 3 / (d·m); t is the actual production time after eliminating the data of zero daily gas production, d, t = (1, 2, 3...); q i (t) is the daily gas production of the ith well that has been put into production corresponding to the actual production time t, in m 3 / d,t=(1,2,3...); is the actual fracturing section length of the i-th well that has been put into production, m, i = (1, 2, 3...m).

[0095] Optionally, the M50 statistical method is used to process the daily gas production and pressure data of each unit fracturing section length corresponding to each production time, and finally obtain the reference daily gas production and reference pressure data corresponding to each production time point. The actual production time t corresponding to the daily gas production of the unit fracturing section length of all the wells that have been put into production The M50 statistical value at time t is the pressure of all the wells in production (P 1 (t), P 2 (t), P 3 (t)……P m-2 (t), P m-1 (t), P mThe M50 statistical method is to sort the daily gas production and pressure data of all unit fracturing section lengths corresponding to each production time from large to small and calculate the arithmetic mean of the data in the interval from 25% to 75% as the daily gas production and pressure of the unit fracturing section length corresponding to the production time. According to the above statistical process, the reference daily gas production and reference pressure data of the wells in the target area that have been put into production are finally obtained, and q S (t) represents the daily gas production corresponding to the tth day of the reference gas production curve for unit fracturing section length, m 3 / (d·m); P D (t) represents the pressure corresponding to time t of the pressure data reference curve, MPa.

[0096] S240. For each production time point, determine a reference daily gas production corresponding to the production time point based on the daily gas production of at least part of the unit fracturing stages corresponding to the multiple shale gas wells that have been put into production, and construct a daily gas production reference curve based on the reference daily gas production corresponding to the multiple production time points.

[0097] Specifically, the actual reference daily gas production per unit fracturing section length that has been obtained is curve fitted and extrapolated, and finally a continuous and smooth reference gas production curve per unit fracturing section length is obtained for the target block. The daily gas production of shale gas wells rises in a short period of time at the beginning of production, and then quickly enters a decreasing stage after reaching the peak value. For the reference daily gas production per unit fracturing section length data of the target block that has been obtained, the initial production increase stage is eliminated, and a curve fitting is performed for the peak daily gas production data per unit fracturing section length. Curve fitting is performed for the reference pressure data of the target block that is actually obtained. Fitting formula for reference daily gas production per unit fracturing section length:

[0098]

[0099] Among them, q S (t) is the daily gas production per unit fracturing section length. The daily gas production on the production curve corresponds to the daily gas production on the tth day, in m 3 / (d·m). C1, C2, C3, C4, and C5 are the coefficients to be solved.

[0100] Specifically, the reference daily gas production corresponding to the multiple production time points determined above is substituted into the fitting formula of the reference daily gas production per unit fracturing stage length to obtain the value of t. S (t) is the daily gas production of the unit fracturing section length reference daily gas production curve corresponding to the daily gas production on the tth day. S (t) and t values, the q at multiple production time points is calculated. S Substituting (t) and t value into the fitting formula of reference daily gas production per unit fracturing section length, the coefficient values ​​of C1, C2, C3, C4 and C5 can be obtained.

[0101] S250. Determine reference pressure data corresponding to the production time point based on at least part of the target pressure data corresponding to the multiple shale gas wells that have been put into production, and construct a pressure data reference curve based on the reference pressure data corresponding to the multiple production time points.

[0102] Specifically, curve fitting and extrapolation are performed on the actual reference pressure data that has been obtained, and finally a continuous and smooth pressure data reference curve of the target block is obtained. The pressure data reference curve fitting formula is:

[0103]

[0104] Among them, P D (t) is the pressure corresponding to time t of the pressure data reference curve, in MPa.

[0105] C6, C7, C8, C9, C 10 are the coefficients to be solved.

[0106] Specifically, the reference pressure data corresponding to the multiple production time points determined above are substituted into the pressure data reference curve fitting formula to obtain the value of t. D (t) is the pressure data reference curve corresponding to the pressure at time t. When P is known D (t) and t value, P at multiple production time points D Substituting the (t) and t values ​​into the fitting formula of the reference daily gas production per unit fracturing section length, we can obtain C6, C7, C8, C9, C 10 The coefficient value of .

[0107] In the process of fitting the daily gas production reference curve and the pressure data reference curve, the fitting accuracy control parameters are the determination coefficient and the adjustment determination coefficient, and the control condition is R 2 >0.9 and R 2 (Adj)>0.9, interpolation processing is performed when the fitting accuracy meets the control conditions.

[0108] The calculation formula of the coefficient of determination is as follows:

[0109]

[0110] Among them, y is the actual observed daily gas production value; To predict the daily gas production value by regression, is the average of all actual observations.

[0111] The formula for calculating the adjusted determination coefficient is as follows:

[0112]

[0113] Among them, k is the number of data points in the data set, and p is the number of independent variables (including constant terms) in the regression equation. After the fitting accuracy meets the above conditions, the daily gas production reference curve per unit fracturing section length and the pressure data reference curve are extrapolated for iterative production prediction.

[0114] S260, determining the shale gas wells to be predicted in the target block, and determining the target predicted daily gas production of the shale gas wells to be predicted based on the daily gas production reference curve and the pressure data reference curve.

[0115] Optionally, the method further includes: obtaining the shale gas wells to be counted in the target block, wherein the shale gas wells to be counted include the shale gas wells that have been put into production, the shale gas wells that have been drilled but not put into production, and the planned deployment wells; determining the average production time rate corresponding to the target block based on the historical production time of the shale gas wells that have been put into production, wherein the average production time rate is associated with the natural time and the actual production time; for each shale gas well to be counted, determining the target predicted production time period corresponding to the shale gas well to be counted based on the preset production prediction time, the average production time rate and the production date corresponding to the shale gas well to be counted; determining the single well predicted production of each shale gas well to be counted in its corresponding target predicted production time period, and determining the target block production of the target block at the production prediction time based on the single well predicted production corresponding to all the shale gas wells to be counted in the target block.

[0116] Specifically, if the shale gas wells to be counted include the shale gas wells that have been put into production, the predicted future production for a single well is continuous production data, and the predicted production needs to be batched into natural years according to the average production time rate of the target block. The remaining effective production time of a given well in production in a year is the product of the natural production time of the year and the average production time rate of the target block minus the actual effective production time of the year, and the actual production time of subsequent years is the product of the average production time rate and the natural year time. If the shale gas wells to be counted include wells that have been drilled but not put into production. The predicted production is superimposed, and each well that has been drilled but not put into production is assigned a production date based on the drilling date and the average well construction cycle of the actual wells in the target block (the shale gas well from drilling to production cycle). If the shale gas wells to be counted include planned deployment wells, they are evenly distributed to be drilled at the beginning of each month in the next year, and the predicted production of each planned deployment well is assigned a designated production date based on the assigned drilling date and the average well construction cycle of the target block. The production scale of the target block consists of three parts, including the predicted production of the wells that have been put into production, the predicted production of the wells that have been drilled but not put into production (drilling wells and fracturing wells), and the predicted production of the planned wells. The production scale of the target block production forecast profile can be automatically adjusted according to the number of wells to be deployed in the future, providing a basis for the future capacity construction deployment and long-term planning of shale gas reservoirs in a timely manner.

[0117] The embodiment of the present invention determines the target daily gas production and target pressure data of the put-in-production shale gas well based on the original daily gas production and the original pressure data corresponding to the put-in-production shale gas well; the valid data in the original data can be accurately determined; then, for each of the put-in-production shale gas wells, the unit fracturing stage daily gas production is determined based on the target daily gas production and the length of the fracturing stage; the unit fracturing stage daily gas production corresponding to the put-in-production shale gas well is accurately determined based on the valid data; then, for each production time point, the reference daily gas production corresponding to the production time point is determined based on at least part of the unit fracturing stage daily gas production corresponding to multiple put-in-production shale gas wells, and a daily gas production reference curve is constructed based on the reference daily gas production corresponding to multiple production time points; a daily gas production reference curve containing the reference daily gas production corresponding to multiple time points is constructed; finally, the reference pressure data corresponding to the production time point is determined based on at least part of the target pressure data corresponding to multiple put-in-production shale gas wells, and a pressure data reference curve is constructed based on the reference pressure data corresponding to multiple production time points. A more accurate daily gas production reference curve and pressure data reference curve were determined, providing a reference basis for the subsequent accurate prediction of daily gas production, thereby improving the accuracy of daily gas production prediction.

[0118] Figure 2b A flowchart of an optional example of a method for predicting gas production of a single shale gas well is provided. Figure 2b As shown, the method for predicting the gas production of a single shale gas well may specifically include the following steps:

[0119] (1) Basic data preparation

[0120] ① Production data preparation: Obtain static data such as the horizontal section length and fracturing section length of the shale gas wells that have been put into production in the target block, and dynamic data such as daily gas production and pressure;

[0121] ② Basic data processing: Taking the daily gas production data of shale gas wells as the benchmark, the data with zero daily gas production (well shut-in) are eliminated to form the continuous daily gas production and pressure data of each shale gas well, and the data are sorted in sequence and recorded as the production time. The production time is marked as 1, 2, 3..., in days;

[0122] ③ Calculation of unit gas production: Calculate the daily gas production data of each shale gas well per unit fracturing section length using the continuous daily gas production data of each shale gas well obtained in step ② and the specific fracturing section length. Assuming that m wells have been put into production in the target block:

[0123]

[0124] in, is the daily gas production per unit fracturing section length corresponding to the actual production time t of the i-th well in production, m 3 / (d·m); t is the production time after excluding the data with zero daily gas production, d, t = (1, 2, 3...); q i (t) is the daily gas production of the ith well that has been put into production corresponding to the actual production time t, in m 3 / d,t=(1,2,3...); is the actual fracturing section length of the i-th well that has been put into production, m, i = (1, 2, 3...m).

[0125] ④Unit data processing: Use the M50 statistical method to process the daily gas production and pressure data of the unit fracturing section length corresponding to each production time, and finally obtain the reference daily gas production and reference pressure data corresponding to each production time point. The actual production time t corresponding to the unit fracturing section length daily gas production of all the wells that have been put into production The M50 statistical value at time t is the pressure of all the wells in production (P 1 (t), P 2 (t), P 3 (t)……P m-2 (t), P m-1 (t), P m The M50 statistical method is to sort the daily gas production and pressure data of all unit fracturing section lengths corresponding to each production time from large to small and calculate the arithmetic mean of the data in the interval from 25% to 75% as the daily gas production and pressure of the unit fracturing section length corresponding to the production time. According to the above statistical process, the reference daily gas production and reference pressure data of the wells in the target area that have been put into production are finally obtained, and q S (t) represents the daily gas production corresponding to the tth day of the reference gas production curve for unit fracturing section length, m 3 / (d·m); P D (t) represents the pressure corresponding to time t of the pressure data reference curve, MPa.

[0126] ⑤ Data fitting of reference curve of daily gas production per unit fracturing section length and reference curve of pressure data

[0127] Figure 2c A sample schematic diagram of a daily gas production reference curve of an optional example of a method for predicting gas production of a single shale gas well is provided. Figure 2cAs shown, the actual reference daily gas production per unit fracturing section length that has been obtained is curve fitted and extrapolated, and finally a continuous and smooth reference gas production curve per unit fracturing section length is obtained for the target block. The daily gas production of shale gas wells rises in a short period of time at the beginning of production, and then quickly enters a decreasing stage after reaching the peak value. For the reference daily gas production per unit fracturing section length data of the target block that has been obtained, the initial production increase stage is eliminated, and a curve fitting is performed for the peak daily gas production data per unit fracturing section length. Curve fitting is performed for the reference pressure data of the target block that is actually obtained. Fitting formula for reference daily gas production per unit fracturing section length:

[0128]

[0129] Among them, q S (t) is the daily gas production corresponding to the tth day in the daily gas production reference curve of unit fracturing section length, in m 3 / (d·m). C1, C2, C3, C4, and C5 are the coefficients to be solved.

[0130] Specifically, the reference daily gas production corresponding to the multiple production time points determined above is substituted into the reference daily gas production fitting formula per unit fracturing stage length to obtain the value of t. S (t) is the daily gas production of the unit fracturing section length reference daily gas production curve corresponding to the daily gas production on the tth day. s (t) and t value, q s Substituting (t) and t value into the fitting formula of reference daily gas production per unit fracturing section length, the coefficient values ​​of C1, C2, C3, C4 and C5 can be obtained.

[0131] Figure 2d A sample schematic diagram of a pressure data reference curve of an optional example of a method for predicting gas production of a single shale gas well is provided. Figure 2d As shown, the actual reference pressure data that has been obtained is curve fitted and extrapolated, and finally a continuous and smooth pressure data reference curve of the target block is obtained. The pressure data reference curve fitting formula is:

[0132]

[0133] Among them, P D (t) is the pressure corresponding to time t of the pressure data reference curve, in MPa.

[0134] C6, C7, C8, C9, C 10 are the coefficients to be solved.

[0135] Specifically, the reference pressure data corresponding to the multiple production time points determined above are substituted into the pressure data reference curve fitting formula to obtain the value of t. D(t) is the pressure data reference curve corresponding to the pressure at time t. When P is known D (t) and t value, P D Substituting the (t) and t values ​​into the fitting formula of the reference daily gas production per unit fracturing section length, we can obtain C6, C7, C8, C9, C 10 The coefficient value of .

[0136] In the process of fitting the daily gas production curve and the pressure data reference curve, the fitting accuracy control parameters are the determination coefficient and the adjustment determination coefficient, and the control condition is R 2 >0.9 and R 2 (Adj)>0.9, interpolation processing is performed when the fitting accuracy meets the control conditions.

[0137] The calculation formula of the coefficient of determination is as follows:

[0138]

[0139] Among them, y is the actual observed daily gas production value; To predict the daily gas production value by regression, is the average of all actual observations.

[0140] The formula for calculating the adjusted determination coefficient is as follows:

[0141]

[0142] Among them, k is the number of data points in the data set, and p is the number of independent variables (including constant terms) in the regression equation. After the fitting accuracy meets the above conditions, the reference daily gas production curve per unit fracturing section length and the pressure data reference curve are extrapolated for iterative production prediction.

[0143] ⑥ Calculate the actual cumulative gas production and pressure drop-time integral of the wells that have been put into production

[0144] Assume that the actual production time of the well in production is n.

[0145]

[0146] Among them, Q i (n) is the cumulative gas production of the ith well in production corresponding to the actual production time n, in m 3 ;q i (t) is the daily gas production of the i-th well that has been put into production corresponding to the actual production time t;

[0147] The actual pressure drop-time integral corresponding to the production time is determined according to the actual casing pressure data of the shale gas well that has been put into production, and is expressed by the following formula:

[0148] S i (n) = ∫1n P i (t)dt-∫1 n P i (n)dt

[0149] Among them, S i (n) is the actual pressure drop-time integral corresponding to the production time n of the i-th production well, in MPa·d; P i (t) is the pressure corresponding to the different production time of the i-th well, MPa; P i (n) is the average pressure level corresponding to the production time n of the i-th well, in MPa.

[0150] It is worth noting that since the corresponding pressure of the production well has been in production for n hours, it may have abnormal values ​​due to shut-in or other measures. We extend a data point forward and take all the data points (P i (n-a+1), P i (n-a+2), P i (n-a+1)……P i (n-2), P i (n-1), P i (n)), the M50 statistical method is used to determine the average pressure level corresponding to the actual production time n. For example, if n is 100, the M50 statistical method is used to delete the first 25 values ​​and the last 25 values, and only the remaining 50 middle values ​​are retained for summing and averaging. Wherein, a is the total number of forward extended data, and the value range of a can be set according to experience, such as 6 to 10, which is not limited in this embodiment.

[0151] (2) Production forecast of wells already in production

[0152] ① The production time of the i-th well that has been put into production is n. Calculate the reference daily gas production per unit fracturing section length and the reference cumulative daily gas production per unit fracturing section length and the reference pressure drop-time integral corresponding to the production time n:

[0153] The calculation formula for the reference cumulative daily gas production corresponding to the production time is as follows:

[0154]

[0155] Among them, Q s (n) is the reference cumulative daily gas production corresponding to the production time n; n is the production time; q s (t) is the daily gas production per unit fracturing section length corresponding to the actual production time t of the well that has been put into production.

[0156] The reference pressure drop-time integral corresponding to the production time is determined based on the pressure data reference curve. The calculation formula of the reference pressure drop-time integral corresponding to the production time is as follows:

[0157] S D (n) = ∫1 n P D (t)dt-∫1 n P D (n)dt

[0158] Among them, S D (n) is the reference pressure drop-time integral when the production time is n, the unit is MPa·d; P D (n) is the pressure value on the corresponding pressure data curve when the production time is n, in MPa.

[0159] ② The product obtained by multiplying the first predicted daily gas production, the first ratio of the actual cumulative daily gas production to the reference cumulative daily gas production, and the second ratio of the actual pressure drop-time integral to the reference pressure drop-time integral and the length of the fracturing section is used as the second predicted daily gas production of the put-in-production shale gas well at the predicted time point. Exemplarily, based on all the production history data corresponding to the production time n, the future daily gas production of the put-in-production wells whose actual production time satisfies n≥90d (days) is predicted:

[0160]

[0161] Among them, q i (n+k) is the daily gas production of the ith well that has been put into production for predicted production time n+k; the unit is m 3 / d; k is the predicted time point in the future time range, k = (1, 2, 3...); q S (n+k) is the daily gas production corresponding to the production time n+k in the daily gas production reference curve, in m 3 / (d·m); is the length of the fracturing section of the i-th well that has been put into production.

[0162] ③ When the production time is shorter than the preset production time threshold, the second predicted daily gas production of the produced shale gas well at the first predicted time point is determined based on the length of the fracturing section of the produced shale gas well and the first predicted daily gas production. For example, when the well has been put into production and the actual production time n<90d (days), the daily gas production of the gas well decreases rapidly and fluctuates greatly at the initial stage of production. The future daily gas production can be directly predicted using the reference curve of the fracturing section length of the produced well and the daily gas production per unit fracturing section length. The calculation formula is as follows:

[0163]

[0164] Among them, q i (n+k) is the predicted daily gas production of shale gas wells with a production time of less than 90 days, in m 3 / d;q S (n+k) is the daily gas production corresponding to the production time n+k in the daily gas production reference curve, in m 3 / (d·m); It is the length of the fracturing section of the gas well with production time n less than 90 days for the i-th well, in meters.

[0165] (2) Production forecast of drilled but unproduced wells

[0166] In the actual development of shale gas reservoirs, the wells that have been drilled but not put into production include wells being drilled, completed wells and fracturing wells. The wells being drilled directly use the product of the unit fracturing section length reference daily gas production fitting extrapolation data, the designed horizontal section length and the horizontal section length fracturing utilization rate of the block to predict the daily production. Assuming there are j wells that have been drilled but not put into production:

[0167]

[0168] Among them, q Drilling (t) is the predicted daily gas production of the well being drilled, in m 3 / d; L is the daily gas production per unit fracturing stage length corresponding to the actual production time t of the i-th well in production; LD Design the horizontal section length for the well being drilled; is the cumulative length of the fracturing stages of the wells in production in the target block, in meters; It is the cumulative horizontal length of the wells that have been put into production in the target block, in meters.

[0169] Production forecast for completed wells and fractured wells is made using the actual completed horizontal section length and horizontal section length fracture utilization rate:

[0170]

[0171] q rest (t) is the daily gas production of completed wells and fractured wells, in m 3 / d;L LA The actual length of the horizontal section of the completed well or fractured well, m. is the cumulative length of the fracturing stages of the wells in production in the target block, in meters; It is the cumulative horizontal length of the wells that have been put into production in the target block, in meters.

[0172] (3) Production forecast of planned wells

[0173] For example, assuming that w wells need to be deployed in the block in the next year, the single well production is predicted based on the average completed horizontal section length and the average horizontal section length fracturing utilization rate of the block. The specific calculation formula is as follows:

[0174]

[0175] Among them, q Deploy (t) The predicted daily gas production of the planned wells, in m 3 / d; is the daily gas production per unit fracturing stage length corresponding to the actual production time t of the i-th well that has been put into production; w is the number of planned deployment wells; is the cumulative horizontal length of the wells in production in the target block, in meters; It is the cumulative length of the fracturing sections of the wells that have been put into production in the target block, in meters.

[0176] (4) Output superposition of target blocks

[0177] ① The predicted daily gas production of the wells that have been put into production is superimposed. The predicted future production of a single well is continuous production data. The predicted production needs to be batched into natural years according to the average production time rate of the target block. The remaining effective production time of a given well in production in a year is the product of the natural production time of the year and the average production time rate of the target block minus the actual effective production time of the year. The actual production time in subsequent years is the product of the average production time rate and the natural year time.

[0178] ② The predicted production of the drilled but unproduced wells is superimposed. Each drilled but unproduced well is assigned a production date based on the drilling date and the average well construction cycle of the actual producing wells in the target block (the period from drilling to production of shale gas wells);

[0179] ③ The planned wells are evenly distributed to be drilled at the beginning of each month in the next year, and the predicted production of each planned well is assigned a designated production date based on the assigned drilling date and the average well construction cycle of the target block;

[0180] ④ The production scale of the target block consists of three parts, including the predicted production of the wells that have been put into production, the predicted production of the wells that have been drilled but not put into production (drilling wells and fracturing wells), and the predicted production of the planned wells. The production scale of the target block production forecast profile can be automatically adjusted according to the number of wells to be deployed in the future, providing a basis for the future capacity construction deployment and long-term planning of shale gas reservoirs in a timely manner.

[0181] The embodiment of the present invention predicts the future production of the wells that have been put into production, the wells that are being drilled but not put into production, and the planned wells through iterative learning of the production data of the wells that have been put into production in the target block, and superimposes the future production scale according to the production timeliness and well construction cycle, and dynamically predicts the overall production scale and the workload of the planned wells. Taking into account the dynamic changes in the update of production history data and the number of wells with different attributes, the dynamic real-time prediction of the production scale of shale gas reservoirs and the annual workload of the wells to be deployed is achieved, and the future production scale can be predicted in time according to the workload of the planned wells to improve the accuracy of reserve prediction.

[0182] Embodiment 3

[0183] Figure 3 This is a schematic diagram of the structure of a shale gas single well gas production prediction device provided in Example 3 of the present invention. Figure 3 As shown, the device includes: a data acquisition module 310, a curve construction module 320 and a gas production prediction module 330.

[0184] Among them, the data acquisition module 310 is used to obtain the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells that have been put into production in the target block; the curve construction module 320 is used to construct a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, original daily gas production and original pressure data respectively; the gas production prediction module 330 is used to determine the shale gas wells to be predicted in the target block, and determine the target predicted daily gas production of the shale gas wells to be predicted based on the daily gas production reference curve and the pressure data reference curve.

[0185] The technical solution of the embodiment of the present invention obtains the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in the target block through a data acquisition module; accurately obtains the associated data of the shale gas wells in production; then, through a curve construction module, respectively constructs a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, original daily gas production and original pressure data; based on the associated data of the shale gas wells in production, the daily gas production reference curve and the pressure data reference curve can be accurately constructed; finally, through a gas production prediction module, the shale gas wells to be predicted in the target block are determined, and the target predicted daily gas production of the shale gas wells to be predicted is determined based on the daily gas production reference curve and the pressure data reference curve, thereby solving the problem of low accuracy in geological reserve prediction of shale gas wells and achieving the beneficial effect of improving the accuracy in geological reserve prediction of shale gas wells.

[0186] Optionally, the curve construction module includes:

[0187] A target gas volume and pressure acquisition unit, configured to determine the target daily gas volume and target pressure data of the shale gas well that has been put into production based on the original daily gas volume and the original pressure data corresponding to the shale gas well that has been put into production;

[0188] A unit fracturing stage daily gas production acquisition unit, used for determining the unit fracturing stage daily gas production based on the target daily gas production and the fracturing stage length for each of the shale gas wells that have been put into production;

[0189] A daily gas production reference curve construction unit is used to determine, for each production time point, a reference daily gas production corresponding to the production time point based on the daily gas production of at least part of the unit fracturing stages corresponding to the multiple shale gas wells that have been put into production, and to construct a daily gas production reference curve based on the reference daily gas productions corresponding to the multiple production time points;

[0190] A pressure data reference curve construction unit is used to determine the reference pressure data corresponding to the production time point based on at least part of the target pressure data corresponding to the multiple shale gas wells that have been put into production, and to construct a pressure data reference curve based on the reference pressure data corresponding to the multiple production time points.

[0191] Optionally, the target gas volume and pressure acquisition unit includes:

[0192] A target daily gas production acquisition subunit is used to obtain the target daily gas production of the shale gas well in production by taking the original daily gas production of the shale gas well in production as a benchmark and eliminating the data of zero in the original daily gas production;

[0193] The target pressure data acquisition subunit is used to eliminate the original pressure data corresponding to the eliminated original daily gas production to obtain the target pressure data of the shale gas well that has been put into production.

[0194] Optionally, the gas production prediction module includes:

[0195] a production time determination unit, configured to determine the production time of the shale gas well that has been put into production based on a first prediction time point corresponding to the shale gas well that has been put into production, when the shale gas well to be predicted is the shale gas well that has been put into production;

[0196] an actual pressure drop-time integral determination unit, configured to determine the actual cumulative daily gas production corresponding to the produced time when the produced time reaches a preset production time threshold, and determine the actual pressure drop-time integral corresponding to the produced time according to the actual casing pressure data of the shale gas well that has been put into production;

[0197] a reference pressure drop-time integral determination unit, configured to determine a reference accumulated daily gas production corresponding to the production duration and a first predicted daily gas production corresponding to a predicted time point based on the daily gas production reference curve, and to determine a reference pressure drop-time integral corresponding to the production duration based on the pressure data reference curve;

[0198] The second predicted daily gas production determination unit is used to determine the second predicted daily gas production of the put into production shale gas well at the first predicted time point based on the first predicted daily gas production, the actual cumulative daily gas production, the reference cumulative daily gas production, the actual pressure drop-time integral and the reference pressure drop-time integral.

[0199] Optionally, the device also includes a second gas production prediction module.

[0200] The second gas production prediction module is used to determine the second predicted daily gas production of the put into production shale gas well at the first predicted time point based on the fracturing section length of the put into production shale gas well and the first predicted daily gas production, after determining the production time of the put into production shale gas well based on the first predicted time point corresponding to the put into production shale gas well, and when the production time is shorter than a preset production time threshold.

[0201] Optionally, the gas production prediction module includes:

[0202] An information determination unit, for determining, when the shale gas well to be predicted is a drilled but unproduced shale gas well, a target well type corresponding to the drilled but unproduced shale gas well and a second prediction time point corresponding to the drilled but unproduced shale gas well, wherein the target well type is a drilling well, a completed well or a fracturing well;

[0203] A third predicted daily gas production determination unit is used to determine a third predicted daily gas production of the drilled but unproduced shale gas well corresponding to a second predicted time point based on the daily gas production reference curve;

[0204] A cumulative segment length determination unit, configured to determine the single well horizontal segment length of the drilled but unproduced shale gas well based on the target well type, and determine the cumulative fracturing segment length and cumulative horizontal segment length of the produced shale gas well in the target block;

[0205] The fourth predicted daily gas production determination unit is used to determine the fourth predicted daily gas production of the drilled but unproduced shale gas well based on the third predicted daily gas production, the single well horizontal section length, the cumulative fracturing section length and the cumulative horizontal section length.

[0206] Optionally, the third information determining unit includes:

[0207] A first single well horizontal section length acquisition subunit is used for acquiring a preset horizontal section length of the drilling well as the single well horizontal section length of the drilled but unproduced shale gas well when the target well type is the drilling well;

[0208] The second single well horizontal section length acquisition subunit is used to obtain the actual completed horizontal section length of the completed well or the fractured well as the single well horizontal section length of the drilled but unproduced shale gas well when the target well type is the completed well or the fractured well.

[0209] Optionally, the gas production prediction module includes:

[0210] a fifth predicted daily gas production determination unit, configured to determine, when the to-be-predicted shale gas well is a planned deployment well, a fifth predicted daily gas production corresponding to the planned deployment well at a third prediction time point based on the daily gas production reference curve;

[0211] A horizontal segment length determination unit, used to determine the cumulative fracturing segment length and the cumulative horizontal segment length of all the shale gas wells that have been put into production in the target block, and determine the horizontal segment length corresponding to the planned deployment well based on the actual completed horizontal segment length of the shale gas wells that have been put into production;

[0212] The sixth predicted daily gas production determination unit is used to determine the sixth predicted daily gas production of the planned deployment well based on the fifth predicted daily gas production, the horizontal level segment length, the cumulative fracturing segment length and the cumulative horizontal segment length.

[0213] The device also includes: a module for obtaining shale gas wells to be counted, a module for obtaining an average production time rate, a module for determining a target prediction time period, and a module for determining a target block production.

[0214] The module for acquiring shale gas wells to be counted is used to acquire the shale gas wells to be counted in the target block, wherein the shale gas wells to be counted include the shale gas wells that have been put into production, the shale gas wells that have been drilled but not put into production, and the planned deployment wells;

[0215] The average production time rate acquisition module is used to determine the average production time rate corresponding to the target block based on the historical production time of the shale gas well that has been put into production, wherein the average production time rate is associated with natural time and actual production time;

[0216] The target prediction time period determination module is used to determine, for each of the shale gas wells to be counted, a target prediction time period corresponding to the shale gas well to be counted based on a preset production prediction time, the average production time rate and a production date corresponding to the shale gas well to be counted;

[0217] The target block production determination module is used to determine the single-well predicted production of each shale gas well to be counted within its corresponding target prediction time period, and determine the target block production of the target block at the production prediction time based on the single-well predicted production corresponding to all the shale gas wells to be counted in the target block.

[0218] The gas production prediction device for a shale gas well provided in an embodiment of the present invention can execute the gas production prediction method for a shale gas well provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0219] Embodiment 4

[0220] Figure 4 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0221] like Figure 4 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0222] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0223] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 11 executes the various methods and processes described above, such as a method for predicting the gas production of a single shale gas well.

[0224] In some embodiments, the method for predicting the gas production of a single shale gas well may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method for predicting the gas production of a single shale gas well described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute the method for predicting the gas production of a single shale gas well by any other appropriate means (e.g., by means of firmware).

[0225] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0226] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0227] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0228] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0229] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0230] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0231] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0232] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for predicting gas production of a single shale gas well, characterized in that: include: Obtain the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells in production in the target block; Based on the fracturing section length, the original daily gas production and the original pressure data, a daily gas production reference curve and a pressure data reference curve are respectively constructed; A shale gas well to be predicted in the target block is determined, and a target predicted daily gas production of the shale gas well to be predicted is determined based on the daily gas production reference curve and the pressure data reference curve.

2. The method according to claim 1, characterized in that The method of constructing a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, the original daily gas production and the original pressure data respectively includes: Determine the target daily gas production and target pressure data of the shale gas well that has been put into production based on the original daily gas production and the original pressure data corresponding to the shale gas well that has been put into production; For each of the shale gas wells that have been put into production, determining the daily gas production per unit fracturing stage based on the target daily gas production and the length of the fracturing stage; For each production time point, determine a reference daily gas production corresponding to the production time point based on the daily gas production of at least part of the unit fracturing stages corresponding to the multiple shale gas wells that have been put into production, and construct a daily gas production reference curve based on the reference daily gas production corresponding to the multiple production time points; Based on at least part of the target pressure data corresponding to the multiple shale gas wells that have been put into production, reference pressure data corresponding to the production time point is determined, and a pressure data reference curve is constructed based on the reference pressure data corresponding to the multiple production time points.

3. The method according to claim 2, characterized in that The determining the target daily gas production and target pressure data of the put-in-production shale gas well based on the original daily gas production and the original pressure data corresponding to the put-in-production shale gas well comprises: Taking the original daily gas production of the shale gas well that has been put into production as a benchmark, eliminating the data of zero in the original daily gas production to obtain the target daily gas production of the shale gas well that has been put into production; The original pressure data corresponding to the original daily gas production is eliminated to obtain the target pressure data of the shale gas well that has been put into production.

4. The method according to claim 1, characterized in that: The step of determining the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve includes: In a case where the shale gas well to be predicted is the shale gas well that has been put into production, determining a first prediction time point and an already produced time length corresponding to the shale gas well that has been put into production; When the production time reaches the preset production time threshold, the actual cumulative daily gas production corresponding to the production time is determined, and the actual pressure drop-time integral corresponding to the production time is determined according to the actual casing pressure data of the shale gas well that has been put into production; Determine a reference accumulated daily gas production corresponding to the production duration and a first predicted daily gas production corresponding to a predicted time point based on the daily gas production reference curve, and determine a reference pressure drop-time integral corresponding to the production duration based on the pressure data reference curve; The second predicted daily gas production of the put into production shale gas well at the first predicted time point is determined based on the first predicted daily gas production, the actual cumulative daily gas production, the reference cumulative daily gas production, the actual pressure drop-time integral and the reference pressure drop-time integral.

5. The method according to claim 4, characterized in that After determining the production time of the shale gas well that has been put into production based on the first predicted time point corresponding to the shale gas well that has been put into production, the method further includes: When the production time is shorter than the preset production time threshold, the second predicted daily gas production of the produced shale gas well at the first predicted time point is determined based on the fracturing section length of the produced shale gas well and the first predicted daily gas production.

6. The method according to claim 1, characterized in that The step of determining the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve includes: In the case that the shale gas well to be predicted is a drilled but unproduced shale gas well, a target well type corresponding to the drilled but unproduced shale gas well and a second prediction time point corresponding to the drilled but unproduced shale gas well are determined, wherein the target well type is a drilling well, a completed well, or a fracturing well; Determine, based on the daily gas production reference curve, a third predicted daily gas production of the drilled but unproduced shale gas well corresponding to the second predicted time point; Determine the horizontal section length of a single well of the drilled but unproduced shale gas well based on the target well type, and determine the cumulative fracturing section length and cumulative horizontal section length of the produced shale gas wells in the target block; The fourth predicted daily gas production of the drilled but unproduced shale gas well is determined based on the third predicted daily gas production, the single well horizontal section length, the cumulative fracturing section length and the cumulative horizontal section length.

7. The method according to claim 6, characterized in that The determining of the horizontal section length of a single well of the drilled but unproduced shale gas well based on the target well type includes: In the case where the target well type is the well being drilled, obtaining a preset horizontal section length of the well being drilled as the single well horizontal section length of the drilled but unproduced shale gas well; In the case where the target well type is the completed well or the fractured well, the actual completed horizontal section length of the completed well or the fractured well is obtained as the single well horizontal section length of the drilled but unproduced shale gas well.

8. The method according to claim 1, characterized in that: The step of determining the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve includes: In a case where the shale gas well to be predicted is a planned deployment well, determining a fifth predicted daily gas production corresponding to the planned deployment well at a third prediction time point based on the daily gas production reference curve; Determine the cumulative fracturing section length and the cumulative horizontal section length of all the shale gas wells that have been put into production in the target block, and determine the horizontal section length corresponding to the planned deployment well based on the actual completed horizontal section length of the shale gas wells that have been put into production; A sixth predicted daily gas production of the planned deployment well is determined based on the fifth predicted daily gas production, the horizontal level section length, the cumulative fracturing section length and the cumulative horizontal section length.

9. The method according to claim 1, characterized in that: Also includes: Acquire the shale gas wells to be counted in the target block, wherein the shale gas wells to be counted include the shale gas wells that have been put into production, the shale gas wells that have been drilled but not put into production, and the planned deployment wells; Determine an average production time rate corresponding to the target block based on the historical production time of the shale gas well that has been put into production, wherein the average production time rate is associated with natural time and actual production time; For each of the shale gas wells to be counted, determine a target predicted production time period corresponding to the shale gas well to be counted based on a preset production prediction time, the average production time rate and a production date corresponding to the shale gas well to be counted; The single-well predicted production of each of the shale gas wells to be counted in the corresponding target predicted production time period is determined respectively, and the target block production of the target block at the production prediction time is determined based on the single-well predicted production corresponding to all the shale gas wells to be counted in the target block.

10. A device for predicting gas production of a single shale gas well, characterized in that: include: A data acquisition module is used to obtain the fracturing section length, original daily gas production and original pressure data of multiple shale gas wells that have been put into production in the target block; A curve construction module, used to respectively construct a daily gas production reference curve and a pressure data reference curve based on the fracturing section length, the original daily gas production and the original pressure data; The gas production prediction module is used to determine the shale gas well to be predicted in the target block, and determine the target predicted daily gas production of the shale gas well to be predicted based on the daily gas production reference curve and the pressure data reference curve.

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