A shale gas well stimulation effect evaluation method

Abstract

The present application provides a kind of shale gas well stimulation effect evaluation method, comprising the following steps: obtaining the pre-treatment production of the well of stimulation implementation and the action interval of treatment;Obtain the historical production of shale gas well, according to the historical production of shale gas well and the pre-treatment production, obtain the base profile of stimulation effect evaluation;The action interval of treatment is divided into multiple time units, and the actual gas production of the well of stimulation implementation in each time unit is obtained;Obtain the influence production of each time unit, according to the influence production of each time unit, actual production and base profile, obtain the final production of each time unit, obtain the total stimulation gas production;Obtain the input cost of treatment, according to the total stimulation gas production and the input cost of treatment, calculate the input-output ratio of treatment.The beneficial effects of the present application are: it can avoid the problems such as fluctuation of existing evaluation method and general calculation, and the calculation result is more accurate and has wide coverage.

Description

Technical Field

[0001] This invention relates to the field of shale gas production dynamic analysis and production prediction technology, specifically to a method for evaluating the effectiveness of shale gas well production enhancement measures. Background Technology

[0002] In the production process of shale gas wells, corresponding production enhancement measures such as drainage and gas production technology, wellhead pressurization, well washing, and well workover must be taken to address production problems such as wellbore fluid accumulation, throttling blockage, and tubing perforation, in order to restore the gas wells to normal production. Evaluating the effectiveness of production enhancement measures is an important task in gas field production dynamic analysis and production operation management. Accurate evaluation helps to select the best and worst measures, thereby continuously improving the effectiveness and production enhancement capacity of the measures and ensuring stable gas well production. Shale gas wells have unique production dynamic characteristics; their production will successively experience rapid increases, rapid declines after reaching a peak, gradual slowdowns, and slow declines. The decline rate varies significantly at each production stage, posing a considerable challenge to evaluating the effectiveness of production enhancement measures.

[0003] To address the issue of low accuracy in evaluating the effectiveness of shale gas well enhancement measures due to significant differences in decline rates across different production stages, a comprehensive evaluation method for shale gas well enhancement measures needs to be established. A patent document titled "An Evaluation Method for the Effect of Drainage Production in Shale Gas" (Publication No. CN113550744A) proposes an evaluation method for the effect of drainage production in shale gas wells. While this method considers both daily gas production before and after the measures and the impact of decline, the decline rate fluctuates with production levels, failing to exclude the influence of objective factors beyond the process itself. The decline rate cannot reflect the actual decline pattern of the gas well, resulting in low accuracy in the calculated increased gas production. Furthermore, this method only applies to drainage production, limiting its applicability. Meanwhile, the calculation methods used in mining operations are rather general, typically employing fixed values ​​for the decline rate, which does not conform to the actual decline pattern of gas wells and fails to consider the differences in decline rates caused by different production stages of individual wells. Summary of the Invention

[0004] The purpose of this invention is to address at least one of the aforementioned shortcomings of the existing technology. For example, one objective of this invention is to propose a method for evaluating the effectiveness of shale gas well production enhancement measures. By establishing a benchmark production profile of the shale gas well at its current production stage, the method ensures that the calculation basis for the increased gas production is accurate and reliable, and that the decreasing trend conforms to the dynamic characteristics of the current production stage of the shale gas well. This avoids problems such as fluctuations in the decreasing rate and general calculations. Then, by subtracting from the actual production and deducting the production impact caused by factors other than the process itself, the calculation results are more accurate and have a wider coverage; moreover, the calculation is flexible and simple.

[0005] To achieve the above objectives, this invention proposes a method for evaluating the effectiveness of shale gas well production enhancement measures, comprising the following steps:

[0006] Obtain the pre-implementation production and the effective range of the measures from the wells where the production enhancement measures were implemented;

[0007] Obtain historical production data of shale gas wells, and based on the historical production data and pre-measure production, obtain a benchmark profile for evaluating the effectiveness of production enhancement measures;

[0008] The effective period of the measures is divided into multiple time units, and the actual gas production of the wells implementing the production enhancement measures is obtained in each time unit.

[0009] Obtain the impact output for each time unit, and based on the impact output, actual output, and baseline profile for each time unit, obtain the final output for each time unit.

[0010] The total increase in gas production is obtained by summing the final increase in production for each time unit within the effective period of the measures.

[0011] Obtain the input costs of the measures, and calculate the input-output ratio of the measures based on the total increase in gas production and the input costs of the measures;

[0012] The effectiveness of shale gas well production enhancement measures is evaluated based on the input-output ratio.

[0013] In a preferred embodiment of this solution, the formula for calculating the input-output ratio of the measure is as follows:

[0014]

[0015] In the formula, χ is the input-output ratio of the measures, and R c Let p be the gas field commodity rate, p be the natural gas price, and C be the price of natural gas. i Costs are incurred for the measures described.

[0016] In a preferred embodiment of this scheme, obtaining the benchmark profile for evaluating the effectiveness of the production enhancement measures based on the historical production data of the shale gas well and the production rate before the measures includes:

[0017] Based on the historical production data of shale gas wells and taking the pre-measures production as a basis, relevant production prediction methods are used to predict the production profile of wells implementing production enhancement measures within the effective range of the measures, which serves as the benchmark profile for evaluating the effectiveness of the production enhancement measures.

[0018] In a preferred embodiment of this solution, the relevant output prediction method includes, but is not limited to, any one of the following: Arps decreasing method, extended exponential decreasing method, Duong decreasing method, power exponential decreasing method, and combined model method.

[0019] In a preferred embodiment of this solution, obtaining the final output of each time unit based on the affected output, actual output, and baseline profile of each time unit includes:

[0020] Based on the actual output of each time unit and the corresponding baseline profile, calculate the initial increase in output for each time unit.

[0021] Calculate the final output for each time unit based on the impact output and the corresponding initial increase in output for each time unit.

[0022] The total increase in gas production is obtained by summing the final increase in production for each time unit within the effective period of the measures.

[0023] In a preferred embodiment of this solution, the formula for calculating the initial increase in production is: Δq t0 =q t实际 -q t基准 ;

[0024] Where, Δq t0 For the initial increase in production in the t-th time unit within the effective period of the measure, q t实际 q represents the actual output in the t-th time unit within the effective period of the measure. t基准 This is the reference profile for the t-th time unit within the effective period of the measure.

[0025] In a preferred embodiment of this solution, the formula for calculating the final output is: Δq t =Δq t0 -qi t ;

[0026] Among them, qi t Let Δq be the output at the t-th time unit within the effective period of the measure. t0 The initial increase in production is defined as the amount of output generated in the t-th time unit within the effective period of the measure.

[0027] In a preferred embodiment of this solution, the time unit is a day, week, month, quarter, or year; or any combination of days, week, month, quarter, and year.

[0028] In a preferred embodiment of this solution, the impact on output refers to the output loss caused by reasons other than the measures themselves.

[0029] In a preferred embodiment of this solution, the effective period of the measures refers to the time between the start time of the production-increasing measures and the end time of the production-increasing measures.

[0030] In a preferred embodiment of this scheme, the production before the measure is the stable gas production of the well implementing the production enhancement measure before the time of the production enhancement measure's action.

[0031] In a second aspect, the present invention provides a computer device comprising: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, the program instructions including instructions for performing the methods described above.

[0032] In a third aspect, the present invention provides a computer-readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the method described above.

[0033] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0034] This invention proposes a method for evaluating the effectiveness of shale gas well production enhancement measures. Based on the historical production data of a single well, a production profile of the well implementing the measures within the effective period is established by using relevant production prediction methods such as accurate production history fitting. This profile serves as the benchmark value for calculating the increased gas production. The difference between the actual production during the implementation phase and the benchmark production during the corresponding phase is then calculated, taking into account the impact on production caused by factors other than the measures themselves. This yields the increased gas production, and an economic evaluation is made in conjunction with the investment in the measures.

[0035] Furthermore, this invention calculates the increased gas production based on the actual decline pattern of gas wells, reflecting the dynamic production characteristics of shale gas wells with large changes in the decline rate. The established benchmark production profile truly reflects the actual decline pattern of shale gas wells in the current production stage, with a stable and unfluctuating decline rate. It has the advantages of high accuracy of calculation results, wide coverage, and flexible, simple, and fast calculation methods, which can meet the actual needs of oil and gas field production operation managers and mining technicians. Attached Figure Description

[0036] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0037] Figure 1 The diagram shows a schematic flowchart of an exemplary embodiment of a method for evaluating the effectiveness of shale gas well production enhancement measures according to the present invention.

[0038] Figure 2 This diagram shows a production profile of an embodiment of a method for evaluating the effectiveness of shale gas well production enhancement measures according to the present invention.

[0039] Figure 3 A schematic diagram of the production profile is shown in another embodiment of the method for evaluating the effectiveness of shale gas well production enhancement measures according to the present invention. Detailed Implementation

[0040] In the following text, an evaluation method for the effectiveness of shale gas well production enhancement measures according to the present invention will be described in detail with reference to exemplary embodiments.

[0041] Exemplary Example 1

[0042] A method for evaluating the effectiveness of shale gas well production enhancement measures includes the following steps:

[0043] S1: Obtain basic data

[0044] Obtain the pre-implementation production and the effective range of the measures from the wells where the production enhancement measures were implemented;

[0045] The effective period of the measures refers to the time between the start time and the end time of the production enhancement measures; the pre-measure production is the stable gas production of the well where the production enhancement measures were implemented before the implementation time of the measures.

[0046] S2: Establish the reference profile

[0047] Obtain historical production data of shale gas wells, and based on the historical production data and pre-measure production, obtain a benchmark profile for evaluating the effectiveness of production enhancement measures;

[0048] S3: Obtain the actual output within the effective range of the measure.

[0049] The effective period of the measures is divided into multiple time units;

[0050] Obtain the actual gas production of the wells implementing production enhancement measures in each time unit;

[0051] S4: Calculate the total increase in gas production

[0052] The actual output of each time unit within the effective period of the measure is subtracted from the corresponding baseline profile to obtain the preliminary increase in output for each time unit.

[0053] Obtain the impact output for each time unit, and calculate the final output for each time unit based on the impact output and the corresponding initial increase in output for each time unit.

[0054] The total increase in gas production is obtained by summing the final increase in production for each time unit within the effective period of the measures.

[0055] The formula for calculating the total increase in gas production is: Δq=ΣΔq t ;

[0056] S5: Calculate the input-output ratio

[0057] Obtain the input costs of the measures, and calculate the input-output ratio of the measures based on the total increase in gas production and the input costs of the measures;

[0058] The formula for calculating the input-output ratio of the aforementioned measures is as follows:

[0059]

[0060] In the formula, χ is the input-output ratio of the measures, and R c Let p be the gas field commodity rate, p be the natural gas price, and C be the price of natural gas. i Costs are incurred for the aforementioned measures;

[0061] The effectiveness of shale gas well production enhancement measures is evaluated based on the input-output ratio.

[0062] In this exemplary embodiment, the formula for calculating the initial increase in production in step S4 is: Δq t0 =q t实际 -q t基准 ;

[0063] Where, Δq t0 For the initial increase in production in the t-th time unit within the effective period of the measure, q t实际 q represents the actual output in the t-th time unit within the effective period of the measure. t基准 This is the reference profile for the t-th time unit within the effective period of the measure.

[0064] In this exemplary embodiment, the formula for calculating the final output is: Δq t =Δq t0 -qi t ;

[0065] Among them, qi t Let Δq be the output at the t-th time unit within the effective period of the measure. t0 The initial increase in production is for the t-th time unit within the effective period of the measure.

[0066] In this exemplary embodiment, the relevant production prediction method includes, but is not limited to, any one of various methods applicable to shale gas well production decline prediction, such as the Arps decline method, the extended exponential decline method, the Duong decline method, the power exponential decline method, and the combined model method.

[0067] In this exemplary embodiment, the time unit is a day, week, month, quarter, or year; or any combination of days, week, month, quarter, and year.

[0068] Regarding time units, an example is needed: if the effective period of a measure is one year, the production increase effect needs to be evaluated separately for each month during this period. This is a combination of a monthly time unit and a 12-month effective period for the measure. Time units are divided according to the stage evaluation required by actual production needs, such as monthly or quarterly evaluations, and can be divided evenly or unevenly.

[0069] In this exemplary embodiment, the impact on output refers to the output loss caused by reasons other than the measures themselves.

[0070] In this exemplary embodiment, step S2, which involves obtaining a benchmark profile for evaluating the effectiveness of production enhancement measures based on the historical production data and pre-measure production of shale gas wells, includes: based on the historical production data of shale gas wells and using the pre-measure production as a basis, employing relevant production prediction methods to predict the production profile of the wells implementing the production enhancement measures within the effective range of the measures, and using this as a benchmark profile for evaluating the effectiveness of the production enhancement measures.

[0071] The flowchart of this exemplary embodiment is shown below. Figure 1 As shown.

[0072] Example 1

[0073] Taking well A-1 in a shale gas field as an example, a method for evaluating the effectiveness of shale gas well production enhancement measures includes the following steps:

[0074] Step 1: The stable production rate (pre-treatment production rate) of well A-1 before the liquid accumulation shutdown was 0.7728 × 10⁻⁶. 4 m 3 / d, followed by the use of foam drainage gas extraction technology to resume production, with the effect period being 30 days.

[0075] Step 2: Based on the historical production data of Well A-1, and using the pre-treatment production as a basis, apply the power-law decreasing method to predict production and establish a production profile for Well A-1 within the effective range of the treatment. This profile will serve as a benchmark profile for evaluating the effectiveness of the production enhancement measures. Figure 2 As shown.

[0076] Step 3: In this embodiment, the time unit is a day, and the effective interval is divided into 30 time units. The actual gas production of each time unit is shown in Table 1.

[0077] Step 4: Subtract the actual output of each time unit within the effective period of the measures from the corresponding baseline profile to obtain the preliminary increase in output for each time unit, as shown in Table 1.

[0078] Since there are no other factors affecting production within the effective range of the measures, the final total increase in gas production Δq is 3.0372 × 10⁴ m³. 3 / d.

[0079] Step 5: Investment cost C for this foam drainage gas extraction process i The gas field commodity rate is 20,000 yuan, and the market value is R. c The percentage is 96%, and the natural gas price is 1.37 yuan / m³. 3 ,according to The input-output ratio (χ) of this measure is calculated to be 1:1.9973.

[0080] Table 1

[0081]

[0082] Example 2

[0083] Taking well A-2 in a shale gas field as an example, a method for evaluating the effectiveness of shale gas well production enhancement measures includes the following steps:

[0084] Step 1: The stable production rate (pre-treatment production rate) of well A-2 before the liquid accumulation shutdown was 0.2527 × 10⁻⁶. 4 m 3 / d, and then resumed production using foam drainage gas extraction technology. The effective period of this measure was from April 1 to June 30, a total of 3 months.

[0085] Step 2: Based on the historical production data of Well A-2, and using the pre-treatment production as a foundation, apply the power-law decreasing method to predict production, establishing a production profile for Well A-2 within the effective range of the treatment. This profile will serve as a benchmark profile for evaluating the effectiveness of the production enhancement measures. Figure 3 As shown.

[0086] Step 3: In this embodiment, the period of action is divided into three time units, with the month as the time unit. The actual gas production of each time unit is shown in Table 2.

[0087] Step 4: Subtract the actual output of each time unit within the effective period of the measures from the corresponding baseline profile to obtain the preliminary increase in output for each time unit, as shown in Table 2.

[0088] Table 3 shows the impact on production in each time unit caused by well shut-in due to reasons other than the measures themselves during the effective period. The final total increase in gas production Δq after deducting the impact on production is 15.1065 × 10 4 m 3 / d.

[0089] Step 5: Investment cost C for this foam drainage gas extraction process i The gas field commodity rate is 60,000 yuan, and the market value is R. c The percentage is 96%, and the natural gas price is 1.37 yuan / m³. 3 ,according to The input-output ratio (χ) of this measure is calculated to be 1:3.3113.

[0090] Table 2

[0091]

[0092]

[0093]

[0094] Table 3

[0095]

[0096] Exemplary Example 2

[0097] This exemplary embodiment provides a computer device.

[0098] The computing device includes: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, the program instructions including instructions for performing the method as described in Exemplary Embodiment 1 or 2.

[0099] Exemplary Example 3

[0100] This exemplary embodiment provides a computer-readable storage medium.

[0101] A computer-readable storage medium stores computer program instructions that, when executed by a processor, implement the method as described in exemplary embodiment 1 or 2.

[0102] The computer-readable storage medium can be any data storage device that stores data that can be read by a computer system. Examples of computer-readable storage media include: read-only memory, random access memory, read-only optical disc, magnetic tape, floppy disk, optical data storage device, and carrier waves (such as data transmission via the Internet through wired or wireless transmission paths).

[0103] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method for evaluating the effectiveness of shale gas well production enhancement measures, characterized in that, Includes the following steps: Obtain the pre-implementation production and the effective range of the measures from the wells where the production enhancement measures were implemented; Obtain historical production data of shale gas wells, and based on the historical production data and pre-measure production, obtain a benchmark profile for evaluating the effectiveness of production enhancement measures; The effective period of the measures is divided into multiple time units, and the actual gas production of the wells implementing the production enhancement measures is obtained in each time unit. Obtain the impact output for each time unit, and based on the impact output, actual output, and baseline profile for each time unit, obtain the final output for each time unit. The total increase in gas production is obtained by summing the final increase in production for each time unit within the effective period of the measures. Obtain the input costs of the measures, and calculate the input-output ratio of the measures based on the total increase in gas production and the input costs of the measures; The effectiveness of shale gas well production enhancement measures is evaluated based on the input-output ratio.

2. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The formula for calculating the input-output ratio of the aforementioned measures is as follows: In the formula, χ is the input-output ratio of the measures, and R c Let p be the gas field commodity rate, p be the natural gas price, and C be the price of natural gas. i Costs are incurred for the measures described.

3. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The baseline profile for evaluating the effectiveness of production enhancement measures, obtained based on the historical production data and pre-measure production of shale gas wells, includes: Based on the historical production data of shale gas wells and taking the pre-measures production as a basis, relevant production prediction methods are used to predict the production profile of wells implementing production enhancement measures within the effective range of the measures, which serves as the benchmark profile for evaluating the effectiveness of the production enhancement measures.

4. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 3, characterized in that, The relevant output forecasting methods include, but are not limited to, any one of the following: Arps decreasing method, extended exponential decreasing method, Duong decreasing method, power exponential decreasing method, and combined model method.

5. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The process of obtaining the final output for each time unit based on the impact output, actual output, and baseline profile includes: Based on the actual output of each time unit and the corresponding baseline profile, calculate the initial increase in output for each time unit. Calculate the final output for each time unit based on the impact output and the corresponding initial increase in output for each time unit. The total increase in gas production is obtained by summing the final increase in production for each time unit within the effective period of the measures.

6. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 5, characterized in that, The formula for calculating the initial increase in production is: Δq t0 =q t实际 -q t基准 ; Where, Δq t0 For the initial increase in production in the t-th time unit within the effective period of the measure, q t实际 q represents the actual output in the t-th time unit within the effective period of the measure. t基准 This is the reference profile for the t-th time unit within the effective period of the measure.

7. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 5, characterized in that, The formula for calculating the final output is: Δq t =Δq t0 -qi t ; Among them, qi t Let Δq be the output at the t-th time unit within the effective period of the measure. t0 The initial increase in production is defined as the amount of output generated in the t-th time unit within the effective period of the measure.

8. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The time unit is a day, week, month, quarter, or year; or any combination of days, week, month, quarter, and year.

9. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The output loss mentioned refers to the output loss caused by reasons other than the measures themselves.

10. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The effective period of the measures refers to the time between the start time of the production-increasing measures and the end time of the production-increasing measures.

11. The method for evaluating the effectiveness of shale gas well production enhancement measures according to claim 1, characterized in that, The production before the measures refer to the stable gas production of the well before the implementation of the production enhancement measures.

12. A computer device, characterized in that, include: At least one processor; A memory storing program instructions configured to be executed by the at least one processor, the program instructions including instructions for performing the method according to any one of claims 1 to 11.

13. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the method of any one of claims 1 to 11.

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