CN-121993185-A - Method, system, equipment and medium for predicting productivity of shale gas well

CN121993185ACN 121993185 ACN121993185 ACN 121993185ACN-121993185-A

Abstract

The invention relates to the technical field of shale gas well productivity prediction, and provides a shale gas well productivity prediction method, a shale gas well productivity prediction system, shale gas well productivity prediction equipment and a shale gas well productivity prediction medium, wherein the method comprises the steps of constructing a single well bottom pressure prediction curve of the shale gas well, wherein the bottom pressure prediction curve is a relationship curve of bottom pressure corresponding to different production days of the single well and time; the method comprises the steps of constructing a single-well productivity prediction curve, wherein the single-well productivity prediction curve is a relation curve between total accumulated gas yield and bottom hole pressure and a relation curve between total accumulated liquid yield and bottom hole pressure, obtaining a relation curve between total accumulated liquid yield and total accumulated gas yield and production days by using the single-well bottom hole pressure prediction curve and the single-well productivity prediction curve, and predicting the productivity of the shale gas well by using the relation curve between total accumulated liquid yield and total accumulated gas yield and production days. The method can be used for forecasting the productivity of the shale gas well based on production characteristics of different stages.

Inventors

WANG QINGRONG
JIANG MI
ZENG LINJUAN
DU ANQI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (10)

1. A method for predicting the capacity of a shale gas well, comprising: Constructing a single well bottom pressure prediction curve of the shale gas well, wherein the single well bottom pressure prediction curve is a relationship curve of bottom pressure and time corresponding to different production days of the single well; Constructing a single well productivity prediction curve, wherein the single well productivity prediction curve is a relation curve between total accumulated gas yield and bottom hole pressure and a relation curve between total accumulated liquid yield and bottom hole pressure; obtaining total accumulated liquid yield and a relation between the total accumulated liquid yield and production days by using a single well bottom pressure prediction curve and a single well productivity prediction curve; And predicting the productivity of the shale gas well by utilizing the total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days.
2. The method for predicting capacity of a shale gas well as claimed in claim 1, wherein the single well bottom hole pressure prediction curve expression is: Wherein, P wf is bottom hole pressure, t is the production days, and the coefficient a 1 、b 1 is determined by a fitting method; the relation between the total accumulated gas yield and the bottom hole pressure is as follows: the relation between the total accumulated liquid yield and the bottom hole pressure is as follows: wherein P wf is bottom hole pressure; is the total cumulative gas yield; The total cumulative liquid amount is n is the cumulative days, and a 2 、b 2 、a 3 、b 3 is the coefficient.
3. The method for predicting capacity of a shale gas well as claimed in claim 1, wherein the relation between total cumulative gas production and production days is: The relation between the total accumulated liquid yield and the production days is as follows: Wherein P wf is bottom hole pressure, t is the production days; Is the cumulative gas yield; the accumulated liquid quantity is n, and the accumulated days are n.
4. The method of claim 1, further comprising verifying the accuracy of the total cumulative liquid production and the relationship between total cumulative liquid production and days of production using actual production.
5. The method for predicting the productivity of a shale gas well according to claim 1, wherein the cumulative production of all shale gas wells in the same block is calculated by using the same total cumulative liquid production and the relation between the total cumulative liquid production and the production days; And comparing the calculated result with the actual yield, and if the error is smaller than the threshold value, representing the accumulated yield of all shale gas wells in the same block by using the same total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days.
6. The method for predicting the productivity of a shale gas well according to claim 1, further comprising calculating a daily gas production amount and a daily liquid production amount of the shale gas well by using a relation between total accumulated liquid production amount and production days, wherein the expression is as follows: Wherein Q g is the gas production amount of the shale gas well on one day, and Q w is the liquid production amount of the shale gas well on one day.
7. The method for predicting the capacity of a shale gas well according to claim 1, wherein the capacity of the shale gas well is predicted by using the total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days, and the prediction time is less than three months.
8. A productivity prediction system for a shale gas well, comprising: the single well bottom pressure prediction curve is a relationship curve between bottom pressure and time corresponding to different production days of a single well; The production curve construction module is used for constructing a single-well production prediction curve, wherein the single-well production prediction curve is a relation curve between total accumulated gas production and bottom hole pressure and a relation curve between total accumulated liquid production and bottom hole pressure; The calculation module is used for obtaining the total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days by utilizing the single well bottom pressure prediction curve and the single well productivity prediction curve; And the prediction module is used for predicting the productivity of the shale gas well by utilizing the total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days.
9. A shale gas well productivity prediction apparatus comprising at least one processor and a memory communicatively coupled to the at least one processor, wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the shale gas well productivity prediction method of any of claims 1-7.
10. A computer storage medium having stored thereon executable instructions which when executed by a processor cause the processor to implement the method of any of claims 1 to 7.

Description

Method, system, equipment and medium for predicting productivity of shale gas well Technical Field The disclosure belongs to the field of shale gas well productivity prediction, and particularly relates to a shale gas well productivity prediction method, system, equipment and medium. Background In the middle and later stages of shale gas well production, gas wells will have different degrees of risk of fluid accumulation due to the gradual decrease in formation pressure. The prediction of shale gas productivity at home and abroad is generally based on a shale gas reservoir flow model and discrete cracks of a shale gas reservoir, a multistage fracturing productivity model is established, and shale gas productivity data under different fracturing completion parameters are calculated. However, the prior art mainly predicts shale gas productivity under different fracturing completion parameters, cannot stand on the gas production engineering, predicts productivity based on production characteristics of different stages, and cannot be used for gas production process decision-making. Disclosure of Invention In order to solve the problems, the present disclosure provides a method, a system, a device and a medium for predicting the productivity of a shale gas well, which are capable of predicting the productivity of the shale gas well based on different stage production characteristics by adopting a method for constructing a relation between total accumulated liquid yield and total accumulated gas yield and production days. The invention is realized by the following technical scheme: A method for predicting the capacity of a shale gas well, comprising: Constructing a single well bottom pressure prediction curve of the shale gas well, wherein the single well bottom pressure prediction curve is a relationship curve of bottom pressure and time corresponding to different production days of the single well; Constructing a single well productivity prediction curve, wherein the single well productivity prediction curve is a relation curve between total accumulated gas yield and bottom hole pressure and a relation curve between total accumulated liquid yield and bottom hole pressure; obtaining total accumulated liquid yield and a relation between the total accumulated liquid yield and production days by using a single well bottom pressure prediction curve and a single well productivity prediction curve; And predicting the productivity of the shale gas well by utilizing the total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days. Further, the method comprises the steps of, The single well bottom hole pressure prediction curve expression is: Wherein, P wf is bottom hole pressure, t is the production days, and the coefficient a 1、b1 is determined by a fitting method; the relation between the total accumulated gas yield and the bottom hole pressure is as follows: the relation between the total accumulated liquid yield and the bottom hole pressure is as follows: wherein P wf is bottom hole pressure; is the total cumulative gas yield; The total cumulative liquid amount is n is the cumulative days, and a 2、b2、a3、b3 is the coefficient. Further, the method comprises the steps of, The relation between the total accumulated gas yield and the production days is as follows: The relation between the total accumulated liquid yield and the production days is as follows: Wherein P wf is bottom hole pressure, t is the production days; Is the cumulative gas yield; the accumulated liquid quantity is n, and the accumulated days are n. Further, the method comprises the steps of, And verifying the accuracy of the relation between the total accumulated liquid yield and the total accumulated gas yield and the production days by using the actual yield. Further, the method comprises the steps of, Calculating the accumulated output of all shale gas wells in the same block by using the same total accumulated liquid output and the relation between the total accumulated liquid output and the production days; And comparing the calculated result with the actual yield, and if the error is smaller than the threshold value, representing the accumulated yield of all shale gas wells in the same block by using the same total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days. Further, the method comprises the steps of, The method also comprises the steps of calculating the one-day gas yield and the liquid yield of the shale gas well by utilizing the total accumulated liquid yield and the relation between the total accumulated liquid yield and the production days, wherein the expression is as follows: Wherein Q g is the gas production amount of the shale gas well on one day, and Q w is the liquid production amount of the shale gas well on one day. Further, the method comprises the steps of, And predicting the productivity of the shale gas well