CN-121993195-A - Method, device and equipment for predicting long-term productivity of shale gas well

CN121993195ACN 121993195 ACN121993195 ACN 121993195ACN-121993195-A

Abstract

The specification relates to a method, a device and equipment for predicting long-term productivity of a shale gas well, which comprise the steps of carrying out fracturing simulation on a non-productive well according to target fracturing construction pumping parameters and stratum parameters of stratum where the non-productive well is located to obtain crack parameters of the non-productive well, calculating shale gas reservoir reserves of the non-productive well according to the well parameters and the crack parameters of the non-productive well, respectively calculating single well utilization rates of all the productive wells according to long-term productivity actual values of a plurality of productive wells in a stratum, constructing single well utilization posterior distribution, determining target single well utilization values based on a Markov chain-Monte Carlo sampling method, and calculating long-term productivity prediction values of the non-productive well according to the shale gas reservoir reserves of the non-productive well and the target single well utilization values so as to enable workers to develop the non-productive well according to the long-term productivity prediction values and fully develop stratum resources and improve the overall efficiency of shale gas development.

Inventors

ZENG BO
CHEN LIQING
LI JUNFENG
LIU WENPING
Feng Jiangrong
WANG SHOUYI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241107

Claims (10)

1. A method of predicting long term productivity of a shale gas well, the method comprising: performing fracturing simulation on the unproductive well according to a target fracturing construction pumping parameter and stratum parameters of a stratum where the unproductive well is located, and obtaining fracture parameters of the unproductive well under the target fracturing construction pumping parameter; Calculating shale gas reservoir reserves of the unproductive well according to the well parameters and the fracture parameters of the unproductive well; Calculating single well utilization rate of each produced well according to long-term productivity actual values of a plurality of produced wells in the stratum, constructing single well utilization rate posterior distribution, and determining a target single well utilization rate value based on a Markov chain-Monte Carlo sampling method; and calculating a long-term productivity predicted value of the unproductive well according to the shale gas reservoir reserves of the unproductive well and the target single well utilization value, wherein the long-term productivity predicted value of the unproductive well is used for guiding the development of the unproductive well.
2. The method of claim 1, wherein calculating shale gas reservoir reserves for the unproductive well from well parameters and fracture parameters of the unproductive well further comprises: Calculating unit reserve coefficients of the unproductive well according to well parameters of the unproductive well; calculating the fracture control volume of the fracturing fracture of the unproductive well according to the fracture parameters; and calculating the shale gas reservoir reserves according to the unit reserve coefficient and the fracture joint control volume.
3. The method of claim 2, wherein the well parameters of the unproductive well comprise average porosity, average water saturation, volume coefficient of gas developed from the formation; The formula for calculating the unit reserve coefficient of the unproductive well according to the well parameters of the unproductive well is as follows: Wherein URI new represents the unit reserve coefficient of the unproductive well, Represents the average porosity of the porous body, which is the average porosity, Represents average water saturation and B g represents volume coefficient.
4. The method of claim 3, wherein the fracture parameters comprise an average fracture half-length, average fracture height for each of the plurality of well sections; calculating a fracture control volume of the unproductive well according to the fracture parameters further comprises: According to the formula Calculating the control volume of each well segment, wherein SRV new_k represents the control volume of the kth well segment of the unproductive well, Average pressure fracture half length of the kth well section representing the unproductive well, Representing the average fracture height of the kth well section of the unproductive well, L wk representing the length of the kth well section of the unproductive well; And summing the joint control volumes of all the well sections to obtain the joint control volume of the fracture joint of the unproductive well.
5. The method of claim 4, wherein the formula for calculating the shale gas reservoir reserves from the unit reserve coefficients and fracture joint control volumes is: OGIP new ＝URI new ×SRV new ; wherein OGIP new represents shale gas reserves.
6. The method of claim 5, wherein the formula for calculating individual well fraction for each of the produced wells based on the actual long term capacity of the plurality of produced wells in the formation is: Wherein, the Representing the single well fraction of the commissioned well, EUR calibrated representing the long-term production actual of the commissioned well, URI prod representing the unit reserve coefficient of the commissioned well, Representing the fracture joint control volume of the produced well.
7. The method of claim 5, wherein the equation for calculating the long-term productivity prediction value for the unproductive well from the shale gas reservoir reserves for the unproductive well and the target single well fraction value is: EUR new ＝RF new ×OGIP new ; Where EUR new represents a long-term production capacity prediction for an unproductive well and RF new represents a target single well fraction value.
8. A long term production capacity prediction apparatus for a shale gas well, the apparatus comprising: the fracturing simulation calculation unit is used for carrying out fracturing simulation on the unproductive well according to the target fracturing construction pumping parameters and the stratum parameters of the stratum where the unproductive well is located, so as to obtain the fracture parameters of the unproductive well under the target fracturing construction pumping parameters; the shale gas reservoir reserves calculating unit is used for calculating the shale gas reservoir reserves of the unproductive well according to the well parameters and the crack parameters of the unproductive well; The target single well utilization rate calculation unit is used for calculating the single well utilization rate of each produced well according to the long-term productivity actual values of a plurality of produced wells in the stratum, constructing single well utilization rate posterior distribution and determining a target single well utilization rate based on a Markov chain-Monte Carlo sampling method; And the long-term productivity predicted value calculation unit is used for calculating the long-term productivity predicted value of the unproductive well according to the shale gas reservoir reserves of the unproductive well and the target single well utilization value, and the long-term productivity predicted value of the unproductive well is used for guiding the development of the unproductive well.
9. A computer device comprising a memory, a processor, and a computer program stored on the memory, characterized in that the processor, when executing the computer program, implements the method of any of claims 1 to 7.
10. A computer readable storage medium, characterized in that the computer readable storage medium stores a computer program which, when executed by a processor, implements the method of any of claims 1 to 7.

Description

Method, device and equipment for predicting long-term productivity of shale gas well Technical Field The embodiment of the specification belongs to the technical field of shale gas well development, and particularly relates to a method, a device and equipment for predicting long-term productivity of a shale gas well. Background Shale gas belongs to an artificial gas reservoir, and because the reservoir is extremely compact, industrial gas flow cannot be formed under natural conditions, and an artificial fracture network is formed by large-scale hydraulic fracturing to establish a gas flow channel. The production capacity of shale gas wells is closely related to an artificial fracture network and the complexity of the artificial fracture network, and the evaluation and quantification of fracture morphology and fracture control volume are the core of the evaluation of the post-compaction effect. However, the means and methods for evaluating artificial fractures are still very limited. Hydraulic fracturing simulation is used as a common numerical calculation means, and fracture morphology information can be obtained by considering various geological and engineering conditions and parameters. Based on fracture dynamic numerical modeling, the complexity of fracture morphology can be characterized in some shale gas reservoirs containing a large number of natural fractures. Hydraulic fracturing is a complex process involving fluid flow and rock deformation, covering problems of fluid flow in the wellbore and fracture, fracture formation and propagation, and fracture interaction with natural weaknesses. In recent years, students at home and abroad have conducted a great deal of research on simulation of the expansion of unconventional oil and gas complex cracks. The existing model adopting the finite element method has limitations in accurately simulating a mechanical mechanism and dynamic growth of the crack, although the expansion of the crack is considered. The extended finite element method and the boundary element method have advantages and disadvantages in fracture simulation. Although the discrete meta-model can solve the three-dimensional complex fracture, the calculation amount is huge and the fracture track needs to be predefined. Currently, in shale gas exploration and development processes, long-term productivity prediction (EUR) of shale gas wells is mainly calculated according to production dynamic fitting. Because this method relies on existing production data, its predictive timeliness is low and it is not possible to provide guidance in time during the fracturing operation to optimize and adjust the fracturing scheme. This results in certain limitations and hysteresis in practical operation. The well control resource amount is calculated according to the well spacing and the reserve abundance. However, since the length and height spread of the fracture is affected by the dual factors of the geological conditions and the fracturing process, there is a large difference between the amount of resources actually used and the theoretically calculated well control amount of resources. This discrepancy results in many cases, in spite of the large amount of well control resources calculated, the EUR for individual wells is low and does not fully exploit the resource potential. Therefore, how to improve the accuracy and timeliness of prediction and how to effectively use the well control resource amount in the actual exploration and development process is a problem to be solved. Disclosure of Invention In order to solve the problems in the prior art, the embodiment of the specification provides a method, a device and equipment for predicting the long-term productivity of a shale gas well. The specific technical scheme of the embodiment of the specification is as follows: in one aspect, embodiments herein provide a method for predicting long-term productivity of a shale gas well, the method comprising: performing fracturing simulation on the unproductive well according to a target fracturing construction pumping parameter and stratum parameters of a stratum where the unproductive well is located, and obtaining fracture parameters of the unproductive well under the target fracturing construction pumping parameter; Calculating shale gas reservoir reserves of the unproductive well according to the well parameters and the fracture parameters of the unproductive well; Calculating single well utilization rate of each produced well according to long-term productivity actual values of a plurality of produced wells in the stratum, constructing single well utilization rate posterior distribution, and determining a target single well utilization rate value based on a Markov chain-Monte Carlo sampling method; and calculating a long-term productivity predicted value of the unproductive well according to the shale gas reservoir reserves of the unproductive well and the target single well utilization value, wherein the long