Optimization method for gas injection parameters of carbonate reservoir

Abstract

The invention discloses an optimization method for gas injection parameters of a carbonate reservoir. The method comprises the steps of 1) determining N gas injection parameters affecting the gas injection yield increase range of the carbonate reservoir and range of values of the N gas injection parameters; 2) using a BBD design method, and designing M numerical simulation schemes for the yield increase range based on the N gas injection parameters; 3) determining the type of a response surface regression model based on the variance of the yield increase range results calculated by M numericalsimulation schemes; 4) based on the discriminant result of step 3), establishing a response surface regression model equation, and establishing the relationship between the increase yield range and the N gas injection parameters; 5) conducting global optimization based on the response surface regression model, and obtaining optimal combination of gas injection parameter values which satisfy a convergence condition. The method avoids the problem that a control variable method or an orthogonal design method has too many experimental design schemes, and avoids the problem that a current method numerical simulation optimization workload is large and an obtained result is not a global optimal solution.

Description

technical field [0001] The invention relates to the field of oil reservoir exploitation, more specifically, to a method for optimizing gas injection parameters in carbonate rock oil reservoirs. Background technique [0002] As an important oil and gas production layer, carbonate reservoirs account for half of the world's oil and gas reserves. According to statistics, more than one-third of the world's carbonate reservoirs are fracture-karst cave reservoirs, and the main storage spaces are structural fractures formed by structural deformation and pores, caves, and fractures produced by karstification. Large caves It is the most important storage space among them. Tahe Oilfield is the largest marine monolithic carbonate oil and gas field discovered and developed in my country, and the Ordovician carbonate fracture-cavity reservoir is currently the largest carbonate reservoir in China. Tahe Oilfield has formed a single-well fracture-cavity unit water injection oil replacement...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems of low precision and cumbersome optimization of gas injection parameters in fractured-cavity carbonate reservoirs, the present invention provides a method for optimizing gas injection parameters in carbonate reservoirs: injection based on response surface and genetic algorithm The gas parameter optimization method is to introduce the polynomial response surface model into the optimal design of gas injection in fractured-cavity reservoirs, to fit the complex nonlinear relationship between injection parameters and production increase, and finally to use the genetic algorithm for global optimization to obtain the optimal Gas injection parameters

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