Gas drive reservoir injection-production parameter step-by-step optimization method

Abstract

The invention discloses a gas drive reservoir injection-production parameter step-by-step optimization method, which comprises the following steps of: 1, based on an intelligent optimization algorithm and black oil numerical simulation, determining the daily liquid production speed of each oil well and the daily gas injection speed of a gas injection well by taking the maximum recovery ratio as a target function; step 2, establishing an optimization mathematical model taking the maximum economic net present value (NPV) as an objective function according to the liquid quantity of each well determined in the step 1 as an initial value, and re-optimizing the liquid quantity of each well of the oil reservoir by adopting component numerical simulation based on an intelligent optimization algorithm and the optimal injection-production parameters obtained in the step 1 so as to obtain the optimal injection-production parameters of the oil reservoir. Therefore, the maximum optimal gas injection speed of the NPV and the daily fluid production speed of each production well are obtained. According to the method, a small amount of conventional experiment test data can be fully utilized, the time consumed by numerical simulation is greatly shortened, the gas drive injection and production parameters are simply, conveniently, quickly and accurately determined, the optimization time of the gas drive injection and production parameters is remarkably prolonged, and the related economic cost is reduced.

Description

technical field [0001] The invention relates to the technical field of oilfield gas injection, in particular to a step-by-step optimization method for injection and production parameters of gas drive reservoirs. Background technique [0002] Gas injection development has now developed into a very important enhanced oil recovery technology, which has been widely used at home and abroad and has achieved good development results. Studies have shown that gas injection development is of great significance for improving the development effect of different types of reservoirs with high water cut, low permeability and shale oil. In recent years, after large-scale gas injection tests in many oil fields, my country's A major breakthrough has been made in gas development, and a complete set of development theory, supporting technology and operation mode has gradually been formed for gas injection enhanced oil recovery, and gas injection enhanced oil recovery is one of the most promising...

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Problems solved by technology

[0004] In the traditional optimization method of gas drive injection and production parameters based on numerical simulation, there are mainly the following methods. The first is to optimize only the injection parameters. This kind of optimization through manual design only pays attention to the injection parameters and ignores the influence of the working system of production wells, which is not the real injection-production parameter optimization; the second is to use the orthogonal design method to However, the orthogonal design scheme is limited, and it is difficult to meet the actual needs of large-scale gas injection well groups in actual reservoirs; the third is the method of sequential optimization of injection-production parameters, which is based on numerical simulation history matching. In the above, according to the method of sequential optimization of injection-production parameters, the key parameters affecting the development effect of gas injection are studied in turn, and then the ultimate recovery factor or cumulative oil production under different schemes is compared to optimize the optimal gas injection development parameters. The method of successive optimization cannot consider the synergistic development effect of injection-production parameters, and cannot achieve balanced gas flooding, which is very easy to form gas channeling and reduce the utilization rate of gas injection; the fourth is to optimize injection-production parameters by combining numerical simulation with optimization algorithms. The biggest defect is that the optimization algorithm needs to call the numerical simulator multiple times, and the optimization effect is better for small gas injection well groups, but it takes a lot of time to optimize the actual oil reservoir, and it is difficult to optimize multiple times and real-time

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