Water Flooding - Gas And Water After Polymer Flooding Alternately Enhanced Oil Recovery Research

This paper studies on the engineering of hydrocarbon reservoir. In the period of completing this paper, the indoor experiment is carried out to study the mechanism of water flooding-polymer flooding-WAG. On the basis of the experiment, the concrete condition is considered about the oil-bearing layer Pu I 1-2 of northeast block in daqing oil field. Analysis shows that in the old oil field WAG is a feasible approach to improve the recovery when the oil field is at the late high water-cut period after water flooding7polymer flooding. In the course of exploitation of the oil field, the oil reservoirs with different sedimentary rhythms take on different rules of oil and water movements and exploitation characteristics, accordingly different exploitation policies and measures are adopted to improve oil recovery. In order to make clear exploitation characteristics of oil reservoir with different sedimentary rhythms, so that the oil reservoir is developed efficiently and furthest improve the recovery of oil reservoir with diversified rhythms. This paper carries on an indoor experiment by three kinds of pressed rhythms to appraise the effect of water flooding-polymer flooding-WAG. Analyzing the experimental data and that of geology and production and then three dimensions geologic model of oil-bearing layer Pu I 1-2 is set up. The production performance of the selected pattern is simulated by CMG through water flooding-polymer flooding-WAG. Completing the selection of well pattern, establishment of hydrocarbon reservoir geologic model, and calculation of fluid PVT, and triphase relative permeability determination, and reserve fitting and history matching, the programs are designed to improve oil recovery of WAG and simulate performance prediction, and also optimize the programs. The residual oil is excavated more efficiently, and the producing degree of low-permeability layer is advanced, and integral production effects of the block are improved. The study cut a new path for the exploitation of oil field after polymer flooding, and provides a reference of scientific theory for strategic decision making of oil field integral exploitation and the exploitative design of congeneric oil field.Creativities of this paper are as follows:This paper carries out the experiment to study the mechanism of water flooding-polymer flooding-WAG by different rhythm models for the first time. Experimental studies are found firstly that the exploitation method and the rules of water flooding-polymer flooding-WAG. Numerical simulation method is firstlyadopted to describe the well pattern course of water flood ing-polymer flooding-WAG. On the basis of simulating production performance, several prediction programs are designed to study the effects on recovery such as the slug ratio of gas and water, gas injection volume, gas injection pattern. And then the gas injection plans are optimized by CMC...