| Separated by faults,WS glutenite reservoirs have diverse pore reservoir structures.The reservoirs have the characteristics of poor physical property,strong anisotropism,low porosity,and low permeability or medium-low permeability.The preliminary exploration shows that the WS reservoirs have a complex pressure system and oil and water distribution,and the effect of initial water injection development is not obvious.Water-flooding offers choices for developers and is certain to become the yardstick by which both here and abroad corporations are measured.On basis of the trait,this paper will further evaluate the adaptability of water flooding development,explore the gas driving of WS glutenite reservoirs,serving as a guide for energy supply practices on the spot.Combining with experimental research,numerical simulation and the reservoir engineering,this paper aims to explore the methods of WS glutenite reservoirs energy supplying.This article mainly carries out the following work:(1)Based on the initial development of WS glutenite reservoirs,it is necessary to fully study the similar development plan and experience of similar glutenite reservoirs at home and abroad,and sufficiently guide for further production and development on the spot.(2)The phase property of crude oil was studied by PVT fluid phase experiment,and the phase profile was simulated by ECLIPSE software.On this basis,CO2,N2 and associated gas injection were simulated respectively.By contrasting CO2,N2 and the influence of entrained gas on the saturated pressure,viscosity and coefficient of expansion of crude oil,we find the solubilization effect of CO2 and associated gas is obvious,which can effectively improve the oil flow performance and provide the evidence for the injection of gas medium for the subsequent gas injection scheme.(3)The minimum miscible pressure of CO2,N2 and associated gas was studied by tube test.The conclusion was that the minimum miscibility pressure of CO2 was less than that of entrapment gas,and it was lower than the original formation pressure.That is how CO2 and associated gas displace the oil.(4)Different combinations of long core flooding presents the displacement efficiency of water flooding,CO2 and associated gas,providing experimental basis for the selection of water injection and gas injection.Finally,through the experimental results of long core flooding,the breakthrough of CO2 was 0.64HCPV,the breakthrough time was the latest,and the recovery degree of oil and water was 14.92%,the recovery degree was 77.37%;the breakthrough of associated gas was 0.43HCPV,the recovery degree was 54.31%.The results showed that the effect of CO2 flooding was the best,followed by the associated gas displacement.(5)Based on the heterogeneity characteristics of reservoir in well 9 of the WS reservoir,ECLIPSE numerical simulation software was used to establish the long core numerical simulation with different heterogeneity and strength,so as to evaluate the effect of heterogeneity on displacement efficiency.(6)By using the reservoir engineering and combining empirical formula and analogy method,this paper demonstrates the development strategy of water injection program.The initial development level,well spacing and water injection,etc play a role in the designing of water injection.(7)Based on the previous study of air drive,the well area suitable for gas flooding is selected and the technical policy of gas injection development is studied.By demonstrating and optimizing the well spacing,injection method,contrast injection medium,injection pressure and injection volume and other parameters,to lay the foundation for the final gas injection program. |
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