Research On Well Pattern Deployment And Fine Water Injection In 71 Block Of Xing-Bei Area

Reserves of low permeability oil field are abundant, reasonable well pattern deployment and of fine water injection development scheme are of great significance for the efficient development of low permeability oilfield. According to the characteristics of low permeability reservoir, respectively, study the law of two-phase seepage, influence of reservoir physical properties, fluid properties and development conditions on rule of water content change, oil displacement efficiency and the difficulty of reservoir producing. In reservoir engineering, the relationship curve between water content and production degree is established, and the water content is set up by using the digital software of Double Fox; The dimensionless productivity, free liquid production index with water cut rate changes in the mathematical model is established by applying reservoir engineering method. Studies have shown that different stages of development, enhanced liquid production measures has different effects on increasing production of oil field; A new method to calculate the recovery factor of low permeability reservoir is provided, the concept of well pattern coefficient is introduced, and the factors are more comprehensive and accurate.On the basis of reservoir engineering research, a numerical model of the study area is established, and a reasonable well pattern deployment scheme is developed for low permeability reservoir development. Through the Sher Cacho J formula and curve intersection method, calculate economic limit well density and economic reasonable well spacing density. Under the constraint of the limit well density, using the numerical model, optimizing well spacing, row spacing, row direction and the crack angle, the well pattern, get the optimal well pattern deployment.Based on the numerical model and well pattern deployment, a reasonable fine water injection scheme is developed. By establishing membership function of water injection influencing factors,combined with the weights, the splitting of water injection into the single well and the layer is obtained. Numerical simulation results show that, compared with general water injection, the layered water injection scheme has better advantage; Through combining reservoir engineering method with numerical simulation method, optimize formation pressure maintenance level under different pre-injection water content and reasonable advance water injection time. As for injection production ratio, apply material balance equation to establish mathematical model of relationship between reservoir physical property, compression coefficient, injection production ratio and water content of formation pressure recovery rate. Apply numerical simulation method to predict development index of different schemes, with water cut rising speed, oil recovery and other indicators as the constraint, obtain reasonable injection production ratio; As for oil production rate, combine dynamic and static parameters with numerical simulation method to calculate the reasonable production rate. Research shows, the formation pressure keep 1.20 times of original formation pressure, advance water injection amount of 46823m3, advanced water injection in 6 months, 1.91m3/(d·m)injection intensity, the injection production ratio of 1.7, 1.4% oil recovery rate, study aera will have a good development effect. Research results have an important guiding significance on rational and efficient development of low permeability reservoirs, enhanced oil recovery and economic benefits.