Study On Carbonate Reservoir Weak-Volatilization Oil Fluid Properties And Distribution

North Troyes oilfield is located at the Caspian Basin southeastern area.The main oil-bearing strata are located in the upper part of Carboniferous system,and the depth of the main development layer is about 2400m named KT-I and KT-II.In the study area the dissolved gas oil ratio,the volume coefficient and the crude oil shrinkage rate,the density and viscosity of the crude oil are low,and the saturation pressure difference is small.Therefore,during the development process,optimization of injection and production parameters,design of water injection timing and pressure recovery speed is critical for efficient development of this oilfield.In this study,the laboratory data of the study area are analyzed,and the characteristics of the relative volume coefficient,viscosity and density of crude oil are studied.Then,the weak volatilization property of the fluid in the study area is determined by the analysis of the composition and transitivity characteristics of the crude oil,and the typical well group model is set up in combination with the geological characteristics of the study area,and the development parameters range of the model recovery speed and injection production ratio are established by combining the development of the study area,five points well pattern and anti-nine well pattern are set up for the typical pore type and the fractured pore type reservoir in the target area.The development model.Finally,the change characteristics of two types of well network of two types of reservoirs are studied under different injection production ratio,different oil recovery speed,different injection timing,recovery level and recovery rate.Through this study,the variation of fluid components and fluid properties in the three-dimensional space is clarified,and it is found that the change of heavy hydrocarbon content has a great influence on the physical properties of the fluid.Then,the study area is divided into two main fluid physical zones with the ratio of C₇+24%as the boundary.Through the establishment of the typical well group model,the oil field development technology chart was completed,and the interaction between the oil recovery speed,injection production ratio,the time of reinjection and the recovery rate of pressure recovery was clarified,and the optimum injection production parameters for the pore type reservoir and fractured pore type reservoir were designed to lay the foundation for the second development of this oilfield.