Experimental Study On Imbibition Oil Potential Of Tight Oil Reservoir In Jimusar

Tight oil reservoirs in the Jimsar region of Xinjiang have been put into production using large-scale hydraulic fracturing,and field tests have been carried out on mud wells after fracturing and achieved good results.The fracturing fluid imbibition and flooding effect is considered to be important for increasing productivity of mud wells Mechanism,but the effects of boreholes in different wells are also very different,and the potential and influencing factors of imbibition and flooding in the study area need further understanding.This paper uses the tight oil reservoir samples of Lucaogou Formation in Jimsar,based on the combination of macro and micro physical properties tests,systematically carried out the experiments of spontaneous imbibition and imbibition oil displacement under different conditions,and carried out Jimusa The oil tight oil displacement potential of the tight oil has evaluated the influence of physical properties,temperature,surfactant and other factors on the oil displacement potential of the imbibition.The main understandings obtained by the research are as follows:(1)The content of clay minerals in the research area is low,the sensitivity to fracturing fluid is weak,the pore structure is stable during the water absorption process,and it has the foundation for the borehole after the fracturing;experiments show that the samples in the research area have strong spontaneous imbibition With the ability of imbibition and expansion,the fracturing fluid has a positive displacement effect on crude oil.The wax-sealed and wax-sealed samples show that the imbibition displacement potential is 20%,and the imbibition displacement potential is important.one of the reasons.(2)Both spontaneous imbibition and imbibition flooding show a long stable time.Research shows that this has an important relationship with the wettability of the sample and the complexity of the pore structure.The macroscopicity of the study area presents the characteristics of neutral wetting.The tight oil reservoir forming rule holds that the small pores are mainly dominated by water wetting,and the medium-and long-term interaction with oil in the large pores is mainly dominated by oil wetting.The reason why fracturing fluid enters the core from the small pores under the action of imbibition causes the large pores It takes a long time to form a flooding drive;at the same time,the study area belongs to a typical high-porosity and low-permeability reservoir,with complicated pore structure and small throat,which is also one of the important reasons for its long imbibition equilibrium time.(3)Laboratory research has found that the oil displacement efficiency is affected by the physical properties of the rock,the viscosity of the crude oil,the temperature,and the nature of the fracturing fluid.Through reasonable selection of wells,optimization of the fracturing fluid system,and formulation of reasonable The countermeasures for slack wells after compression can effectively exert the potential of imbibition and flooding,and improve the effect of stagnation wells in tight oil reservoirs in the study area.