Study On Water Quality Adaptation And Plugging Mechanism Of Solid Suspension

At present,one of the most basic development methods of global on Sore oilfields is water injection development.When the natural energy of the reservoir is gradually depleted,water injection is often used in secondary oil recovery,which is one of the important measures to stabilize oil production in oilfield development.At the same time,low-permeability reservoirs account for a fairly high proportion of proven oil and gas reserves worldwide.With the conventional oil reservoirs in China generally entering the middle and late development stages of secondary oil recovery and tertiary oil recovery,the rational and efficient development of low-permeability oil and gas reservoirs has become a key task of major oil fields in China.The S area of the domestic P oilfield is a typical low-permeability water injection development oilfield.Since 2011,solid-phase suspensions in the injected water have blocked the formation pores,resulting in a significant decline in the water injection capacity of the single well.It is urgent to repleni S the formation energy and improve the water injection capacity.Further improve the development effect of the S area.The purpose of this paper is to determine the water quality index requirements for solid suspensions in different blocks within the S-zone by conducting laboratory tests.The water quality indicators include solid-phase suspension particle size and solid-phase suspension mass concentration,and pass the core CT scan test.To study the microscopic mechanism of the effect of solid suspension on the permeability reduction of the formation.In this paper,the solid phase suspension content and the solid phase suspension particle size were determined by carrying out the mass concentration of solid phase suspension in the injected water and the particle size of the solid phase suspension.Due to the lack of sufficient natural cores for use,this paper identifies the core particle size distribution,mineral composition,especially clay mineral composition,by particle size analysis and X-ray diffraction experiments on natural cores.The core,and carry out the artificial core availability verification experiment,and then carry out the water quality adaptation experiment research on the solid phase suspension.Through CT scanning of natural core,the damage mechanism of solid suspension to core permeability was studied,and the results were verified by acid flooding experiment.Through indoor experiments,different types of areas within the area were identified,and the water quality index requirements of solid suspensions were formed,and a standard plate was formed.It was clarified that the solid phase suspensions reduced the permeability by changing the core pore connectivity.Mechanism.