The Study Of Physical And Mechanical Properties Of The Sandstone After Being Saturated With Graphene

During fracturing of the tight oil and gas reservoirs,natural fractures are expected to be disturbed and reactivated,which is beneficial to tight reservoirs stimulation.At present,in most publications,numerical simulation was explored to study the activation of natural fractures,only considering changes in pore pressure.In this paper,graphene were dispersed and injected into the sandstone samples retrieved around natural fractures,studying this problem on wettability and friction.The effects of graphene on the mechanical properties and microstructure of sandstone samples were studied by measuring the wetting angle,uniaxial compressive strength test,Brazilian tests,the friction angle,three-point bend tests and microstructure analysis.The results show that sandstone after being saturated with graphene solution,(1)the mechanical properties are obviously weakened,unconfined compression strength decreases 9.55MPa(33.2%),which is caused by decreasing of internal frictional angle,cohesion and effective stress.(2)From a microscopic point of view,the injection of graphene reduces contact angle and increasing bend radius,meanwhile lowing the firction between grains,resulting significantly in weakened mechanical properties.(3)The thermal conductivity are enhanced,due to graphene as a thermal bridge between the particles.