Shale Mechanics Parameters Test And Brittleness Evaluation

Shale gas as one of unconventional oil and gas resources is extremely rich,more and more attention has been paid to its exploration and development.The inherentcharacteristics of shale gas reservoirdetermine its development ways,which differ from the conventional oil and gas.The long horizontal well and massive volumefracturing technology are viewed as the main approachs to develop shale gas reservoir,Best effect of the long horizontal well and massive volumefracturing technology depends on shale brittle characteristic.Therefore,it is very important to study shale brittleness.The specific contentsare as follows:(1)In this paper,taking underground reservoir shalesample in A well and outcrop shalesample near A well in sichuan basin development block as the research object,the shale sonic properties,uniaxial and triaxial strength test and research of mineral component are conducted.(2)Based on micro nano pumped experiment of shale mineral and study,we can attain scope of elastic modulus and hardness value for silica,calcium and clay minerals of shale content,the research also analyzesthe relationship of the transformation between the shale microscopic elastic modulus and the macro elastic modulus under different confining pressures.(3)Based on research for the mineral components control shale damage friction characteristics and degree of fracture development,we explore a new method to evaluate shale matrix brittleness,which combine the mineral components and micro elastic modulus.we analyze correlation degree between silicon,calcium,clay minerals in shale content composition,density of shale and shale brittle evaluation new method the results,respectively.(4)Based on thephysical parameters and mechanical characteristicsparameters tested in this paper and combining with shale brittleness evaluation method commonly used,we conduct validation of new method by contrast,results of the new method brittleness evaluation are in good consistency with results indoor rock mechanics experiment brittleness evaluation method.Through testing the rock mechanic parameters and brittlenessevaluation of shale,It canhelp borehole wall stability control and prevent,can helpfracture interval optimization and fracturing effectoptimization,also can helpmud density and drilling equipmentoptimization.