Characteristics And Compression Resistance Analysis Of Shale In Shahejie Formation Of Bonan Sag

As a new type of unconventional oil and gas resources,shale gas is paid more and more attention.Es formation of Bonan sag develop a large set of shale.It has the geological condition to form commercial shale gas and huge resource potentiality.But it haven't been broken through at present.The compression resistance of shale is the key factor to evaluate shale gas wells.The fracturing technology is the main bottleneck which restricts exploitation of shale gas.It's necessary to analyse the compression resistance of shale.We synthetically analysed core data and result of slice observation and ascertained mineral composition of shale gas.We divided shale in Es formation of Bonan area into five lithofacies types,massive slime limestone,massive gray mudstone,lamellar slime limestone,lamellar gray mudstone,layered shale.Based on analysis of mineral composition characteristics of all lithofacies,we divided lithofacies in key wells.Combined with analysis of electron microscope.South bohai region shahejie formation shale fracture types are divided into structural fractures,mineral seam shrinkage joint,abnormal pressure,interlayer seam,structural fracture is one of the most important reservoir space types.The porosity of different lithofacies and reservoir space types,lamellar phase of the shale reservoir performance evaluation for good,grain layer calcareous mudstone and grain layer argillaceous limestone facies evaluation for the better,the massive argillaceous limestone as general block calcareous mudstone evaluation for the poor.South bohai region TOC distribution between 2%-8%,main body between 2-4%,TOC and negatively correlated with brittle mineral content,and clay mineral content were positively correlated.We did some experiments on the compression resistance of shale(triaxial stress experiment,uniaxial tensile strength experiment,the velocity of seismic p-wave and s-wave experiment).Young's modulus with carbonate mineral content,quartz,feldspar content increases,the poisson's ratio decreases with the increase of content of quartz,feldspar,but we in the bohai sea south in shahejie formation sand a shale rock brittleness mineral and young's modulus and poisson's ratio found in contrast,the relationship between young's modulus decreases with the increase of the content of quartz,poisson's ratio increases with the increase of content of quartz,this is due to the bohai sea south in a sand shale buried shallow,low maturity,the result of weak diagenesis.Grain layer thickness and the relationship between rock mechanics parameters is not significant,the thickness of the laminated effect on shale resistance to pressure is not a major role.Horizontal core direction of young's modulus is greater than the vertical direction of the core of young's modulus,elastic modulus decreased with increasing Angle of the core.Layer parallel to the grain direction of the tensile strength of core is lower than perpendicular to the direction of the laminated core of tensile strength;Parallel to the direction of laminated core of slightly less than the compressive strength of the perpendicular to the direction of the laminated core of compressive strength.Based on evaluation of the compression resistance of shale from two aspecst.brittleness index of shale and fault tenacity.