Characteristics of Pore Structure in Xujiahe Formation,Guangan Area

For Xujiahe Formation in Guangan area,its reservoirs mainly include Xujiahe 6 and Xujiahe 4 members.Characteristics of rock pore structure are the key factor affecting the reservoir capability of reservoir fluid(including oil,gas andwater),the hydrocarbon production and the permeable capability of reservoir rock.As a result,to make sure the characteristics isvery essential to increase both productivity and recovery efficiency.A conventional physical-property analysis forcore-sampling interval shows that the reservoirs in this studiedarea,which is characterized by very strong heterogeneity,belong to extra low-porosity and extra low-permeability to low-porosity and low-permeability ones.And there are in part some mediumporosity and low permeability reservoirs.Parameter variation ofpore structure was analyzed by mercury-injection experiment and the development of reservoir and the distribution and variation of pore and throat were also studied.In addition,the porosity,permeability and some pore structure parameters were calculated by a univariate regression method.After that,the relation diagram between pore structure index and reservoir productivity index wasdrawn up in terms of porosity and permeability.The result indicates that there is a high negative correlation between thesetwo indexes.