Deep reservoir characteristics and its controlling factors at Gaoliu area,Nanpu depression

The deep Shahejie formation consists of low porosity and low to extremely low permeability sandstones at Gaoliu area,Nanpu depression.The porosity is 3%-18%and the permeability as(0.1-100)×10~(-3)μm~2,The porosities in deep horizon include the secondary intraparticle porosity,the interparticle porosity,the moldic porosity,and the dissolved cement porosity and fractures.Controlling factors of deep horizon reservoir include diagenesis and abnormal pressure. Severe dissolution generates a secondary porosity interval between 3 250 m and 3 800 m.Faults and uncomformities, served as the leaching path of ground water,alone with the abnormal high pressure,is a key factor to the secondary porosities distribution.Superior reservoirs are possibly in the places near the Gaobei fault,the footwall of Shuohe fault, Tanghai area,and Shichang sub-depression near the foot-wall of the Baigezhuang faults.