Shale pore characteristics of Shahejie Formation: Implication for pore evolution of shale oil reservoirs in Dongying sag, north China  

作　　者：Shun Zhang Huimin Liu Min Wang Xinjin Liu Huilai Liu Youshu Bao Weiqing Wang Runze Li Xin Luo Zhengwei Fang 

机构地区：[1]Research Institute of Petroleum Exploration and Development,Sinopec Shengli Oilfield Company,Shandong,Dongying,257022,China [2]Postdoctor Scientific Research Stations,Sinopec Shengli Oilfield Company,Shandong,Dongying,257000,China [3]Petroleum Development Center of Shengli Oilfield,Shandong,Dongying,257022,China [4]Petroleum Development Center of Shengli Oilfield,Beijing,100007,China [5]Chongqing Gas Field of PetroChina Southwest Oil&Gasfield Company,Chongqing,400021,China

出　　处：《Petroleum Research》2019年第2期113-124,共12页石油研究（英文）

基　　金：The work was supported by the National Science and Technology Major Project of China(No.2017ZX05049);the National Basic Research Program of China(973 Program)(No.2014CB239102);the National Natural Science Foundation of China(No.41572087).

摘　　要：The pore characteristics of shale reservoirs in the lower submember of Member 3 to upper submember of Member 4 of Shahejie Formation in Dongying sag are analyzed,influences of mineral content and organic matter content on porosity and pore size are also investigated,and through the diagenetic thermal simulation experiment,the main pore evolution is further discussed.The results show that the pore structure of shale reservoirs is complex,the micron-nanometer pores can storage liquid hydrocarbons,and the free-phase crude oil is mainly distributed in intergranular dissolution pores of calcite,recrystallized intergranular pores,intergranular shrinkage fractures of clay mineral which have large pore size.Framework minerals and organic matter content directly influence porosity and pore size of shale reservoirs,relationship between porosity and content of felsic mineral as well as content of organic matter content is linear and positive,while relationship between content of carbonated mineral is negative.At the buried depth from 2500 to 3500 m,concentration of organic acid from hydrocarbon generation and expulsion of organic matter,increasing range of pressure coefficient,are well corresponding to highporosity intervals;pore formation in shale oil reservoirs are almost controlled by diagenetic evolution of clay minerals;framework storage spaces formed by carbonate grain crystals as well as intergranular and intergranular dissolution pores of carbonate increases porosity of shale oil reservoirs;local increase of porosity at the depth of 3500e3800 m is mainly caused by coupling of hydrocarbon-generating overpressure and dissolution,and size,distribution and connectivity of pores are enhanced obviously.

关 键 词：Shale oil Pore and fracture DIAGENESIS Clay mineral transformation Dissolution Recrystallization Hydrocarbon-generation and acid expulsion PALEOGENE Dongying sag 

分 类 号：P61[天文地球—矿床学]