The Research Of Sedimentary Facies And Reservoir Characteristics About Chang8Reservoir In Liu Zhuang

It is known that chang8reservoir of yanchang groupr is the main oil layer of exploration and development in the Liu zhuang area, Basied on the study of fine stratigraphic classification and correlation,the paper has carried on the thorough analysis of each small layer structure characteristics, distribution characteristics of sedimentary facies and reservoir characteristics.Based on comprehensive study,the structure of changS reservoir in liu zhuang has feature of the east west high low monoclinal structure, grade6to8m per kilometer, due to the inequality of the sedimentary sand body and the differences of diagenetic compaction, each small layer forming area, small nose-like uplifts in different tectonic elements.Through observation of the core in the study area and combination with characteristics of log facies, chang8reservoir group is delta front deposition, and also identify the underwater distributary channel, distributary bay, mouth bar, underwater crevasse splay and subsea natural barrier, six microfacies types. On the basis of the discussion of each small layer of chang8reservoir in time and space,the distribution rule of sedimentary microfacies will be discussed.The main rock type in chang8reservoir is shallow celadon fine-grained feldspar sandstone, dissolution, residual intergranular pore and intergranular hole dissolution intragranular pore is the main reservoir pore types, pore and fine throat is the main type of pore structure.physical property analysis results show that the research district chang8oil layer belongs to low porosity, low permeability reservoir, chang81average-pore permeability is longer than the81low, chang8reservoir mainly experienced compaction, cementation, dissolution and fracture effect,chlorite cementation of rim-feldspar dissolution facies, feldspar dissolution-iron iron cementation of calcite crystal stock calcite cementation facies, and argillaceous cementation compaction phase are distributed. the diagenetic facies have different combinations of diagenesis and reservoir development characteristics. Reservoir sensitivity analysis showed that the chang8sandstone reservoir is of weak velocity sensitive, strong water sensitivity, moderate salt sensitivity, acid sensitivity and medium to strong alkali sensitivity. According to the classification criteria of reservoir in shanbei region, the conclusion indicates that the study area mainly exist Ⅱ b Ⅲa and Ⅲb types of reservoir.