Research on the rule of reservoir enrichment of Chang10 Formation in Ansai oilfield of Ordos Basin
LI Ke-yong1, LI Wen-hou1, CHEN Quan-hong2, LIU Hao-wei3
(1 Department of Geology, Northwest University, Xi′an 710069,Shaanxi, China；2 CNOOC Beijing General Research Institute, Beijing 100027, China；3 Research Institute of Petroleum Exploration and Development，Beijing 100083, China)
Abstract:
Based on the fundamental geological elements of the reservoir forming, some influences and controlment effects on the reservoir forming were analyzed,such as the source rocks, sedimentary systems, association of reservoir rock and rap rock, reservoir perfect area, paleostructure and paleotopography of lake basin. The effective source rock of Chang7 and Chang9 Formation controlled by the distribution of deep lake provided oil sources for Chang10 Formation of Ansai oilfield. Distributary channel sandbodies delta plain was the main places for reservoir forming. What′s more, secondary porosity formed by diagenesis improved properties of reservoirs,good association of reservoir rock and rap was also formed in the delta -lake sedimentary system. Corresponding sequence stratum and development of sand was controlled by paleostructure and paleotopography of lake basin.
KeyWords:
Ansai oilfield； Yanchang Formation； association of reservoir rock and rap rock； the rule of reservoir enrichment
