STUDY ON POOL-FORMING MECHANISM BY TECTONIC COLLAPSE IN THE DONGYING ANTICLINE OF THE BOHAIWAN BASIN

In the Dongying Anticline of the Bohaiwan Basin, hydrocarbon was mainly accumulated in the Dongying and the Guantao formations. And on its eastern and western two sides, i.e., the Xinzhen Anticline and the Xianhe Fault Step Zone, hydrocarbon was mainly accumulated in the Sha-2 Member. Based on the study of hydrocarbon source, accumulation, migration, trapping and preservation conditions, it was considered that the distribution of hydrocarbon pools in the Dongying Anticline was of great differences on the plane from longitudinally, which were closely related to regional structural background, regional cap-rock, fault activities and the time-space matching relations among the three. During the active periods of structures, tectonic collapse resulted in the rapid longitudinal migration of hydrocarbon in wide area, which was characterized by paroxysmal and eventful. As during the calm periods of tectonic activities, most of faults lost the behaviours of passages gradually and hydrocarbon may seep monophasically along a few big active faults. The two mentioned above formed together the complex vertical migration of hydrocarbon in the Dongying Anticline.