STUDY ON THE EVOLUTIONARY HISTORY OF SOURCE ROCK AND THE POOL FORMING PERIODS OF HYDROCARBON IN THE DAQING BLOCK OF THE TARIM BASIN

Based on the analysis on the general geological and geochemical characteristics of hydrocarbon source rock in the Daqing block of the Tarim Basin,the burial history,thermal evolutionary history,hydrocarbon generating history and hydrocarbon expulsion history are restored in this paper.The study reveals that the source rock of Daqing block has the burial characteristics of "the early stage with little subsidence,the middle stage with slow oscillation and the late stage with large subsidence" and the mature and evolutionary characteristics of the Lower Paleozoic source rock with slow evolutionary progress and the Upper Paleozoic source rock with fast one.Affected by above factors,source rock has two major hydrocarbon generating periods and three hydrocarbon expulsion periods,and accordingly every pool forming period of hydrocarbon has three stages.As each pool forming period has different assemblage of generating,storage and capping and different preservation conditions and distributive ranges for the hydrocarbon entered,corresponding strategies should be taken in exploration.