塔里木盆地大庆区块烃源岩演化史与油气成藏期研究

本文在分析了塔里木盆地大庆区块烃源岩的一般地质地球化学特征的基础上,恢复了烃源岩的埋藏史、热演化史、生烃史和排烃史.研究表明:大庆区块烃源岩在埋藏上具有“早期沉降小、中期振荡缓、晚期沉降大”的特点,在成熟演化上具有下古生代源岩演化进度慢、上古生界源岩演化进度快的特点.受上述因素的影响,烃源岩具有两次主要生烃期和3次排烃期,相应地油气成藏期有3个阶段.各成藏期由于油气进入的生储盖组合不同,保存条件和分布范围不同,在勘探中应有相应的对策.

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.