新和——三道桥地区古近系——白垩系油气藏形成条件及控制因素

Formation conditions and controlling factors of Paleogene-Cretaceous oil and gas reservoirs in the Xinhe-Sandaoqiao area

新和—三道桥地区古近系—白垩系已成为塔里木盆地北部重点勘探层系。针对该地区古近系—白垩系油气成藏条件及其主控因素等问题,通过烃源岩特征、储盖层组合、断裂及圈闭作用分析,明确了油气藏形成条件及控制因素。研究结果表明,该地区油源主要来自陆相三叠系—侏罗系的煤系烃源岩。盖层发育有三套,即古近系库姆格列木群及苏维依组泥岩、含膏泥岩和膏岩、白垩系下统巴西盖组上段泥岩及舒善河组泥岩。油气成藏主要受控于断层、圈闭和盖层,圈闭与盖层是关键因素,断裂带控制了油气的富集区域,圈闭控制了油气的聚集,盖层控制了油气藏保存状况。

The Paleocene-Cretaceous system in the Xinhe-Sandaoqiao area has become a key exploration formation in the northern Tarim Basin.The formation conditions of oil and gas reservoirs and their main control factors in the Paleocene-Cretaceous system in this area are clarified through the analysis of hydrocarbon source rock characteristics,reservoir cap rock combination,fault,and trap.The research results show that the oil source in this area mainly comes from the coal-derived hydrocarbon rocks of the terrestrial TriassicJurassic system.There are three sets of developed caprocks:namely,mudstones of the Paleoproterozoic Kumgremu and Suwayi Formations,paste-bearing mudstones and paste rocks,mudstones of the upper part of the Lower Cretaceous Basigai Formation and mudstones of the Shushanhe Formation.The formation of oil and gas is mainly controlled by faults,traps,and caprocks,and the traps and caprocks are the key factors.The fault zones control the enrichment area of oil and gas,traps control the accumulation of oil and gas,and caprocks control the preservation of oil and gas reservoirs.