泌阳凹陷下二门油田构造特征与油气聚集

STRUCTURAL FEATURE AND PETROLEUM ACCUMULATION IN XIAERMEN OILFIELD, THE BIYANG DEPRESSION

该文依据三维地震和大量钻井资料,结合区域构造背景,分析了下二门油田的构造特征和演化过程,并恢复了构造控制下的油气成藏历史。下二门构造是一个被后期断裂复杂化的背斜,古近纪末期的构造运动在泌阳凹陷主要表现为挤压抬升并形成凹陷的褶皱构造格局,断层则形成于新近纪末期。其构造演化和油气成藏经历了3个阶段:a)廖庄期及廖庄期前沉积沉降阶段,发育低幅度的逆牵引背斜,核一—廖庄期发生早期油气缓慢充注;b)古近纪末期区域挤压隆升阶段,背斜幅度显著加大,油气快速充注形成古背斜-岩性油气藏;c)新近纪末期发生拉张断裂作用,背斜构造复杂化,古油气藏被破坏,油气沿断层调整运聚形成次生断层-岩性油气藏。

Based on 3D seismic data and well information and combining with regional tectonic background, the structural feature and its evolution were analyzed and formation history of hydrocarbon accumulation was restored in Xiaermen oilfield. Xiaermen structure is an anticline complicated by the later faults. The tectonic activity at the end of Paleogene was characterized by compression and uplift, and folds were developed in Biyang depression. The faults in the depression were formed in the end of Neogene. The structural evolution and formation of hydrocarbon accumulations passed through 3 stages, i.e.(1) subsidence and deposition with development of reverse drag anticline in Early Paleogene, early migration and accumulation of hydrocarbon; (2) regional compression and uplift in the end of Paleogene, formation of anticline lithology reservoirs; and (3) extension and fault movement in the end of Neogene, complicated anticline, destruction of reservoir, and formation of secondary fault lithology reservoirs.