辽西低凸起与辽中凹陷油气成藏期次的异同

Similarity and Difference of Hydrocarbon Accumulation History in Liaoxi Low Uplift and Liaozhong Sag

为了准确认识油气藏形成和分布规律,在运用泥岩声波时差法和地层趋势外推法确定古近纪末期剥蚀量的前提下,综合生烃史、流体包裹体均一温度、热史、埋藏史、原油性质、储层温压特征等因素探讨了辽西低凸起和辽中凹陷的油气成藏期次.研究表明剥蚀量整体处于150450 m范围;辽西低凸起和辽中凹陷区的油气均为晚期成藏,均是12 Ma以来甚至更晚才有油气充注;不同在于辽西低凸起上的沙河街组油气为两期充注,后一期充注为主,潜山的油气充注晚于沙河街组;而辽中凹陷的油气为一期充注.

In order to get an accurate understanding of the formation and distribution of hydrocarbon reservoirs,on the premise of reconstructing the strata denudation thickness in Liaodong bay area of late-stage of Paleogene based on analysis of sonic time difference and stratigraphy trend thickness method,the hydrocarbon accumulation history in Liaoxi low uplift and Liaozhong sag has been revealed based on hydrocarbon generating history,homogenization temperatures of fluid inclusions,geothermal history,burial history,oil characteristics,temperature and pressure of reservoir as well.The research indicates that the denudation ranges from 150 to 450 m in range,and the key hydrocarbon charging time of the oil and gas in Liaoxi low uplift and Liaozhong sag are after 12 Ma,both are late-stage petroleum accumulation.The difference is： the oil from Shahejie Formation of Liaoxi low uplift was charged twice,the later is the chief one,and the charging of the oil in buried hill is after the one from Shahejie Formation.However,the oil in Liaozhong sag was charged only once.