油气化探轻烃指标间关系与烃运移地表显示——以松辽盆地东南隆起区十屋断陷为例

RELATIONS BETWEEN THE LIGHT-HYDROCARBON INDICATORS IN PETROLEUM GEOCHEMICAL EXPLORATION AND THE SURFACE EXPRESSIONS OF HYDROCARBON MIGRATION

烃类气体在地表以游离态(free gas)、吸附态(adsorbed gas)、溶解态(dissolved gas)、气液包体(gas-liquid inclusion)等不同赋存方式存在。松辽盆地南部十屋断陷孤家子、后五家户气田区地表油气化探检测结果表明,酸解烃、热释烃和顶空气烃类指标互不相关,可能有不同的烃类来源,更多的是反映了赋存状态的差别。各种烃类指标包含了丰富的油气信息,指标异常分布区与构造区域和气田范围有较好的对应关系。气藏与地表烃类指标异常之间的渊源关系表明,深部油气聚集体中烃类物质垂向微运移至地表,是产生地表烃类指标异常的主要原因。

Hydrocarbon gases exist in the forms of free gas, adsorbed gas, dessolved gas and gas-liquid inclusion in surface. Petroleum geochemical prospecting in Gujiazi and Houwujiahu gas field areas in the Shiwu Fault Depression in Southeastern Songliao Basin shows that the indicators of acid-digestion hydrocarbon, heat-release hydrocarbon and head-space gas are not correlative with each other. This means the hydrocarbons have different sources. The indicators of acid-digestion hydrocarbon, heat-release hydrocarbon and head-space gas contain abundant oil and gas information. The anomaly distributions of these hydrocarbon indicators are corresponding with the structures and gas fields in the study area. The correlation between gas field and surface hydrocarbon anomaly shows that it is the hydrocarbon vertically migrating to the surface from deep oil and gas accumulation that bring the hydrocarbon anomalies into existence in the surface.