另外一种类型的差异聚集作用：油气的差异溶解作用

Another type of oil and gas differential accumulation:Differential dissolution

经典的油气差异聚集理论描述了油气在一系列不同盖层条件圈闭中的聚集现象:在盖层封闭性较好的圈闭序列中油气的聚集过程表现为差异聚集作用,在盖层不好的圈闭序列中油气的聚集过程表现为差异渗漏作用。当新生成的油气再次充注到老的油藏里时,将采用另外一种类型的差异聚集方式进行聚集——差异溶解作用。差异溶解作用的实质是油、气分子之间的溶解不平衡,其表现形式为新生成的油气在原有油藏里边溶解边聚集。差异溶解作用的结果是造成油气分布的复杂性,并呈规律性的变化:圈闭近源区充满干气或凝析气,远源区为油。

The classical differential accumulation theory describes a process of oil and gas accumulating in a series of correlative traps as that differentially accumulating in a series of traps with better sealed caprocks,or that differentially leaking in a series of traps with bad caprocks.When the new oil or gas recharged into an old reservoir,it should be accumulated by another process of differential accumulation,which is the differential dissolution.The differential dissolution indicates that the new oil and gas would be dissolved as well as entrapped in the pre-existing reservoir when they migrate to the traps,i.e.,the new oil and gas will accumulate in an old reservoir by a process of dissolution.The hypostasis of differential dissolution is that the molecules of oil and gas dissolve and diffuse differently.The differential dissolution makes oil and gas distributed in the reservoir complicatedly,but with certain regularity：the traps close to the source would be fully filled with dry gas or condensational gas,and those far away from the source would be filled with oil.