盐间非砂岩低渗透油藏中原油运移动力学分析

独特的江汉盆地潜江凹陷潜江组盐间非砂岩油藏生储同层 ,盐岩封盖条件极佳 ,但储集层渗透能力极低 ,油气运移条件差。目前的众多证据表明 ,就是在渗透能力如此低下的盐间层中 ,非断裂区的原油也顺层发生了一定规模的运移。在压实作用、流体热增压、有机质生烃生气增压以及毛细管压差等应力作用下 ,盐间原油得以从烃源岩层中排除 ,并在低渗透的盐间层运移主干道中顺层侧向 (或断裂区垂向穿层 )从生烃次洼向构造高部位等低势区聚集。从动力学的角度证明了盐间非砂岩低渗透油藏中原油顺层运移的可能性 ,并指出了盐间石油的运移方向和有利聚集区。

DYNAMIC ANALYSIS OF THE MIGRATION OF CRUDE OIL ALONG INTER-SALT LAYER IN INTER-SALT NON-SANDSTONE LOW PERMEABILITY RESERVOIR

In the exceptional inter-salt non-sandstone reservoir, source rock bed is also a reservoir bed and the seal is very completed, too, but reservoir bed's permeability is very low, so the conditions of oil migration are poor. However many pieces of evidence indicate the inter-salt oil of non-fractured areas migrates on a large scale along such a low permeability inter-salt non-sandstone reservoir. Under the stress effect of compaction, fluid thermal pressure boost, organic matter generation pressure boost, and capillary pressure differential and so on, the inter-salt crude oil can be released from inter-salt source rocks, and can migrate from generation depression to high structural areas along the low permeability inter-salt reservoir in the non-fractured zone (or across salt beds in the fractured areas). The possibility of migration of the inter-salt oil along the low permeability inter-salt bed has been testified from the analysis of migration dynamics and migration directions and the best accumulation areas have also been proposed.