深洼区岩性油气藏成藏机理研究与思考

Reservoir-Forming Mechanism of the Lithological Pools in Deep Subdepression

基于断陷盆地深洼区岩性圈闭成因类型分析和成藏过程的研究,指出深洼区岩性油气藏成藏机理主要为隐蔽输导和幕式置换。由此可以引申,深洼区岩性圈闭是油气运聚过程中的小型油气集输站:油源断层将众多岩性油气藏中的油气水幕式汇聚到中浅层大中型构造圈闭;同时,砂岩透镜体等岩性圈闭的地层水不断被排出,造成早期油气聚集在盆地外部、晚期油气聚集在盆地内部的环状分布。该成果有利于指导断陷盆地的隐蔽油气藏勘探。

Based on analyzing the genesis types and reservoir-forming course of lithological trap in the deep subdepression in the downfaulted basin, reservoir-forming mechanism of lithological pool is subtle passage and episodic replacement. The Derived results is that lithological traps are miniature oil-gas gathering and transferring stations in course of hydrocarbon migration and accumulation,the hydrocarbon of numerous litholocgical pools is episodically gathered by the faults, forming large and medium size tectonic pools. At the same time, the formation water of lithological traps, such as the sand lens, is ejected continually. It results in that the oil and gas is annularly distributed outside the basin during the early stage and inside the basin during the late stage. The effort benefits the exploration of the subtle reservoirs in the downfaulted basins.