小洼地区古潜山裂缝特征及油气成藏模式

Fracture characteristics and hydrocarbon accumulation pattern of erathem buried hill in Xiaowa area

辽河盆地中部小洼地区古潜山裂缝系统主要由中生代台安-大洼断层左行走滑活动形成,新生代强烈伸展对裂缝产生叠加改造作用,改善了裂缝储集性能。岩心薄片鉴定表明古潜山岩性主要为混合花岗岩,潜山裂缝发育较规则、连通性较好、开度大,裂缝倾角多在60°~85°,以高角度缝为主,油气显示良好。油气成藏研究表明,小洼古潜山靠近生油洼陷,油气供给充足,存在断层运移、顶部不整合面运移、内部裂缝运移等多种油气运移通道及多套储集体系,具有较大的油气成藏潜力。

The buried hill fracture system in the middle of Liaohe basin is mainly affected by Mesozoic left transtensional activities.The new generation strong stretching role has the modification of the superposition effect on cracks,and it is good for improving fracture reservoir performance.Core slice identification show that the lithology of buried hill is mainly of mixed granite,with regular buried hill fracture development,good connectivity and wide open degree.The fracture dip is more at 60° ~ 85°,mainly of high angles and good hydrocarbon shows.Oil and gas accumulation research suggests that small depression buried hill is near source sub-sag,with adequate oil and gas supply.There is fault migration,the unconformity surface migration at the top,migration of internal cracks,other oil and gas migration channel and multiple sets of reservoir system.And therefore,it has great potential for hydrocarbon accumulation.