新海27块低饱和度稠油油藏成因探讨

Approach to low saturation heavy oil reservoir genesis in Xinhai 27 Block

新海27块作为中国石油天然气集团公司确定的2007年老油田二次开发示范工程,目前已进入规模推广阶段,为了进一步改善油田开发效果,有效提高采收率,以测井解释、岩心分析、生产测试等为基础,对研究区稠油油藏低饱和度特征进行了分析,并对其低饱和度成因进行了深入研究,确定成藏位置距生油中心远,构造幅度小,储层岩石颗粒分选差、孔隙结构差异大,油藏强亲水,束缚水饱和度高,油、水密度差小,后期构造运动等是导致低饱和度油藏主要原因。

Xinhai 27 Block was a demonstrative engineering project of old oilfield redevelopment defined by CNPC in 2007, and has been in a stage of popularization at present. The characteristics and genesis of low saturation heavy oil reservoirs in the study area have been analyzed based on log interpretation, core analysis, and production test. The main reasons resulting in low saturation reservoir involve that the location of hydrocarbon accumulation is far from oil generation center, the structural relief is low, reservoir rock is poorly sorted, pore structure differs a lot, the reservoir is strongly water wetting, irreducible water saturation is high, the density difference between oil and water is low, as well as late tectogenetic movement.