大庆杏南地区葡Ⅰ组三角洲前缘储层的非均质性

当油田主力油层进入高含水期时,非主力油层接替主力油层将成为必然趋势。三角洲前缘亚相储层非均质性较强,一直以来被作为非主力油层。为提高非主力油层的储量动用程度,必须精细研究三角洲前缘亚相储层非均质性特征,查明剩余油分布规律,从而有效指导油田开发的调整挖潜。利用密井网、岩矿鉴定等资料对杏南地区葡I油层组前缘亚相储层进行研究,将三角洲前缘细分为枝状、朵状、席状3种类型,详细分析了不同沉积环境下砂体的成因类型,描述了不同类型砂体在平面上、空间上的展布特征和组合关系,不同砂体内部性质的差异以及砂体内部微观孔隙结构的类型和分布特征,从平面、层间、层内以及微观特征等方面研究了三角洲前缘储层的非均质性。在此基础上分析了储层非均质性对剩余油分布的影响,指出不同三角洲前缘储层中剩余油的富集位置。

The Study on Heterogeneity of Delta Front Reservoir of PI Formation in the South of Xingshugang,Daqing

When the oilfield major reservoirs are in the high water period,replacing the major reservoirs by the non-major reservoirs becomes an inevitable trend.The reservoirs of delta frontal sub-faces are taken as non-major reservoirs because of strong non-homogeneous.To improve reserve's producing degree,it is necessary to describe fine reservoir heterogeneity,and to ascertain the law of residual oil distribution,then to guide the oilfield development adjustment plan.In this paper,the characteristics of reservoir of delta frontal sub-faces of PI Formation in the south of Xingshugang are studied with the data of dense well pattern and rock-mineral identification.The delta frontal sub-faces can be divided into lobate delta frontal sub-faces,branched delta frontal sub-faces and sheeted delta frontal sub-faces.The genetic types of sand bodies in different sedimentary envivonments are analyzed in detail,and the distribution and space-matching relationship of different sand bodies are studied.The micro-pore structure type is studied on the base of the thin section analysis,so the reservoir heterogeneity is studied including plane heterogeneity,interlayer heterogeneity,in-layer heterogeneity and microcosmic characteristic.The influence of reservoir heterogeneity remained oil is analysed,and enrichment position of remained oil in reservoir of different delta frontal sub-faces is pointed out at last.