珠江口盆地陆丰A油田低渗砂岩油藏储层分类评价

The Classification and Evaluation of Low Permeability Reservoir in Lufeng A Oilfield, Pearl River Mouth Basin

为了制定科学合理的油田总体开发方案,针对陆丰A油田文昌组低渗砂岩储层物性较差、微观非均质性较强、开发可动用储量难以确定的问题,综合运用扫描电镜分析、铸体薄片鉴定及压汞测试等资料,对储层孔隙结构特征进行分析。结果表明:渗透率与孔喉分选系数、最大孔喉半径、孔喉半径均值、排驱压力和退汞效率的相关性较好,相关系数分别为0.78、0.83、0.87、-0.87和-0.61。综合沉积微相、岩性、物性、含油性及测试数据,将储层划分为3种类型,其中,Ⅰ类、Ⅱ类具有工业性自然产能,Ⅲ类需进行储层改造。建议主要动用Ⅰ类储层,兼顾Ⅱ类储层,暂不动用Ⅲ类储层,该认识对油田的高效开发具有重要的指导意义。

The low permeability sandstone reservoir of Wenchang formation in Lufeng A oilfield, Pearl River Mouth basin has poor physical properties, strong micro-heterogeneity and the developing available reserves are difficult to determine. The formulation of oilfield development plan is lack of basis. The reservoir pore structure characteristics were analyzed by means of scanning electron microscopy(SEM), casting thin section identification and mercury injection test. The results showed that the reservoir permeability has a good relevance to reservoir sorting coefficient, maximum pore throat radius, average pore throat radius, displacement press and mercury removal efficiency, and the correlation coefficients are 0.78, 0.83, 0.87,-0.87 and-0.61. According to the above parameters, the reservoir can be divided into three types by sedimentary microfacies, lithology, physical property, oiliness and testing data. Class Ⅰ and class Ⅱ have industrial natural productivity, class Ⅲ requires reservoir modification. This paper suggests that class Ⅰ reservoir should be mainly developed, class Ⅱ reservoir should be taken into account, and class Ⅲ reservoir should be temporarily non developed, which provides a strong decision basis for rational and efficient development of the oilfield.