水下分流河道单砂体剩余油分布规律与挖潜对策

Remaining oil distribution law and potential tapping measures of subaqueous distributary channel single sandbody

依据层次分析法,对升平油田葡萄花油层葡Ⅰ油组水下分流河道单砂体的层次及平面展布形态进行研究,并通过油藏工程分析及数值模拟,研究各类单砂体的剩余油分布规律、影响因素及相应的挖潜对策。结果表明:研究区单砂体相当于复合河道砂体层次,可分为连片式、交切条带式、孤立条带式3种展布样式,单砂体宽度和厚度逐次降低;砂体越连片,厚度越大,受平面非均质性和沉积韵律影响越严重;砂体越分散,厚度越小,受注采不完善影响越严重;高含水期的剩余油挖潜对策为连片式砂体调整为五点法注采井网,交切条带式调整为枝状分散河道注水、交切区采油的注采井网,孤立条带式调整为点状交错注采井网,同时注水井采用周期注水方式,采油井采取放大生产压差提液,对薄差砂体部位的水井实施酸化改造,油井实施压裂改造。

Based on the analytic hierarchy process, the hierarchy and planar distribution characteristics of single sandbody of Pu I oil group in Putaohua reservoir of Shengping Oilfield were studied. Then the remaining oil distribution, influencing factors and the potential tapping measures were researched by using reservoir engineering analysis and numerical simulation. The results show that the single sandbody is equal to compound channel sandbody hierarchy, and could be divided into flaky form, cross-cutting banded form and isolated banded form. The width and thickness of single sandbody successively reduce. The more contiguous the sandbody and the greater the thickness, the more seriously the plane heterogeneity and sedimentary rhythm influences remaining oil distribution. The more scattered the sandbody and the smaller the thickness, the more seri- ously uncompleted well pattern influences remaining oil distribution. The potential tapping measures are as follows. The well pattern of flaky form single sandbody could be adjusted into five-spot water flooding pattern, with cross-cutting banded form single sandbody ,the branched channel sands inject water, the cross-cutting areas product oil. The well pattern of isolated banded form single sandbody could be scattered and crossed water flooding pattern. The water injection mode could be adjus- ted into cyclic waterflooding and the production wells could be enlarged the drawdown pressure. Injectors in poor sands could be acidified and producers in poor sands could be fractured.