塔河油田三叠系低阻油气层油水倒置分析

The Analysis on Oil-water Inversion of Low Resistivity Reservoir in Triassic,Tahe Oilfield

储层岩性、物性等纵横向非均质性控制了油水分布的复杂性和多样性,尤其在低渗透油藏中,可造成油藏顶部富含可动水。塔河油田盐上地区三叠系油藏普遍发育低阻油气层,生产测试表明,油藏高部位的部分低阻油气层存在油水同出情况,而低阻油气层下部的正常油气层测试为纯油层,将此种不符合油藏高部位为油、低部位为水的复杂油水关系现象称为油水倒置。油水倒置是由低幅度油藏条件下储层岩性、物性等纵横向非均质性造成。在探讨油水倒置成因基础上,结合本区沉积与构造类型,将本区油水倒置分为背斜圈闭型和河道砂体型,并针对不同类型油藏优化开发工艺,重点开采正常油气层。

The longitudinal and lateral heterogeneity of reservoir lithology and quality control the complexity and di-versity of oil-water distribution,in particular in low-permeability reservoirs,which can create a reservoir top of movable water-rich condition.Yanshang area of Triassic reservoir in Tahe oilfield develop widely the low resistivity reservoirs, and the production tests have shown that parts of low resistivity reservoir,which are located on the upper part of oil res-ervoir,produce both oil and water at the same time,however,the lower part of low resistivity reservoir produce oil only, so the author call this phenomenon that does not accord with the situation which oil lie high in the reservoir and water lie low as oil-water inversion.The auther consider that the oil-water inversion which is inverted under the low amplitude res-ervoir conditions,result from the longitudinal and lateral heterogeneity of reservoir lithology and quality.On the basis of oil-water invertion,the author combined the sedimentary characters with tectonic type in this district,dividing the oil-wa-ter invertion into two types：anticlinal trap type and channel sand body type.In addition,the auther recommended that the development process should be optimized for different types of reservoirs,with a focus on exploitation of normal reser-voirs.