吐哈盆地某油田低渗砂岩储层特征及敏感性评价

Characteristics and sensitivity evaluation of low permeability sandstone reservoir in an oilfield in Turpan-Hami basin

采用X射线衍射、铸体薄片、压汞试验、扫描电镜等方法对吐哈盆地某油田低渗砂岩储层特征进行了研究,并利用岩心驱替试验方法对储层敏感性进行了评价。结果表明:研究区块储层中黏土矿物含量较高,且以蒙脱石、伊/蒙混层和高岭石为主;储层孔隙度主要分布在5%～10%,储层渗透率主要分布在10×10^(-3)～50×10^(-3)μm^2,属于低孔、低渗储层,储层物性较差;地层水型为NaHCO_3型。敏感性试验评价结果表明:研究区块内储层存在中等偏弱的速敏,水敏损害程度为强,碱敏损害程度为弱到中等偏弱,不存在盐酸敏感性,土酸敏损害程度为弱。针对以上储层特征及储层敏感性研究结果,在低渗砂岩储层开发过程中应注意控制采出速度和入井流体的矿化度,选择合适的钻完井及酸化增产工艺参数。

The characteristics of low permeability sandstone reservoir in an oilfield of Turpan-Hami basin are studied by means ofX ray diffraction, casting thin film, mercury pressure test and scanning electron microscope, and reservoir sensitivity is evaluated bycore displacement method. The results show that the content of clay minerals in the reservoir is high and mainly with montmorillonite,illite / montmorillonite mixed layer and kaolinite. The porosity of the reservoir is mainly distributed between 5% and 10%, and the reser-voir permeability is mainly distributed between 10×10-3and 50×10-3μm2, which belongs to low porosity and low permeability reservoirwith poor physical property, and the formation water type is NaHCO3 . The sensitivity test results show that the reservoir in the study ar？ea has moderate weak speed sensitivity, the degree of water sensitive damage is strong, the degree of alkali sensitive damage is weak tomedium weak, the degree of hydrochloric acid sensitivity is not existed, and the degree of soil acid sensitivity is weak. In view of the above reservoir characteristics and reservoir sensitivity research results, in the development process of low permeability sandstone reser-voir, we should pay attention to controlling the production speed and the salinity of the fluid in the well, and selecting the appropriatedrilling and completion and acidification process parameters.