冀东南堡油田某区块沙一段为高温(160℃)、特低渗油藏,突出的地质特征是非均质性强,油层多且单层薄,物性差,敏感性中等偏强,在钻井、完井、采油及后期修井作业中储层污染严重,产量下降快。[6]为彻底解除地层污染,恢复油气井正常生产,研制形成了超高温低渗透砂岩储层复合酸深部酸化技术。针对重度污染储层,采用快反应的低浓度土酸与一种或几种缓速酸形成的复合酸做为主体酸,在低浓度土酸快速解除近井污染的同时,利用缓速酸穿透距离长的特点,对储层深部污染进行解堵,最大程度恢复储层渗透率,最大限度恢复油气井产能,该项研究成果达到国内领先水平。现场应用3井次,有效率100%,目前已累计增油30345吨,取得了良好的效果。 The sandstone section of a block in a block of Jidongdongpu Oilfield is characterized by high temperature (160 ℃) and ultra-low permeability. The prominent geological features are high heterogeneity, more oil layers and thin single layer, poor physical properties and moderate sensitivity. In the well completion, oil recovery and post-well workover, the reservoir is seriously polluted and the output declines rapidly. [6] In order to completely remove the stratum pollution and resume the normal production of oil and gas wells, a deep acidification technology of composite acid for the ultra-high temperature and low permeability sandstone reservoir has been developed. For heavily polluted reservoirs, the compound acid formed by the low concentration of soil acid with one or several kinds of retarded acid is used as the main acid. When the low concentration of earth acid is used to quickly release near-well pollution, It has the features of long distance and long distance, and removes the deep reservoir contamination, restores the reservoir permeability to the utmost, and restores the production capacity of oil and gas wells to the maximum extent. The research achievement has reached the advanced level in China. The field application of 3 wells, the efficiency of 100%, the current total oil has been 30345 tons, and achieved good results.