义289井井壁稳定钻井液技术

Drilling Fluid Technology of Borehole Stability About Yi 289 Well

义289井是胜利油田重点评价井,位于济阳坳陷沾化凹陷义107鼻状构造带义289断块高部位。该区块地质构造复杂,上部地层造浆严重;沙河街组存在膏泥岩、油页岩和硬脆性灰岩,井壁失稳严重;井底存在异常高压,邻井完井电测井底温度超过180℃,高密度钻井液流变性调控困难。通过使用聚合物防塌钻井液和双聚防塌钻井液,配合现场钻井液维护处理工艺,保证该井顺利完钻,施工中井壁稳定,井下安全,为提高该区块勘探与开发进程提供了技术保障。

Yi 289 well was an important appraisal well in Shengli Oilfield. The geologic structure was complex. Mud-making clay formation was heavy and upper. Borehole was easily instable in Shahejie Formation because of creaming drilling fluidstone, kerogen shale and hard and brittle limestone. It had abnormal high-pressure in downhole because downhole temperature in adjacent well was higher than 180 ~C , and the regulating and controlling rheology behavior of high density drilling fluid was very difficult. After polymer and anti-caving drilling fluid and double polymerization drilling fluid was applied, with the help of onsite drilling fluid techniques, the well was successfully finished. Borehole was stable during the course of drilling. At last, the success of drilling the well provided technology support to drill other wells safely and effectively in the oilfield.