伊朗TABNAK区块的钻井与固井技术

DRILLING AND CEMENTING TECHNOLOGY USED IN TABNAK BLOCK IN IRAN

伊朗TABNAK区块地层含泥页岩、盐水、石膏且层间压力系数变化大,钻井中常出现页岩垮塌、井漏、缩径等井下复杂情况,固井中易出现水泥浆返高不足、注替效率极低等。针对钻井及固井难题,采用先进的钻井工艺、合理的钻井介质,并结合优化钻具组合和钻头选型等钻井技术措施,成功地解决了钻进中遇到的严重井漏、缩径、井涌等复杂情况,实现了安全快速钻进。通过优化水泥浆体系,采用合理简便的固井工艺技术,成功地解决了大尺寸井眼、低压漏失井的固井难题,提高了固井质量优质率。所介绍的TABNAK区块采用的钻井和固井技术,对类似地层情况的其他区块钻井和固井工作具有一定的指导作用。

At TABNAK block in Iran, mudstones, shales, brine and gypsum are contained in formations, and the pressure coefficient is greatly varied at different layers, which often cause shale sloughing, circulation loss, tight hole, and other complicated downhole problems during drilling, and insufficient cement return and poor displacement in cementing. As regards to those challenges, advanced drilling techniques, appropriate drilling medium, and optimal BHA's and drill bits are adopted, the serious circulation loss, undergauging, and well kicks are effectively controlled, and the safe fast drilling is realized. Through optimization of cement slurry system and adoption of proper cementing techniques, the disadvantages of large size cementing and low pressure lost-circulation well cementing are overcome, the cementing quality is thus improved. Those drilling and cementing techniques adopted in TABNAK block introduced herein will be significant for application in similar formations or other blocks.