大港油田液力提升全封闭取芯钻井技术

Hydrolift Full Closure Coring Technology Application in Dagang Oilfield

为对大港油田官西-沈家铺地区致密油开展研究,在官108-8井应用贝克休斯公司的液力提升全封闭取芯工具实施"单趟钻三筒芯"取芯钻井作业。分析了连续取芯钻进过程中存在的主要技术难点,阐述了连续取芯工具的结构特点、工作原理以及所采用的取芯钻井工艺。现场应用结果表明,该井经过24趟钻实现连续取芯488.50 m,平均岩芯收获率达99.12%,平均单趟取芯进尺达20.35 m,节省了大量的辅助钻进时间。最后提出以下建议:在取芯钻进过程中,钻时变慢时要仔细观察扭矩和微钻时的变化情况,不要急于判断堵芯而割芯起钻;连续取芯钻具组合只适用于直井取芯,斜井取芯作业时卡钻风险很大;每次出芯后必须对取芯工具和取芯钻头等仔细检查测量,将液压提升工具清洗干净,发现损坏应立即更换,防止因工具失效造成丢芯。

To study the tight oil reservoir in Guanxi Shenjiapu area in Dagang Oilfield,'three barrels of cores by single trip'coring drilling operation was conducted in the Well Guan108-8 using Baker Hughes hydrolift closure coring tool. The critical technical difficulties of continuous coring operation have been analyzed. The design features,working principle and coring drilling techniques of the continuous coring tool have been introduced. Field application of 24 times continuous coring drilling in 488. 50 m long well section had an average core recovery rate of 99. 12% with the average single trip coring footage of 20. 35 m,saving a lot of drilling assisting time. Recommendations are put out that,taking close look at the torque and micro-drilling time changes when the drilling time slow down before rush to identify a blocked core and make a core cutting and tripping out. The continuous coring assembly is only applicable to vertical wells and has great stuck risk in deviated well. The coring tools and coring bit should be carefully inspected after tripped out. And it is necessary to clean up the hydrolift tool and replace the damaged part to prevent lost core due to tool failure.