哈拉哈塘地区钻井难点分析与提速关键技术

Drilling difficulty analysis and rate increasing techniques in Halahatang area

哈拉哈塘区块是中国石油塔里木油田黑油增储上产的主要区块之一,该区油藏埋深通常在6 800 m左右,钻井过程中存在中上部地层阻卡严重,容易泥包钻头,二叠系、石炭系井壁稳定性差,易垮塌,深部地层可钻性差,机械钻速低,超长裸眼事故复杂多和目的层含硫化氢、又漏又溢等技术难点。储层超深、地层复杂、钻井难度大、钻井周期长,严重制约了油田增储上产的步伐。针对这些施工难点,进行了优化钻井水力参数、优选钻头和涡轮、旋冲工具复合钻井、事故复杂预防、超长裸眼井壁稳定、碳酸盐岩储层安全钻井技术等研究应用,取得了明显成效,平均单井钻井周期较之前缩短1个月以上,有效控制了事故复杂的发生,实现了该区安全快速钻井的目标,解决了该区钻井速度慢、事故复杂多的技术难题。

Halahatang area is one of the main blocks for black oil reserve increasing in Tarim Oilfield, CNPC. The reservoir depth is usually around 6 800 m. the drilling process is troubled by pipe freezing in middle-upper formations, balled bit, weak wellbore stability in formations of Permian System and Carboniferous System, prone to collapse, poor drillability of deep reservoir formations, low rate of penetration, super-long open hole with more trouble, hydrogen sulphide bearing target, leakage and blowout coexisting, etc. Oil field reserve increasing pace is constrained by super-deep reservoir, complex formation, difficult drilling, long drilling period, etc. According to these difficulties, a series of studies are conducted, such as optimizing hydraulic drilling parameters, selecting bit and turbine, accident prevention, super-long open hole wellbore stability, and carbonate formation safe drilling, and good beneft has been obtained, with aver- age individual drilling period shortened by one month, and good control of accidents happening. The objective of safe and fast drilling was obtained and the difficulties of low drilling rate and accidents prone are solved.