井口传扭式钻进捞砂工艺的研究与应用

Development and Application of the Wellhead Torquetransmitting Bailing-while-drilling Techniques

常规机械捞砂工艺是解决负压和水敏油井井筒积砂的理想方法之一,但是对于地层砂沉积时间较长、结盐或结垢的油井却由于无法捅破"硬质砂盖"而导致捞砂无进尺。鉴于此,在优化机械负压捞砂技术的基础上,研发了一种井口传扭式钻进捞砂工艺。该工艺可以传递扭矩到特殊的钻磨式捞砂锥上,通过钻压和扭矩的综合作用压迫、捣碎"硬质砂盖",再通过抽汲方式将碎砂和散砂抽进储砂管内,从而克服捞砂无进尺的无效作业弊端。现场应用结果表明,井口传扭式钻进捞砂工艺可有效捣碎表层硬质砂面,达到顺利捞砂进尺的目的。

Conventional mechanical bailing operations can effectively remove accumulated sands in wellbore with negative pressures or water-sensitive wellbores. But for wells with prolonged accumulation of formation sands, salts or scales, these techniques may fail due to incapability of breaking such ＂hard sandstone cover＂ . Accordingly, the wellhead torque-transmitting bailing-while-drilling techniques have been developed based on optimized mechanical negative-pressure bailing techniques. These new techniques may effectively transmit torques onto special bailing cone with drilling and milling capacities. Through joint actions of WOB and torques, the hard sandstone covers can be smashed. Then, the smashed sands can be sucked into the sand-storage pipes to enhance performances of bailing operations. On-site applications show that the new technique can effectively smash the ＂hard sand-stone cover＂ and enhance bailing performances. Relevant research results for the new technique may provide significant guidance for development of borehole bailing tools in the future.