摘要
针对六盘水煤田实施煤层气L型水平井时存在井位选择难、浅层漏涌严重、精准着陆难、水平段托压严重、储层污染、产套固井质量差等难题，从井位与钻机适配选型、封堵及钻井方式、轨道设计、钻具组合、钻井液、完井管串、固井配方及工艺等方面进行了研究。通过钻井设备优选，有效节约了用地面积；采用套管跟钻技术，有效解决了永宁镇组浅层漏涌同存的难题；采用六段制的轨道剖面及实时追踪对比技术，有效规避了单增单稳轨道调整后出现全角变化率急剧变化的现象，同时也提高了二开一次性着陆成功率；采用优配后的钻井液体系，有效降低了储层污染,增强了轨道润滑性；三开采用“两弹扶+一滚珠”间装扶正模式及固井三段法，保证了产套的固井质量；PZ￣H井的成功实施，有效解决了该区水平井钻井所面临的难题，为后续煤层气水平井降本增效开发提供了宝贵的工程经验和技术支撑。
Abstract
In view of the difficulties such as difficult well location selection, serious shallow gushing, difficult precise landing, serious horizontal section support pressure, reservoir pollution and poor cementing quality in the implementation of coalbed methane L-type horizontal well in Liupanshui coalfield, this paper studies the adaptation and selection of well location and drilling rig, plugging and drilling mode, track design, drilling assembly, drilling fluid, completion pipe string, cementing formula and technology, etc. Drilling equipment optimization can save land area effectively. The problem of shallow leakage and gushing in Yongningzhen Formation was effectively solved by using the technology of casing and drilling. Using the six-stage system orbit profile and real-time tracking and comparison technology, it can effectively avoid the phenomenon that the dog leg changes sharply after the adjustment of the single increase and single stability orbit, and also improve the success rate of one time landing of second spud. The optimized drilling fluid system can effectively reduce reservoir pollution and enhance track lubrication. In the third spud, "two bullets + one ball" is used to install the centralizing mode and three-stage syetem of cementing to ensure the cementing quality of the production casing. The successful implementation of the well PZ-H effectively solves the difficulties faced by horizontal well drilling in this area, and provides valuable engineering experience and technical support for the subsequent development of the horizontal well of coalbed methane with cost reduction and efficiency improvement.
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