泡沫钻井液配合生物酶在煤层气钻井中的应用  

Application of Foam Drilling Fluid Combined with the Bio-enzyme in CBM Drilling

作　　者：宋一男 窦亮彬[2] 

机构地区：[1]中石油煤层气有限责任公司 [2]西安石油大学石油工程学院

出　　处：《石油机械》2014年第7期7-11,共5页China Petroleum Machinery

基　　金：国家重点基础研究发展计划(973计划)项目"深井复杂地层安全高效钻井基础研究"(2010CB226704);国家自然科学联合基金重点支持项目"页岩气钻探中的井壁稳定及高效钻完井基础研究"(U1262201)

摘　　要：针对煤层气井施工过程中易垮塌、裂缝渗漏及水平段携岩困难等问题,研究并应用了泡沫钻井液配合生物酶钻井液技术。利用泡沫钻井液能够降低正压差,降低储层的应力敏感性,减少滤液侵入储层和水锁伤害的特点,并且生物酶可对钻进过程中侵入地层和粘附在井壁上的钻井液物质进行生物降解,实现解堵。在优选生物酶的基础上,将泡沫钻井液应用于WL05-1H井进行了试验研究。研究结果表明,在水平段长达627 m的长井段煤层钻进过程中,未进行短起下,井眼稳定通畅,泡沫钻井液防塌抑制能力强,悬浮携带能力较强,能满足施工需要;泡沫钻井液配合生物酶技术具有很好的降解能力,能够很好地保护煤储层的原始状态。泡沫钻井液配合生物酶技术为韩城地区水平井钻探提供了技术保障。CBM well is prone to collapse, leak in fractures and difficult cutting transporting in horizontal section. To address these issues, the foam drilling fluid combined with biological enzymes is researched and ap- plied. The applied foam drilling fluid can reduce the bottom hole differential pressure, the reservoir stress sensitivity, filtrate invasion and water blocking. Bio-enzymes can biodegrade the drilling fluid invaded in the formation and adhered on wall of well during drilling, achieving plugging removal. Based on the bio-enzyme optimization, the foam drilling fluid is applied in well WL05 - 1 H for test. The results showed that no short trip has been conducted during drilling the up to 627 m horizontal section of coal bed with stable and clear wellbore. The foam drilling fluid performs a strong caving-preventing capacity with great inhibiting ability and has a great cutting transporting capaci- ty to meet the operation requirements. Combined with the biological enzyme, the foam drilling fluid could protect the coal reservoirs and keep it in original state with great degradation ability. The technology of foam drilling fluid combined with biological enzyme has provided technical support for the horizontal well drilling in Hancheng area.

关 键 词：煤层气 水平井 泡沫钻井液 生物酶 降解能力 

分 类 号：TE254[石油与天然气工程—油气井工程]