渭北煤田蒲白矿区雷衙井田钻探施工技术

摘要

The Leiya minefield, Pucheng-Baishui mining area is a typical Weibei Permo-Carboniferous coalfield with complex strati-graphic configuration. Many operational hard nuts have existed such as extra-thick overburden, fractured strata, serious loss of circula-tion, pulverous coal hard to coring, thus great difficulty in drilling. In allusion to the strata characteristics, repeated practices and studies have been carried out, some countermeasures put forward such as:wall protecting mud drilling in extra-thick overburden, use of high performance low solid mud in fractured strata, rib PDC bit, expanding of annular space, leak stoppages including casing sealing, bridge plug, cement, flushing fluid wall protection and inert material plugging, wire-line coring in pulverous coal seams. Thus a suit of drilling technology propitious to the area’s complex strata has found and made average rig efficiency per month from 470.88m in 2010 increased to 688.51m in 2011, better operation effect and considerable economic benefit obtained and provided a reference for drilling operation in the area henceforth.%蒲白矿区雷衙井田属典型的渭北石炭-二叠系煤田，地层结构复杂，在钻探施工中存在着覆盖层巨厚、地层破碎、漏失严重、粉未煤层难以采取等诸多难点，钻探施工难度大。在施工中，针对地层特点，进行了反复实践研究，提出了在巨厚覆层下泥浆护壁钻进，在破碎地层采用优质低固相泥浆保护孔壁，采用肋骨复合片钻头，增加环空间隙，在漏失地层采取了套管封隔、桥塞堵漏、水泥堵漏、冲洗液护壁堵漏和惰性材料堵漏，在粉未煤层采用绳索取心工艺等措施，从而找到了一套适合该地区复杂地层施工的钻探技术工艺，使平均钻月效率由2010年的470.88m，提高到2011年的688.51m，取得了较好的施工效果和可观的经济效益，为今后在该地区钻探施工提供了技术上的借鉴。