甘肃张掖三岭湾ZC1井超厚沉积层岩心钻探施工技术

Core drilling technology for ultra thick sedimentary layers of ZC1 well in Sanlingwan， Zhangye， Gansu

摘要:

沉积地层稳定性较差，易出现缩径、崩塌、掉块、吸附卡钻等事故，在沉积地层中开展取心钻进工作，一直是钻探领域的技术难题。本文介绍了甘肃张掖地热岩心钻探工程（ZC1井）在超厚沉积层岩心钻探施工技术，该项目通过创新应用多种钻进工艺方法，开展了冲洗液体系、深孔取心机具、跨口径绳索取心钻进等的研究应用，解决了超厚沉积层导致的孔壁失稳、吸附卡钻、钻具失效、钻进效率低等难题，形成了针对超厚沉积层连续取心钻进工艺体系，为后续同类型复杂地层钻孔施工提供了借鉴。

Abstract:

The sedimentary strata has poor stability， and accidents such as shrinkage， collapse， block falling， and adsorption sticking are prone to occur. Conducting core drilling in sedimentary strata has always been a technical challenge in the drilling field. This article introduces the construction technology of core drilling in ultra thick sedimentary layers for the Zhangye geothermal core drilling project （ZC1 well） in Gansu Province. The various drilling techniques has been innovatively applied in this project， the research and application of flushing fluid systems， deep hole coring equipment， etc.， are conducted， which solved the problems of borehole instability， adsorption sticking， drilling tool failure， and low drilling efficiency due to ultra thick sedimentary layers. It has formed a continuous core drilling process system for ultra thick sedimentary layers， providing reference for the subsequent drilling constructions in the similar complex formations.