玉北1-1井欠平衡钻井技术应用与分析

玉北1-1井是在新疆玉北地区部署的第2口欠平衡井,钻探目的是评价奥陶系中-下统鹰山组含油气特性,为研究该区油气成藏条件提供依据。介绍了该井的钻井液密度、欠压值及水力参数等关键参数设计,并结合实钻过程论述了井底欠压值、井口压力控制技术。该井钻探过程中,选择合理的欠压值和井控技术进行欠平衡钻进,有效防止了该区奥陶系中-下统鹰山组裂缝、溶洞型储层的漏失问题,保护了储层,提高了深井钻井速度。最后针对新疆巴麦地区低压储层段的欠平衡钻井技术应用提出了建议。

Application of Underbalanced Drilling Technology in Well 1-1 of Yubei

Well 1-1 of Yubei is the second underbalanced well deployed in Yubei region of Xinjiang.The drilling purpose is to assess the oil and gas property of the lower-middle Ordovician Yingshan formation in order to provide the basis for investigating the condition of oil and gas accumulation in the region.The key design parameters such as drilling fluid density,underbalance pressure value and hydraulic parameter were introduced.The bottomhole underbalance pressure value and wellhead pressure control technology were discussed referring to the practical drilling process.The reasonable underbalance pressure value and well control technology were chosen to conduct underbalanced drilling,effectively preventing the leakage in the fractured-vuggy reservoir of the lower-middle Ordovician Yingshan formation in the region.The reservoir was protected and the deep well drilling speed was improved.Finally,the suggestion was given about the application of underbalanced drilling technology in lower pressure reservoir intervals in the Bamai region of Xinjiang.