特色录井技术在川渝页岩气开发中的应用

Application of Characteristic Logging Technology in Shale Gas Development of Sichuan-Chongqing Area

页岩气水平井钻井过程中充气钻井、旋转导向工具等新钻井工艺被广泛地使用。岩屑相对较小,使得地层岩性难以识别,增加了页岩气水平井储层追踪和解释的难度。为此,将自然伽马能谱绘制成四川盆地下志留统龙马溪页岩储层的特征。实践表明将XRF元素录井和自然伽马能谱录井技术应用于页岩气勘探开发,可以很好地识别各种细粒岩性,建立地层剖面,划分地层界线,进行地层对比和划分,判断优质页岩剖面;钻井时准确识别龙马溪组优质储层,实时调整井眼轨迹,确保优质页岩储层钻井速度;可计算水平段矿物含量、含气量等,对储集层进行评价,为试油层段的优选分段提供依据。

New drilling technologies such as aerated drilling and rotary steering tool are widely applied in shale gas horizontal well drilling.Due to relatively small cuttings,it is difficult to identify formation lithology,which increases the difficulty of reservoir tracking and interpretation in shale gas horizontal wells.Therefore,XRF element logging and natural gamma spectrometry logging technology are applied in shale gas exploration and development,which can well identify various fine-grained lithology,establish stratigraphic profile,divide stratigraphic boundaries,conduct stratigraphic correlation and division,and judge high-quality shale profile.During drilling,the high-quality reservoir of Longmaxi formation is identified accurately,and the well trajectory is adjusted in real time to ensure the drilling speed in high-quality shale reservoir.Mineral content,TOC content and gas content in horizontal section can be calculated by characteristic logging,the reservoir is evaluated,so as to provide the basis for the optimal selection of oil test layer.