充气欠平衡钻井液技术在DP4井水平段的应用

DP4井是中石化华北分公司在鄂尔多斯盆地大牛地气田布置的一口充气欠平衡水平井，该井目的层为盒1段，地层压系数较低，压力系数范围0．83—0．99（平均0．93），为了有效保护气层，DP4井水平段全过程采用了充气欠平衡钻井工艺技术。欠平衡钻井工艺采用充气钻井液技术，通过该工艺在DP4井的实施，在盒1气层保护上取得较大成功。主要介绍了充气欠平衡钻井液技术的技术工艺、实施过程和现场实施情况，并对充气欠平衡钻井液技术在该井实施效果进行了分析评价。

Application of Aerated Underbalanced Drilling Fluid Technology in Horizontal Section of DP4 Well

DP4 well is a horizontal one, locating at the Daniudi gas field of Ordos Basin and drilled with aerated underbalanced drilling technology. The target formation is He 1 with lower formation pressure coefficient from 0. 83 to 0. 99 （ average 0.93）. To effectively protect He 1 formation, aerated underbalanced drilling technology was implemented in the whole horizontal section with aerated drilling fluid, and the protection was successful. The paper mainly introduced the aerated underbalanced drilling fluid about the technique ＆ technology, implemetation process and the field situation; and also analyzed and evaluated implemetation effect of aerated underbalanced drilling fluid in this well.