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文章分析了国内外的石油工业勘探开发形势，得出欠平衡钻井是适应新形势下的钻井技术；阐述了实现欠平衡钻井的各种手段，讨论了欠平衡钻井技术的特点与自身的技术优势，认识到欠平衡钻井具有减少地层伤害，提高钻速，避免漏失，减少卡钻等优点，有着广阔的应用前景。总结了国内外欠平衡钻井的应用现状，结果认为其效果是显著的，能降低钻井成本和适应特殊油气藏开发的需要。同时，例举了国内外成功使用欠平衡钻井的实例。文章还分析了欠平衡钻井的水平与不足，指出开展欠平衡钻井应注意地层是否适合，钻井液基液的选择以及安全等问题

Application Prospects of Underbalanced Drilling

In this paper,the petroleum exploration and development situation at home and abroad is analyzed,and it is concluded that the underbalanced drilling is a drilling technology suited to the new situation.The various measures for realizing underbalanced drilling are expounded and the characteristics of underbalanced drilling technology and its technical superiority are discussed.It is understanded that the underbalanced drilling has many advantages:reducing formation damage,raising penetration rate,avoiding circulation loss and lessening drillpipe sticking,etc.,having a wide application prospects.Then,the current application situation of the underbalanced drilling at home is summarized,considering that the effect is obvious,being able to reduce drilling cost and to suit to the requirements for exploiting special oil and gas reservoirs.In the paper,the examples of successfully applying the underbalanced drilling at home and abroad are also cited,the underbalanced drilling and its shortcomings are analyzed,and the points for attention for unfolding underbalanced drilling (whether or not the formation being suitable,the selection of the base fluid of drilling fluid and its safe operation,etc.)are pointed out.