控压钻井及其在高温地热勘探开发中的应用

Controlled Pressure Drilling and the Application in High-temperature Geothermal Exploration

摘要:

控压钻井包括管理压力钻井、欠平衡钻井和空气钻井。控压钻井可以减少非钻进时间和事故、提高机械钻速、预防漏失、消除压差卡钻、保护低压产层以提高产能。地热井具有温度高、地层硬度高、裂隙发育、地层压力低伴随浅部地层压力变化大等特点。在地热勘探开发中应用控压钻井技术有利于提高钻进速度、预防漏失、提高产能。介绍了控压钻井及其关键技术，同时阐述控压钻井在地热勘探开发中的应用。

Abstract:

Abstract: Controlled Pressure Drilling (CPD) involves three subsets, Managed Pressure Drilling (MPD), Underbalanced Drilling(UBD) and Air Drilling(AD). CPD could be used to decrease non drilling time and mitigate drilling hazards, increase rate of penetration (ROP), prevent lost of circulation, eliminate sticking, protect reservoir with low pressure and improve productivity. Geothermal wells are of characteristics of high temperature, hard rock, fractured formation and low pore pressure along with likely high pressure of shallow formation. It is proved that CPD could increase ROP, prevent lost of circulation and improve productivity. This paper introduces CPD technology and its application in geothermal energy exploration and development.