空气钻井提高钻速机理研究

我国一些地区为提高深井和大尺寸井眼的机械钻速，降低钻井成本，采用了气体钻井技术，因此需要对气体钻井技术提高钻速的机理进行研究。首先对石油钻井过程中降低井底压降、旋冲钻井、提高清洁效率、避免重复破碎等提高破岩效率的方法进行了简单总结．然后通过对相关文献提供的数据和图表资料的分析，比较了空气钻井与常规钻井液钻井的差别，最后指出空气钻井能大幅度提高机械钻速的主要机理是：负压差作用、井底岩石力学性质和应力状态发生变化、钻头旋转；中击破碎岩石、井底清洁及热应力等。这为进一步研究提高空气钻井的机械钻速机理提供了参考依据。

The Mechanisms of Increasing ROP during Air Drilling

Technology of air drilling is employed in some area to increase the ROP and decrease drilling cost of deep or large diameter wells.Therefore,it is necessary to study how to increase the ROP of air drilling.This article firstly carry out a simple summary about methods of decreasing bottom-hole pressure,rotary percussion drilling,improving cleanness efficiency and avoiding repetitive smash,which are high efficiency broken rock approach in petroleum drilling.And then,investigations on data and charts presented in relevant documents are carried out,the differences between air drilling and conventional mud drilling are compared,at last it is conclu- ded that the main mechanisms for high ROP with air drilling are underbalanced action,the rock mechanics properties and stress state of the bottom hole changed,bit rotates and impacts grinding rock,bottom-hole cleaning and thermal stress.The mechanisms provide references for further study on how to improve air drilling's ROP.