新型射流提高机械钻速机理及研究进展

在油气井钻井中，喷射钻井技术能够较大幅度地提高钻井速度，其实质是喷嘴射流辅助钻井破岩，提高了井底破岩效率。为此，文章在如何向井底输送能量和充分利用井下水力能量研究的基础上，进行了多种新型射流的研究与应用。文章对断续射流、自激振荡脉冲射流、自振空化射流和它激振荡脉冲射流4种形成新型射流的理论和方法，提高机械钻速机理进行了分析。现场应用结果表明，新型射流能够较大幅度地提高机械钻速，具有广泛的研究和开发应用前景。

MECHANISM OF ENHANCING PENETRATION RATE BY NOVEL JET AND ITS PROGRESE IN RESEARCH

In oil and gas drilling, the penetration rate can be greatly raised by applying jet drilling technology, which crux is the auxiliary jet rock break in drilling, thus enhancing downhole rock-broken efficiency. For this reason, the research and application of several novel jets were carried out on the basis of deciding how to transport the hydraulic energy to the bottom hole and fully utilize it. There are four kinds of novel jets, i.e. intermittent jet, self-induced vibration oscillation pulse jet, self-vibration cavitation jet and separatly induced oscillation pulse jet. Their formation theories and methods, and the mechanisms of enhancing penetration rate were analyzed. Through applying on the spot, it was indicated that the novel jets could greatly raise penetration rate, thus opening up a vast range of prospects for studying, developing and applying this kind of drilling technology. (Financed by the project of the National Natural Science Foundation, No,90210022)