摘要
气助正循环水井钻探新技术主要适用于以岩溶地层为特征的严重漏失地层。该技术通过在双壁钻具的内外管之间泵入压缩空气,举升在钻具与孔壁之间的"环空"形成的空气泥浆。"环空"的气举加速作用阻碍了钻井循环液在地层方向的漏失,并且加速了钻屑的上返速度。该技术的优点在北京房山区岩溶漏失地层的600m水井钻探生产试验中得到了证实。试验结果表明,利用该技术可使泥浆正循环中因严重漏失造成的循环液中断得以恢复,"环空气举作用"大幅度提高了上返的泥浆流量。经对比试验证明,气助正循环工艺在岩溶漏失层的钻进速度高于气举反循环和泥浆正循环,是解决岩溶漏失层钻井液循环中断、钻头烧钻、埋钻等钻探事故的有效方法。
This technique is mainly concerned with a new study of water-well drilling method, which is well applied in severe leakage stratum, especially in karst stratum. Unlike other drilling method, air-lift drilling technique applies the compressed air through the dual wall drilling pipe, lifting the air-mud in annular space between the outer pipe and the wall of hole. The accelerated air-mud speeds up the circulating mud to reduce the leakage capacity and lift cuttings rapidly. Several advantages of this drilling technique were found in the fieldwork research which undertook in the 600 m water well drilling in Fangshan, Beijing. The fieldwork re- search mainly carried out by the experiment of air-lift drilling tools revealed that the broken circulation of drilling mud had been recovered and the flow of the return mud had been largely improved. The drilling speed of this technique is quicker than the air-lift reverse circulation or the mud drilling method. In severe- leakage stratum, this technique has been proved to be efficient in solve drilling problems, such as broken cir- culation and burned drill bit. Further study of air-lift drilling method should be made in relation to other rou- tine water well drilling methods in different karst strata.
出处
《中国岩溶》
CAS
CSCD
2012年第4期453-458,共6页
Carsologica Sinica
基金
地质调查项目"岩溶地下水勘查气助正循环钻探技术应用"(1212010535417)
关键词
岩溶漏失层
气助正循环
双壁钻具
环空气举作用
karst stratum with severe-leakage
air-lift circulation drilling
dual wall drilling pipe
air-lift in annular space
