摘要
瓦斯抽排孔套管直径设计一般在Φ450~Φ1500mm。由于套管质量较大,远远超过钻机的提升能力,研究和选择合适的下管方法显得尤为重要。以山西省高平市长平矿的瓦斯抽排井为例,介绍了漂浮下管技术的原理,并进行了相关的计算,对下管的技术措施进行了较为全面的说明。应用表明,该技术更适合直径较大、套管壁较厚、套管柱总质量较大的工程井;对套管与钻孔直径间隙要求较大,一般≥250mm;对井身质量要求较高,如井眼的垂直度、狗腿度等;钻井过程中要严格控制钻井液的滤失量,抑制泥页岩地层的吸水膨胀,同时采用固控设备最大限度去除钻井液中无用固相,使井壁形成的泥皮薄而致密。
The casing diameter designed for gas drainage well is 0450 -1500mm generally. But because of large weight, well over rig hoisting capacity, thus study and select casing method appear particularly important. Taking gas drainage well in the Changping coalmine, Gaoping City, Shanxi Province as an example, introduced the principle of casing floating technology, carried out relevant computation, and overall illustrated technical measures. The application has shown that the technology more adaptable to well engineer- ing with larger diameter, thicker wall and larger casing string total weight; but needs larger annular clearance, generally 〉 250mm; better wellbore qualities, such as verticality, dogleg severity etc. Drilling fluid loss should be strictly controlled during drilling process, and argillutite strata water - swelling restrained. Meanwhile, uses solid control equipment farthest removing useless solids to make mud cake on wall thin and compact.
出处
《中国煤炭地质》
2017年第4期62-65,共4页
Coal Geology of China
关键词
瓦斯抽排孔井
漂浮下管技术
平衡液
应用
gas drainage well
casing floating technology
equilibrium fluid
application
