定向钻穿越不良地层施工技术新突破

Breakthrough of Construction Technology with Directional Drilling Crossing through Unfavorable Stratum

利用水平定向钻穿越江河、湖泊、沼泽、森林、大型建筑物和构筑物等有许多成功的先例,但穿越卵砾石层和微风化花岗岩等不良地层在我国一直是禁区。在长春—吉林输油管道工程建设中,中国石油天然气管道局采用了德国TRACTO-TECHNIK TT600型夯管锤夯入钢套管隔离卵砾石层,使用DD580钻机,运用地面信标和有线控向技术,进口了专用的钻头和牙轮,配制了特殊的泥浆,提高了携带岩屑的能力,历时54天,成功地穿越了松花江,填补了我国定向钻穿越此种不良地层的空白,推动了定向钻穿越技术的发展。文章结合工程实例,从钻导向孔、控向、扩孔、回拖、泥浆配比、风险预测和防范措施等方面,论述了定向钻穿越卵砾石层和微风化花岗岩地层的方法,为定向钻技术的应用和发展提供了宝贵的资料和可借鉴的经验。

In the construction of Changchun -Jilin Crude Oil Project, China Petroleum Pipeline Bureau (CPP) adopted a Tracto -Technik TT600 pipe rammer made in Germany to ram a steel casing pipe against gravel stratum, utilized DD-580 drilling machine, aboveground beaconing and cable orientation control, together with the imported special drill bit and gear wheel, and configured special slurry. The pipeline crossing Songhua River was implemented successfully. This fills the technical vacancy of pipeline crossing at such kind of poor stratum in our country. The article discusses the methods adopted for directional drilling crossing at gravel and minor-weathering granite stratums in aspects of drilling pilot, orientation control, reaming, back-pulling, slurry mix, risk forecasting and prevention.