半周期自修正防弯钻具在易斜地层中的应用

Application of the semi-cyclic self-correction deviation prevention drilling tool in deflecting strata

摘要:

对于司家营铁矿岩层结构完整、岩石可钻性高的特点，施工中深孔岩心钻探勘查，控制钻孔弯曲度超差属于钻探技术难题，更是确保钻孔质量的关键，自2009年施工至今已施工中深孔30个左右，其中三分之二的钻孔因孔斜超差严重均被降级使用，使得地质技术人员头痛，更让钻探技术人员棘手。在钻探施工过程中，曾因个别钻孔发生孔内事故，采取螺杆造斜和下偏心楔子造斜绕过事故钻具均未成功。地层岩石完整且硬，钻孔纠斜、造斜无法实现，解决中深孔钻孔弯曲超差，严重成为该矿区亟待解决的技术难题，解决不好就严重影响该矿区“攻深找盲”目标的实现；2018年该矿区深部续作设计钻孔孔深1500 m，为避免类似影响钻孔质量现象发生，在采取常规的钻孔防斜技术措施以外，采用“S75 mm半周期自修正防弯钻具（XBZX）”试验解决司家营铁矿中深孔弯曲超差严重技术难题；通过同勘探线2015年施工钻孔比较，取得了一定效果，为解决司家营铁矿中深孔钻孔弯曲超差严重技术难题提供了技术保障，为同类型矿区施工中深孔防止钻孔弯曲超差提供实践经验和施工技术。

Abstract:

As the Sijiaying iron ore rock has the characteristics of complete structure and of high rock drillability， medium-deep hole core drilling works and control the out-of-tolerance of drilling bending belong to the drilling technical problems and also the key to ensure the drilling quality. Since 2009 about 30 medium-deep holes has been constructed， two-thirds of them have been downgraded because of severe out-of-tolerance of the well deviation which confused the geologist as well as the drillers. In the process of drilling， some borehole accidents occurred， and deflected by screw drilling and eccentric wedge were failed to solve the problems. The formation rock is complete and hard， and the drilling deviation correction and building can not be realized， as a result， the severe out-of-tolerance of borehole bending in medium-deep holes has become an urgent technical problem which seriously affect the realization of the goal of "exploring the deep and blind area". In 2018， the design of drilling depth was 1500m， conventional drilling anti-inclination technique measures were adopted in order to ensure the drilling quality. What’s more， S75mm half-cycle self-correcting anti-bending drilling tool （XBZX） was tested， and achieved success to some extent compared to the construction in 2015， which provided technical support to solve the severe technical problem of bending out-of-tolerance drilling in medium-deep hole of Si-jiaying Iron Mine， and also provided practical experience and construction technology to prevent bending out-of-tolerance drilling in medium-deep hole of the same type of mining area.