防塌雾化钻井技术

An Anti-Collapse Mist Drilling Technology

针对雾化钻井井壁稳定时间短、适用地层出水量低等技术难题,提出构建防塌雾化液体系的方法和原则,在此基础上以非离子型和阴离子型表面活性剂为雾化剂,通过研究关键处理剂,确定了防塌雾化液体系配方。该防塌雾化液对天然砂岩岩心的一次回收率达98.8%,48 h相对回收率达95.4%;被清水稀释10倍后,16 h相对回收率保持在91.2%。这说明,雾化基液中防塌剂在井壁上吸附能力强,在地层出水量大、环空气/液流体中防塌剂含量大幅降低的情况下仍保持井壁稳定。该体系于川东北地区进行了现场应用,井壁稳定时间由3~5 d提高至11 d,循环利用率达92%,最大出水量达55 m3/h,没有出现钻具泥包等现象。

In consideration of the technical problems of short time of borehole wall stability,and low water production in relevant formation,etc.,the method and the principles for establishing an anti-collapse misting solution system were suggested,and non-ionic surfactant and anionic surfactant were chosen as the misting agent accordingly. The formulation of the anti-collapse misting solution system was identified by studying key treatment agents. The primary recovery rate reached 98. 8% when this anti-collapse misting solution was used in the core of natural Sandstone with the 48 h relative recovery rate being 95. 4%,and the16 h relative recovery rate remained at 91. 2% after the anti-collapse misting solution diluted with clean water for 10 times was used. The application of this anti-collapse misting solution has shown that the anti-collapse agent in the misting base solution can be adsorbed onto the borehole wall firmly and that the borehole wall can remain stable in the case of large formation water production and substantial reduction of anti-collapse agent in the gas/liquid in annular space. This system has been used in the field of drilling in northeastern Sichuan Province. The time period in which borehole wall remained stable was increased from 3-5 d to 11 d with the recycling percent of the system being 92% and the maximum water production being 55 m^3/h without any coating of mud on drilling tool,etc.