“适度抑制”及“储层保护”钻井液的研制及应用

王洪伟 黄治华 李新建 王伟吉 刘畅 黄维安

中海油田服务股份有限公司油田化学事业部，天津 300452 中国石油大学（华东）石油工程学院，山东 青岛 266580

Oilfield Chemistry Department of COSL, Tianjin 300452, China College of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China

BZ29-4油田明化镇组上部地层泥岩体积分数较高，下部储层主要为中—细粒岩屑长石砂岩，物性较好。在上部地层使用PEC钻井液体系钻进时，出现起下钻不畅、憋泵、憋扭矩、钻井液黏度和切力增大等复杂情况，加入氯化钾后起泥球程度下降，但起下钻不畅程度加剧，且倒划眼更加困难。为解决该技术难题并有效保护物性较好的明下段储层，文中提出“适度抑制、加强封堵”的防塌方法，选用兼具井壁稳定和储层保护作用的胺基硅醇（HAS）为主要处理剂，构建了高性HAS钻井液。该钻井液抑制性适中，既能抑制泥岩水化，防止钻头泥包、憋泵、钻井液黏切增大，又能杜绝过度“硬化”井壁，避免起下钻遇阻和倒划眼困难，而且润滑性好、抗污染能力强、储层保护效果优良。现场应用表明，“适度抑制、加强封堵”的防塌方法可行，无钻头泥包现象，起下钻顺畅，井眼规则，显著提高了钻井效率。

The upper strata in Bozhong 29-4 Oilfield has the characteristics of high clay content, while the lower strata is mainly moderate to fine grained lithic arkose with a good physical property. Down hole troubles such as high pump pressures and torques, pipe sticking as well as the viscosity and shear force rising were encountered when implicating PEC in the upper strata. When potassium was introduced into PEC, the drop in the mud ball degree occurred, while unsmooth tripping and backreaming deteriorated. To deal with these problems and protect the lower strata with good physical property, this paper proposes the high performance collapse prevention method with appropriate inhibition and strengthen sealing, and designs a silicon amino alcohol drilling fluid formulated with silicon amino alcohol (HAS) which has borehole wall stability and reservoir protection at the same time. The drilling fluid with moderate inhibitory can inhibit shale hydration, prevent the bit balling, suppress pump, the viscosity and shear force rising, prevent the form of excessive hardening wellbore, avoid slacking off and difficult redressing. It also owns good lubricity, strong ability to resist pollution, and good reservoir protection. Field application shows that the method with appropriate inhibition and strengthen sealing is feasible, it can provide smooth trip free from bit balling and irregular borehole and improve the drilling efficiency significantly.

10.6056/dkyqt201406027