钻井液用聚醚胺基烷基糖苷在方3井的应用研究

Study on the application of polyetheramido alkyl glucoside in drilling fluids in Fang 3 well

针对中原地区方3井泥岩地层掉块垮塌,导致井壁失稳的问题,填井侧钻,在钻井液中加入自主研发的聚醚胺基烷基糖苷(NAPG)新产品,并进行了现场应用试验。试验结果表明:NAPG加入钻井液后,显著提高了钻井液的抑制防塌性能,有效解决了现场坍塌掉块、卡钻等井下复杂难题。介绍了NAPG产品的制备方法及其特性。对NAPG产品的配伍性能、抑制性能、润滑性能及生物毒性进行了测试评价,结果表明:NAPG与常规水基钻井液配伍性好,抑制性能和润滑性能优异,无生物毒性。岩屑一次回收率大于96.80%,相对回收率大于99%,相对抑制率大于95%;润滑系数小于0.1;EC50值为528.8g/L,远大于排放标准30 g/L。简述了NAPG产品在方3井的应用情况及应用效果,其较好地解决了该井侧钻井段出现的井壁失稳问题,表现出突出的井壁坍塌后的现场补救能力,实现了安全、快速、高效钻井,为该产品在强水敏性泥岩、含泥岩、泥岩互层等易坍塌地层及页岩气水平井的推广应用提供了较好的技术指导。

In view of the drop of mudstone in Fang 3 well of Zhongyuan Oilfield, leading to wellbore instability, so filling the borehole and taking sidetrack drilling, the new drilling fluid treating agent of polyether amido alkyl glucoside （NAPG） is adding into drilling fluids and the field application test is carried out. The results show that adding NAPG into drilling fluids can increase the inhibition and collapse prevention performance significantly, solve the downhole complicated problems including side-wall coring and jamming of drilling tool effectively. The preparation method of NAPG products and its characteristics are introduced. The properties of NAPG such as compatibility, inhibiting performance, lubrication performance and biotoxicity are tested and assessed. The results show that the compatibility of NAPG with conventional water-based drilling fluids is good, the inhibiting performance and lubrication performance of NAPG is excellent, and no toxicity. The first cuttings recovery rate is more than 96. 80%, the relative cuttings recovery rate is more than 99%, the relative inhibition rate is greater than 95% ; lu- brication coefficient is less than 0. 1 ; EC50 value is 528. 8 g/L, which is far more than the emission standard of 30 g/L. The application situ- ation and application effect of NAPG in Fang 3 well are introduced. NAPG product solves the problem of borehole instability of sidetrack drilling section, exhibits outstanding site remediation ability after the collapse of the borehole, the safe, fast and efficient drilling effect is achieved, and good technical guidance is provided for the NAPG products in the sloughing formation of strong water sensitive shale, mudstone, mudstone cross layer and shale gas horizontal wells applieation.