考虑壁面滑移效应的高密度油基钻井液流变性研究

Study of the Rheological Properties of High-Density Oil-Based Drilling Fluid Considering Wall Slip Effect

李文哲 钟成旭 蒋雪梅 李郑涛 曹世平 吴双

LI Wenzhe ZHONG Chengxu JIANG Xuemei LI Zhengtao CAO Shiping WU Shuang

四川长宁天然气开发有限责任公司，四川成都 610051 中国石油西南油气田分公司页岩气研究院，四川成都 610051 中国石油川渝页岩气前线指挥部生产运行部，四川成都 610000

Sichuan Changning Natural Gas Development Company Limited, Chengdu, Sichuan, 610051, China Shale Gas Research Institute, PetroChina Southwest Oil & Gas Field Company, Chengdu, Sichuan, 610051, China Production Operations Department, PetroChina Sichuan-Chongqing Shale Gas Frontline Command, Chengdu, Sichuan, 610000, China

壁面滑移效应会严重影响高密度油基钻井液流变性测量的准确性，需要对其进行检测和校正。基于Tikhonov正则化方法，建立了高密度油基钻井液流变性测量过程中的壁面滑移效应校正方法；利用六速旋转黏度计，进行了考虑滑移效应的深层页岩气井现场高密度油基钻井液流变性测量试验，分析了高密度油基钻井液壁面滑移特性，优选流变模型并计算了流变参数。计算结果表明，与校正前的流变参数相比，滑移校正后的深层页岩气井现场高密度油基钻井液的动切力更小，而流性指数更大且接近于1.00，其真实流变性可用宾汉模型表达；壁面剪切应力大于临界剪切应力时，滑移速度随壁面剪切应力增大而呈指数增大。研究结果表明，测量高密度油基钻井液流变性时会产生滑移效应，滑移校正前后的流变模式与流变参数存在明显差异，因此应消除滑移效应的影响。

Wall slip effect seriously affects the accurate measurement of the rheological properties of high-density oil-based drilling fluids, and it needs careful detection and correction. A correction method for the wall slip effect during the measurement of the rheological properties of high-density oil-based drilling fluids was established based on the Tikhonov regularization method. Rheological property measurement experiments of high-density oil-based drilling fluids in deep shale gas wells considering wall slip effect were carried out using a six-speed rotational viscometer, and the wall slip characteristics of high-density oil-based drilling fluids were analyzed. The rheological model was optimized and the rheological parameters were calculated. The calculation results demonstrate that, when compared with the rheological parameters before correction, the dynamic shear force of high-density oil-based drilling fluids in deep shale gas wells is reduced after correction, while the liquidity index is increased to nearly 1.00. The results demonstrate the real rheological properties can be expressed by Bingham model. When the wall shear stress is higher than the critical shear stress, the slip velocity will increase exponentially with increasing wall shear stress.The results show that a slip effect exists during the measurement of the rheological properties of high-density oil-based drilling fluids. It demonstrates, too, that the rheological model and rheological parameters before and after slip correction are significantly different, and the influence of slip effect should be eliminated for accurate measurement.

中国石油西南油气田分公司科技计划项目“泸州区块深层页岩气水平井钻完井技术研究”（编号：20180302-12）、四川长宁天然气开发有限公司科研项目“深层页岩气水平井钻完井技术研究”（编号：20180601-18）联合资助

https://doi.org/10.11911/syztjs.2020085