论文详情
川西低渗气藏井壁修补强化钻井液技术
断块油气田
2021年 28卷 第2期
阅读：132
查看详情
Title
Wellbore stability drilling fluid technology for low permeability gas reservoir
in Western Sichuan
单位
中国石化石油工程技术研究院，北京 100101
页岩油气富集机理与有效开发国家重点实验室，北京 100101
Organization
Research Institute of Petroleum Engineering, SINOPEC, Beijing 100101, China
State Key Laboratory of Shale Oil and Gas Enrichment Mechanism and Effective Development, Beijing 100101, China
摘要
针对川西低渗气藏水平井开发过程中存在的井壁失稳与定向段托压难题，采用水分散聚合方法设计合成了一种能够在温度激发下吸水膨胀的井壁修补强化剂（SM￣SCH），形成了可对不同尺寸微裂隙实施准确匹配与有效封堵的材料配方。在此基础上，优选了聚胺抑制剂、环保高性能润滑剂等核心处理剂，研制了适用于川西低渗气藏的井壁修补强化钻井液。室内评价表明：SM￣SCH初始粒径在0.5~7.0 μm，主要粒径范围集中在2.5 μm左右，能够在温度超过75 ℃时被激发产生吸水膨胀，膨胀倍率达15倍以上，可以有效提高钻井液体系的封堵范围，实现对不同尺寸微裂隙的准确匹配与有效封堵；由此研制的井壁修补强化钻井液在120 ℃下热滚老化16 h后，沙溪庙组岩心的线性膨胀率为3.31%，岩屑滚动回收率为96.33%，极压润滑系数为0.061，泥饼黏附系数为0.038，表现出优异的封堵防塌和润滑减阻性能。现场试验结果表明，井壁修补强化钻井液体系能够有效解决川西低渗气藏水平井施工过程中存在的井壁失稳和定向段托压难题。
Abstract
Aiming at the problems of wellbore instability and high frictional resistance during the development of horizontal wells in low-permeability gas reservoirs in Western Sichuan, a kind of wellbore repair enhancer (SM-SCH) was designed and synthesized by water dispersion polymerization method, which can absorb water and expand under temperature excitation. A plugging material formula was formed which can accurately match and effectively block micro fractures of different sizes. On this basis, polyamine inhibitor, environmental protection high performance lubricant and other core treatment agents were optimized, and the enhanced drilling fluid for wellbore repair of low permeability gas reservoirs in Western Sichuan was formed. Laboratory evaluation shows that the initial particle size of SM-SCH is between 0.5 μm and 7.0 μm, and the main particle size range is about 2.5 μm. SM-SCH can be excited to generate water swelling when the temperature exceeds 75 ℃, and the expansion ratio is more than 15 times. It can effectively improve the plugging range of drilling fluid system and realize the accurate matching and effective plugging of micro fractures of different sizes. After rolling aging at 120 ℃ for 16 h, the liner expansion rate of core in Shaximiao Formation is 3.31%, the rolling recovery rate of cuttings is 96.33%, the extreme pressure lubrication coefficient is 0.061, and the adhesion coefficient of mud cake is 0.038, showing excellent plugging and anti-sloughing performance and lubricating resistance reduction performance. The field test results show that the enhanced drilling fluid system can effectively solve the problems of wellbore instability and high frictional resistance during the horizontal section construction of low permeability gas reservoirs in Western Sichuan.
论文详情