Abstract:

Drilling in ultra-deep formation is faced with complex geological environment such as ultra-high temperature, ultra-high pressure and ultra-high stress, as well as salt paste layer and fractured formation, which leads to conformational changes such as fracture and twisting of key materials such as fluid loss reducer in drilling fluid, resulting in complex situations such as increased fluid loss and deterioration of rheological properties during drilling. Therefore, from the perspectives of optimizing linear polymer molecular structure, and regulating polymer condensed state structure and nano-composite technology, this paper reviewed the research progress of polymer fluid loss reducer for ultra-deep drilling fluid and pointed out the shortcomings of the existing three methods. In addition, it was proposed to use nano micron spherical or hyperbranched tree structure, further study the synergistic mechanism between zwitterionic polymer groups, introduce materials with hydrophobic groups to improve the dispersion stability of nanomaterials, and use molecular simulation combined with laboratory experiments to develop polymer filtration reduction agents with high performance and strong universality. Moreover, artificial intelligence and big data technology should be combined to improve the self-regulation and optimization function of drilling fluid.

Key words: ultra deep well, ultra high temperature, drilling fluid, polymer, fluid loss reducer

摘要：

超深地层钻井面临超高温、超高压、超高应力等复杂地质环境以及钻遇盐膏层、裂缝发育地层，导致钻井液降滤失剂等关键材料发生断裂、蜷曲等构象转变，造成钻井过程中滤失量增大、流变性能恶化等复杂情况。因此，本文从优化线型聚合物分子结构、调控聚合物凝聚态结构、利用纳米复合技术角度出发，对超深井钻井液用聚合物降滤失剂的研究进展进行综述，指出现有3种方法所存在的不足，并提出采用纳微米球形或超支化树形结构、深入研究两性离子聚合物基团间的协同增效机理、引入带疏水基团的材料提高纳米材料的分散稳定性、采用分子模拟与室内实验相结合等方法研发高性能、普适性强的聚合物降滤失剂，并且未来应结合人工智能和大数据技术提高钻井液的自我调节和优化功能。

关键词: 超深井, 超高温, 钻井液, 聚合物, 降滤失剂