高温高密度高矿化度钻井液流变性的调控机理及新方法

When drilling deep formation under complex conditions such as high temperature, high pressure and high salinity, the drilling fluid technology is a great challenge around the world. Rheological properties and stability controlling are of vital importance for the drilling fluid under HTHP and high salinity conditions (“three high” for short). Based on the theories of higher concentration solid-liquid two-phase flow, granular flow, microscopic kinetic theory and packing theory, also in combination with the progress of suspension-colloid and interface chemistry and novel sensitive materials science, the micro-mechanism of high concentration solid-liquid two-phase flows for the drilling fluid under HTHP conditions will be studied, and the effect of high salinity on the structure of solid-liquid media will be researched. Meanwhile the rheological properties of drilling fluids under “three high” conditions, and the thermodynamics-chemical response mechanism of the rheological properties and sedimentation stability will be investigated. Furthermore, methods of modifying the rheological properties and rheological modifiers for drilling fluids under “three high” conditions will be optimized. This research will propose a solution to rheological properties modification for the drilling fluids under “three high” conditions, enrich the basic theory of drilling fluid and provide drilling fluid technology for deep formation drilling under complex “three high” conditions.

高温、高压、高矿化度复杂条件深部地层钻井液技术属于世界性难题。针对高温高密度高矿化度（简称“三高”）钻井液的流变性及稳定性调控等热点问题，基于高浓度固液两相流理论、颗粒流微观动理论和颗粒堆积理论等，结合悬浮-胶体界面化学和新型敏感性材料科学最新研究进展，重点探索高温高密度钻井液中高浓度固液两相流变性的微观机制、高矿化度对固液介质结构的影响规律、“三高”钻井液流变性及沉降稳定性的热力学-化学响应机理等，优化研究“三高”钻井液的流变性调控新方法及流型调节剂等。本研究可望解决“三高”钻井液流变性调控技术难题，丰富复杂深层钻井液基础理论，为我国“三高”复杂深层钻井工程提供钻井液技术支撑。

高温、高压、高矿化度复杂条件深部地层钻井液技术属于世界性难题。本项目基于高密度钻井液中高浓度固相两相流的微观结构及颗粒间的物理化学-力学作用机制剖析，借助颗粒流理论与颗粒堆积理论等交叉学科的新理论，探讨了高温高密度高矿化度条件下水基钻井液性能变化规律及微观作用机理，以此开展了关键性能的调控方法研究，研制出抗高温高密度水基钻井液聚合物降滤失剂与流型调节剂，最终形成了深井超深井超高温超高密度高矿化度水基钻井液体系配方。.研究了高温、高固相浓度与高矿化度对钻井液主要性能的影响规律，探索了亚临界水的物理化学特性及其对水基钻井液性能的影响，揭示了高温高压环境下，亚临界水对钻井液处理剂中部分组分的萃取作用是导致处理剂高温失效的重要原因。.基于颗粒流理论、微观动理论以及颗粒堆积理论，建立了基于颗粒紧密堆积原理的超高温超高密度水基钻井液流变性调控机理与新方法，即利用合理的颗粒级配将加重剂等固相颗粒在超高温超高密度水基钻井液中的分散状态更加趋向于颗粒离散态。基于磺化酚醛树脂的交联特性，建立利用高温下磺化处理剂适度交联以调控超高温超高密度水基钻井液滤失造壁性及沉降稳定性的方法。.基于亚临界水的物理化学特性，通过分子结构设计，研制出一种抗高温两性离子疏水缔合聚合物降滤失剂SDT10，其具有良好的抗高温增粘降滤失能力，其在Cl-1浓度高达90000ppm以上、Ca2+浓度高达5000ppm以上、Mg2+浓度高达15000 ppm以上的低pH复合盐水钻井液中，可显著降低钻井液滤失量，性能优于国内外同类产品。基于超高温超高密度高矿化度水基钻井液体系粘度结构特征，研制出一种适用于高温高密度高矿化度水基钻井液的接枝木质素磺酸盐类流型调节剂CFP，其抗温达200℃，且可有效改善高温下钻井液流变性。.提出了“协同增效”的超高温超高密度水基钻井液体系配方优化方法，并以新研制的处理剂为主，研制出了抗温220～240℃、密度达2.46～2.55g/cm3的超高温超高密度水基钻井液体系配方。