海洋深水水基钻井液恒流变性调控的化学、物理方法研究

There are abundant resources such as conventional oil & gas and gas hydrate in deepwater area of the ocean, and huge potential for drilling and exploitation. Rheology controlling in a wide range of temperature (especially low temperature) is one of technical problem to hold back the exploitation of petroleum resources in deepwater area. Current research jobs of this field are focused on macroscopical aspects such as drilling fluids formula optimizing, additives selecting and so on. There are none report about micromechanism of chemical methods, physical field and its mechanism for regulation flat rheology of offshore deepwater water-based drilling fluid. Therefore, based on the suspension property of offshore deepwater water-based drilling fluid, according to Maron viscosity equation,the adjusting and controlling performance and mechanism of composion and character of continuous phase and dispersed phase, especially micro-nano sized barium sulphate for rheology under high temperature and low temperature of offshore deepwater water-based drilling fluid will be studied by modern analysis instrument. Furthermore, the effects of high frequency alternate current field and ultrasonic wave agitation on the fluid's rheology are explored. Finally a feasible and highly efficient rheology controlling scheme combined with chemical and physical approach for offshore deepwater water-based drilling fluid will be established. The research results will contribute to the development of suspension rheology, provide significant technical value for efficiently exploiting deepwater oil and gas resources and be benefit to reduce the usage of drilling fluid additive and protect ocean environment.

海洋深水区域蕴藏着丰富的常规油气和天然气水合物资源，钻探开发潜力巨大。但宽温度范围（尤其低温）内的海洋深水水基钻井液流变性调控难题目前是制约海洋深水油气资源钻探的技术瓶颈之一，该领域当前研究主要集中在钻井液配方优化和处理剂研选等宏观方面，在化学调控方法微观机理、物理场的调控作用及机制方面国内外尚无报道。为此，本项目基于海洋深水水基钻井液的悬浮液特性，依据Maron悬浮液黏度方程，借助现代分析手段，从微观上研究连续相、分散相的组成和性质（特别是微纳米硫酸钡）对海洋深水水基钻井液低温、高温流变性的调控规律及机理，研究高频交流电场、超声波场对海洋深水水基钻井液流变性的调控作用及机制，最终形成可行、高效的海洋深水水基钻井液恒流变性调控化学方法和物理方法。研究成果对发展悬浮液流变学、完善海洋深水钻井液理论体系有重要科学意义，并有利于深海油气资源高效开发，减少钻井液添加剂用量、保护海洋环境。

海洋深水水基钻井液流变性与其功能实现、井下安全和海洋环境保护紧密相关，本项目围绕海洋深水水基钻井液流变性调控方法与技术开展了基础性研究工作。首先研究基于分散相的海洋深水水基钻井液恒流变性调控方法及其机理发现，钙基膨润土、海泡石、凹凸棒石和高岭石配成的基浆虽然流变性对温度不敏感，优化了配浆条件，弄清了超微重晶石、四氧化三锰的加重特性，并优化了复配使用条件；通过基于连续相的海洋深水水基钻井液恒流变性调控方法及其机理研究，揭示了各种处理剂对流变性的影响规律及其机制，优选出具有一定恒流变特性的用剂；设计了高频高压电场调控装置，通过研究高频高压交流电场对钻井液流变性影响，发现了电场参数与水基钻井液流变参数之间的响应关系和记忆作用；设计了超声波场调控装置，发现了超声波对膨润土基浆、高分子处理剂以及典型配方的影响规律及其机制。实验结论和研究成果已经用于指导海洋深水水基钻井液以及深井高温高压水基钻井液体系构建，对海洋油气资源、极地油气资源和深层油气资源勘探开发具有应用前景。