深水蜡晶与水合物多相混输管道固相沉积与安全输运机制

针对蜡与水合物相关研究现状及水平、我国海洋石油发展及理论技术瓶颈的客观分析，以深水油气田采出流体多相混输为对象，依托自主研发的水合物流化装置，采用配套试制系统、先进仪器手段及理论分析方法，围绕深水混输管道不同温压和流动条件下蜡与水合物析出、聚集与沉积机理、耦合沉积与安全控制机制等科学问题，剖析深水管蜡晶、水合物及其共晶体的微观形态与晶型结构，揭示蜡晶与水合物耦合作用及生成机制；探究蜡晶与水合物聚集、沉积及动态演化过程，建立相应的动力学模型；探究运行与停输工况下管内蜡和水合物生成、沉积过程、流型转变及压降，揭示海管阻力特性与管堵机制，建立深水立管及海管内外流-固-热等多场耦合模型，实现海管蜡和水合物生成量、动态沉积、黏度及压降的准确预测，形成基于蜡晶-水合物沉积与堵塞控制的深水多相混输安全保障机制，突破深水含蜡油气水混输流动保障的理论技术瓶颈，具有重要科学理论价值和广阔应用前景。

In view of the current research status and level of waxes and hydrates and the objective analysis of China's offshore oil development and theoretical technology bottlenecks, taking the multiphase transport of fluid produced in deep-water oil and gas field as the research object, relying on the self-developed hydrate fluidization device and using the matching trial-produced systems, advanced instruments and theoretical analysis methods, some scientific issues such as the mechanism of precipitation, aggregation and deposition of waxes and hydrates in deep-water pipelines, and their interactions, coupled deposition and safety control mechanism under different temperature, pressure and flow conditions will be studied to analyze the microscopic morphology and crystal structure of wax crystals, hydrates and their eutectics and to reveal the coupling effect and formation mechanism of wax crystals and hydrates. The process of aggregation, deposition and dynamic evolution of wax crystals and hydrates will be explored to establish the corresponding kinetic models. The law of formation and deposition of waxes and hydrates, flow pattern transition and pressure drops under normal and shutdown operating conditions will be investigated, the resistance characteristics and pipe blocking mechanisms of multiphase flow in sub-sea pipes will be revealed and the liquid-solid-heat multi-field coupling models for deep-water risers and sub-sea pipes will be established to achieve reliable prediction of wax and hydrate formation, dynamic deposition, effective viscosities and pressure drops, to form a safe transport mechanism for deep-water multiphase transportation pipelines under the control of wax crystal-hydrate deposition and plugging, to further break through the theoretical and technical bottlenecks of flow assurance for deep-water waxy oil-gas-water mixed transportation pipelines, which has important scientific theoretical values and engineering application prospects.