Abstract:

With the large-scale exploration and development of deep-water condensate gas fields, the problem of coupling deposition of hydrate and wax in deep-water condensate gas transmission pipelines has attracted increasing attention. Verifying the mechanism of influence of wax on the blockage and unplugging of hydrate deposition, effectively controlling the coupling deposition and plugging process, and forming efficient plugging removal technology can effectively promote the transition of hydrate flow assurance strategy from complete inhibition to risk management. Based on the research results of hydrate and wax deposition and blockage removal in the oil-gas mixed pipeline flow system in recent years, the effects of wax on hydrate nucleation, growth, accumulation, deposition blockage and fluid rheology were described. The effects of hydrate and wax coupling prevention and control and blockage removal under the conditions of injection thermodynamic inhibitor and pressure reduction were analyzed, and the current research status of hydrate decomposition kinetic model was reviewed. The characterization of mass and heat transfer of wax by the model was analyzed. Based on this overview, the next step is to fully consider the distribution form of water phase and wax, couple the influence of flow parameters, characterize the shear strength of the sedimentary layer, and further analyze the mechanism of hydrate and wax deposition clogging in the condensate gas pipeline. The mechanism of mass and heat transfer in the process of hydrate and wax coupling deposition should be revealed, and the prediction model of hydrate and wax coupling blockage for deep water condensate gas transportation pipeline need to be established and perfected, which can provide a theoretical basis for improving the hydrate flow support technology system of deep water oil and gas mixed transportation pipeline and supporting making decisions in production field.

Key words: gas hydrates, wax, condensate gas, plug removal, pipelines

摘要：

随着深水凝析气田的大规模勘探和开发，深水凝析气输送管道中水合物与蜡耦合沉积堵塞问题日益引发关注。探明蜡对水合物沉积堵塞和解堵的影响机制，有效控制水合物和蜡耦合沉积和堵塞过程，形成高效的解堵技术，能够有力推动水合物流动保障策略从完全抑制向风险管理转变。本文围绕近年来油气混输管流体系下水合物和蜡沉积堵塞及解堵的研究成果，阐述了蜡对水合物成核、生长、聚集、沉积堵塞和流体流变性的作用规律，解析了注热力学抑制剂和降压条件下水合物和蜡耦合防控和解堵效果，梳理了水合物分解动力学模型研究现状，分析了模型对蜡的传质传热作用表征情况。基于此建议下一步针对深水凝析气输送管道的特点，充分考虑水相和蜡的分布形式，耦合流动参数影响，表征沉积层抗剪强度，深入解析凝析气输送管道水合物和蜡沉积堵塞机制；揭示水合物和蜡耦合沉积堵塞解堵过程中的传质传热机理，建立并完善适用于深水凝析气输送管道的水合物与蜡耦合堵塞的解堵预测模型，为完善深水油气混输管道水合物流动保障技术体系提供理论基础，支持现场防控决策。

关键词: 水合物, 蜡, 凝析气, 解堵, 管道