导流片型旋流场中非稀疏相油滴破裂、迁移与聚并规律研究

With the development of offshore oil field, the water content of output fluids is increasing year by year, and in some oil wells the water content has reached to 98 percent and above, which brings new challenges to the existing treatment technology on platform. To solve these problems, a number of oil fields try to introduce the pipe separation technology into the system of oil and water pre-separation for the high water content of output fluids, namely using the vane-type separator completely or partly replace the gravity settling tank. In this content, it is particularly important to study the behavior rules of non-sparse oil droplets/water mixture in the cyclone when the oil content exceeds 0.1 percent. To study the breakup, migration and coalescence of non-sparse droplets in swirling field, this work will focus on the following three aspects: the distribution characteristics of hydro-cyclone flow field, the breakage and coalescence mechanism of oil droplets in rotating flow field, and the migrate movement rule of oil droplets in rotating flow field. The models will be established by the theoretical analysis and the unknown items or parameters by the experimental testing. Finally, the established theoretical system will be verified by comprehensive experiments. The results are expected to establish the mechanism and distribution models of breakup and coalescence of non-sparse droplets, to obtain the motion law of oil droplets in the cyclone field, and to prefer the method and structure of flow field distribution to form the swirling flow for oil and water pre-separation. All the above will provide the theoretical guidance for the design of oil and water hydro-cyclone separator.

随着海上油田开采时间增长，采出液中含水率逐年增加，部分井液含水率高达98%以上，给目前已有的平台处理工艺带来新的挑战。为了解决这些问题，一些油田尝试将管道式分离技术应用到高含水采出液的油水预分离系统中，即用旋流分离器替代或部分替代重力沉降罐。在这种背景下，研究含油率不低于0.1%的非稀疏相油滴/水混合物在旋流器内的行为规律显得尤为重要。本课题拟将以此为研究对象，主要针对非稀疏相油滴在旋流场中的破碎、迁移和聚并等开展工作，包括：旋流器内旋流场的分布特征、油滴在旋流场中破碎及聚并机理、以及液滴在旋流场中的迁移运动规律。课题将通过理论分析建立模型，试验测定未知项或参数，最后通过系统的试验来检验所建立的理论体系。研究成果有望建立非稀疏相油滴在旋流场中破碎、聚并模型及分布规律，得到油滴在旋流场中的迁移运动规律，优化油水预分离的旋流产生方式以及流场分布结构，从而为油水旋流分离器的设计提供理论指导。

海上油田生产中后期，高含水采出液的预处理为现有平台预分离工艺带来了严峻的挑战。为克服这一挑战，可将旋流分离技术应用于高含水采出液预处理中，分离出其中的油相。在该种背景下，旋流场内非稀疏相油滴的行为规律尤为重要。本课题通过一系列理论研究、实验测试和数值模拟，探索了旋流场内非稀疏油滴的破碎、迁移和聚并规律：（1）揭示旋流场中连续相速度、压力分布规律，通过旋流数表征沿程旋流强度的发展和衰减；（2）给出了启旋装置上下游油滴破碎聚并的变化趋势及影响因素，据此明确了旋流场中液滴群特征粒径的变化规律，探讨了液滴-连续相的相互作用机制；（3）明确了旋流场油滴迁移运动趋势及影响因素；（4）探讨了破乳剂、界面张力、油相密度等对油滴粒径分布变化的影响；（5）结合工程背景，将研究成果应用于海面溢油回收，证实旋流分离可有效提高溢油回收液含油率，改善溢油回收效果。相关研究成果可为油水旋流分离器的设计和优化提供理论指导。