Study On Force And Agglomeration Characteristics Of Hydrate Particles

Hydrate particle agglomeration process leads to hydrate blockage in pipelines, which is a severe threat for normal operation of oil and gas transfer operation, especially for deep-sea oil and gas field development, for its unique environmental condition favors the formation of hydrate particles. Thus prevention of hydrate particles agglomeration has become a hot spot today. However, relative researches are far from satisfaction, especially research on microscopic agglomeration mechanism and characteristics of hydrate particles, which are the keys for agglomeration prevention and hydrate slurry preparation, are rarely covered by Chinese researcher. This thesis studies hydrate particles microscopic agglomeration characteristics from three different perspectives: hydrate particles force analyzation,experimental research and numerical simulation, which are of significant importance for prevention of hydrate particles agglomeration.Firstly, liquid bridge force between hydrate particles was studied, by clarifying its influencing factors, methods are proposed to reduce or even eliminate the force. Secondly, a comprehensive analysis of forces acting on the particles was executed to determine the major agglomeration force and separation forces, then based on the theory of force balance, a hydrate particles agglomeration model was raised, which allows us to calculate the maximum hydrate particle size and study the influencing factors of hydrate particle agglomeration.Thirdly, hydrate particles agglomeration characteristics were studied by experiments, results show that hydrate particle size distribution follows the lognormal distribution, the shearing suppresses agglomeration and high hydrate content facilitates agglomeration of hydrate.Finally, a three-dimensional turbulent Euler-Euler model was suggested, a UDF program considered the influence of fluid shear force and agglomeration force on the particle size was developed. Then hydrate particles agglomeration and sedimentation characteristics weresimulated by CFD software, the results are in consistent with theoretical expectation,indicating that the suggested three-dimensional model can be used to predict the micro-agglomeration characteristics of hydrate particles and provide instructions for production.