Design And Research Of A New Centrifugal Vacuum Degasser

Drilling fluid is one of the most important working fluids in the process of oil drilling. Density control of drilling fluid is the key technology for the pressure balance of drilling process, while gas-cut phenomenon will affect the actual density of drilling fluid. Serious gas-cut phenomenon can cause the blowout and well kick leading to unexpected accidents. Therefore, to ensure the safety of drilling process, removing the gas from drilling fluid is a necessary step. Degasser is the equipment objected to the gas-cut drilling fluid process.Currently, vacuum degasser is widely used in field sites. However its degassing efficiency is not ideal according to the feedback from field sites. Up to now, domestic and foreign researches are concentrated on the field of engineering application, the literature about the basic theory of degassing is still a gap. Researches of new type degasser has been stagnating since 1990s. There is a lack of standard reference and basic theories for the designing process, which cannot provide effective support to those designers who always depended on semi-empirical method. To solve these problems, this paper designed a new type of centrifugal vacuum degasser through an in-depth research of the degasser. The author utilized CFD software to simulate the working process of degasser, test the degassing efficiency and analyze the fluid field. Optimization of working parameters and structure is based on the characteristics. The paper summarized the factors which affect the degassing efficiency. The main content of this paper includes three parts:early survey and analysis, designing calculation and theoretical analysis, validation of degassing efficiency and optimization.The first part of this paper summarized the development process of degasser from numerous research achievements and writings. In this part, the author summarized the common degasser model, degassing method, and the domestic research and abroad. The author indicated the problems exist in the degasser's research field, summarized the meaning of research.The second part of this paper illustrated the classic mechanical theory of designing the structure of water ring vacuum pump, centrifugal impeller, main motor, V-belt transmission device, main shaft, and performed a new structure of vacuum cans.In the third part of this paper, the author utilized the 3D modeling software to construct a model of degasser (i.e., vacuum tank). Software Fluent is used for testing the degassing efficiency, researching the flow field, and summarizing the factors and laws that influence degassing efficiency. Based on the results of researches, the author optimized the working parameters and structure of degasser.