Research On The Jet Mixing System Used For Preventing Sludge Deposition In Large Underground Water Seal Caverns

Human demand for energy is increasing,and oil known as “industrial blood” has become an indispensable source of energy.Due to its small footprint,large storage capacity,strong emergency response capability,low cost,and high safety performance,the underground water seal caverns The advantages of strong preparation capabilities and other advantages have become an increasingly important oil reserve in the world.Crude oil is a mixture of colloidal solution,solid hydrocarbons,asphaltenes and fine sediments.After long-term operation of underground crude oil reservoirs,sludge deposition problems will inevitably occur.Due to the large scale,complicated construction technology and high requirements for safe operation,China has not yet developed a relatively mature sludge removal and cave cleaning technology,while the theory of oil anti-deposition technology is basically mature in land storage tanks.Referring to the ground storage tank sludge cleaning technology,a set of oil anti-deposition system for underground water caverns is proposed to solve the problem of sludge deposition in the long-term operation of underground caverns.The basic theory of the construction of groundwater seal caverns at home and abroad,the technology of clearing tanks,the system of clearing tanks and the submerged jets were comprehensively expounded.The main research method of this paper is numerical simulation,so the related theoretical knowledge in the numerical simulation of jet flow field is introduced,including: control equation,discrete method of governing equation,multiphase flow model and so on.A simplified model of the anti-soil deposition jet system of the groundwater sealing reservoir was established,and the numerical simulation calculation of the jet operation process was realized by FLUENT software.Numerical simulation calculations were carried out for different types of nozzles,such as the type of nozzle,structural parameters of the nozzle,sludge density,sludge thickness,jet velocity,and nozzle spacing.It is concluded that the optimal nozzle selection of the jet system is cylindrical nozzle,the optimal structural parameter range of the nozzle,the range of jet velocity,the influence of sludge density,sludge thickness and nozzle spacing on the jet to the groundwater seal.The cavern anti-mud sedimentation jet system provides a theoretical basis for the jet operation process.Finally,based on the results of numerical calculations,combined with the literature materials,the anti-soil deposition jet device of the groundwater sealing reservoir and its operation flow under different working conditions are proposed.