New Design Of Impeller-type Swirl Wax Preventing Device And Performance Analysis

Nowadays,the production fluids of most oilfields in China are waxy crude oil,and the wax mass fraction in most crude oils is above 20%,of which the crude oil content of Daqing Oilfield is as high as 28.44%.Waxing of oil wells can cause oil pipe blockages,and serious accidents such as production shutdown or damage to oil production equipment can occur.Waxing of oil wells has become an urgent problem in major oil fields.Especially the rodless pumping method,due to the lack of the agitating action of the reciprocating or rotating motion of the sucker rod,the wax on the tubing is more serious than the rod-based method.The traditional techniques of wax removal and prevention such as mechanical scraper wax removal,hot washing,and chemical wax removal and removal techniques all have more or less defects.Traditional wax removal and protection technologies such as mechanical scraper wax removal,thermal and chemical wax removal and removal technologies all have more or less defects.Therefore,there is an urgent need to design a wax cleaning and anti-waxing technology and device for rodless pumping wells that are convenient,safe,reliable,and effective in preventing wax.The impeller-type swirl wax prevention device uses the impeller as the core component,which is connected by a hollow rod and driven by a motor.It can increase the speed of the well fluid,and cause it to form a spiral flow,flushing the paraffin wax that has been deposited on the pipe wall.The increasing of shear stress can destroy the wax crystals that have been formed,and make the wax molecules more uniformly dispersed In oil flow.It can effectively prevent the formation of oil wall wax concentration gradient.The impellers are installed in the wax-prone position of the well,and is arranged in the tubing in a non-uniform manner with different density.As a kind of physical wax removal and prevention technology,it inherits the advantages of mechanical wax removal technology,and similar to chemical agents that can destroy the microstructure of wax crystals in the oil stream.This technology avoids damage to equipment,high cost,difficult implementation,environmental pollution and long recovery period of oil wells,and has the advantages of low cost and oil wells suitable for different production fluids.Aiming at the impeller-type swirl wax-prevention device,the influence of geometric parameters and process parameters on the performance of the device was carried out to complete the design of the device.The impeller part of the device was designed based on the design theory related to computational fluid dynamics and axial flow pump.The specificcontent includes modeling and completing the meshing work,and using ANSYS CFX to design the impeller diameter,inlet and outlet angle,length,number of impeller blades,and blade thickness.In terms of process parameters,the simulation of CFX and OLGA software were used to complete the design of the device’s rotation speed,impeller installation position and the distance of impellers.After the above work was completed,a field test of the device was performed,and the wax-proof performance of the device was judged by measuring the change in the parameters of the oil well that was operated for 30 days using the device,and a hot washing experiment was performed on it.The experimental results show that this impeller-type swirl wax-prevention device can not only slow down the occurrence of wax deposition,but also increase the fluid velocity of the well to increase its oil-oil properties,and it can complete the hot-washing work,and the well-washing effect is good.It greatly simplifies the hot washing process and reduces the cost of well washing.As a new type of physical cleaning and anti-wax device,it combines the advantages and advantages of a variety of traditional cleaning and anti-wax technologies.The device can effectively increase the production rate,reduce operating costs,protect oil production equipment,effectively extend the cycle of well washing and pump inspection,and at the same time provide new ideas and directions for the research of oil well cleaning and antiwaxing technology and equipment.