Research On Gravel Pack Completion Tool And Simulation Analysis Of Radial Horizontal Well

With the continuous development and improvement of radial horizontal well technology,radial horizontal well technology is used more and more frequently in unconsolidated sandstone reservoir.But this kind of geological oil well has the characteristics of serious sand production.When the formation sand enters the downhole tool,it will corrode the tool.When the sand production is serious,it will bury the oil producing section and cause the oil well to close down.Therefore,how to more effectively prevent sand has become the most important link of radial horizontal well completion.By comparing several sand control completion methods,gravel pack sand control completion has obvious sand control effect,long sand control time and high oil production compared with other sand control completion methods.Gravel packing technology is to use gravel to form a uniform packing layer with high permeability,high strength and high density in the screen casing annulus and near the well area.Based on the comprehensive consideration of the advantages and disadvantages of sand control tools of major oil companies,this paper designs a six in one gravel packing tool(well washing,setting,filling,backwashing,releasing,well completion)suitable for radial horizontal wells.On the basis of previous studies,the mathematical model is used to describe the ?-packing process of radial horizontal wells,which can theoretically explain the gravel packing mechanism of radial horizontal wells.According to the standard of gravel optimization,sand production and construction parameters of major oil fields,aiming at how to improve gravel packing effect and prevent sand plugging in radial horizontal wells,taking gravel filling process parameters: mortar displacement,sand carrying ratio and viscosity of sand carrying liquid as the research object,using the method of orthogonal test and numerical simulation calculation,according to the results of orthogonal test and numerical simulation,comprehensive Select the optimal construction process parameters.Through the above two methods,the following results are obtained: the order of influence of filling parameters is obtained by range method: displacement > sand carrying ratio > viscosity of sand carrying liquid.By calculating the average value of comprehensive evaluation index of the level,the trend chart of each factor level with comprehensive evaluation index is made.It is concluded that the best combination of parameters in this orthogonal test is that the displacement of mortar is 850L/ min,the sand carrying ratio is 15% and the viscosity of sand carrying liquid is 8m Pa.s.The characteristics of gravel packing process in radial horizontal well can be seen from the gravel volume nephogram,Divided into In the two filling processes,the best combination of parameters in the numerical simulation is similar to the results of the orthogonal test,and in the comparative test,it is concluded that: high displacement,long distance of gravel transportation,easier to reach the end of the horizontal section of the radial horizontal well;high sand carrying ratio,the more gravel content in the mortar,the faster the gravel sinking speed,the faster the sand bed accumulation speed;high viscosity of sand carrying fluid,strong carrying capacity,transportation The gravel is further away and less likely to cause plugging.