Design And Performance Of A New Autonomous Inflow Control Device For Horizontal Well

Horizontal wells have unique development advantages in low-permeability,small-reservoir marginal reservoirs and various reservoirs.However,in the production process of long horizontal wells,especially in the bottom water reservoirs,premature water breakthrough is usually encountered due to the imbalanced production profile.This imbalanced phenomenon could be caused by the heel–toe effect,reservoir anisotropy,reservoir heterogeneity or natural fractures,seriously restrict the production of oil wells.Inflow control device(ICD)has gained popularity since its first introduction to oil industry.However,ICD cannot automatically adjust with changing reservoir production conditions,and the current technology is not yet perfect.Autonomous inflow control devices(AICD)can effectively delay the bottom water breakthrough along the horizontal well to improve production.In this paper,a new autonomous inflow control device for horizontal Wells is designed by improving y-type AICD,combining with screw separation and existing AICD technology.And general computational fluid dynamics is used to simulate the fluid motion,the influence mechanism between the flow channel structure and water control mechanism is analyzed to optimize the flow channel structure of the device,the new AICD works best when the inlet is tangentially connected and the number is one,and the minimum radius of curvature of the spiral baffle is 6.By analyzing the influence of the factors of fluid viscosity,density,flow rate and water content on the performance of the new AICD,the sensitivity of the new AICD to fluid properties,the flow field characteristics of the device and the performance of water limiting and flow control are described.The new AICD model was made,and the water control performance of the new AICD was further analyzed through experimental research.The new AICD can stabilize oil production while generating greater flow resistance to water to inhibit its outflow,and has a strong erosion resistance.The working performance of the new AICD is less sensitive to the density of the fluid and more sensitive to the viscosity of the fluid,and different flow rates correspond to different viscosity turning points.Therefore,the new AICD can effectively inhibit the output of water and low-viscosity fluids.In addition,the new AICD can also effectively inhibit the outflow of high-water-content fluid,the pressure drop generated by the fluid with a viscosity of 200 m Pa·s and a water content of 90% is about 4 times that of the pure oil pressure drop of 200 m Pa·s.In general,the new AICD can produce high flow resistance to water,high water content and low viscosity fluid.It can achieve the purpose of inhibiting water flow and stabilizing oil output.The above research results can not only provide theoretical support for the new AICD performance research and structural design,but also have certain guiding significance for field application.