Design And Research Of Automatic Inflow Controller For Horizontal Wells

In the production process of horizontal wells in bottom water reservoir,the profile of the wellbore fluid will be unbalanced,and the bottom water will be easily coned,due to the influence of well trajectory,wellbore friction,and formation heterogeneity.This will cause the water content to rise sharply in the short term,which will seriously affect the production of oil wells and recovery of oil fields.Before the breakthrough of the bottom water,AICD can balance the fluid production profile and delay the bottom water cone;after the bottom water breakthrough,AICD can automatically identify the fluid and restrict the water flow.Therefore,the in-depth study of automatic inflow controller is of great significance to the efficient exploitation of bottom water reservoirs.Based on the research of the existing AICDs,this paper selects three representative flow channel type AICDs,and use CFD analysis the flow field,sensitivity and water control performance.Results indicate that:water will produce high-speed swirl inside the AICD,and the oil will not produce swirl;all three AICDs are sensitive to viscosity and water content,and are not sensitive to density;all three AICDs have certain water control capacity but not maximized.On the basis of summarizing the advantages and disadvantages of the AICD structures,the design criteria of the new AICD were developed and the structure of the new AICD was designed.Structural optimization based on flow field analysis results,and the optimization results show that:the optimal position of the T-shaped structure is 90 degrees,the optimal number of inlets is 2,the optimal angle of the Y-shaped structure is 60 degrees,and the optimal number of Y-shaped structures is 10.Then the sensitivity analysis and water control performance comparison analysis of AICD were carried out.The results show that:the new AICD has the same fluid sensitivity as the existing three AICDs,and the water control performance is significantly improved.Then,the application range of the viscosity was analyzed,it was found that:the optimum viscosity of the new AICD increased with the increase of the flow rate,the minimum applicable fluid viscosity at 5m3/d is about 5mPa·s,the maximum applicable fluid viscosity applicable at 40m3/d is about 640mPa·s.Finally,comparing the experimental results with the CFD simulation results,the results show that the actual water control performance of the new AICD is almost consistent with the simulation results,which verifies the water control performance of the new AICD.This paper developed a new type of AICD through CFD simulation and laboratory experiments,which has important guiding value for the research and development of domestic intelligent water control tools,and has important application value for water control and oil production enhence in oil fields.