Study On The Migration Rule Of Plugging Agent In Horizontal Well

Due to the internal heterogeneity of the formation and the complexity of the formation structure,the migration path of the water shutoff agent in the formation may not necessarily follow the high permeability channel to reach the predetermined position,but there is great randomness,in order to give full play to the water The role of flat well plugging agent in controlling water and stabilizing oil requires clarification of the migration law of the plugging agent in the reservoir.This article tries to establish an effective method for quickly calculating the position of the front edge of the plugging agent to clarify the migration and distribution of the plugging agent in the formation.In this way,the development effect of horizontal wells is further improved,the ultimate oil recovery rate of the oil field is increased,and the amount of plugging agent can be designed to save the cost of plugging agent,which has obvious economic benefits.Based on the principle of nodal analysis,this paper first analyzes the flow characteristics of the plugging agent from the wellhead of the horizontal well to the formation in each stage,and calculates the pressure loss at each stage.Among them,through the establishment of a horizontal well fluid production profile prediction model,the output section of the horizontal well is obtained,and the flow pressure loss of the plugging agent from the outlet end of the bend section to the output section of the horizontal well is calculated;the pseudo three-dimensional idea is used to analyze the plugging agent in the horizontal well.For the flow near the well area,establish the flow pressure drop model of the plugging agent in the near well area.Then,according to Darcy’s law and equivalent seepage resistance method,the differential expression of the plugging agent flow,namely the mass conservation equation,is used to obtain the differential expression of the pressure difference,and the mathematical model of the front migration of the plugging agent can be obtained through mathematical operations.To quickly and accurately describe the migration law of the plugging agent front in horizontal wells,and explore the migration position of the plugging agent in the formation.Finally,use digital simulation software to verify the rationality and applicable scope of the built model,and provide guidance on the field application of this model through example calculations.The research results show that the established mathematical model can quickly and accurately calculate the propulsion front of the plugging agent in the formation,and by determining the propulsion front of the plugging agent,the construction dosage of the plugging agent can be reasonably designed;the permeability of the plugging target layer is greater than at 1.0μm~2,the error of the calculated front edge position of the plugging agent calculated by the built model is less than 10%compared with the results of the digital simulation;the field application shows that under the designed plugging agent dosage conditions,the cost of measures is reduced and the plugging is improved.Efficiency,oil increase effect is remarkable.