Pumping Control And Optimization For The Producing Tube String Of Perforation-bridge Plug In Horizontal Wells

The hydraulic pumping perforation-bridge plug combined pipe string segmented fracturing technology is one of the main methods for shale gas development at home and abroad.It has the characteristics of unlimited stage fracturing stages and accurate fracture placement.Research on the control model and key mechanical parameter design of the pumping process of the perforation-bridge plug combined pipe string in horizontal wells is to solve the passability of the combined pipe string structure,optimize the pumping displacement,control the cable speed,pump safety and other key issues.The main work and conclusions of this paper are as follows.(1)The structural parameter design of the joint pipe string.Based on the structural characteristics of unconventional horizontal well perforation and bridge plug combined string,this article focuses on factors such as wellhead sealing and well trajectory to determine the choke tube length,the number of weight bars and the maximum length/maximum outer diameter of the combined string and other parameters.On this basis,with regard to the factors affecting the design of the structural parameters of the combined pipe string,the wellhead pressure,well trajectory,choke tube and cable gaps were further selected and analyzed.(2)The pumping control mechanics model of the combined pipe string.According to the pumping process of unconventional horizontal well perforation and bridge plug combined string,considering the three-dimensional well trajectory,a horizontal well combined string pumping mechanical model was established.In view of the environmental load conditions of the pumping combined pipe string,the control equation of the pumping displacement is established,and the quantitative analysis method is selected to affect the pumping displacement of the well trajectory,wellhead pressure,the weight of the combined pipe string,and pumping Factors such as fluid viscosity,bridge plug size,and cable lowering speed.(3)The cable tension control of the pipe string transmission.In the process of pumping down/up of the combined pipe string,the cable tension control model was established for the vertical and horizontal well sections,and the reasonable control range of the cable tension during the pumping dynamic process was proposed,which provided a great impact on the successful implementation of the combined technology.(4)Cooperate with the software development of the pipe series pumping control system.Based on the results of this paper,such as the optimization design of pipe string structure parameters and the mechanical model of the pumping control process,the unconventional horizontal well perforation and bridge plug combined pipe string pumping design software system was developed,and the basic data management and wellbore were integrated.The integration realizes functions such as basic data management,well trajectory description,pipe string structure parameter calculation,pumping displacement design,cable tension analysis,and construction report output.