Productivity Prediction And Fracture Parameter Optimization Of Radial Horizontal Well In Hydraulic Fracturing

Based on the radial well which is drilled by high pressure water jet, radial well fracturing technology is fracturing on the radial well to form high conductivity fractures near well bore and increase oil production. Currently, the technology is in the experimental stage in China, lacking of theoretical research. Productivity prediction and fracture parameter optimization of radial horizontal well is a subject of urgent research to achieve efficient development of radial well in hydraulic fracturing. As the diameter of radial well wellbore is small and the completion is open hole, for reservoir recovered by radial well distal fracture, the influence of the wellbore pressure drop and the fluid confluence and cracks in fracture of distal segment should be taken into consideration when calculating productivity. Taking into account the radial wellbore fluid flow is variable mass flow, based on the law of conservation of mass, momentum theorem and the theory of infinitesimal line congruence, the radial wellbore flow model was derived, based on the complex potential theory, the mirror image principle, the fluid percolation model in the reservoir was derived, and then productivity calculation model considering wellbore pressure drop was derived, and productivity calculation model of distal radial shaft fracture was derived, combination of the both is productivity calculation of radial well fracturing. Based on hydropower similar principle, electrical simulation experiment models of radial well fracturing are designed, and the numerical models of radial well fracturing are designed by Eclipse numerical simulation software. Under condition of vertical fractures, measure and simulate voltage distribution, electric current and production value of different number of fractures, different fracture spacing, different fracture lengths. Analysis the influence of radial fracture parameters to radial well productivity, optimize the fracture parameters, and productivity prediction model is validated.The average error between productivity calculation model and electrical simulation results is 8.83%, the average error between productivity calculation model and numerical simulation results is 12.88%, and the error between productivity calculation model and well Gao 6-82 is 7.50%, all are less than 15%, in line with the actual requirements of the project. Research on this subject lays a theoretical foundation of radial well fracturing.