Productivity Prediction for Stacked Multilateral Horizontal Well Under Open Hole Series Completion Methods

Productivities of stacked multilateral horizontal well under open hole series completion methods were predicted by an analytical model. The analytical model was established using conformal transformation, mirror image, potential superposition and equivalent flow resistance. The ideal well’s formula will be simplified to the famous Borisove’s formula when stacked well has only one branch and locate it in middle vertical depth of reservoir. Several productivity influencing factors were analyzed to provide references for stacked well completion design. Case studies show that, stacked well productivity decreases with higher screen filtration precision; Conventional horizontal well productivity is more sensitive to filtration precision than that of stacked well; Stacked well’s vertical location in reservoir with upper and lower sealed boundary has little impact on productivity; Analytical model overestimates productivity because of ignorance of seepage disturbance and well bore flow pressure drop, an infinitesimal sectional model works as a correction model and a correction coefficient is obtained to effectively reduce the error of analytical model. Key words : Stacked well; Open hole; Analytical model; Mirror image; Potential superposition; Seepage resistance