A new algorithm to quantify water coning in hydraulically fractured tight oil reservoirs

摘要

This paper shows a general mathematical correlation and procedure to predict breakthrough time of water in the hydraulic fractured tight oil reservoirs obtained through numerical simulation modelling. The research work exhibits a 3D simulation model which is run for different ranges of fracture conductivity, k*w (md-ft), reservoir permeability, k (mD), anisotropy ratio, k/k, density difference, ρ-ρ (lb/ft3), water oil contact, WOC (ft), fracture length, L (ft), fracture height, h (ft) and oil viscosity, μ (cp) to find time to breakthrough t. More than 20,000 data points are obtained by around 20,000 number of simulation runs by coupling the commercial reservoir simulator with MATLAB. Multivariate regression technique is employed to obtain generalized correlation for time to breakthrough in hydraulically fractured vertical well in tight oil reservoirs (TOR). The algorithm is obtained by applying multivariate regression technique with mean absolute percentage error less than 5 percent. Results show the good agreement with the unseen data. Correlation parameters are transformed to dimensionless form in order to get generalized correlation. It is observed that breakthrough time highly depends on fracture height and dimensionless fracture conductivity in the hydraulic fractured vertical tight oil well.