This paper shows refrac results from three fields including the Olmos formation of the Tilden oil field. Initial treatments in the Tilden utilized low sand concentrations. Refracs were designed to place 14+ ppg proppant. The results from 17 refracs are shown to provide sustained production increases in many wells by placing higher conductivity fractures. Similar results in an undisclosed South Texas field at 3000 ft depth placed 12/20 sand in refracs up to 10 ppg and documented 83% success rate with restimulation.
With the current unfavorable economic climate caused by uncertain oil prices and a curtailed gas market, restimulation of existing wells to increase production rates and/or economically recoverable reserves has become an alternative to exploration or drilling development wells. Production increases realized from refracturing in several areas have demonstrated that recompletion of certain wells can be one of the best investment opportunities available.
Developments in fracturing technology and interpretation have increased the potential for successful restimulation in an increased number of wells. Because of recent advances in fracturing technology employing more efficient fluids capable of transporting high sand concentrations and modified surface equipment, treatments can be performed that were previously not possible.
Case histories of two oil reservoirs, including the sizes of the initial fracturing treatment and refracturing treatment plus production after each, are presented. Unfortunately, very little information on gas wells is available because of the current economic climate.
Author(s): M.W. Conway, D.E. McMechan, J.M. McGowen, D. Brown, P.T. Chisholm, J.J. Venditto, Halliburton Services
Paper Number: SPE 14376