In Northwestern China, four low perm oil wells were refractured with higher conductivity proppants. Field “S” has an average permeability of ~ 7 md, at a depth of 9800 ft. Well testing indicated the degradation of the initial fracture conductivity with time. Refracs performed with a higher permeability ceramic proppant substantially increased production rates.
Several key problems concerning refracturing in low permeability reservoirs have been studied, i.e. effectiveness of initial fractures, effects of water cut, reservoir pressure on post refrac performance and selection of candidate wells, optimization of fracture length, treatment design, implementation and evaluation. Both technological and economic achievements have been obtained.
Author(s): Fengjing Wang, Yunhong Ding, Yong Lu, Langfang Branch of Research Institute of Petroleum E. & D., CNPC
Paper Number: SPE 50912