Simulation Of Proppant Migration During LPG Fracturing

Hydraulic fracturing process using 100% liquefied petroleum gas(LPG)has demonstrated quick and complete fracture fluid recovery,significant production improvements and dramatically longer effective fracture lengths.The process gels the LPG for efficient fracture creation and proppant transport.With that there is no compromise in the fracture treatment placed when compared to conventional treatments.However,once the fracture treatment is complete and the viscosity of the gelled LPG is broken,the unique properties of LPG create an ideal fluid for complete cleanup.Removal of this fluid from the invaded zone is easily achieved;relative permeability effects,irreducible saturation behavior and capillary pressure demands are eliminated.Complete recovery of the LPG is consistently demonstrated.Following conventional hydraulic fracture treatments,effective fracture lengths are frequently observed to be much less than anticipated fracture lengths.A precursor to the poor fracture performance is poor recovery of the fracturing fluid;often less than 50% is recovered during clean-up.In many reservoirs this unrecovered fracturing fluid remains immobile within the formation creating an obstruction to flow.This significantly compromises effective frac length and results in decreased production.During the fracturing process and subsequent closure of the fracture,the bulk of the fracturing fluid invades the reservoir matrix along the fracture face,referred to as the “invaded zone”.This fluid is forced into the reservoir by the significant pressure differential between fracturing pressure and reservoir pressure.Once in the matrix,removal of fluid from the invaded zone can be very difficult as it is held by relative permeability,irreducible saturation,and/or capillary pressure effects.This paper deals with the Ansys simulation(CFD model)on proppant Suspension using,simulation bases on how LPG suspend proppant along the vertical wellbore,Slant wellbore Horizontal wellbore and finally along the fractures.It further analyses the effects of various boundary conditions on LPG proppant suspension especially the effects of fluid viscosity,Density,flow rate,proppants size,and Proppant concentration.This study verifies the feasibility of proppant transport by LPG fracturing in fractures and can provide the basis for LPG fracturing design.