Acid_Fracturing_MBS_01麦克史密斯酸压理论讲义.ppt

Acid Fracturing Theory Application E-StimPlan Modeling E-StimPlan Gridded Flow/Acid Transport Simulation(Allows detailed, rigorous simulation of acid reaction with different layers, with varying temperature along the fracture - i.e., a “REALISTIC” simulation!) Multiple Layers of Varying Mineralogy, Fluid Loss, etc. Multiple Fluids Including Pad/Acid Fracs Reaction Rates/Acid Diffusion E-StimPlan Fluid Loss “Normal” Matrix Fluid Loss Matrix “Wormholing” Natural Fractures (including acid etching of the natural fractures) Gel Filtercake from “Pad” Stages Multiple Acids (including organic acids) E-StimPlan Finite Element Solutions Allows Calculating Stress Reduction Due to Acid Etching Allows Detailed Acid Etched  KFW Calculations E-StimPlan Allows Multiple Fracture Initiation Zones(limited entry) E-StimPlanMultiple Initiation with Limited Entry E-StimPlanMultiple Initiation with Limited Entry E-StimPlanMultiple Initiation with Limited Entry E-StimPlanMultiple Initiation with Limited Entry Acid Fracturing Simple in Theory Chemical Details COMPLICATED ! Desire XF KFW XF Controlled By Fluid Loss Acid “Spending” KFW Controlled By Rock “Dissolution” Formation Heterogeneity Acid Fracturing Acid Fracturing Acid Fracturing Advantages No Proppant so Simpler Pumping Procedures Screenout Problems, or Flowback/Cleanup Problems Associated withProppant Disappear Acid Fracturing Disadvantages Acid is More Expensive Can Only Achieve Limited XF (Due to Fluid Loss Reaction) Fluid Loss Often Non-Uniform Hard to Predict Achieved KFW and Will it Last ?Hard to Predict ! Acid Selection Controls Acid etched KFW Acid Strength (Dissolving Power) Acid Selection What Controls XF Acid Reaction Rate Acid Mass Transport (Molecular Diffusion) Fluid Loss Control (Viscosity of Acid Fluid) Wellbore Considerations Corrosion Inhibition Very important at Higher Temperature Acid Fracturing - XF Etched XF Controlled by Acid “Spending” Acid Reaction Rate Acid D