Day 2 4 carbonate acid fracturing stimulations

slide Geology ME  slide ! Enormous permeability contrast matrix - fracture system ! Short flush production of oil/gas ! Unwanted inflow of water through fracture system ! Large variation in reservoir types Breakthroughs required É Reduction of water production ! Substantial increase in production reduction in well cost slide Well Type Conclusions Vertical Slanted !  Least Expensive !  Would require 85¡ penetration !  Straight-forward to frac of reservoir for significant benefit !  Would exit area before reaching base of reservoir "  Selected for Phase #  Not Suitable Horizontal Multi-Lateral !  Expensive to drill at this depth !  Complex & costly (at this depth) !  More difficult to frac !  Limited productivity improvement due to low / no vertical permeability !  More difficult to frac !  Technology constantly developing but not yet sufficiently mature #  Not Suitable #  Potential for Longer-Term slide ! Enormous permeability contrast matrix - fracture system ! Short flush production of oil/gas ! Unwanted inflow of water through fracture system ! Large variation in reservoir types Breakthroughs required É Reduction of water production ! Substantial increase in production reduction in well cost slide Chemical Fracture Shut‐off  NEED to KNOW……….  flow into the well bore  ●     How does water  ●     How do I stop it????  slide Oil or Water ????  slide Coiled tubing Gelant in sea water Water flooded Zone Oil bearing Zone Re-perforation target Calcium Chloride/Bromide Fill slide IN-DEPTH FLOW DIVERSION Injector Producer Low k zone High k zone Low k zone Water injection flushing mainly the high k zone Injection of system to block flow through high k layer Injected water diverted to low k layers resulting in improved oil production slide 10 Acid fracturing fluids &  addiΚves  !  (cross‐linked) Pad + HCL  !  Gelled Acid  !  Chemically Retarded Acid  !  Emulsified acid  slide 71 Acid Fracturing – Acid selecΚon Chart  GAS    So Chalk  Treatment size               Small (5 m3/m)          Temp 100¡  Legend  28% HCl  15% HCl  Retarded HCl Calcite          Temp 100¡  Dolomite          Temp 100¡  Oil      So Chalk          Temp 100¡  Calcite          Temp 100¡  Dolomite          Temp 100¡  slide 72 RetardaΚon effecΚveness of acid systems  Acid Type  !  !  !  !  !  !  !  !    950   15% Plain    1  Linear gel   2.5  X‐linked gel  0.8  Organic/HCl   1.5  Oil external emulsion  6.5  Acid external emulsion    1.6  Chemically retarded  Surfactant viscosifier