Page 221 - Formulas and Calculations for Petroleum Engineering
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214 Formulas and calculations for petroleum engineering



              4.22   Damaged/undamaged zone productivity comparison (acidizing)

              Input(s)
                 F k :  Permeability Ratio (dimensionless)
                 r e :  Drainage Radius (in.)
                 r w :  Wellbore Radius (in.)
                 r s :  Damaged Zone Radius (in.)


              Output(s)
                 J s :  Damaged or Stimulated Formation Productivity Index (STB/day/psi)
                 J o :  Undamaged Formation Productivity Index (STB/day/psi)

              Formula(s)


                                                    J s     F logr =r w
                                                             k
                                                                 e
                                                      ¼
                                                    J   logr =r + F logr =r
                                                     o     s  w   k   e  s
              Reference: Williams, B. B., Gidley, J. L., & Schechter, R. S. (1979). Acidizing fundamentals. Henry L. Doherty Memorial
              Fund of AIME, Society of Petroleum Engineers of AIME, Page: 6.

              4.23   Density of brine (completion and workover fluids)

              Input(s)
                 ρ m :  Density of Brine at ambient Surface Pressure and Temperature (lbm/gal)
                 C te :  Coefficient of Thermal Expansion or Volume Expansion Factor (dimensionless)
                 T m :  Ambient Temperature of Brine-Density Measurement (°F)
                 T s :  Standard Reference Temperature (70 °F)


              Output(s)
                 ρ s :  Density of Brine at Standard Reference Temperature (lbm/gal)


              Formula(s)


                                                    ρ ¼ ρ 1+ C   T  T
                                                     s   m     te  m  s
              Reference: Bridges, K. L. (2000). Completion and Workover Fluids (Vol. 19). Society of Petroleum Engineers, Page: 45.


              4.24   Dimensionless fracture width for linear vertical fracture (Geertsma & Klerk)
              Input(s)
                                                    0.5
                 C:   Over-all Fluid-Loss Coefficient (m/(s ))
                 h:  Fracture Height (m)
                                                              2
                 E:  Young’s Modulus of the Formation Rock (kg/m-s )
                                        3
                 i:  Fluid Injection Rate (m /s)
                 t:  Total time for Fluid Injection (s)
                 w w :  Fracture width at the Wellbore (m)
                                         3
                                            2
                 V spt :  The Spurt Volume (m /m )
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