Page 59 - A Practical Companion to Reservoir Stimulation
P. 59

FRACTURE CALIBRATION TREATMENTS






            EXAMPLE D-9                                            The leakoff coefficient can then be found from Eq. 7-96:
            Impact of Fracture Height on Leakoff Coefficient                    (2) (465) (3.8 x  lo-’)
            and Fracture Length Calculation                               c, =
                                                                                (3.14) (501 140) 65
            Repeat the calculation in Section 7-4.5.1 but use h, = 140 ft
            (instead of 70 ft). Use the same well and pressure data as in     = 5.3 x  10~’ft/min,”’       (D-30)
            Tables 7-4 and 7-5.
                                                                 which is four times larger than the value in Section 7-4.5.1.
            Solution (Ref. Sections 7-4.5 and 7-4.5.1)             The  fracture  half-length  can  then  be  calculated  from
            The fracture compliance can be calculated from Eq. 7-23a, and   Eq. 747 using q = 0.46, V, = 2850 ft3 and g,, = 1.52 (from
            thus,                                                Table.7-3, a = 0.6). Thus,
                   (3.14) (0.74) (140)                                              (1  - 0.46) (2850)
              ci  =                 =  3.8 x  IO-’ft/psi.  (D-29)   xi  =
                     (2) (4.3 x  loh)                                  (2 x  140) (2 x  1.52) (5.3 x  lo-’)  (50/ 140) 65

              This compares with  1.9 x   ft/psi for the example in
            Section 7-4.5.1.                                        =  165ft,                              (D-31)
                                                                 which is one-fourth of the value calculated in Section 7-4.5.1.




















































                                                                                                             D-9
   54   55   56   57   58   59   60   61   62   63   64