Page 50 - A Practical Companion to Reservoir Stimulation

D. Fracture Calibration Treatments

EXAMPLE D-1
Doubling the leakoff coefficient (or, conversely, halving it
Calculation of the Fracture Length by its control) has a much more pervasive influence on the
from Material Balance
created length than the ability to increase the fracture width.
For this exercise, doubling the leakoff coefficient to
Calculate the fracture half-length for the well, reservoir and 2 x ftlGn would result in a reduction in the fracture
treatment variables listed in Table D-1. What would be the length to 11 26 ft. If it were an order of magnitude larger, the
impact of doubling the leakoff coefficient? What if it were an fracture half-length would be 338 ft.
order of magnitude larger?

Solution (Ref. Section 7-2)
Since h,, = 75 ft and h, = 150 ft, then r,, = 0.5. 9; = 40BPM
From Eq. 7-7 (converting appropriate units) and using I hf = 150ft I
2g,, G 3,

(40) (5.615) (1) (60)
x, =
(2) (150) [(0.2 I 12) + (3) ( (0.5) (J60)]

13,476 Table D-1-Well, reservoir and treatment variables for
-
- = 1587ft
300 (0.0 167 + 0.0 1 16) Example D-1 .

The relative impact of the created fracture width (first term
within the brackets in the denominator) and leakoff (the
second term) can be compared readily.

A complete example for pressure decline is included in Res-
ervoir Stimulation. Only additional calculations are included
in this volume.

D- 1