Stewart discussed the case histories of more than 70 completions requiring sand control in a variety of reservoirs. His study found that frac packs provided average skin values of +0.4 while gravel packs achieved +21. These case studies also indicate that the frac packs provided superior sand control, eliminating costly workovers, and minimizing post-completion acid jobs
This paper discusses case histories of more than seventy completions requiring sand control. Approximately half of these wells were gravel packed (both slurry and water packs) between 1990 and 1995 while the remaining completions were fracture stimulated (frac-packs) from 1992 through 1995. The case histories include: geopressured oil reservoirs of moderate permeability, normal pressured high perm oil and gas formations, partially depleted high perm gas sands, and shallow dry gas formations. Results of bottom hole pressure transient analyses are included that compare skin values and completion efficiencies of both gravel packed and frac-packed completions. Production plots and decline curves are presented depicting accelerated as well as improved reserve recovery with the frac-packed completions. The associated costs of frac-packing is discussed along with a net present value analysis justifying these costs.
Author(s): B. R. Stewart, M. E. Mullen, R. C Ellis, Pennzoil Exploration and Production Company; W. D. Norman, Schlumberger-Dowell; W. K. Miller, NSI Technologies
Paper Number: SPE 30470