Bill Grieser

Overbalanced perforating Field study in the Tubb Sand, Bravo Dome Field

This paper provides results of a study comparing several parameters from 40 wells that were fracture-stimulated with conventional perforating techniques to 30 wells fracture-stimulated with overbalanced perforating (OBP). All wells are in the Bravo Dome Field and are producing from the same formation. The parameters used for comparison are (1) interval length and depth, (2) number of perforations and phasing, (3) perforating technique. (4) average and maximum bottomhole calculated treating pressure (BHTP), (5) proppant volume to job volume ratio, and (6) production results. There were two opinions on the benefit/risk of using OBP as an initial step in completing wells that may require fracture stimulation. One opinion suggests that OBP reduces near-wellbore tortuosity and creates a dominant fracture geometry, resulting in lower injection pressures and reduced chance of early screenouts. The other opinion suggests that OBP increases tortuosity and creates multiple fractures that could lead to high injection pressures and early screenouts.