In-depth Evaluation of Deep-rock Hydrajet Results Shows Unique Jetted Rock Surface Characteristics (SPE 153333)

The use of hydrajetting for perforating of wells has been commonplace since the sixties. During those early years, wells were relatively shallow; and jetting success was consistently demonstrated. However, as wells became deeper, and rock formations tend to be harder at those depths, performance of hydrajetting was less dependable; as subsequent stimulation failures more often occur from the lack of fracture initiation. In order to remedy this situation, a series of tests were performed to define new best practices for hydrajet perforating of rock under high ambient pressure. Various rocks were subjected to these tests; which were done using different jetting pressures and different abrasives. The perforation surfaces were then dissected, and then evaluated using photographic and chemical means. Further assessments are then made to determine as to what actually happened during the hydrajetting process. This paper discusses various tests results; and new constraints for jetting are defined and presented.