A comparison of multiple radial fracturing enhancement techniques – Laboratory investigation

The laboratory testing program described in this paper was designed to investigate the optimal use of propellants in rock matrix fracturing. Three techniques are compared: the single burn approach, the consecutive burn approach, and the pulse tailoring approach. The single burn approach involves the simple burn of a single propellant charge within a wellbore. The consecutive burn approach is similar to the single burn approach but utilizes a second burn at the same wellbore location as the first burn. The pulse tailoring approach involves the use of secondary gas sources which are designed to feed propagating fractures with “late time” gas. Laboratory-scale tests of these concepts were performed under polyaxial load conditions in a rock simulant using miniature propellant packages. The results indicate that both the consecutive burn and pulse tailoring approaches significantly improve matrix fracturing when compared to the single burn approach and that the pulse tailoring approach is substantially more energy efficient than the consecutive burn approach.