Thermally stable explosive system for ultra-high-temperature perforating

Abstract

As oil and gas companies continue to expand drilling and completion operations into increasingly demanding environments, perforating systems must be developed for these extreme conditions. Several upcoming oil and gas frontiers are being developed by operators that will have downhole temperatures exceeding 450°F (230°C); this means perforating operations at these temperatures will push, or even exceed, the limit of traditional explosive systems using HMX and HNS. The thermal deficiency of these explosives will be magnified further whenever the perforating guns are conveyed by tubing rather than wireline because the operational times will be significantly increased. This paper describes a perforating system based on the thermally-stable explosive PYX, which overcomes the temperature/time limits of traditional explosives. Desirable characteristics of the bulk PYX explosive are discussed, along with design considerations for the major components that comprise the system: percussion detonator, detonating cord, detonation transfer elements, and shaped charges. The role of specialty booster explosives that complement PYX performance, such as NONA and BRX, is also discussed. The testing infrastructure and methodology undertaken to validate thermal performance at both the component and system levels are described, along with results of test programs that demonstrate successful performance to levels up to 480°F (250°C) for 100 hr. Additionally, steps that promote operational success in the field, such as gun-preparation and loading techniques, are also presented. Copyright 2013, Society of Petroleum Engineers.