Real-Time Optical Monitoring of Bottomhole Pressure During Extreme OverbalancedPerforating and Production Testing of a Remote Alaskan Exploration Well

摘要

Permanent downhole pressure gauges are becoming a standardrncompletion component in many production wells. However,rntheir use in exploration wells to date has been limited.rnWireline-deployed memory gauges are more likely to be usedrnto obtain downhole pressure data during testing of explorationrnwells. Unfortunately, pressure data from memory gauges doesrnlittle to help the operator manage and optimize the completionrnand testing of a well where uncertainties in rock strength, porernpressures, and production rates can be high. Installation of arnpermanent downhole gauge in an exploration well can providernvaluable data for real-time management of the productionrntesting process. In addition, it can continue to monitorrnreservoir pressure after the well is shut-in.rnThis paper discusses the installation, application, and value ofrna permanent optical sensing pressure and temperature gaugernsystem installed in an exploration well (Carbon #1) in thernNational Petroleum Reserve, Alaska (NPRA) during Aprilrn2004. The well was a delineation/confirmation well in a largernhydrocarbon accumulation discovered during previous winterrndrilling seasons. All exploration work in the NPRA is donernfrom ice roads and pads and therefore the season is limited byrnweather. Challenges and unique aspects of the installationrnincluded arctic winter operations, flawless integration of therndata into surface well testing data acquisition systems and thernability to monitor real time bottom hole treating pressuresrnduring an EOB (extreme overbalanced) perforating treatment.rnThe real time data proved to be invaluable for determining therneffectiveness of the stimulation treatment as well asrnoptimizing the duration of the production test and finalrnpressure build-up test. The ability to monitor pressure data realrntime rather than having to run and retrieve multiple memoryrnpressure gauges provided nearly “textbook” data quality during multi-rate testing. The well is now temporarilyrnabandoned and is available for use as a pressure monitoringrnwell during future development. The results of the stimulationrnand well testing operation were very successful and will leadrnto a future commercial development in the NPRA.