Integrating Real-time Downhole Data to Enhance Gas-lift Completion Strategies and Perforation Practices

Abstract

This paper discusses the use of downhole gauges not only for monitoring pressure and temperature, but also production-optimization, enhancing completion design, perforating activates and costmanagement efforts.Real-time downhole gauges have been used in oil fields for many applications in the past. Despite this, permanent downhole gauges have only been installed for gas-lift wells in one of PDO's fields since 2007. The requirement for the monitoring system was to closely monitor the bottomhole conditions for the purpose of water injection in a 5-spot pattern application.Openhole logs and individual reservoir pressure data of a well in 2007 indicated a variation in reservoir pressure values across the encountered zones. The decision to install permanent gauges offered the possibility to perforate the wells selectively in stages and measure the extent of underbalance prior to and during perforation operations. A technical and commercial comparison among perforation operations methods revealed that such an approach could result in better production performance and cost management. Data from the gauges provided ideas for improving perforation practices, such as spotting light oil against the perforated interval to minimize reservoir impairment.Installing permanent gauges in 2008 clarified three important areas: the wireline operations prior too perforation; the correct method for perforating; and the adherence to the issued program.While kicking off the well using gas lift, readings from the gauges revealed a gas-lift valve problem that instantly led to the decision to suspend perforation and change the malfunctioning valves. After rectifying the issue, perforating operations resumed and individual production tests were carried out to clarify the well's further potential. As a result, an operating-expense saving of more than $500,000 was achieved in the 2008 new well campaign. The added benefit of improved completion operations and production optimization has proved very useful.