Fiber-Optic Distributed-Temperature-Sensing Technology Used for Reservoir Monitoring in an Indonesia Steamflood

Abstract

Abstract The world's largest steam-flood operation is conducted on the island of Sumatra in Indonesia. Fiber-optic Distributed Temperature Sensing (DTS) surveys are used in the Sumatra fields to provide valuable data for reservoir management. The DTS profile data can determine the temperature and extent of a steam chest as well as the temperature gradient for either over-burden- or under-burden reservoirs. This information is vital for properly setting steam-injection target rates. The information is also used to mitigate steam breakthroughs and eruptions as well as to identify bypass oil. Steam flood operations experience many types of problems: i.e., inefficient injection rates, wasted heat to the casing, sanding in producers, liner failures, pump failures as wells as the need to improve the efficiencies of the vapor collection systems, well-test stations, and central gathering stations. Based on these challenging problems, periodic wellbore temperature surveys are required in order to improve heat management and ultimately improve profitability. Conventional temperature logs cannot be run in these wells without first pulling the pumps from the completion. Therefore, employing a fiber-optic DTS system that would be attached to the production tubing was suggested. This paper will present case histories of successful applications of fiber-optic DTS surveys that improved steam- flood management in this steam- flood field in Indonesia. The benefits from the fiber-optic DTS monitoring were: Significant improvement in the understanding of steam breakthrough zones along the pay zone interval of production wellsImproved understanding of the steam path in steam-injector wellsImprovement in the real-time temperature profile in observation wells to identify steam-zone development and unswept or bypassed oil zones in the steam flood patterns.