Using Fibre-Optic Distributed Temperature Measurements to Provide Real-Time Reservoir Surveillance Data on Wytch Farm Field Horizontal Extended-Reach Wells

Abstract

Abstract BP-Amoco operated Wytch Farm has installed fibre optic distributed temperature systems on 2 of their recent ERD (extended reach drilling) wells in order to provide real time reservoir surveillance. This novel new approach to reservoir monitoring has provided important information about the well and reservoir performance. This type of zonal contribution and fluid data would normally be acquired by running production logs on the end of coiled tubing at infrequent intervals, however the dual completion on Wytch Farm’s M-12 well made conventional production logging impossible. Distributed temperature data has been recorded over 2 years throughout well tests and shut-ins, as well as during normal periods of production. Data analysis is performed both visually, by correlating time related thermal events observed in the well with known reservoir and production anomalies, and theoretically by comparing recorded temperature data with that predicted by thermal profiles generated using nodal analysis fluid flow and heat transfer software*. Use of this software* allows estimates of production by zone to be compared to actual recorded temperature data, enabling a variety of production scenarios to be investigated and the most likely identified. The installation of real time fibre optic distributed temperature monitoring on Wytch Farm field has enabled the asset to recognise flow behind casing and cross flow during shut-in in the M-12 well and water finger encroachment to be identified in the M-17 well. This data has provided important information about both the reservoir and well performance in real time, which would not usually have become available until later in the wells life.