Maximising ESP Uptime in Forties Field-Introducing Successful Frac Packs to the North Sea

摘要

This paper demonstrates, via a comprehensively described recent case history, the transfer of established completion technology into the North Sea. Further, in performing the process the technique has been successfully extended beyond its normal criteria of application. Today artificial lift in the Forties Field is provided by a large number of electric submersible pumps (ESPs) lifting from shale inter-bedded sandstone sequences. Overall production is affected by the achieved ESP run-life in a field where sand-face failure is not uncommon. ESP failure in the Forties Delta well FD5-1 was found to be due to pack-off from a high proportion of fine shale/siltstone in addition to formation sand. Although simultaneous fracturing and gravel packing are commonly performed in other hydrocarbon producing regions none had been directed at controlling the mechanism of flowing shales and/or claystones. The well intervention was designed to protect the ESP from shale or sand grain production and provide minimal impairment to well productivity. Both objectives were achieved by increasing the formation face area for inflow and in so doing physically support the formation face in the first such frac and pack treatment executed in the UK Sector of the North Sea. ESP protection was achieved and subsequent well productivity was show to be minimally affected by the presence of the gravel pack. This case history describes the formation failure mechanism; the detailed corrective well intervention and the resulting well productivity in bring well FD5-1 successfully back into full production up-time.