BANCHORY, UK – Xcite Energy has concluded the pre-production well test on the Bentley heavy oil field in the UK northern North Sea.
The aims of the Phase 1A work program were to demonstrate the mechanical and operational aspects of the drilling, completion, and flow of the proposed well design for application in Phase 1B; and to collect additional reservoir and production data to improve calibration of the reservoir engineering model and production facilities design for the field development.
The pre-production test comprised two horizontal wellbore sections (9/3b-7 and 9/3b-7Z), drilled through more than 4,200 ft (1,280 m) of net reservoir.
Xcite says the 9/3b-7 well was placed at a depth close enough to the oil/water contact for water to be produced throughout the flow test. It was successfully geo-steered within 5-10 ft (1.5-3 m) of the attic of the reservoir. Downhole control valves were successfully operated, delivering flow from each wellbore individually and in combination.
About 147,000 bbl of crude oil were produced during Phase 1A without any environmental incidents.
Timing of first water ingress to the wellbore and subsequent water build-up was better than expected. As a result, the ratio of oil to water produced was also above expectations, and provided important data for modeling future oil recovery from the field.
The flow test also confirmed the existence of a large, active aquifer, which should provide long-term pressure support during life-of-field production.
Analysis suggests the Bentley field is behaving within the range of modeled outcomes. The data will also assist planning of an enhanced oil recovery program for the field.
Other successful trials during the test included design confirmation of offshore separation, metering and export systems; the impact on flow rates of demulsifier, defoamer and other specialized chemicals and diluents; and verification of all main process simulations, including subsurface diluent injection, downhole heating, pipeline flow assurance, and crude oil blending.
The well will now be suspended, with both wellbores retained for use in the next field development phase.
Once the well test equipment has been removed from the Rowan Norway, the rig will be towed to Dundee, eastern Scotland, and released back to Rowan.
The Scott Spirit tanker has left the field to discharge the collected water and transfer the Bentley blended crude for onward shipment to the refinery.