Oil and gas group Encore Oil (LON:EO.) , this morning reported that testing operations had been successfully completed at the Cladhan appraisal well, located in UK Northern North Sea Block 210/29a. The company is still working on identifying the size of the Cladhan accumulation but believes the current well could eventually produce at over 15,000 barrels of oil per day (bopd). Separately, EnCore said it was hoping to begin a programme of drilling between two and four wells on its Catcher discovery in the North Sea in late September or early October.
A discovery was first made at Cladhan in December 2008 and the follow up well aimed to refine the range of oil volumes by gaining a better understanding of the distribution and thickness of the Upper Jurassic reservoir sands. The well 210/29a-4Z flowed at a stable rate of around 5,903 bopd for over 13 hours through a 28/64 inch choke with a final wellhead pressure of 1,874 psi (pounds per square inch). The flow rate was restricted by the capacity of surface facilities and due to the small diameter of the testing tools and the 3.5 inch tubing used while testing. The well operator, Sterling Resources, has indicated that with larger 4.5 inch completion tubing the well is capable of producing over 15,000 bopd. The testing confirmed light oil with a gravity of approximately 34 degrees API and a gas oil ratio (GOR) of 245 scf/bbl.
After completing the well test operations, the well will be plugged back and a further side-track well will be drilled downdip and to the southeast of the original discovery to better understand the location of the oil water contact (OWC) in the field. The side-track operation will commence later this week and is expected to take approximately two weeks subject to weather and operational delays. The equity in the Cladhan joint venture partnership comprises EnCore Oil (16.6%), Sterling Resources Ltd (39.9%, operator), Wintershall (UK North Sea) Ltd (33.5%) and Dyas (10%). For discussion about EnCore Oil and the Cladhan discovery, click here.
Alan Booth, EnCore's chief executive, said: “The quality and deliverability of the Cladhan reservoir has been further confirmed by this excellent test result. Until we can establish the depth of the OWC, it will be difficult to accurately define the size of the Cladhan accumulation although we believe that it is very likely that a commercial accumulation at Cladhan has already been established. We look forward to the results of the side-track well which we hope will enable us to define the location of the OWC.”
He added: “Aside from the operations at Cladhan, at Catcher in UKCS Central North Sea Block 28/9, we are finalising the well locations with our partners following the acquisition of site surveys which are now almost complete. The necessary technical, drilling and safety evaluations for the use of the Transocean Galaxy II heavy duty jack-up rig are continuing and, subject to the necessary regulatory approvals of these, we hope to return to drilling at Catcher in late September / early October for a programme of between two and four wells. The turnkey contract with ADTI for use of the Galaxy II rig is being negotiated and it should be ready for signature once the necessary approvals have been received. Until such time as the contract is signed, exact timing of the drilling programme cannot be guaranteed.”
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