Crawford, Don area expansion gain momentum

Development planning for the Crawford field in the UK central North Sea is at an advanced stage, according to partner Valiant Petroleum.

Offshore staff

WOKING, UK -- Development planning for the Crawford field in the UK central North Sea is at an advanced stage, according to partner Valiant Petroleum.

Operator Fairfield Energy is working on a program of multi-lateral horizontal production wells in Crawford’s Triassic reservoir, and one or more wells in the Tertiary horizon.

The multi-laterals are being designed to maximize the amount of open hole connected to the reservoir. Currently, Valiant says, the plan is to drill three “motherbore” wells into the compliant Cretaceous limestone, each with eight lateral wells penetrating the Triassic reservoir below.

Oil export options include Marathon’s East Brae platform to the south or direct offloading from a standalone production facility to a shuttle tanker. The new target date for first oil is towards the end of 2012.

Valiant is also a partner in the EnQuest-operated Don area fields in the northern UK sector. This summer, the semisubmersible John Shaw has been drilling production wells in the northern part of the Don Southwest field.

The focus is on the Horst compartment, discovered in 2009, which was found to contain some of the field’s best-quality reservoir. Production from the Horst producer started this July at an initial stabilized rate of 17,000 b/d, lifting total oil output from Don Southwest above 30,000 b/d.

Valiant adds that a water injector well on the field has been completed ahead of schedule, and should start up later this month. This fall the John Shaw is scheduled to drill an appraisal of the H compartment in the southern part of Don Southwest, potentially holding up to 12 MMbbl.

At West Don, production has fallen back following an intermittent blockage in one of the producer wells, and issues concerning the water injection scheme. However, output should be restored this fall once a third producer has been brought onstream, says Valiant. EnQuest plans a well intervention in October to tackle the blockage.

Now that the second-phase development of the Don fields is largely complete, planning has started for a third phase, likely starting during the first half of next year. This will focus on another panel in the Don Southwest area, and testing of further exploration and appraisal targets.

09/08/2010

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