EnCore Oil says that the Cladhan appraisal well 210/30a-4x, the final well in this current four well programme located in UK North Sea Blocks 210/29a & 210/30a, has reached Total Measured Depth of 10,614 feet.

The appraisal well was drilled as a side-track to evaluate a channel to the south of the current Cladhan discovery. The well encountered an Upper Jurassic reservoir with a gross True Vertical Thickness (TVT) of 171 feet and 105 feet of net sand. Reservoir quality is excellent with porosities up to 25 per cent. Log and pressure data indicates that an uppermost sandstone unit of five feet TVT is hydrocarbon bearing with an "Oil Down To" at 10,177 feet True Vertical Depth Sub Sea (TVDSS) and a calculated Oil Water Contact at 10,200 feet TVDSS based on the pressure data. An oil sample was obtained from this interval. Below this oil bearing sand, a further 100 net feet of water-wet sands were encountered. Pressure data shows that the sands are over pressured in this well, and these are similar to the pressure trend encountered in the Central Channel drilled by the 210/30a-4y well, and therefore in a separate pressure regime from the main Cladhan accumulation. The presence of an Oil Down To indicates potential for a new accumulation, separate from Cladhan, up dip of the current well location and also potential up dip of the previously drilled 210/30a-4y well. The well will now be suspended for potential reuse in the development of the Cladhan area.

This final well completes the current phase of drilling at Cladhan and has helped delineate the discovery and provided greater clarity on what has been discovered in the Cladhan area, although there is still further appraisal work to be carried out in the area. An infield survey and pipeline survey is now planned to commence later this month to determine the best development options for the Cladhan discovery.

Commenting on the latest well result, Alan Booth, EnCore's Chief Executive Officer said: "Although the well results to date have been somewhat mixed, we have accomplished our main aim of identifying and delimiting the areal extent of the Cladhan field, or perhaps this should now be fields. A significant amount of work still lies ahead in integrating and calibrating the extensive well and core information into the seismic data, although initial analysis appears to suggest that the original Cladhan discovery is confined to the Northern Channel Belt immediately North of this current well. In the Northern Channel Belt, we have now established a hydrocarbon column of greater than 1,200 feet where reservoir quality, rather than an actual Oil Water Contact may well delimit producibility from the deeper, down dip 'fan area' of the discovery.

"The Central Channel area, drilled by the 210/30a-4y and the current 210/30a-4x wells, is in a separate pressure regime. This area is also over pressured, although not to the same degree as Cladhan. This latest well appears to have intersected the edge of an oil column and a potential Oil Water Contact some way down dip from the crest in a separate channel system. The sand quality in this location is excellent and suggests important potential further up dip in this channel. It gives us greater encouragement that the Central Channel (drilled by well 210/30a-4y) may well also contain oil trapped up dip, as this well was located some 1,000 feet below the mapped up dip limit of that particular channel.

"Further appraisal drilling, likely in the first half of 2012, will be required to understand the up dip potential in both these two new channel systems. In the mean time the Operator will continue with on going development planning.

"In terms of EnCore's upcoming work programme, development studies and planning continue on our Catcher, Varadero and Burgman discoveries on the EnCore-operated UK Central North Sea Block 28/9. Further seismic data is to be acquired over the summer which will assist in this work and the Group hopes to be in a position to be able to return to Block 28/9 in late 2011 or early in 2012 to continue with further exploration and appraisal drilling.

"Our next well to be drilled will be on the EnCore-operated Tudor Rose discovery in UK Central North Sea Block 14/30a, which is expected to commence in September 2011. A Letter of Award has been signed with ADTI for use of the Sedco 704 rig to drill an appraisal well on the Tudor Rose accumulation to establish the gravity and viscosity of the oil in place, both critical issues in determining if Tudor Rose can be commercially exploited."

Tags: EnCore Oil plc