Licence P1667, block 43/22b, Relinquishment Report - Centrica Energy Upstream 1 General 1 2 Synopsis 2 3 Exploration Activities 2 4 Prospectivity Analysis 2 5 Reserves Summary 5 6 Clearance 5
List of figures 1.1 Licence P1667, block 43/22b location.............................................. 1 4.1 Carna discovery - depth to Base Permian Unconformity.............................. 3 4.2 Base Permian Unconformity depth (ftss)............................................ 4 4.3 SW-NE 3D seismic line over licence.............................................. 4
Licence P1667, block 43/22b, Relinquishment Report - Centrica Energy Upstream - 1 General Page 1 1 General Introduction This report documents the full relinquishment of Licence P1667, block 43/22b, see Fig. 1.1 Fig. 1.1 Licence P1667, block 43/22b location Licence Summary Licence Number P1667 Licence Round 25 Licence Type Traditional Block Number(s) 43/22b Operator/Partner % Centrica 90% / Volantis 10% Commitments / Restrictions This is a traditional licence with a start date of 12 th Feb. 2009. The agreed work programme at Schedule 1 provides that by 11th Feb. 2011 the licensee must make a firm commitment to complete Part 2 of the work programme, or the licence will automatically expire. The work programme was a 2 year drill or drop. Either drill to a depth of 3500m or to the Namurian whichever is shallower, or elect to allow the licence to automatically cease. At this time Centrica and its partner see no prospectivity in the licence, and elect to let the licence cease. Document last updated 15-11-2010 14:46 GMT
Licence P1667, block 43/22b, Relinquishment Report - Centrica Energy Upstream - 2 Synopsis Page 2 2 Synopsis Licence P1667 containing block 43/22b was awarded in the 25 th round with a start date of 12 th Feb. 2009. The licence is situated on the southern margin of the Silverpit basin, just north of the primary Leman sandstone play-fairway. The licence was acquired for the potential extension of the Carna prospect into the block. It was originally assumed that the prospect contained both Permian and Carboniferous prospectivity, and depending on the resulting gas water contact, the licence may have contained a sizable extension of the Carna prospect. Centrica wish to relinquish this licence in its entirety. 3 Exploration Activities Wells Drilled There are no wells drilled within the licence. However, the Carna, 43/21b-5z well, drilled in spring 2009, provides key information to the resulting prospectivity within the licence. 43/21b-5z encountered no Permian sandstones, but did find Namurian sandstones that flowed at 8.8 mmscf/d. The Kilmar field, operated by ATP also provides useful information, their latest development well on the NW of the field has been plugged and abandoned. Seismic Database The basis of the interpretation over the licence and environs was the 2009 acquired, merged and reprocessed 'Andromeda' 3D. Portions of the following cda 3D data codes were used in the processing; VE083D0001, GE943F0001, PP963DXQ43, WG973F0004, and AT933F0001. 4 Prospectivity Analysis Reservoir The main reservoir recognised within the licence is Carboniferous fluvio-deltaic sandstones of Namurian age. Studies of wells in this Namurian play-fairway generally exhibit a low net to gross system with poor porosities and permeabilities. Prediction of actual reservoir facies and lateral extent of these sandbodies is difficult to predict, even in small structures such as Carna. Although Permian Leman sandstones are produced successfully to the SW of this licence in the Johnston and Ravenspurn North fields, a dramatic reduction in sand quantity and quality is seen in a SW-NE direction as we enter the Silverpit basin, in which shales and halites are the dominant facies. Prediction of Leman sands over any Base Permian closures identified is very difficult to predict and thus high risk, no Permian sands were encountered in the Carna, 43/21b-5z well.
Licence P1667, block 43/22b, Relinquishment Report - Centrica Energy Upstream - 4 Prospectivity Analysis Page 3 Source Carboniferous coal measures are present and mature providing gas for any closure in the area. Seal Silverpit shales and halites provide the top seal to any closures within this licence. Trap style Usually, accumulations are concentrated in the highest reservoir unit beneath the regional seal, whether the reservoirs are Carboniferous or Permian. No independent Base Pemian closures have been recognised within the licence. The licence was applied for on the grounds of a potential Carna extension into the licence. However, the 43/21b-5z Carna well showed no Permian sandstone upside and the GWC within the Namurian placed no volume in the licence, Fig. 4.1. Fig. 4.2 and Fig. 4.3 show the structural style across the licence. Fig. 4.1 Carna discovery - depth to Base Permian Unconformity
Licence P1667, block 43/22b, Relinquishment Report - Centrica Energy Upstream - 4 Prospectivity Analysis Page 4 Fig. 4.2 Base Permian Unconformity depth (ftss) Fig. 4.3 SW-NE 3D seismic line over licence. Line goes from Carna 'extension' to Kilmar
Licence P1667, block 43/22b, Relinquishment Report - Centrica Energy Upstream - 4 Prospectivity Analysis Page 5 Remaining Prospectivity No remaining prospectivity is recognised. 5 Reserves Summary GIIP Calculations The assesment of both the Carna discovery and Kilmar field show no volumes within the P1667 licence. 6 Clearance Publication Clearance All 3 rd party ownership rights (on any contained data and/or interpretations) have been considered and appropriately cleared for publication purposes.