June 2014 RELINQUISHMENT REPORT LICENCE P1454

Transcription

1 June 2014 RELINQUISHMENT REPORT LICENCE P1454

2 Relinquishment Report Licence P1454, Block 208/11 and 214/15 1. Licence Information Licence number P1454 (Figure 1) Licencing Round 24th First Term Awarded 1 st of April 2007 Licence Type Traditional 4 years Initial Licence term extended 1+1 years with commitment to drill Glenrothes prospect Blocks 208/11 and 214/15 (208/16 relinquished after first term) Equity DONG E&P (UK) LTD 40% (Operator) DANA Petroleum E&P LTD 30% GDF SUEZ E&P UK LTD 30% Firm Commitment All firm commitments are completed Reprocess 900 km 2 3D seismic (450km 2 firm) Feasibility study of SBL technique within licence area Diagenetic study of Paleocene sandstone in well 214/19-1 Fault integrity analysis Drill-or-drop by 30 th March, 2011 (drill committed) 1 year extension to secure rig before 30th March, year extension to drill well before 30th March 2013 Second term 67% partial relinquishment February 2013 Entered second term 1 st of April 2013 All post well analysis were evaluated prior to relinquishment of Licence P1454 on 1 st April 2014

3 Glenrothes Prospect 214/8 214/9 DONG E&P Licences 214/10 208/6 P1454 P1454 original outline 208/7 208/8 N 208/9 Glenrothes 208/ /13 214/14 214/15 208/11 208/12 208/13 208/14 214/18 214/19 214/20 208/16 208/17 208/18 208/19 214/23 214/24 214/25 208/21 208/22 208/23 208/ km Projection: ED 1950 UTM Zone 30N Figure 1. Location map of Licence P1454 showing the outline of the licence before and after partial relinquishment (67% relinquishment). 2. Licence history The Licence P1454 was relinquished after drilling the 208/11-1 Glenrothes well. No other prospectivity remained in the licence. The two Glenrothes analogue leads were not prospective due to the disappointing Glenrothes well. Licence P1454 was awarded as a Traditional Licence in the UK 24 th Licensing Round. The initial licence term was a normal 4 years with a drill or drop decision by 30 th of March The Glenrothes prospect and a Glenrothes analogue were described as a lead/concept in the 24 th Licence round. The main lead of the application was the Upper Glenesk Paleocene Lead. The Glenrothes lead was worked up to be drillable as a lower Vaila Fm prospect. Additional Glenrothes analogous leads were also identified during the licence term. Evaluation of the Glenesk lead showed that the amplitude was not an indication of hydrocarbons. The Glenesk area was relinquished in the partial relinquishment in February No other wells had been drilled in the area covered by the licence and therefore no undeveloped discoveries were analysed. After the initial 4 years partners had committed to drill the Glenrothes prospect. The licence was extended with one year to secure a drilling rig by 30 th of March 2012 and thereafter with another one year extension to

4 drill the well before 30 th of March % of the licence was relinquished when entering the second term in February The Glenrothes prospect was drilled by the West Navigator back to back with the Cragganmore prospect (well 208/17-3) of Licence P1598. The well was spud the 27 th of September 2012 where the top hole of Glenrothes was drilled. Thereafter the Cragganmore well 208/17-3 was drilled and the Glenrothes well was re-entered after completion of Cragganmore. The Glenrothes well 208/11-1 was completed the 2 nd of February The Glenrothes prospect was a failure, due to tight reservoir, and therefore the leads in the area could not be matured to prospect. The licence was relinquished prior to entering the second year of the second term (1 st of April 2014). The second term was entered after drilling of the Glenrothes 208/11-1, 1 st of April During the second term the well results were analysed and the remaining prospectivity of the licence was evaluated. 3. Exploration activities and work program During the initial term the licence was evaluated and several leads/prospects were identified. Only the Glenrothes prospect that was applied as a lead/concept in the 24 th Licence round, was matured to drilling. The licence obligation work programme as set from the reward of the 24 th Licence round: 1. Reprocess 450 km 2 3D seismic 2. Feasibility study of SBL technique within licence area 3. Diagenetic study of Paleocene sandstone in well 214/ Fault integrity analysis 5. Drill-or-drop by 30 th March, 2011 (drill committed) During the licence term 900 km 2 3D seismic was reprocessed from field tapes (Figure 2). The re-processing technique clearly improved the visualization of the geology in the area and furthermore gave an extended geophysical offset dataset for AVO analysis. The new seismic data set was re-interpreted and AVO analysis was undertaken. A feasibility SBL study and fault integrity study was performed in parallel with geophysical tasks for the Glenesk Lamba Fm lead. Unfortunately the Glenesk Lead was downgraded due to conclusions from the seismic interpretation and concurrent AVO work. Instead, the licence group successfully matured the Glenrothes lead/ prospect to drilling. The geological model for deposition in the northern part of Flett Sub-basin was updated. The Vaila Fm in this basin was deposited as turbidites in a ponded basin, controlled by the underlying Maastrichtian and Danian mudstone. In line with the geological model the hydrocarbon system and charging of the area was reevaluated.

5 Figure 2. Seismic line pre (top) and post re-processing (bottom) showing the improvement of the seismic quality, especially in relation to noise reduction. The diagenetic history of well 214/19-1 was evaluated as a proprietary study by Ichron pre-drilling. Post well Glenrothes 208/11-1 the diagenesis was re-visited as a proprietary study by Ichron. The petrographic analysis included grain-size and modal analysis of mineralogy, XRD and SEM. The results indicate a complicated diagenetic history and therefore QemScan analysis has been undertaken. The complete understanding of the diagenetic effect in the area is still under investigation. Post well analysis of the 208/11-1 Glenrothes well also included extended biostratigraphic (micropalaeontology and palynology) and side wall core analysis, which were compared to nearby wells.

6 The Glenrothes well 208/11-1 found gross 500m tight Vaila Fm sandstone. The reservoir consisted of ponded turbidite deposits. The reservoir quality was considerably lower than anticipated pre-drilling. There were indications of gas shows in the well. 4. Database Figure 3 shows the 3D seismic coverage of the area and the nearby wells. The Licence P1454 is covered by the re-processed merged survey. The key wells in the area are 208/11-1, 208/ /17-2, 208/17-3, 208/19-1, and 214/19-1. Figure 3. Well and seismic database over the P1454 Licence in the Flett Sub-basin. 5. Prospectivity analysis The matured prospect Glenrothes was drilled with the well 208/11-1. The primary target was the Vaila Fm sandstone reservoir level within the ponded Flett Sub-basin. The Vaila Fm is a deep marine turbiditic system derived from the Shetland Platform. The local topography of the area was controlled by the Maastrichtian and Danian underlying mobilised mudstone (Figures 4 and 5).

7 Figure 4. Seismic line through the ponded Vaila Fm system in the Flett Sub-basin. Stippled line indicate the top or reservoir and the green close to base of reservoir.

8 P1454 Relinquishment Report Figure 5. Geo-seismic cross section through the pond of the Glenrothes prospect with well tie to the 214/191. The mapping envelope was from the T35 to T10 of Ichron biostratigraphic subdivision. The yellow indicates the T22 biostratigraphic zone. Palaeogene deep water plays in the Vaila Fm has been proven in the Faroe Shetland Basin. With the 208/19-1 well in the adjacent P1598 Licence the Lower Vaila Fm fairway sand system was proven as a working reservoir. The Flett Sub-basin is also known as a working hydro-carbon system. The full interpretation of the reprocessed 3D seismic resulted in the Glenrothes prospect matured for drilling. The Glenrothes prospect was a four way dip closure (Figure 6) with an additional stratigraphic trap component. The original seismic mapping of the Glenrothes prospect pre-drilling was not modified post drilling. The depth conversion was updated according to the well results. Reservoir sandstone of the Lower Vaila Fm with indications of hydrocarbons was found in 208/11-1 well. The reservoir quality was found to be very low and classified as tight reservoir. The well was plugged and abandoned. The remaining leads in the licence prior to drilling were interpreted as being analogous to the Glenrothes prospect. Post evaluation of the Glenrothes well had a negative influence on the leads such that they could not be matured further.

9 P1454 Relinquishment Report Figure 6. Depth structure map over the Glenrothes 208/11-1 four way dip closure. 6. Additional technical work The post well technical work of the P1454 Licence was to evaluate the well results from the 208/11-1. The well analysis included: Wireline logging and derived CPI SWC analysis CCAL SCAL Petrography (TS, XRD, SEM) Biostratigraphy Fluid inclusion Geochemical gas analysis VSP MDT fluid sampling Diagenetic evaluation Vitrinite reflectance QemScan The results of the analysis have been presented above. All well data results from Glenrothes were evaluated in comparison to nearby key wells.

10 7. Resource and risk summary Any potential remaining prospectivity in the licence was disqualified by the Glenrothes well as described above. 8. Conclusion According to the interpretation by the licence holder there is no remaining prospectivity in Licence P1454 and the licence was therefore completely relinquished on April 1 st Clearance The Operator, DONG E&P (UK) Ltd. and partners GDF Suez E&P UK Ltd. and Dana Petroleum E&P Ltd. confirm that DECC is free to publish information documented in this report and that all 3 rd party ownership rights have been considered and cleared for publication purposes.