Relinquishment Report for Licence P1818 Block 30/1a

Transcription

1 Central North Sea Relinquishment report Relinquishment Report for Licence P1818 Block 30/1a Date: June 2016

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3 Relinquishment Report - Licence P1818 Block 30/1a Document last updated :28 BST

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5 Relinquishment Report - Licence P1818 Block 30/1a 1 Licence Information: 1 2 Licence Synopsis: 2 3 Work programme summary 3 4 Database: Seismic Database Key Wells 10 5 Prospectivity Update: Reservoir Trap Seal Source Further Technical work undertaken 22 6 Resource and Risk Summary 23 7 Conclusions: 29 8 Clearance 30

6 List of figures 2.1 P1818 Location Map Faraday Pre-Drill Location Map Faraday Seismic Section /1a-11 CPI Fulmar C & B Petrophysics Faraday Post Well Seismic Interpretation Seimic Coverage of 30/1a Veritas 2007 Reprocessing area Comparison of CGG 2007 PrSDM vs Legacy data CGGVeritas 2012 PreSDM Reprocessing area Triassic Lead A Top Sele Lead B Upper Jurassic Well Correlation Near Top Pentland Time Structure Inline Crossline Near Top Triassic Time Map Top Sele Time Faraday HPHT Farady MDT pressure Plot Lower Heather Well Correlation Faraday Post Well Seismic Interpretation Marlowe Depth Map Triassic Lead A Top Sele Lead B

7 List of tables 1.1 C o n s o r t i u m d e t a i l s : P r e - D r i l l U n r i s k e d I n - p l a c e v o l u m e s / 1 a P e t r o p h y s i c a l A v e r a g e s - C u t o f f s a p p l i e d V s h a l e = 1 0 % ( * i n t e r v a l w i t h A v e r a g e R e s e r v o i r P r o p e r t i e s f o r F u l m a r F a r a d a y H e a t h e r T u r b i d i t e s I n p u t s F a r a d a y H e a t h e r T u r b i d i t e s v o l u m e s F a r a d a y F u l m a r I n p u t s F a r a d a y F u l m a r v o l u m e s M a r l o w e H e a t h e r T u r b i d i t e s M a r l o w e W e s t H e a t h e r T u r b i d i t e s v o l u m e s M a r l o w e E a s t H e a t h e r T u r b i d i t e s v o l u m e s M a r l o w e F u l m a r i n p u t s M a r l o w e W e s t F u l m a r v o l u m e s M a r l o w e E a s t F u l m a r v o l u m e s T r i a s s i c L e a d A I n p u t s T r i a s s i c L e a d A v o l u m e s F o r t i e s L e a d B I n p u t s F o r t i e s L e a d B v o l u m e s

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9 1 Licence Information: 1 Licence Information: Licence Number: Licence Round: Licence Type: P th Round Traditional Block(s): 30/1a Table 1.1: Consortium details: Companies Equities ENGIE E&P UK Ltd (Operator) 30% Maersk Oil North Sea UK Ltd 30% INEOS (RWE Dea UK SNS Ltd) 25% Nippon Oil Expl. & Prod. U.K. Limited 15% ENGIE E&P UK Limited Page 1

10 2 Licence Synopsis: 2 Licence Synopsis: This report is in support for an early relinquishment of Licence P1818, block 30/1a, which is currently in it's second term. The License was originally awarded in the 26th Licensing round as a 'Traditional' License ( years), with a start date of 10th January The original award group comprised of GDF SUEZ E&P UK Ltd (now ENGIE E&P UK Limited) 30%, Maersk Oil North Sea UK Ltd 30%, RWE Dea UK SNS Ltd (now INEOS) 25% & JX Nippon Exploration and Production (UK) Limited 15%. The License covers an area of sq km Fig '0"N 56 50'0"N 1 48'0"E 2 0'0"E 2 12'0"E Machar Z Key: 6Y Commander Z 18 1R01 A8 B1Z 22/30e 2Z A7 Faraday Discovery 6Z 2 A6 B1 10Z Sh 2R01 ENGIE Licence P Y 23/26a BP 19Z 2 ENGIE Non-Op 19 3R ENGIE Operator Shearwater 23/26b ChTx W1 15 W1Z W4 Erskine 21 A12 A13Z 14 4 A Elgin 4Z /29b B1 G8Y K1Z Endeavour Tot 22/30c Tot K1 22/30b Sh 23/26c No op 7 23/27b BGI 9 4 Faraday Glenelg F6Z (Heather) F4 F5Z 2 Ockley H1 1 West H2 H1Z F10Y 4 8 H3 4R01 Franklin /4d 11 2A Z Tot 8 Thunderer 1 Faraday 10 30/2b BG Franklin 30/1a 10 29/5c Tot 30/2a BGI 29/5b Tot ENGIE Thunderer 2 30/1g 9 Maer 9Z 6 29/5d Tot 3 5Z Y Marconi Courageous 13Y 5A 13 13Z 5AR01 Puffin Kessog 13A 4 30/2c CnPh calie 3R01 6 J12 Jade Jackd 1 3 1A 4 3 1R01 30/1f 29/4a Sh /5a Sh 29/5e Itha 9 J7 2 7 ENGIE 30/1c BP 30/1b ENI 5 3Z 1 3 Jade B1Z 29/10c Sh B1Y B2Z Lear South 5A 1 B1X Stella Z Hurricane 5 30/6c CnPh elia 4Y 29/10b Itha 5Z 4 5Y 8 9 4Z 8Z A3 8 A1Z A2Z A3Z Julia 6 29/10a 30/7c 2 Sh 10 CnPh30/7b CnPhCrathes 1 Jasmine 10Z Jill Kilometers 1 48'0"E Fig. 2.1 P1818 Location Map 2 0'0"E 2 12'0"E 9 Jud 57 0'0"N 56 50'0"N The License is approaching the end of the 2nd term. ENGIE E&P UK Limited and it's partners are electing to fully relinquish the licence, having fulfilled all work commitments which led to the discovery of the Faraday hydrocarbon accumulation (well 30/1a-11). Faraday is uneconomic; furthermore, the partnership do not see any remaining economically viable prospectivity within the license. Page 2 GDF SUEZ E&P UK Ltd

11 3 Work programme summary 3 Work programme summary The original work programme required the Licensees to drill one well on the Faraday Prospect to a depth of 5,569m or 100m into the Jurassic Pentland Formation, whichever was the shallower. The 30/1a-11 well spudded on the 31st July 2011 and reached a TD of 18,382ft MD, -18,203ft TVDSS (5,602m MD, -5,548m TVDSS) on the 22nd December The primary target reservoir for this HPHT exploration well was the Upper Jurassic Late Oxfordian Fulmar Sandstone Formation. The prospect was located on the western flank of a rotated fault block, where the Fulmar appeared to onlap onto the Middle Jurassic Pentland Formation Fig. 3.1 Fig /1a Fig. 3.1 Faraday Pre-Drill Location Map. Sub-Regional Depth map at Top Fulmar ENGIE E&P UK Limited Page 3

12 3 Work programme summary Fig. 3.2 Faraday Seismic Section. Predrill Cross section. Data courtesy of CGG The key pre-drill geological uncertainty was the base/lateral seal. There was a concern that the Fulmar sands may be deposited directly onto the underlying Pentland, which the updip 30/1f-8 well had proven to be water wet with only minor shows. However, analysis of offset wells had indicated that there should be a basal seal of Lower Heather Shale approximately ft thick separating the Fulmar from the Pentland and pressure analysis indicated that there was a ~30Bar (435psi) pressure difference between the Fulmar and Pentland gas gradients in the Franklin wells. The overall pre-drill geological risk was estimated at 26%, while the in-place volume estimate ranged from 145 to 1,124bcf (see table below). Table 3.1: Pre-Drill Unrisked In-place volumes P90 P50 P10 Mean GIIP Faraday (bcf) , Whilst drilling through the Heather section, the well encountered ~89 ft of hydrocarbon bearing Intra Heather Turbidite sands between 16,756-16,845ft MD, with good gas shows and resistivities in the ohm-m range. The well was deepened to 17,359ft MD, encountering loss, gain and differential sticking issues whilst drilling from 17,038 and 17,359ft MD. Hole problems led to the running of a 7" liner at the top of the Fulmar (shoe at 17,356ft MD), which in turn meant that data acquisition had to be limited to acquiring LWD GR & Resisitivity data over the Heather Sands and wireline Density and Porosity data through casing. At the top of the Fulmar Formation 17,357ft MD (-17,191ft TVDSS), some thin sands were encountered with total hydrocarbon gas levels of 15%. The main body of sand within the Fulmar (17,357.5ft, (-17,191.5ft TVDSS) to 17,666ft MDRT (-17,500ft TVDSS), 309ft TVT), comprised variable quality sandstone ranging from well sorted, moderately porous with good hydrocarbon shows, to very fine and silty with shows; two cores were cut within the main sand body (47.6ft in total). Two further sand bodies were developed in the Lower Heather unit and a series of thinner sand developments within the Pentland Formation Fig Petrophysical analysis indicates that the Heather Turbidites have good Hydrocarbon Saturations of ~83%. The Fulmar C interval was found to be poorly developed at Faraday, whereas in offset fields this is often extensive and Page 4 GDF SUEZ E&P UK Ltd

13 3 Work programme summary Fig /1a-11 CPI. Petrophysical evaluation of Jurassic Section amalgamated with the underlying B sands. The petrophysical estimation of the C sands is problomatic as they straddle the 7 5/8" casing shoe, but it was noted that whilst drilling these sands, losses were encountered followed by a gas kick of >14.5% total gas. The Fulmar B sand petrophysics suggest very high porosities in the 20-30% range, unlike these sands in any of the offset wells. Hydrocarbon saturations are estimated to be low at ~27%. For such good quality sands the transition zone would be expected to be sharp; the core over this section had oil fluorescence suggesting either the very base of a hydrocarbon column or possibly a palaeo-contact. For volumetric analysis, a contact of -5,317m TVDSS has ben assumedfig ENGIE E&P UK Limited Page 5

14 3 Work programme summary Fulmar C Fulmar B Fig. 3.4 Fulmar C & B Petrophysics Table 3.2: 30/1a-11 Petrophysical Averages- Cut offs applied Vshale =<50% and Porosity =>10% (*interval with poorly defined properties due to poor logs) Zone Name Top Base Gross Net N:G Av Por Av Sw ft MD ft MD ft ft %bv %pv Heather Turbidites Fulmar csg shoe* Fulmar Lower Heather Unit Lower na Heather Shale Pentland Eight runs of the RCX tool were attempted in the 6 3/4" hole section, which achieved moderate pressure data and recovered four fluid samples from the Fulmar sands at 17,580 ft MD. All four were gas condensate samples but they were heavily contaminated with mud filtrate. The well was not tested due to higher than anticipated temperatures and pressures. The well was plugged and abandoned as a Gas Condensate discovery in accordance with Oil & Gas UK guidelines. Post well analysis indicates that the Heather sands are J56 in age, older than the J62 Turbidites seen in both Erskine and Shearwater. The Fulmar sands are J54b and J52 in age, similar to those in Shearwater and Elgin Franklin (for full correlation see GFB Fig. 3.4]). Page 6 GDF SUEZ E&P UK Ltd

15 3 Work programme summary The post well seismic interpretation on reprocessed seismic data has mapped an Intra Heather Sandstone structure, with stratigraphic pinch out to the east and either independent down dip closure to the west, or a larger downthrown fault closure to the north and south. At Fulmar level, a similar stratigraphic pinch out structure is seen with independent closure to the west using the 17,444ft TVDSS water up-to as seen in the 30/1a-11 Lower Fulmar Sst. Fig. 3.5 Max 5600m 600m column Faraday East Independent Spill 5475m 475m column WUT 5317m GDT 5085m 85m column Faraday Top Heather Sandstone Depth (m) Top Fulmar Depth (m) Fig. 3.5 Faraday Post Well Seismic Interpretation.. On 2012 PrSDM Final TMA Stack volume ENGIE E&P UK Limited Page 7

16 4 Database: 4 Database: 4.1 Seismic Database The P.1818 License is covered by a patchwork of proprietary and non-proprietary seismic, including the PGS Megamerge and the CGGVertias 2001 Q30 Phase 1 Long Offset data Fig Fig. 4.1 Seimic Coverage of 30/1a In , GDF Suez and its partners contracted CGGVeritas to conduct a proprietary PSDM reprocessing project over 30/1a and its neighbouring blocks Fig The reprocessing comprised of six input surveys with varying bin and cable length, giving a total of 827 sqkm input area and a 432 sqkm output area. This resulted in significant improvement to the imaging of the Pre-Cretaceous section (note the 30/1a-11 well was drilled on this seismic volume) Fig Fig. 4.2 Veritas 2007 Reprocessing area. Page 8 GDF SUEZ E&P UK Ltd

17 4 Database: Megamerge PSTM GDF Suez 2007 PrSDM Fig. 4.3 Comparison of CGG 2007 PrSDM vs Legacy data. Data courtesy of CGG Following the drilling of the Faraday well and the acquisition by CGGVeritas of further Long offset data, CGGVeritas were contracted in 2012 to conduct further PrSDM reprocessing over the area. The input surveys included four from CGGVeritas' Central North sea multi-client database - Q30 Ph I, Q30 Ph IV, Q22 Ph III and Q22 Ph VI, the CNS Cornerstone 3D, and infill data from three other surveys - Erskine 1986, Shearwater 1996 and Shearwater The migration input area was 893km² and the output area was 475.7km² Fig. 4.4 Fig. 4.4 CGGVeritas 2012 PreSDM Reprocessing area ENGIE E&P UK Limited Page 9

18 4 Database: The block is also covered by the CGG Cornerstone Q30 Phase 8 BroadSeis 3D which ENGIE and its partners purchased in Key Wells The P1818 License lies within a prolific HPHT area with a number of wells drilled in and around the Elgin, Franklin, Shearwater, Erskine and Kessog discoveries. Within the license itself is the 30/1f-8 well, drilled by Enterprise in 1991, on the western margins of the J ridge, which targeted Jurassic and Triassic prospectivity. The well TD'd at 5,010m MD (16,435ft MD) within the Middle Jurassic Pentland Formation. Oil and Gas shows were seen throughout the Pentland Formation. On the operators comp log a 52ft sand is present at the top of the Pentland section and has been labelled Puffin Formation (Equivalent to the U. Jurassic Fulmar). Proprietary chemostartigarphic analysis conducted for ENGIE E&P UK Limited indicates this is most likely to be a thick Pentland channel sst, suggesting that this well was drilled updip from the Fulmar pinch out edge. Three cores were cut in the Pentland but the well was not tested. Minor oil shows were also seen in the Tertiary Forties Sandstone. Other Key offset wells include all the exploration/appraisal and development wells from the Elgin Franklin Fields, which have producing sections in the Jurassic Fulmar, Pentland and Triassic. Further wells include: the Shearwater 22/30c-15 & 15z and 22/30b-11 wells drilled by Shell as appraisal wells, which encountered thick hydrocarbon bearing Upper Jurassic Fulmar sections topped by Heather turbidite sequences; the Erskine 23/26b-14 and 15 wells which encountered Fulmar sections; and the Kessog 30/1c -4, 5 & 6 wells which have important Pentland and Triassic sections. Page 10 GDF SUEZ E&P UK Ltd

19 5 Prospectivity Update: 5 Prospectivity Update: In the original 26th Round application document, in addition to the Faraday prospect, two other leads were identified on the awarded license. Lead A was at Triassic level and comprised two fault blocks. The westerly block had dip closure to the west, north and south and fault closure to the east. The eastern fault block was a down thrown graben feature with fault closure to the north, east and west and dip closure to the south. The eastern fault block is down thrown relative to the high drilled and tested by the dry 30/1c- 2A well. The crest of the structure occurred at approximately 4,800m (15,750ft) TVDSS with a maximum closing contour at 5,120m (16,800ft) TVDSS. The estimated in place volumes were Mean 212bcf gas, with the key risks identified as top and lateral seal. Fig. 5.1 Fig. 5.1 Triassic Lead A. As mapped in the 26th Round application. Lead B was a small 4-way dip closed structure at top Sele level with its crest at approximately 3,068m (10,064ft) TVDSS and a closing contour at 3,086m (10,125ft) TVDSS, giving total closure of 18m (65ft).The lead was located some 1.5km to the east of the 30/1f-8 well, which encountered minor shows in the Forties sandstone. The most likely reservoir was expected to be the Forties, which is present over the area. The estimated in place volumes were Mean 5bcf gas, with the key risk being reservoir presence and quality. Fig. 5.2 ENGIE E&P UK Limited Page 11

20 5 Prospectivity Update: Fig. 5.2 Top Sele Lead B. As mapped in the 26th Round Application. Page 12 GDF SUEZ E&P UK Ltd

21 5 Prospectivity Update: 5.1 Reservoir The principle reservoir in the area is the Upper Jurassic Fulmar Fm. together with the Upper Heather Turbidite sands. The Fulmar sands form the main reservoir at the on trend 22/30c Shearwater field, as well as the nearby 22/30b & 29/5b Elgin/Franklin and 23/26b Erkine fields. In the Late Oxfordian, the Fulmar and Heather Formations were deposited as a progradational / aggradational shoreline or barrier shoreline to shelf succession that was ultimately transgressed, being overlain by retrogradational sandy shoreface successions (Early-Middle Kimmeridgian) and then by shelfal mudstones and sandstones of the Heather Formation (Late Kimmeridgian) Fig The reservoir quality of the Fulmar is primarily controlled by grain size and the degree of sorting. The best quality reservoir occurs in the higher energy, coarser grained upper shoreface sands. This is largely to do with the higher energy environment winnowing away the fines that reduce porosity and permeability. The more distal the facies the greater the clay content and the greater the degree of bioturbation, both of which result in reduced reservoir quality. Even though primary reservoir facies is one of the key determining factors for reservoir quality, there are a number of other factors within the HP/HT environment that can help to preserve porosity. These include: early hydrocarbon migration as an inhibitor to the cementation process, restricting diagenesis; overpressure which helps to arrest the effects of compaction; and the presence and dissolution of sponge spicules in certain facies, helping to create secondary porosity. Average petrophysicaly derived reservoir properties from offset wells are tabulated below. Well Field Net Reservoir Net Pay Gross Net N/G Av Phi Av Sw Gross Net N/G Av Phi Av Sw TVDSS m TVDSS m TVDSS m TVDSS m 22/30c-8 Elgin /30c-10 Elgin /30c-11 Shearwater /30c-13 Elgin /26b-8 Erskine /26b-14 Erskine /26b-15 Erskine /26a-21 Endeavour /4b-4 Glenelg /5b-4 Franklin /5b-6 Franklin /5b6z Franklin /5b-8 Franklin AVERAGE ENGIE E&P UK Limited Page 13

22 Page 14 Fig. 5.3 Upper Jurassic Well Correlation. 29/5b-8 LITHOSTRAT Heather Sst Fulmar Sst LEGEND 22/30c-13 BIOSTRAT J62 J56 J54b J54a J52 J46 J44 CHEMOSTRAT J7 J6 J5 J4 J3 J2 J1 22/30b-11 23/26b-15 30/1a-11 30/1c-3 5 Prospectivity Update: GDF SUEZ E&P UK Ltd

23 5 Prospectivity Update: Table 5.1: Average Reservoir Properties for Fulmar Other reservoirs that are important in surrounding blocks but as yet unproven in this license include the Tertiary Rogaland Sands as proven by the 30/1f-13 Marconi well, the Forties Sst as proven in the 30/2-1 Courageous well and its subsequent appraisals, the Cretaceous Hod Chalk Formation as proven in the Ockley 30/1d-10, 301d-12 and the original 30/1c-2A well, the Middle Jurassic Pentland Fm. as proven in the 30/1c-4 Kessog wells and finally the Triassic as proven in the 30/2c Jade Field and the 30/2a-10 Thunderer well. ENGIE E&P UK Limited Page 15

24 Crossline Prospectivity Update: 5.2 Trap Following the drilling of the 30/1a-11 Faraday well, a number of interpretations have been concluded, initially on the 2012 PSDM volume, Fig. 3.5, and more recently on the CGG Q30 Phase 8 BroadSeis PSTM, over the whole of 30/1a. On the BroadSeis data Time structure maps have been generated for the following key horizons: Top Sele Formation Top Forties Sandstone Top Ekofisk Base Cretaceous Unconformity Near Top Pentland Formation Near Top Triassic Near Top Julius Mudstone Near Top Judy Sandstone Near Top Smith Bank Formation Top Rotliegendes Faraday at both Heather Turbidite and Fulmar level, is a combined stratigraphic and dip closed structure. Fig. 5.4 Fig. 5.5 Fig. 5.6 The up dip closure is related to an intra-heather unconformity which is linked to gravity slumping of the Fulmar and Heather sequences. There is dip closure to the west and possible fault closure to the North and South. Faraday Salt Diapir Block 30/1a Limit of BroadSeis 3D Seismic Data Inline Marlowe East & West Time CI = secs 5 km Fig. 5.4 Near Top Pentland Time Structure. On CGG BroadSeis PrSTM volume Page 16 GDF SUEZ E&P UK Ltd

25 5 Prospectivity Update: Fig. 5.5 Inline Dip line through the Faraday prospect, from Q30PH PrSTM TMA BroadSeis (Time). Data courtesy of CGG S Lead Marlowe Top Sele N Top Forties Top Ekofisk BCU Near Top Pentland Potential for Heather and Fulmar in Lead Marlowe TWT msecs Near Top Triassic Near Top Julius Mudstone Near Top Judy Sandstone Near Top Smith Bank Fm Top Salt 2.5 km Fig. 5.6 Crossline Data courtesy of CGG Top Rotliegendes Marlowe East and West are two fault-bounded fault blocks to the east of Faraday between Faraday and the 30/1d-12 Oakwood Fulmar discovery in the adjacent block. There is the potential for a similar reservoir combination of Heather turbidites and Fulmar sands in Marlowe, however, the presence of Fulmar is then very dependent on how the Top Pentland is tied across the faults and if a higher pick is believed this then reduces the potential reservoir thickness. As a comparison with the original 26th Round application, a copy of the Near Top Triassic and Top Sele time map is also included to show the similarity between the two vintages of interpretation Fig. 5.7 Fig. 5.8 ENGIE E&P UK Limited Page 17

26 Crossline Crossline Prospectivity Update: Block 30/1a Inline Limit of BroadSeis 3D Seismic Data Fig. 5.7 Near Top Triassic Time Map Block 30/1a Lead B Inline Limit of BroadSeis 3D Seismic Data Fig. 5.8 Top Sele Time. Q30 Ph8 PrSTM TMA BroadSeis (Time) Page 18 GDF SUEZ E&P UK Ltd

27 5 Prospectivity Update: 5.3 Seal For the prime Upper Jurassic Reservoirs, the top seal is provided by the overlying Heather and Kimmeridge Clay Fms, which are prevalent across the area and provide the regional seal to most of the offset fields. A key consideration in all HPHT prospects/fields is the impact of overpressure on top seal failure. A cross plot of the CNS HPHT fields temperature vs pressures demonstrates that Faraday is similar to Elgin and Franklin, with a top reservoir pressure of 15,750psig (1,086 bar) and temperature of 375 Deg F (190.5 Deg C) Fig Faraday FARADAY Estimated Max. From RCX Pre Tests & Samples: BHP = psig BHT = 375 Deg F Fig. 5.9 Faraday HPHT A more detailed plot of the sub-regional RFT/MDT data reveals that the Faraday Fulmar B sands are in a similar but not exact overpressure (6,000-8,000psi) regime to Shearwater Fig However the depth of the crest of the Faraday structure at Fulmar level is below (-5,100m) the fracture gradient. Another key factor for the Faraday discovery is the requirement for a base seal to separate the Fulmar sands from the underlying Pentland Fm. and help explain why the updip 30/1f-8 well only had shows in the Pentland. Pre-drill it had been recognised that there was a correlatable Lower Heather Shale in all offset wells that separated the Fulmar from the Pentland Fig Pressure analysis indicated there was often a pressure difference between these two zones thus confirming a potential barrier. The 30/1a-11 well actually encountered 105ft (32m) of Lower Heather Shale. A number of MDT pressure points were attempted in the Pentland sands but unfortunately they were all tight. ENGIE E&P UK Limited Page 19

28 5 Prospectivity Update: Heather Turbidites Faraday Crest m Shearwater GWC m Fulmar Fm 30/1a-11 Logs HCWC m Lower Heather Shale Pressure regression between Faraday Fulmar and Pentland Pentland Fm Fig Farady MDT pressure Plot 29/5b 8 Franklin 22/30b 15z Shearwater 22/30b 11 Shearwater 30/1a 11 Faraday 23/26b 15 Erskine Turbidites L. Heather Shale Fig Lower Heather Well Correlation Page 20 GDF SUEZ E&P UK Ltd

29 5 Prospectivity Update: 5.4 Source The primary source rock in the Central North Sea is the Kimmeridge Clay Fm with the Heather FM providing a secondary source. Seismic mapping indicates that the primary hydrocarbon kitchen in the area lies to the west in a structural low between 29/5b and 30/1a. This also acts as one of the local sources for both the Elgin - Franklin and Shearwater fields. Furthermore, the presence of proven hydrocarbons in the 30/1a-11 Faraday well confirms the presence of a working petroleum system. Regional Vitrinite reflectance mapping indicates that the Kimmeridge Clay is locally expected to be in the Ro 0.7 to 1.0 range Late Oil to Gas phase. The 30/1a-11 well was not tested, however, four RCX samples were acquired at 17,580ft MD in the Fulmar Sandstone. All four were confirmed as Gas Condensate samples but with heavy mud contamination. No samples were acquired in the upper Heather Turbidite sands but fluid inclusion analysis did identify light oil to gas condensate inclusions at 16,780ft MD. ENGIE E&P UK Limited Page 21

30 5 Prospectivity Update: 5.5 Further Technical work undertaken Post the 30/01a-11 well a number of geological studies were undertaken, including: Riley Geoscience Ltd - Biostratigraphy Ichron - Biostratigraphy Chemostrat - Chemostratigraphy Analysis Ichron - Core Sedimentology and Petrography Core Labs - Routine Core analysis Core Lab - SCAL Core Lab - Compositional and Water Analysis of RCX samples FIT - Fluid Inclusion Analysis Following the drilling of the Faraday well, the partnership initiated a 2012 PSDM Reprocessing of the CGGV Long cable data over the Faraday Discovery (see Section 4 Database for more information). Page 22 GDF SUEZ E&P UK Ltd

31 6 Resource and Risk Summary 6 Resource and Risk Summary FARADAY The Faraday field was discovered by the 30/1a-11 well and encountered hydrocarbons in the Heather turbidites and Fulmar sands Fig. 6.1 Max 5600m 600m column Faraday East Independent Spill 5475m 475m column WUT 5317m GDT 5085m 85m column Faraday Top Heather Sandstone Depth (m) Top Fulmar Depth (m) Fig. 6.1 Faraday Post Well Seismic Interpretation.. On 2012 PrSDM Final TMA Stack volume Table 6.1: Faraday Heather Turbidites Inputs Parameter P90 P50 P10 Net to Gross Porosity Sg GWC (m) CEF (1 scf) Recovery Factor Gas ENGIE E&P UK Limited Page 23

32 6 Resource and Risk Summary Table 6.2: Faraday Heather Turbidites volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe Table 6.3: Faraday Fulmar Inputs Parameter P90 P50 P10 Net to Gross Porosity Sg GWC (m) CEF (1 scf) Recovery Factor Gas Table 6.4: Faraday Fulmar volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe MARLOWE Prospect The Marlowe prospect is split into an Eastern and western fault block, with potential reservoirs at both Heather Turbidite and Fulmar level. The key risks are reservoir presence and effectiveness, followed by seal risk, and side seal in particular Fig. 6.2 Fig. 6.2 Marlowe Depth Map. On 2012 PrSDM Final TMA Stack volume Page 24 GDF SUEZ E&P UK Ltd

33 6 Resource and Risk Summary Table 6.5: Marlowe Heather Turbidites Parameter P90 P50 P10 Net to Gross Porosity Sg Marlowe West GWC (m) Marlowe East GWC (m) CEF (1 scf) Recovery Factor Gas Table 6.6: Marlowe West Heather Turbidites volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe Table 6.7: Marlowe East Heather Turbidites volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe Table 6.8: Marlowe Fulmar inputs Parameter P90 P50 P10 Net to Gross Porosity Sg Marlowe West GWC (m) Marlowe East GWC (m) CEF (1 scf) Recovery Factor Gas ENGIE E&P UK Limited Page 25

34 6 Resource and Risk Summary Table 6.9: Marlowe West Fulmar volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe Table 6.10: Marlowe East Fulmar volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe Lead A & Lead B The Triassic Lead A and the Tertiary Sele/Forties Lead B volumes remain as calculated in the 26th Rnd application. Lead A reservoir is anticipated to be either Triassic fluvial Josephine or Joanne Sandstones, similar to those encountered in Kessog to the east. Top seal is likely to be provided by intra-formational shales within the Skagerrak Formation such as the Jonathan or Joshua Mudstones Members. The key risks are charge and migration and more particularly how the overlying Kimmeridge and Heather charge the Triassic. The lateral seal is a concern particularly to the east. A further concern is how Lead A is isolated from the dry updip 30/2a-1C well which tested a Triassic section. Fig. 6.3 Fig. 6.3 Triassic Lead A. As mapped in the 26th Round application. Page 26 GDF SUEZ E&P UK Ltd

35 6 Resource and Risk Summary Table 6.11: Triassic Lead A Inputs Parameter P90 P50 P10 GRV Net to Gross Porosity Sg CEF (1 scf) Condensate Yield stb/1e6scf Recovery Factor Gas Table 6.12: Triassic Lead A volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe Recoverable mmboe The most likely reservoir in Lead B is anticipated to be the Forties Sandstone. For volumetric purposes, reservoir properties were derived from the offset Courageous field (30/2a) and a Gas Condensate similar to Courageous was also assumed Fig Fig. 6.4 Top Sele Lead B. As mapped in the 26th Round Application. ENGIE E&P UK Limited Page 27

36 6 Resource and Risk Summary Table 6.13: Forties Lead B Inputs Parameter P90 P50 P10 Net to Gross Porosity Sg CEF (1 scf) Condensate Yield stb/1e6scf Recovery Factor Gas Table 6.14: Forties Lead B volumes Volumes Units P90 P50 P10 GIIP bcf HIIP mmboe 40 Recoverable mmboe Page 28 GDF SUEZ E&P UK Ltd

37 7 Conclusions: 7 Conclusions: There are a significant number of hydrocarbon discoveries at many different stratigraphic levels in this area of the HPHT Central North Sea. The 30/1a-11 Faraday discovery is, however, too small and currently uneconomic. Other undrilled prospectivity on the P.1818 license in the Fulmar and Heather Turbidites are also uneconomic. These include the Marlowe Prospect, Triassic Lead A and very small Lead B in the Tertiary. ENGIE E&P UK Limited Page 29

38 8 Clearance 8 Clearance The operator has obtained confirmation from all partners and CGG that this document and all information contained within can be published. Page 30 GDF SUEZ E&P UK Ltd

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