Mungo Case Study: Unlocking the late-life field development with HDOBC seismic. Mark Williams DEVEX, Thursday 10 th May, 2012

Transcription

1 Mungo Case Study: Unlocking the late-life field development with HDOBC seismic Mark Williams DEVEX, Thursday 10 th May, 2012

2 Mungo: Outline Introduction to the Mungo field Location within N.Sea Structure & Stratigraphy Overview Field History Mungo Imaging Progression Legacy datasets HDOBC justification Early HDOBC insights Effects on Static picture Dynamic influence New Opportunities Principal conclusions and Mungo s immediate future Implications for Phase III 2

3 Mungo: Field Introduction Equity: 69% BP, 13.6% Murphy, 12.4% Total, 5% JX NEPUK. Located in the East Central Graben of the Central North Sea, 143miles east of Aberdeen in 88m water depth. Discovered in 1989 by well 23/16a-3. On production since Development facilities consist of a Normally Unattended Installation (NUI) tied back 22km to ETAP Central Processing Facility. 13 producers 3 water injectors 1 gas injector (offline) Current development strategy: maximise oil production by maintaining pressure support from water injection with a future blowdown phase. Top Structure (mtvdss) 3

4 Mungo: Structure: Ben Mungo SW Salt Diapir structure draped Palaeocene sandstones overlying Cretaceous Chalk reservoir. Extensive oil column, ~965mtvd with a small gas cap. Reservoir dips ~ (reaching 85 0 in SW) STOIIP ~420mmstb GIIP ~40bscf, solution 480bscf API Structurally & stratigraphically complex SW Mungo NE GOC 1680m tvdss OWC 2640m tvdss Top Forties depth viewed from the SW Top of reservoir to OWC ~ 1100m Top Forties Depth Map with fault traces Metres 5 18 / 8 Metres / Drilling Problems / Paleocene Chalk 175 Mungo Oil Column 965m (tvd) GOC 1680m OWC 2640m 4

5 Mungo: Outline Introduction to the Mungo field Location within N.Sea Structure & Stratigraphy Overview Field History Mungo Imaging Progression Legacy datasets HDOBC justification Early HDOBC insights Effects on Static picture Dynamic influence New Opportunities Principal conclusions and Mungo s immediate future Implications for Phase III 5

6 Mungo: HDOBC Seismic Roadmap 1991 ETAP 3D Mungo Baseline D D spec 3D 2010 HDOBC 2011 HDOBC First Oil D PreSTM+PoSDM processing D PreSDM (VTI) processing 2011 HDOBC processing (Fullfield) D PreSTM+PoSDM processing D PoSDM processing 2002/3 3D PreSDM (Isotropic) processing Datasets used in pending seismic succession D PreSDM (TTI) processing D PreSDM (TTI) processing 2010 HDOBC processing (East) D PreSDM (TTI) processing 6

7 Mungo: HDOBC HDOBC Justification Business justification Multi-well proposal for future Field Infill campaign (Phase III), 1st well scheduled for 2014). Maximise remaining field infill campaign, both Palaeocene reservoir & Chalk development. De-risk current Phase III infill targets and address any future potential. Realise up to ~30mmboe of resources; (10-20mmbbls Palaeocene in East, with circa. 10mmboe combined Palaeocene & Chalk in the West). Palaeocene Potential HM Model (H5/33/173) Mobile Oil Height With Phase 2 (W3,NW1,W1) Remaining at 2023 N1(161) 1mmboe NE3,NE1 (165) W5(167) 2-4mmboe 0-3mmboe W4(167) 0-3mmboe E2 (165) 2mmboe Technical justification Improve the static image for optimum well placement. identify, quantify, prioritise and reduce uncertainty around infill drilling targets proposed for Phase III. Mobile Oil Height (m) (So > 0.25) SW1 (169) 0-3mmboe E1(168) 2mmboe SE3 Accel (174) 2-4mmboe SE1 (174) 0-2mmboe S1, SE1 (171) 2-4mmboe better internal reservoir definition allowing identification of stratigraphic compartments and sand packages. inform potential options post Phase III. help characterise the chalk reservoir potential? 7

8 Mungo: HDOBC HDOBC Justification HDOBC justification over Towed Streamer Acquisition uplift: Improved Signal to Noise ratio - sensors on seabed (quieter environment and stationary). N Top Sele Depth contours / /20-3Z A09Z(W169) A06 A05(W161) 22/20-6 W A15(W172) W23/16A-4 A06Z(W167) A11(W170) A13(W173) A04(W165) A02(W162) A09 A17 A17Z A17Y(W176) A03Z(W163) 22/20-5 A08(W168) A03 23/16A-3 A07(W164) W 23/16A-5Z 23/16A-5 23/16A-5Y A12(W174) A01(W160) Noise attenuation (denoise P&Z components independently, attenuation of backscatter noise) m 5000m HRZ:( , ) TSELE_TTI2_TWT_DEPTHTTI Processing improvements: Ease of acquisition and survey repeatability. A16(W175) W A10(W171) Enhanced Low frequency signal Dominance of far offsets Allows detection of shear C-waves High fold with diversity of raypaths through subsurface Multi-azimuth illumination of 360deg structures for full wavefield imaging. HDOBC Survey Design m 1cm. = 1000 meters Demultiple via PZ summation. Improved Velocity modelling via Full Waveform Inversion -> better shallow model. Azimuthal diversity to optimise illumination. 8

9 Mungo: HDOBC Acquisition Design Shots Receivers 10 km West acquired in 2011 East acquired in 2010 Field Outline 5 km Mungo East Almost acquisition: 75% of the field covered with 3 ~39sqkm HDOBC patches and 100% of ~50% the field field covered coverage with with 4 patches 2 patches (Two (1x 6x10km patches and 6x10km patch and 1x Two 7x8km patches). 7x8km patch) plus 1x 400m outboard cable 50m receiver spacing 400m receiver cable spacing 50m x 50m source, dual source, flip-flop. 3km shot offsets limited to 7500m radius. Acquired by RXT 15 km 8km Mungo West: Further ~50% coverage with 2 additional patches in the West providing 100% of field covered. 0m 5000m 1cm. = 1000 meters 25m receiver spacing 400m receiver line spacing 50m x 50m shot spacing. Acquired by WesternGeco m 2.8km 2.4km Patch of 7 cables spaced 400m Patch of 6 x 10km cables spaced 400m 10km 9

10 Mungo: Data succession 1991 Towed Streamer 1991 TS acquisition, 2006 PreSDM reprocessing W166 (A18) A06 (W167) 20-3 W161 (A05Z) 20-3z W172 (A15) Mungo Top Forties Depth map A09z (W169) 20-5 W167 (A06X) W173 (A13) EWT A-4 W170 (A11) W162 (A02) W165 (A04) W176 (A17Y) A03z (W163) W164 (A07) W169 (A19) 16A-3 W168 (A08) 16A-5 Section view 16A-5z 16A-5Y W160 (A01) W174 (A12) W175 (A16) W171 (A10) Top Sele Top Ekofisk Top Sele Top Ekofisk 10

11 Mungo: Data succession 2001 Towed Streamer 2001 TS acquisition, 2006 PreSDM reprocessing W166 (A18) A06 (W167) 20-3 W161 (A05Z) 20-3z W172 (A15) Mungo Top Forties Depth map A09z (W169) 20-5 W167 (A06X) W173 (A13) EWT A-4 W170 (A11) W162 (A02) W165 (A04) W176 (A17Y) A03z (W163) W164 (A07) W169 (A19) 16A-3 W168 (A08) 16A-5 Section view 16A-5z 16A-5Y W160 (A01) W174 (A12) W175 (A16) W171 (A10) Top Sele Top Ekofisk Top Sele Top Ekofisk 11

12 Mungo: Data succession HDOBC (Alpha) dataset 2011 HDOBC acquisition, 2011/12 Alpha processing W166 (A18) A06 (W167) 20-3 W161 (A05Z) 20-3z W172 (A15) Mungo Top Forties Depth map A09z (W169) 20-5 W167 (A06X) W173 (A13) EWT A-4 W170 (A11) W162 (A02) W165 (A04) W176 (A17Y) A03z (W163) W164 (A07) W169 (A19) 16A-3 W168 (A08) 16A-5 Section view 16A-5z 16A-5Y W160 (A01) W174 (A12) W175 (A16) W171 (A10) Top Sele Top Ekofisk Top Sele Top Ekofisk 12

13 W166 (A18) Mungo Top Forties Depth map 20-3 W161 (A05Z) A06 (W167) Mungo HDOBC vs. Towed Streamer W167 (A06X) A09z (W169) W172 (A15) 20-3z EWT A-4 W170 (A11) W173 (A13) W165 (A04) W176 (A17Y) W162 (A02) 20-5 A03z (W163) W169 (A19) Raw migration stack (Depth) comparison W164 (A07) Section view 16A-5 16A-5z 16A-5Y W174 (A12) W160 (A01) W175 (A16) Raw TS (MMM) Stack W168 (A08) 16A-3 W171 (A10) Raw HDOBC (Alpha West) Stack 1. Higher resolution in overburden due to higher fold, improved S:N) 2. Improved imaging and better continuity of the reflectors, especially on the flank of the diapir structure, data being richer in low frequencies and illuminated better with rich azimuthal content. GOC 1680m OWC 2640m Top Sele Top Sele Salt Top Ekofisk Salt Top Ekofisk 3. Inherent demultiple advantages during PZ summation of HDOBC superior to TS which requires post-migration demultiple 4. Broadband nature of HDOBC datasets will allow enhancement of high frequencies to maximise internal architecture of reservoir interval. 13

14 Mungo: Outline Introduction to the Mungo field Location within N.Sea Structure & Stratigraphy Overview Field History Mungo Imaging Progression Legacy datasets HDOBC justification Early HDOBC insights Effects on Static picture Dynamic influence New Opportunities Principal conclusions and Mungo s immediate future Implications for Phase III 14

15 Mungo: HDOBC Insights Early structural highlights Interpretation synopsis: Current interpretation based upon the West Alpha products Panel 12 Additional undrained terrace in Panel 12?? Top Sele Coherency extraction (80ms) generated from Alpha MG data Panel 9&10 Red lines denote 2010 VIP faults major (solid) minor (dashed) Existence of internal baffle to support dynamic connection between W175 (Inj) and W171 (prod) 15

16 Mungo: HDOBC Insights Reservoir Management : Assisting the dynamic history Reconciling the dynamic performance between Injector W175 and producer W171 situated in Panels 9 & 10. Producers W160 and W171 drilled in 2000 into in southern areas of field. Injector W175 drilled in 2005 to support both producers. Post W175, W171 displayed minimal pressure support whilst W160 demonstrated elevated pressure -> direct connectivity. A baffle between W175 and W171 was inferred although no features were evident from previous seismic datasets. HDOBC coherency extraction illustrates a clear lineation (radial fault) located between the two wellbores which corroborates the dynamic behaviour. Potential future injector to support W171? Panel 9&10 Top Sele coherency (40ms windowed extraction) W160 W171 Reservoir Pressure psia Both wells show initial Pressure decline prior to W175. W175 Injection start-up W160 Injection support trend W171 Depletion trend W160 expressed increase in pressure support post W175, W171 sustained much lower support and maintains on depletion trend. W160 W175 W Red lines denote 2010 VIP faults major (solid) minor (dashed) 16

17 Mungo: HDOBC Insights Infill Targets: Untapped resources in Panel 12? W166 producer, a single off-take point is situated in Panel 12. Panel 12 Producer W166 drilled in 2009 into undrilled area in north of field. MDT pressures ~-600psi indicate partially isolated communication to remainder of field. Well displayed rapid early Pressure decline, rate now reduced; mild decline with ~20%wcut -> aquifer influx. Mapped STOIIP ~28mmbbls, Material Balance suggests contacted oil volume of 6.66mmstb -> remaining resource. Well drilled deep on structure, near to the OWC with potential for up-dip resource and/or adjacent fault block. HDOBC coherency extraction illustrates baffle adjacent to W166 which may isolate the area and delineate a potentially undrained fault block. Top Sele coherency (40ms windowed extraction) W166 Well currently Shut-in due to integrity loss. Potential future sidetrack location? W Alloc. Oil Rate - W161 Test Oil Rate - W166 Alloc GOR - W161 Test GOR - W166 Alloc Watercut - W161 Water Cut - W166 Rapid initial Pressure decline Wcut has risen steadily to ~20% A Mar-09 Jul-09 Oct-09 Jan-10 May-10 Aug-10 Nov-10 Feb-11 Jun-11 Sep-11 0 Red lines denote 2010 VIP faults major (solid) minor (dashed) 17

18 Mungo: Outline Introduction to the Mungo field Location within N.Sea Structure & Stratigraphy Overview Field History Mungo Imaging Progression Legacy datasets HDOBC justification Early HDOBC insights Effects on Static picture Dynamic influence New Opportunities Principal conclusions and Mungo s immediate future Implications for Phase III 18

19 Mungo: HDOBC Insights Preliminary conclusions What has the uplift been? Early indications are encouraging, observing some early uplift above the conventional Towed Streamer datasets. Imaging: Clear uplift in image quality, higher S:N, higher fold and illumination with rich azimuthal content, less multiple -> better continuity of reservoir defining reflectors. Structure: Much improved image of the diapir, particularly on the steeplydipping flanks. Reservoir envelope surfaces (Top & Base) are readily mapped (albeit poorer quality in SW). Internal architecture still remains a challenge -> function of thinning wedge, heterogeneity of individual reservoir packages and strong impedance contrasts of the Top & Base events. Salt body better imaged, particularly the canopy which control the up-dip pinch-out of the reservoirs. Extent of the events into the gas cap & thereby connectivity have always been uncertain. Dynamic reconciliation: Intriguing early observations that help reconcile both field & well performance. Assisting a fully integrated static and dynamic understanding HDOBC (East) Depth Sharper character and better continuity of reflectors Less noise and dominance of low Frequencies High Fold, greater S:N -> better resolution combined with multiazimuthal illumination gives a significant uplift in seismic image. NB- this isn t the final result! 19

20 Mungo: HDOBC Insights Way Forward What s next? Final East & Alpha products evaluated so far. Raw Beta dataset due imminently, (Final Beta datasets due in July 2012). Static description & Phase III target selection will continue on the Alpha products in the interim to improve the integrated understanding. Static & Dynamic workflows has been built with this succession of datasets in mind, i.e. iterative and for quick static model refinement. Rank options and quantify uncertainty prior to final option selection. Detailed well planning (fault placement and final target selection) will utilise the Beta Final datasets upon delivery. Phase III infill drilling campaign potentially commencing Future? Yet to quantify the final uplift of HDOBC over TS on Mungo diapir, although early results look promising. Understanding of such a structurally complex field has certainly been enhanced by the step change in HDOBC technology. HDOBC subsequently acquired over Machar field in Potentially a future 4D HDOBC? CGGV Alpha & Beta processing timeline A succession of datasets Date: Nov-10 Dec-10 Jun-11 Jul-11 Mar-12 Apr-12 May-12 Jun-12 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Aug-11 Sep-11 Oct-11 Nov-11 Dec-11 Jan-12 Feb-12 Jul-12 Mungo East product delivery Initial MG Raw MG Final MG 8.5mths 10mths Mungo West Alpha delivery* assuming learning s from Mungo East survey, plus double data volume. 12mths 4-5mths Fast track Mungo West Beta delivery* Raw MG: 3rd May 8mths Final MG: 6 th Jul 10mths Aug-12 AVO: 12 th Jul 12mths Sep-12 20

21 Mungo: HDOBC Insights Acknowledgements Mungo Partnership: Murphy Oil, TOTAL & JX NEPUK. Co-author Steve Campbell & BP Seismic Delivery Team (SDT) Seismic Processors: CGGV ETAP Mungo Reservoir Team: Mary Ward, Alison Davies, Dave O Gorman, Richard Pollard also Leendert Padmos and Marie O Hanlon. 21