The Evolution of a Proven Giant Oil & Gas Play in Subsalt Miocene Lower Slope Sands-Reservoirs of the Federal Offshore OCS Shelf, US Gulf of Mexico Clint Moore with Bill Lefler, Tom Uphoff, Rich Heaney, & Mike Neese SIPES Houston Houston, Texas September 21, 2017
Objectives Highlight depositional systems of reservoir sands in the Miocene-age Lower Slope section of the Offshore Central Louisiana Gulf of Mexico Show these Conger-Mahogany-Hickory ancestral Mioceneage Lower Slope sands, as proven highly productive reservoirs with further potential in surrounding undrilled mini-basins of the play Demonstrate that the Miocene-age Lower Slope is NOT a bypass zone, but is a broad, widespread area of sandfilled confined mini-basins with sand-filled lowstand levels of amalgamated and channelized fans.
Re-Emerging Shelf Miocene Sub-Salt Oil Sand Play
Evolution of the Shelf Miocene Sub-Salt Play The play was 1 st produced in the 1990 s but older technology left potential giant fields behind Thick sand below salt discovered by accident SMI 200 well discovered 1000 of thick reservoir sand below an unexpected salt sheet, in late 1985 Shift to Deepwater Seismic advances lead to massive discoveries in deepwater GoM, followed globally (Brazil, West Africa, East Africa, and others) Extensive R&D spending on sub-salt imaging & drilling due to global size of the prize GulfSlope Captures Leading Lease Position Industry applies RTM to Shelf Miocene Sub-Salt play GulfSlope acquires a leading position in the Shelf Miocene Sub-Salt play - 1990 - Shelf Miocene Sub-Salt Play 1 st Developed - 2000 - Sub-Salt Seismic Successful in deepwater - 2010 - Deepwater Technology Re-applies to the Shelf Mahogany discovered in 1993, with 400+ MMboe discovered in play by 2000 Shelf Miocene Sub-Salt Exploration Limited by Seismic Clarity Early sub-salt seismic has difficulty with GoM shelf Play limited by drilling depth capabilities Seismic Advancements New Reverse Time Migration (RTM) more accurately images sub-salt RTM and other technologies proven successful in sub-salt deepwater GoM, Brazil, West Africa, & East Africa
Subsalt Miocene Slope Sand Production EUR 400+ MMboe were discovered in the 1990s Conger >250 MMBoe Discovered 1 St Prod 1998 2000 Hickory >55+ MMBoe Discovered 1 St Prod 1998 2000 Mahogany >50+ MMBoe Discovered 1 St Prod 1993 1997 Monazite Enchilada Tanzanite Mahogany Agate Teak Tarantula Hickory Tanzanite >20 MMBoe Discovered 1 St Prod 1998 1999 Conger Enchilada >30 MMBoe Discovered 1 St Prod 1995 1997 GSPE Lease Blocks Previous Sub-Salt Discoveries Oil and Gas-Producing Field Tarantula >15 MMBoe Discovered 1 St Prod 2001 2004
Conger-Mahogany-Hickory Field Play Area ST GI VR SMI EI SS EW GB GC
Lower Slope Miocene-Age Sand Mini-Basin Area ST GI VR SMI EI SS EW GB GC
Conger-Mahogany-Hickory Play Area Ultra-Deep Gas Shelf Miocene Deepwater Miocene & Lower Tertiary North Lafitte Shelf Hickory Mahogany Conger Tahiti Jack Deepwater South 5,000 Plio-Pleistocene Supra-Salt 10,000 15,000 Proven & Potential Section Salt 20,000 25,000 30,000 Lower Tertiary Upper Miocene Lower Miocene 35,000 Salt 8
5000 of Salt - Lowers Subsalt Temperature 35+ degrees (F) North South DAVY JONES MAHOGANY HICKORY CONGER TAHITI JACK SL Shelf Deepwater 10K Salt Salt 200 250 300 200 200 Salt Salt 20K 350 245 254 200 234 150 150 200 200 400 30K 450 250
Highly Productive Slope and Basin Floor Sands Slope Sand Miocene Producing Fields UM UM Miocene Subsalt Pay Sands Slope Fans + Basin Floor Fans UM MM UM UM MM MM LM LM UM MM LM Upper Miocene Middle Miocene Lower Miocene Basin Floor Sand Miocene Producing Fields LM
Hess Garden Banks 215 # 8 Conger Field Well Analog to Quark-Tachyon-Photon Peak Production Level 12,500 BOPD & 52.7 MMCFGPD 36.8 API GOR 6.1 to 1 ISIP 12,967 #
Porosity vs Depth (BML) for Miocene Slope Sands 40.0 35.0 30.0 Trend Line 25.0 20.0 POROSITY % 15.0 Above 22,000 you can expect >25% Porosities 10.0 5.0 0.0 5000 10000 15000 DEPTH BML ft 20000 25000 30000
Dynamic Salt & Sediment Model
Bathymetry of Modern Sea Floor * An Analog for sediment fed Intraslope Basins *Modified from Diegel et al., 1995, Prather, 1998
Bathymetry of Modern Sea Floor * An Analog for sediment fed Intraslope Basins *Modified from Diegel et al., 1995, Prather, 1998
Delta, Slope, & Basin Floor Prograde Seaward
15+ Sequences - Lowstand Sand Potential mya Sequences Primary Zones Sub Epoch
15+ Successive Lowstand Cycles in Miocene
Lowstand Deltas Feed the Salt-Supported Extended-Slope Creating Confined Mini-Basins with Amalgamated & Channelized Fans
Upper Miocene Messinian Fairways Mini-basin fill downslope from Shelf-edge Deltas Hickory Tanzanite Tarantula Mahogany Conger
15+ Sequences - Lowstand Sand Potential mya Sequences Primary Zones Sub Epoch The 6+ LSTs of the Tortonian Stage 7.0 11.6 MYA
Bathymetry of Upper Miocene Tortonian Stage OUTER SHELF TORTONIAN PALEOENVIRONMENTS* Locations for Cross Sections A-A and B-B SHELF MARGIN DELTAS SHELF MARGIN DELTAS UPPER BATHYAL SHELF EDGE MIDDLE BATHYAL A HICKORY B LOWER BATHYAL EI385 TANZANITE MAHOGANY TARANTULA GARDEN BANKS AREA B AREA OF DETAIL CONGER FIELD GREEN CANYON AREA ABYSSAL PLAIN TIGER TAHITI CRESTED BUTTE ASPEN KNOTTY HD DBL MTN A TONGA * Interpretation based upon BOEM Public Data
Bathymetry of Upper Miocene Tortonian Showing Lower Slope Mini Basins as Primary Basins * FILL AND SPILL LOWER SLOPE MINIBASINS LOWER BATHYAL SALT-SUPPORTED RIDGES/SHEETS AREA OF DETAIL GARDEN BANKS AREA GREEN CANYON AREA ABYSSAL PLAIN Primary Basin *Interpretation based upon 3D Seismic Isopach mapping
A A MIDDLE BATHYAL NORTH-SOUTH STRUCTURAL SECTION LOWER BATHYAL TOE OF SLOPE ABYSSAL PLAIN MESSINIAN PLIOCENE TORTONIAN PLIOCENE SALT OLIG EOCENE
WEST-EAST STRATIGRAPHIC SECTION B Showing 3 Major Tortonian Lowstand Episodes B CONGER FIELD EI 385 MAHOGANY FIELD TARANTULA FIELD HICKORY FIELD STRATIGRAPHIC DATUM TOP TORTONIAN 7.1 MY LST 100+ GAS PAY 200+ OIL PAY CATINASTER MEXICANUS 7.83MY HST 100+ OIL PAY#A14 8.4MY LST DISCOASTER BOLLII 9.21MY LST MINIBASIN TOP SERRAVALLIAM 11.6MY SALT DOME GLOBOROTALIA MAYERI 10.5MY LST DISCOASTER KUGLERI 11.58MY SALT RIDGE
Base of Miocene Structure ST GI VR SMI EI SS EW GB GC
Trap Styles result from Salt & Sand Dynamics
Geological & Geophysical Advantages Confined Mini-basin Fan Sands Continuous Reservoirs Excellent Porosities (25-30+%) & Permeabilities (800-1200+ md) Key Fields Conger, Mahogany, Hickory, Tarantula, Enchilada Proven Petroleum System Excellent Reservoirs, Traps, Seals, Source Advanced Seismic Processing (RTM+) Clarifes Sub-Salt Images Economic Advantages Water Depths: 300-450 - Super Gorilla Jackups for 365/24/7 Modern Drilling Technology below Salt Synthetic Mud & MPD Mostly Jack-up Rig Access - $70-95K/day - $20-45MM per wildcat Mostly Conventional Platforms - $40-50 MM per platform Extensive Existing Platform-Pipeline Infrastructure across area
Conclusions Lower Slope sands are extensively deposited across the Miocene ancestral slope, and are most commonly found as amalgamated and channelized fans in intraslope confined minibasins Miocene-age Lower Slope sands have produced well in Conger- Mahogany-Tanzanite-Hickory reservoirs to date (350+ MMBOE produced 400+ MMBOE EUR) The GOM Miocene-age Lower Slope is NOT a bypass zone, but consists of widespread sand-filled confined mini-basins with sizeable untested field potential across a 400+ block 2+ million acre area of the present day Louisiana outer shelf
Acknowledgements The Author would like to thank his fellow members of the GulfSlope Geoscience team, and specifically the geological & geophysical contributions of Bill Lefler, Tom Uphoff, Rich Heaney, and Mike Neese.