geology of the gull lake north asp flood, upper shaunavon formation, southwest saskatchewan
TRANSCRIPT
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
1/17
Geology of the Gull Lake North ASP
Flood, Upper ShaunavonFormation, Southwest
Saskatchewan
By Sid Leggett, Husky Energy
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
2/17
Acknowledgements
Husky Energy
Members of the Gull Lake ASP Team
Graham Jackson
Curtis Cymbaluk
Dorian Holgate
Wendy Shier
Doug Flaig
Kent Barrett
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
3/17
Talk Outline
What is Alkali/Surfactant/Polymer (ASP)
flooding?
Criteria for pool selection.
Gull Lake Upper Shaunavon pool.
Stratigraphy, sedimentology and environment
of deposition.
Reservoir details.
Summary
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
4/17
What is Alkali Surfactant Polymer Flood?
Alkali: Sodium Hydroxide (NaOH) or Sodium
Carbonate (Na2CO3).
Reduces adsorption of the surfactant on the rock
surfaces Reacts with acids in the oil to create natural
surfactant.
Surfactant (Soap!)
Reduces interfacial tension.
Polymer
Improves the sweep efficiency.
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
5/17
ASP Screening Criteria
Sandstone preferred over carbonates
Thick unstratified reservoir with few barriers
No bottom water or gas cap
Low clay content ( 100md
Porosity > 15%
Residual oil saturation after water flood > 35% Size
Light to intermediate crude with organic acids
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
6/17
Location Gull Lake
North Pool
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
7/17
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
8/17
Upper Shaunavon
Regional Geology
Isopach
Top Mississippian to
Top Lower Shaunavon
Modified from J.E. Christopher, 1964
Mississippian to Lwr
Shaunavon isopach
reflects Upr Shaunavon
depositional surface.
Center of the Williston
Basin to the southeast.
Truncated to the
northwest by the
Sweetgrass Arch. Gull Lake North area
located on the Gull Lake
Front east of the
Tompkins Apron.
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
9/17
The Upper
Shaunavon at
Gull Lake
NW-SE trendingtidal channel thatforms the reservoirfor the Gull Lake
North pool. Channel is up to
10.3m thick.
Discovered in 1953.
Waterflood initiatedin 1956.
22.3API, 24 cpintermediate crudeA2 Member Channel Isopach
Upr Shaunavon Fm.
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
10/17
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
11/17
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
12/17
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
13/17
Coquina and
Calcareous
Sandstone
Thin walled bivalve coquinas, crinoids, peloids, and raregastropods.
Marine environment of deposition.
Early calcite cementation during a period of subaerialexposure.
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
14/17
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
15/17
Trapping
Mechanism
Fluid flow towards anorth-southhydrodynamic low.
Gas structurally updipto the northeast.
Oil only along the mainfairway (green).
Oil is trapped instructural highs andupdip pinchouts (blue).
Gull Lake N is locatedat transition.
Gull Lake N
Oil and Gas Hydrodynamic Fairway
Map
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
16/17
Reservoir Details
Estimated reserves for
the entire reservoir:110MM bbls OOIP.
Gull Lake North poolreserves: 76MM bblsOOIP, recoverable withwater flood 26MMbbls(34.5%).
Average net pay of 4.6m(up to 9.6m), porosity of20% and averagepermeability of 384md.
Downdip water leg withan oil/water contact of -372.5mSS.
Clays: between 0.5 and0.9% Kaolinite and 0.2and 0.6% Illite.
Upr Shaunavon, A2
Channel, Net Porosity
Map
Water
Oil
-
7/27/2019 Geology of the Gull Lake North ASP Flood, Upper Shaunavon Formation, Southwest Saskatchewan
17/17
Summary
Gull Lake North Upper Shaunavon pool is a large incised tidalchannel composed of a mixture of porous sandstone and tightlimestone.
Hydrodynamic/structural trap resulted in oil accumulating in theupdip part of the tidal channel.
The pool met most of the key criteria for an ASP tertiary flood: Sandstone.
Thick unstratified reservoir.
No gas cap.
Low clay content.
Permeability > 100md.
Porosity > 15%.
Residual oil saturation > 35%.
Intermediate crude with organic acids.
Size.
Only one negative criteria: water leg. X
Srl, 4/09