AAPG Woodford Shale Forum April 11, 2013 Woodford Shale: From Hydrocarbon Source Rock to Reservoir Brian J. Cardott Oklahoma Geological Survey
Outline of Presentation Woodford Shale: Terminology and distribution As a hydrocarbon source rock As a reservoir Hydrocarbon production
Taff (1902) introduced the name Woodford Chert for outcrops north of the town of Woodford on the south side of the Arbuckle Mountains.
WOODFORD CHERT: Taff (1902), Gould (1925), Wilmarth (1938) WOODFORD FORMATION: Morgan (1924), Amsden (1957, 1960); Wilson (1958), OBrien and Slatt (1990) WOODFORD SHALE: Tarr (1955), Jordan (1957, 1959, 1962), Urban (1960), Hass & Huddle…
Woodford Shale Stratigraphy Based on conodonts, Hass and Huddle (1965) determined a Late Devonian (Frasnian) age for most of the formation; uppermost part is Early Mississippian (Kinderhookian) Unconformity
Modified from Johnson and Cardott, 1992
Pre-Woodford Geologic Map From Amsden, 1980
Woodford Shale Members Three informal members based on palynomorphs (Urban, 1960; Von Almen, 1970), geochemistry (Sullivan, 1985), log signatures (Hester and others, 1990; Lambert, 1993) From Hester and others (1990) [Anadarko Basin]
USGS Bulletin 1866-D
From Hester and others (1990) [Anadarko Basin]
15 Stratigraphic Units Described by Caldwell, 2011
Paleogeography and Facies Distribution in the Late Devonian Kirkland and others, 1992
Isopach Map of Woodford Shale Comer, 1992
Gas Shales Gas shales are varieties of hydrocarbon source rocks (an important part of a petroleum system). HYDROCARBON SOURCE ROCK CLASSIFICATION Organic matter type refers to the kerogen or maceral type and can be lumped into gas…
Woodford Shale as a Hydrocarbon Source Rock Type II Kerogen (oil generative organic matter) High total organic carbon (TOC) Contains vitrinite (vitrinite reflectance analysis) to determine thermal maturity
Hydrocarbon Source Rocks of Oklahoma Caney II 1-8 Modified from Johnson and Cardott, 1992
Woodford Shale From Comer, 1992
Gamma ray plotted full scale shows details TOC is highest in fissile shale From Paxton and Cardott, 2008
Vitrinite is a coal maceral (organic) derived from the cell wall material or woody tissues of vascular plants (post Silurian)
Vitrinite Reflectance (%Ro) is a measurement of the percentage of light reflected off the vitrinite maceral at high (500X) magnification in oil immersion (average of many values)
Woodford Shale is the oldest rock in Oklahoma that contains wood (vitrinite) from the progymnosperm Archaeopteris (organ genus Callixylon)
Guidelines for the Barnett Shale (Based on Rock-Eval Pyrolysis) VRo Values Maturity
Woodford Shale as a Reservoir Rock Biogenic Silica Rich (Brittle) Porous organic matter network
Woodford Mineralogy [grab samples] A B C D E Quartz 63-68% 29-87% 30-60% 9-61% 27-53% K-Feldspar 4% 0-2% 2-10% 2-42% 0-2% Plagioclase 3% 1-4% Calcite 10% 5-25% 0-7% 0-11% Dolomite 6-9% 0-56% 0-5% 0-10% 0-6% Pyrite 5-7% 0-1% 0-5% 2-30%…
Rather than depending on the mineralogy of grab samples, a better approach to shale mineralogy distribution is by electric logs such as the Elemental Capture Spectroscopy log
Extent of Biogenic Silica in the Woodford Comer, 2008 AAPG Poster
The primary mechanism of gas [& oil] production from shales is the fracture network in the reservoir. Gas residing in the very tight matrix system is forced to flow into the fracture network, first through chemical desorption and then…
Genetic Bitumen Classification Pre-Oil Solid Bitumen: early-generation products of rich source rocks, probably extruded from their sources as a very viscous fluid, and migrated the minimum distance necessary to reach fractures and voids…
Two Common Pre-Oil Bitumen Optical Forms Based on Landis and Castao (1994) [regression equation is based on homogenous form] Homogenous form Granular form OPL 1333 500X OPL 1076 500X
Use of pre-oil solid bitumen as thermal maturity indicator following solid hydrocarbon reflectance to vitrinite reflectance equivalent regression equation of Landis and Castao (1994) VRE = (BRo + 0.41)/1.09
Nanopores associated with organic matter using ion milling and SEM (from Loucks and others, 2009)
Curtis and others, 2012
Focused Ion Beam (FIB) milling + SEM Backscatter Electron Imaging: Higher thermal maturity (1.4% Ro; OPL 1387) Woodford Shale core containing wispy post-oil bitumen network 500X
Higher magnification of previous slide showing nanoporosity in wispy post-oil bitumen network
Low Thermal Maturity Woodford Shale 3D image from serial sectioning of 2D slices of Dual Beam Imaging (sequential ion- milling and backscatter AOM, lamalginite, electron telalginite, and pre-oil imaging of a solid bitumen…
Low Thermal Maturity Woodford Shale 3D image of organic matter from serial sectioning of 2D slices of Dual Beam Imaging (sequential ion- milling and AOM, lamalginite, backscatter telalginite, and pre-oil electron solid…
Woodford Production: Where are the Woodford Shale plays in Oklahoma Why are the plays where they are What types of hydrocarbons are produced
Woodford Shale Plays 4Biogenic Methane 2Condensate 1Dry Gas 3Oil Geologic provinces from Northcutt and Campbell, 1995
2,461 Woodford Shale Wells (2004-2012) 376 2,085
Woodford Shale Wells (2010-2012)
Woodford Shale Wells (2012-2010)
Woodford Shale IP Gas vs. Depth 2,348 Woodford-only wells: (2004-2012) 320 vertical: depth 430-13,046 ft, IP 1-2,681 Mcfd; 2,028 horizontal: depth 786-16,259 ft TVD, IP 3- 12,097 Mcfd
Woodford Shale Horizontal Well Laterals (2005-2012) 13,378 ft
Emphasis of presentation will be on the importance of thermal maturity (by vitrinite reflectance) on the Woodford Shale oil and gas plays.
Isoreflectance Map of the Woodford Shale in Eastern Oklahoma (Updated November 2011) Distribution of 117 Woodford Shale samples with vitrinite- reflectance data (n 20; whole-rock pellets) Cardott, 2012b
Woodford Shale Structure & Vitrinite 1 Isoreflectance 2 3 Map 4 Maps prepared by R. Vance Hall using Petra Cardott, 2012b
Most of the following maps are from an August 2011 presentation and have not been updated (published in 2012).
Woodford Oil/Condensate/Gas Production Caveat Gas production is reported by the Oklahoma Corporation Commission by WELL. Oil/condensate production is reported by the Oklahoma Tax Commission by LEASE [production by well is only on…
Woodford Shale Oil/Condensate/Gas Production (2004-2011) Production in first few months is interpreted as flowback from oil-based drilling mud Condensate based on 54.4 API DEG Cardott, 2012b
(1) Newfield 3H-36 Genevieve (36-6N-11E; Hughes Co.; IP 2,118 Mcfd) Liquids production only in first few 2.05%VRo months interpreted as flowback
(2) Cimarex 3-34H Hall (34-3N-11E; Coal Co.; IP 1,740 Mcfd) Intermittent liquids production in 2.05%VRo first few months interpreted as oil- based drilling mud flowback
Woodford Shale-Only Condensate Wells Excluding Early Month Spikes Cardott, 2012b
Andrews, 2009
3 4
(3) St. Mary Land & Exploration 3-14 Marvin (14-1N-10E; Coal Co.; IP 3,125 Mcfd) Example of Woodford condensate 1.67%VRo produced later in wells life
(4) Antero 30-1H Harris (30-1S-11E; Coal Co.; IP 1,334 Mcfd) Spikes in production may be from intermittent trucking 1.6%VRo
Anadarko Basin Woodford Shale Isoreflectance Map based on 81 wells (Cardott, 1989)
Anadarko Basin Initial Potential (Cana Play Beginning in 2007) Cardott, 2012b
Anadarko Basin Produced Liquids USING THE SAME CRITERIA AS FOR THE ARKOMA BASIN TO EXCLUDE WELLS WITH LOW AMOUNTS OF EARLY LIQUID PRODUCTION Cardott, 2012b
Anadarko Woodford IP Liquids BPD (2004-2012)
Woodford Shale VRo on Structure Cardott, 2012b
Woodford Shale IPs on Structure Cardott, 2012b
Shale Oil Plays The Bakken Shale (Late Devonian-Early Mississippian; North Dakota & Montana) is the analog for shale oil plays. However, the reservoir of the Bakken is a permeable, non-shale middle member. Other formations considered…
Woodford Production on Structure Oil production from silica-rich rock is from natural fractures Cardott, 2012b
Ardmore Woodford IP Liquids BPD (2004-2012)
http://www.ogs.ou.edu For more information, please visit the Oklahoma Geological Survey Web Site
2,768 records
THANK YOU Typical Calf Creek point of Woodford chert found in Haskell County, Oklahoma (Norman Transcript, March 11, 2007, p. E1)
Loading...
