Analogs to the San Andres Horizontal Play? A Fresh Look at the Glorieta – Yeso Play in Southeastern New Mexico December 2018 Steve Melzer* Evan Allard** With Considerable Assistance & Advice from R. Trentham, UTPB * Consulting Geological Engineer ** Summer Intern, CO 2 ROZ Conference and Graduating Senior, UTPB
Outline of Talk • Introduction • Benchmarking: The San Andres ROZ • The Permian Basin Carbonate Shelf Settings • The Two San Andres ROZ Plays • The Story of Two Different Sub-Basins (Midland & Delaware) • The Glorieta-Yeso (ROZ?) Play • Passing Comments on the Deeper Abo Formation
“Flip” Your Mind to ROZ Thinking • Transition Zone (TZ) Thinking has long been a Hindrance to Advancing Reservoir Understanding in the O&G Industry • Having said that, Transition Zones Do Exist! • Residual Oil Zones (ROZs) are a Broader Concept – Reservoir Rocks and Oils Are Often Affected by Mother Nature’s Water Flooding – Can be Much Thicker and Have Substantial Economic Value – Are Most Often Due to Later-stage Tectonics (Post-Entrapment) – Can Occur Where no Main Pay Zones Exist (“Greenfields”) • Opening One’s Mind to the Reservoir Evolution and Changing Properties Above Can be Essential
Paleogeographic Map of the Permian Basin with its Two Major Sub- basins (Delaware and Midland) and Nearby Regions
Permian Basin Stratigraphic Chart* (Permian Only) * Adapted from Kerans, C. C., Bureau of Economic Geology, PBGSP Annual Meeting, 2/27-2/28/06, Austin, TX
The Two San Andres ROZ Plays 1) CO 2 EOR 2) Horizontal Well Depressuring
The San Andres ROZ Mapping Yoakum County
Examples: ROZ Profile Types (Greenfields)
The Seminole ROZ
The Idealized Seminole ROZ (Type A Profile) ~250’ Thick
1) CO 2 EOR in the ROZ
2) The Horizontal San Andres (ROZ) Play
The Six-County Study Area 1 Together with the Horizontal Wells and Mapping 2 of the San Andres Residual Oil Zones 450 Laterals Making 35,000 bopd as of May ’18 1 Residual Oil Drives New Resource Play, Melzer, L.S. (2018), Amer Oil & Gas Reporter, Oct (PBIOS) Edition, October 2018 2 Identifying and Developing Technology for Enabling Small Producers to Pursue the Residual Oil Zone (ROZ) Fairways in the Permian Basin San Andres Formation, Trentham, R.C., Melzer, L.S. & Vance. D. (2016), Research Partnership to Secure Energy for America and U.S. Dept of Energy Final Report, www.netl.doe.gov/file%20library/research/oil-gas/10123-17-final-report.pdf
We Need to Show How the San Andres ROZ Studies Provide Insights to Another On-going Horizontal Play but First: The Story of Two Different Permian Sub-Basins (Midland & Delaware)
The Two Sub-Basins • The Western (Delaware) Sub-basin of the Permian Basin was a very Deep Basin in the Late Pennsylvanian and Early Permian Ages • The Eastern (Midland) Sub-basin was Shallower • The Wolfcampian Series (Late Pennsylvanian and very Early Permian was the era when both Sub-basins began to fill • The Midland Sub-basin Filled First and the Delaware Much Later
Basin Geometry Impacts on Commerciality • The Deeper the Basin, the Thicker the Source of Hydrocarbons • The Deeper the Basin, the Steeper the Basin edge Slopes are to the Rimming Sediments (Carbonate Shelves) • The Deeper the Basin, the More Likely there are Stacked Reservoirs in the Carbonate Shelves since the Geographical Position of the Basin Rims Remain Relatively Fixed* * We are assuming here that subsidence and/or uplift tectonics are relatively inactive as the Basin Fills
Conceptualized Image of Stacked Reservoirs at the Shoreline Around a Deep Basin
Regions of “Stacked” Reservoirs
In Shallower Basins… • The Slopes to the Basin Sediments are gentler and the Rimming Sediments Prograde into the Basin as the Basin Fills • The Area Occupied by the Basin Shrinks over Time • The Midland Basin Shows this Trend During the Periods from the Wolfcamp through Lower San Andres to Grayburg
This Looks at the Midland Sub-basin * Meanwhile, the Delaware Sub-basin remained of Relatively Constant Size * Adapted from Original Work by Bob Ward, Gulf Oil, Pers. Comm, 1992. Modified by Bob Trentham, 2007
Image of Prograding Basinward Reservoirs at the Shoreline Around a Shallow Basin
Note the Huge Expanses of the Flat Carbonate Shelf (Sabkha)
Animation of the Interglacial Flooding Event in Lower San Andres To see animation of interglacial flooding in the Lower San Andres, see “Interglacial Flooding” Animation at http ://melzerconsulting.aptapb.com/residual-oil-zones/
Deep and Shallow Basins: Rimming Shelves
The Effect of the Depth of the Basin on the Shelf Surrounding the Basin Can Be Dramatic • The Width of the Inner and Outer Carbonate Ramps (IR & OR) where the Reservoir Quality Rocks (i.e., missing the finer-grained sediments) are located can be much wider • Geological Time Scale Sea Level Changes (even fairly minor ones) can broaden the Reservoir Quality Rock in IR & OR • The Salt Flats or Sabkha can be Very Large in Areal Extent
Carbonate Shelves Rimming Deep and Shallow Basins Deep Basin To see animation of deep vs shallow Basin Effects on the carbonate shelf reservoirs, see “Deep & Shallow Basin” Animation at http://melzerconsulting.aptapb.com/residual-oil-zones/
Deep Basins: Why is this Important? • Deep Basins have Huge Thicknesses of Organic-rich Sediments that can Hold Large Volumes of Oil to be Exploited with Horizontal Wells • Those Basins are Rimmed with Stacked Reservoirs which can be Receptacles for Migrated Oil and be Accessed with Single Vertical Wells • An Analog to this is the Delaware Sub-basin, its Northwestern Shelf and West Side of the Central Basin Platform
Shallow Basins: Why is this Important? • Shallow Basins have Wide (Lateral) Expanses of Reservoir Quality Rocks • Sea Level Changes can Provide Reservoir Quality Rocks Over Large Lateral Distances • Large Expanses of Reservoir Quality Rocks can Host Very Large Volumes of Oil and Provide Avenues (Flush Fairways) for Natural Water Floods Leading to Large Areal Extents of Residual Oil Zones • An Analog to this is the Midland Sub-basin and its North Shelf and East Side of the Central Basin Platform
The Glorieta – Yeso Horizontal Play
Key Diagnostics for Identifying (Type 3) Carbonate Reservoir ROZs Using Experience from the San Andres ROZ Studies • Excellent Mud Logs Shows of Oil (and Gas) but Drill Stem Tests and/or Production Tests Making only Sulfur Water w/ a “Trace of Oil” • Conventional Whole Core Test Results with 8-20% Oil Saturations (So) – Oil Wet Rock • Reservoir Trends Showing ‘Fairways’ (allows Sweep Pathways) • Tilted Oil/Water Contacts for the Main Pay Zones • Horizontals Making Large Volumes of Sulfur Water often with Delayed Oil Production that is Sour Oil • Pervasive Dolomitic Lithologies • Slightly Low to Very Low Produced Water Salinities When Compared to MPZs • Suppressed Methane & Enhanced H 2 S, CO 2 & NGL Gas Compositions • Bow-shape Porosity and Resistivity Logs
Additional Factors to Consider Interbedded (or Stacked) MPZs and ROZs • Andrews County San Andres and the Gl-Yeso Formation Profiles Occasionally Show Some Evidence of ROZs with Interbedded (isolated and unflushed) Main Pay Zones • “Shingles” on Top of the ROZ are not Uncommon – Provide Immediate Oil Confusing the Longer-lived (large Reservoir) ROZ Production • Where Can the Sweep Water Come From? – Sacramento Mtn Outcrop – Transmissive Fault Path From Another Reservoir? • What About the Sweep Water Discharge?
32 Glorieta/Yeso Reefal Trend (NM) Main Pay Zones Artesia Carlsbad
Glorieta-U. Yeso Type Fm Density Log Logs Resistivity Log Mud Log
Reference Map for Following Cross Sections Carlsbad
Stratigraphic Cross Section of the Yeso Formation Showing the Porosity Trend in the Glorieta - Upper Yeso (Datum – Top of Glorieta Formation)
Structural Cross Section of the Yeso Play (Datum – Minus 900 Feet Mean Sea Level) 400’ Artesia
Passing Comments About the Deeper Abo Formation (Better Documented in Literature) • Lies Immediately Below the Yeso Fm • Also is a Carbonate Shelf Trending in the Same Position as the Yeso (Stacked Fomations) • Possesses Even More Evidence of ROZ Characteristics including a Documented Tilted Oil/Water Contact in the Empire Abo Field • Better Analog to Gl-Yeso than the San Andres
Permian Basin Stratigraphic Chart* (Permian Only) * Adapted from Kerans, C. C., Bureau of Economic Geology, PBGSP Annual Meeting, 2/27-2/28/06, Austin, TX
39 Abo Reefal Trend Map in New Mexico Eddy Lea Co. Co. After Lemay (1960), Southwestern Federation of Geological Societies Transactions, Oct 12-14, 1960
40 Abo Cross-Section Through Major NM Fields Note: Tilted OWC After Lemay (1960), Southwestern Federation of Geological Societies Transactions, Oct 12-14, 1960
41 Empire Abo Map Illustrating Down to the East Tilted OWC Note: OWC Tilt = ~200’ in 10 miles After Lemay (1960), Southwestern Federation of Geological Societies Transactions, Oct 12-14, 1960
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