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
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Analogs to the San Andres Horizontal Play? A Fresh Look at ... · The Six-County Study Area1 Together with the Horizontal Wells and Mapping2 of the San Andres Residual Oil Zones 1
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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, CO2 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
* 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 ROZsUsing 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