Sheep Mountain

From Global Energy Monitor
This article is part of the Global Fossil Infrastructure Tracker, a project of Global Energy Monitor.
Sub-articles:

Sheep Mountain is a 96.8% pure natural carbon source field[1] located in south-central Colorado in Huerfano County and operated by Occidental.

Sheep Mountain CO2 field. Credit: U.S. Bureau of Land Management

Unitized in 1976,[2] carbon produced at Sheep Mountain is crucial for oil drilling as an injectant for CO2 enhanced oil recovery in Texas' Permian Basin, the global epicenter of CO2 EOR for Carbon Capture Utilization and Storage. It is one of the five major producing Natural CO2 Source Fields in the United States at 203,000 acres in size.

Sheep Mountain carbon is sent via the 405-mile Sheep Mountain CO2 Pipeline[3] to Texas' Permian Basin, in which the produced carbon is injected under the ground to free up an additional 8-20% of oil. CO2 EOR is also sometimes called "carbon flooding" or "tertiary recovery."[4]

Natural carbon dioxide is currently the source of over 80% of the CO2 for CO2 EOR in the United States[5] and CO2 EOR currently is the final carbon sink for nine of the ten biggest U.S.-based Carbon Capture and Storage (CCS) projects currently commercially operational.[6]

Traditionally known as CCS, CO2 EOR is a central component of a rebranding effort which began in 2012 known as CCUS, or carbon capture utilization and storage. The "U" in CCUS, in this case, is using carbon to drill for more oil.[7]

According to a 2014 U.S. Department of Energy study, 97% of the industrial marketed carbon is used for CO2 EOR.[8]

A 2020 academic study concluded that CO2 enhanced oil recovery using CO2 source fields like the Jackson Dome, McElmo Dome, Bravo Dome, Sheep Mountain, and Doe Canyon “cannot contribute to reductions in anthropogenic CO2 emissions into the atmosphere.”[9] A study the year before, published by the U.S. Department of Energy echoed that conclusion, writing that CO2 production for CO2 EOR "does not contribute towards a net reduction in CO2 emissions to the atmosphere."[10]

Multiple studies have also called into question the climate benefits of CO2 EOR production even with anthropogenic carbon, pointing to the process as a net-positive greenhouse gas emitting process.[11]

Field Details

  • Start Year: 1983[12]
  • Operator: Occidental
  • Location: Huerfano County, Colorado
  • Production: 5.06 million MCF[13]
  • Active Production Wells: 26[14]
  • Status: Operating

Comparison to Oil, Gas Drilling

An industry engineer told the outlet Capital & Main that CO2 drilling is akin to drilling for oil and gas, at its core.

“It’s really the same tools, the same equipment, the same calculation going on. It’s just using different types of numbers,” the engineer stated. “But you find a CO2 source field, which obviously can be several thousand feet underground, and you move a drilling rig in and you drill for it.”[15]

1982 CO2 Release

In 1982, Sheep Mountain Unit was the source of one of the largest CO2 leakages and the largest recorded industrial release of the chemical compound in human history.[16]

According to a 1985 paper written by engineers employed by ARCO, who operated the field at the time of the release, during the week-long period that the CO2 well on site spewed carbon, it did so in a formation that was “softball-sized" and went "hundreds of feet into the air.”[17] A 2007 science paper discussing the well blowout further detailed that “on one of the first mornings of the blowout period[,] a car engine stopped when being driven through a low spot on the way to the drillsite.” It took an additional nearly two weeks to fully contain the massive leak.[18]

Worried about the possibility of future mass CO2 leakage events, residents formed a group called Huerfano Valley Citizens Alliance to act as a community industry watchdog.[19]

Greenhouse Gas Emissions, Co-Pollutants

Natural CO2 Source Fields disclose their production levels under Subpart PP of the U.S. Environmental Protection Agency (EPA)'s Greenhouse Gas Reporting Rule, which is a self-reporting mechanism. As a CO2 producer, the company only must report its production levels and not its emissions under the statute. 328,109 metric tons of Sheep Mountain CO2 was injected underground in 2019, according to EPA data.[20]

The operative language of Subpart PP of the Mandatory Greenhouse Gas Reporting statute reads, "The owner or operator of a CO2 production well facility must maintain quarterly records of the mass flow or volumetric flow of the extracted or transferred CO2 stream and concentration and density if volumetric flow meters are used."[21]

CO2 enhanced oil recovery wells, a key component of Carbon Capture Utilization and Storage, also must report emissions generated via the production activity under the Greenhouse Gas Reporting Rule under Subpart UU of the Mandatory Greenhouse Gas Reporting statute.[22] But it is assumed as a carbon storage mechanism and no companies self-report emissions as part of that process.

Outside of greenhouse gas emissions, Sheep Mountain emits co-pollutants, including high levels of carbon monoxide, formaldehyde, VOC's, PM 10, and NOx.[23]

In a 2015 Environmental Assessment for two CO2 wells done by the U.S. Bureau of Land Management under the Obama Administration, the agency wrote that it was "reasonable to conclude that the project would have no measurable impact on the climate." The EA does mention that "Most of the CO2 gas produced at this location is transported to West Texas to support oil and gas production," but does not explain the climate emissions footprint of Carbon Capture Utilization and Storage or CO2 enhanced oil recovery.[24]

CO2 EOR Climate Impacts

Multiple studies have pointed to the climate change impacts of beefing up CO2 enhanced oil recovery. They come with the backdrop of a 2019 U.S. Department of Energy report concluding that there has been "no official mechanism for reporting leaks" of CO2 for most of the history of CO2 EOR production. "In addition, little information is available on project post-closure status and CO2 behavior in the subsurface post-injection," the report continues.[25]

A 2019 study published in the journal Applied Energy concludes that "from [a] thermodynamics point of view, CO2 enhanced oil recovery (EOR) with CCS option is not sustainable, i.e., during the life cycle of the process more energy is consumed than the energy produced from oil."[26]

A decade earlier, another study came to the same conclusion: CO2 EOR is a carbon-positive emissions drilling process. That paper, published by researchers at Carnegie Mellon University in the journal Environmental Science & Technology, surmised that “without displacement of a carbon intensive energy source, CO2-EOR systems will result in net carbon emissions.”

"We calculated that between 3.7 and 4.7 metric tons of CO2 are emitted for every metric ton of CO2 injected. The fields currently inject and sequester less than 0.2 metric tons of CO2 per bbl of oil produced," the researchers further detailed. "In order to entirely offset system emissions, e.g., making the net CO2 emissions zero, 0.62 metric tons of CO2 would need to be injected and permanently sequestered for every bbl of oil produced. The only way to sequester this amount of CO2 would be to operate a sequestration project concurrently with the CO2-EOR project."[27]

In 2020, researchers June Sekera and Andreas Lichtenberger came to similar summations in doing a survey of over 200 studies done on Carbon Capture Utilization and Storage to date with regards to greenhouse gas emissions in their paper titled, "Assessing Carbon Capture: Public Policy, Science, and Societal Need: A Review of the Literature on Industrial Carbon Removal."

"We found that papers that deem CCS-EOR to be a climate mitigation technique either fail to account for all emissions (i.e., they perform only a partial life cycle analysis) and/or they make an assumption that CCS-EOR-produced oil 'displaces' conventionally produced fossil fuel energy," they wrote, surmising instead that "data show that the process actually results in net emissions."[28]

U.S. Environmental Protection Agency data further shows that at the CO2 treatment facilities servicing some of the major CO2 EOR fields at Texas' Permian Basin, the facilities emit high levels of carbon dioxide and other copollutants into the atmosphere.

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One of them, the SACROC CO2 treatment facility servicing the SACROC CO2 EOR field -- operated by Kinder Morgan Energy Partners -- emitted 425,971.5 metric tons of CO2 into the atmosphere in 2019.[29] That amounts to 92,640 passenger vehicles driven for a year and 77,375 homes' electricity use for one year, according to the EPA's Greenhouse Gas Equivalencies Calculator.[30] The SACROC facility also emits high levels of PM 10, VOCs, ammonia, PM 2.5, carbon monoxide, formaldehyde, methane, NOx, and sulfur dioxide, according to EPA pollution data.[31]

The Denver Unit and Wasson CO2 removal plans, both of which service the Denver Unit CO2 EOR field, also emitted a total of 153,035.7 metric tons of CO2 into the atmosphere in 2019. [32][33] That equates to 33,282 passenger vehicles driven for one year and 27,798 homes' electricity use for one year.[34]

Occidental's Denver City CO2 removal plant in Denver City, Texas. Credit: Google Maps.

The Denver Unit CO2 removal plant also emits high levels of sulfur dioxide, nitrogen oxides, carbon monoxide, as well as PM 2.5 and PM 10, according to the EPA Air Pollutant Report for the facility.[35] The separation facility is located within three miles of over 5,100 people, 66% of whom are people of color and over 75% of whom have a family income of below $75,000 per year. Only just above 15% of the population in that 3-mile radius has a college degree and 63% of the population in that radius has a Latinx ethnic origin.[36][37]

Denver City CO2 removal plant next to oil rigs. Photo Credit: Google Maps

According to Texas Center on Environmental Quality data, the Wasson CO2 Removal Plant owned by Occidental also emitted 19,312 pounds of carbon monoxide via designated illegal air pollution incidents into the atmosphere between January 1, 2020 and February 24, 2021. The facility also emitted over 3,400 pounds of H2S; over 15,700 pounds of non-methane, non-ethane natural gas; over 2,250 pounds of oxides of nitrogen; and over 314,000 pounds of sulfur dioxide[38]

Between January 2020 and March 14, 2021, Occidental's Anton CO2 dehydration plant in Shallowater, Texas had 11,800 pounds of carbon monoxide incidents, 637 pounds of H2S; over 9,200 pounds of non-methane, non-ethane natural gas; and over 56,300 pounds of SO2, and 1,672 pounds of NOx.[39]

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And between June 2020 through January 2021, the company's Denver Unit CO2 Recovery Plant had incident events which emitted over 40,400 pounds of carbon monoxide into the atmosphere, more than 65 pounds of H2S, over 23,200 pounds of non-methane/non-ethane natural gas, over 5,000 pounds of NOx, and over 6,000 pounds of SO2.[40]

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Three of the company's CO2 processing plants sit within the top ten most polluting facilities in Texas when ranked by SO2 emissions, according to a 2020 report by the group Environment Texas, when ranked by illegal air pollution events. They include the West Seminole San Andres Unit CO2 facilities, the Seminole Gas Processing Plant, and the Willard CO2 Separation Plant. But when measuring all co-pollutants, five of the top six polluters in the TCEQ's Region 2 (Lubbock) are CO2 separation/removal/recovery plants.[41]

Top 10 polluters for TCEQ Region 2. Credit: Environment Texas
Willard CO2 Plant in Denver City, Texas. Credit: Google Maps

The main Permian-area gas plants which create carbon as a by-product, thusly used for CO2 EOR production, are also highly polluting, according to U.S. Environmental Protection Agency (EPA) data.

The Pikes Peak Gas Plant -- located in Fort Stockton, Texas and operated by Occidental -- is in the 87.8 percentile for PM 2.5 emitted into the atmosphere, 92.7 percentile for ozone, 86.1 for other air toxics, and on the 83.9 percentile for respiratory hazard index.[42] The plant also emits high levels of benzene, formaldehyde, toluene, carbon monoxide, ethylbenzene, xylene, VOCs, hexane and climate change-causing CO2 into the atmosphere, according to other EPA data.[43]

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The Terrell Gas Plant in Sheffield, Texas shows similar attributes, sitting in the 68.9 percentile for PM 2.5, 70.3 for ozone, 67.8 for air toxics cancer risk, and 66.7 for respiratory hazard index.[44] Like Pikes Peak, the plant is operated by Occidental. The facility also emits high levels of VOCs, formaldehyde, CO2, methane, toluene, acetaldehyde, benzene, carbon monoxide, PM 2.5, acrolein, SO2, hexane, methanol, and NOx into the atmosphere.[45] Greenhouse gas emissions data from the EPA shows that the facility emitted 50,011 metric tons of CO2 into the atmosphere in 2019. [46]

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Beyond Texas, at Denbury's Bogue Chitto, Mississippi's CO2 EOR site, the company emits high levels of nitrogen oxides (NOx), hexane, carbon monoxide, VOCs, benzene, formaldehyde, and PM 2.5, according to U.S. Environmental Protection Agency data.[47]

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Local Economic Dependence

A 2007 article by The Denver Post noted that Huerfano County's government was nervous about what would come next for raising tax revenue in the county[48] with a population of 6,897,[49] once production level decline at Sheep Mountain.

"Services have been cut back, notably in the sheriff’s department, where six deputies represent half the staffing level of the 1980s," reported The Post. "The boom-to-bust scenario is reminiscent of earlier in the 20th century when Huerfano County was a coal-mining center and its population burgeoned to 17,000 in the 1930s."

The Post reported that 30% of the county's tax base came from CO2 extraction at the time the article was published and at its peak, it was 50% of the county's tax base.[50] But the Huerfano County Assessor's Office has told Global Energy Monitor that drilling for CO2 at Sheep Mountain now consists of only 1.67% of its tax base as of 2020, with the level of CO2 production down to miniscule levels.

Sequestering vs. Recycling

During the CO2 EOR process, CO2 is not merely stored underground immediately. Instead, it is recycled as part of what the Global CCS Institute describes as a "closed loop," which "reduces the need to purchase additional CO2."[51]

A closed-loop CO2 EOR system, exhibited in a 2013 NETL report.

A 1976 study commissioned by the Federal Energy Administration pointed out that, from the onset, CO2 EOR would not be economically feasible for the oil industry without recycling technology. The study explained the industry will necessitate "major improvements in...recycling...before the full potential of this recovery tech­nique can be realized."[52]

As early as 1981, a petroleum engineering coordinator for Shell told colleagues at the Society for Petroleum Engineers that CO2 for CO2 enhanced oil recovery should be recycled because it "is a very valuable commodity" and "it does involve large amounts for oil recovery."[53]

In 1991, a production supervisor at Shell at the Jackson Dome further explained, "We're recycling everything we produce. Eventually the flood will be mature enough that all we'll be doing is recycling. We won't have to bring any more down from Jackson Dome."[54]

In 2016, the U.S. Department of Interior's Office of Natural Resources Revenue also explained the CO2 EOR process as one centering around recycling in a legal ruling pertaining to disputes over royalty payments at the Bravo Dome. "At the surface, the CO2 is separated from the oil," explains the filing. "The oil is sold and the CO2 reused again in the EOR reservoir. This means the CO2 is part of a continual process and is not sold."[55]

In a 2018 presentation, Denbury further concluded that by 15 years into a CO2 EOR operation, 20% of its CO2 will be recycled. By 20 years, that number goes up to 50%. By 25 years, that number goes up to 70% and by 30 years, that number goes up to 80% recycled.[56]

The U.S. Department of Energy's National Energy Technology Laboratory put it more simply in a 2019 paper on CO2 EOR, writing, "the objective of CO2 EOR operations is not to store CO2, but to maximize oil production. However, some of the injected CO2 ultimately does get stored in the reservoir as part of the process.[57]

“The need for the field to purchase new CO2 is gradually reduced over time,” further explains a 2019 paper published by the U.S. Department of Energy. “As a result, a greater percentage of the CO2 injected is from production, separation, and recycling versus newly-purchased CO2.” That paper further explained that “approximately half has been recovered and recycled” and more broadly “CO2 EOR operators try to maximize oil and gas production and minimize the amount of CO2 left in the reservoir.”[58]

A 2010 paper by the National Energy Technology Laboratory also explains the exact money saved by doing the recycling process, writing that "Because of the cost of naturally sourced CO2—roughly $10-15 per metric ton—a CO2 flood operator seeks to recycle as much as possible to minimize future purchases of the gas."[59]

Articles and Resources

Related GEM.wiki articles

References

  1. ↑ P. Markewitz, W. Kuckshinrichs, Et Al, "Worldwide innovations in the development of carbon capture technologies and the utilization of CO2," Energy & Environmental Science, Feb. 29, 2012
  2. ↑ "Appeal from a decision of the Acting Associate State Director, Colorado State Office, Bureau of Land Management, dismissing a request for State Director Review of the approval of the first revision of the initial Entrada Formation Participating Area 'B,' Sheep Mountain Unit Agreement, Huerfano County, Colorado," U.S. Department of Interior, SDR-CO-95-3, Sept. 24, 1998
  3. ↑ "Oil recovery project: Seminole unit employs CO2," Longview News-Journal, April 24, 1983
  4. ↑ Nelson, Cody, "Inside the Dirty, Dangerous World of Carbon Flooding," Capital & Main, April 5, 2021
  5. ↑ "Supply and Demand Analysis for Capture and Storage of Anthropogenic Carbon Dioxide in the Central U.S.," Working Document of the NPC Study Meeting the Dual Challenge: A Roadmap to At-Scale Development of Carbon Capture, Use, and Storage, U.S. Department of Energy, National Petroleum Council, Dec. 12, 2019
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  8. ↑ "Subsurface Sources of CO2 in the Contiguous United States - Volume 1: Discovered Reservoirs," DOE/NETL-2014/1637, March 5, 2014
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  10. ↑ "CO2 Leakage During EOR Operations – Analog Studies to Geologic Storage of CO2," DOE/NETL-2017/1865, National Energy Technology Laboratory, U.S. Department of Energy, Jan. 30, 2019
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  17. ↑ R. Lynch, E. McBride, Et Al, "Dynamic Kill of an Uncontrolled CO2 Well," Journal of Petroleum Technology, pp. 1267–1275, Paper Number: SPE-11378-PA, V. 37, Issue 7, July 1985
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  19. ↑ "Crews fail to plug leak at gas field," The Daily Sentinel, March 29, 1982
  20. ↑ "Oxy USA, Sheep Mountain CO2 Facility - 2019," U.S. Environmental Protection Agency, Facility Level Information on GreenHouse gases Tool (FLIGHT)
  21. ↑ Electronic Code of Federal Regulations, "Suppliers of Carbon Dioxide," Title 40, Chapter I, Subchapter C, Part 98, Subpart PP. Accessed May 2021
  22. ↑ Electronic Code of Federal Regulations, "Injection of Carbon Dioxide," Title 40, Chapter I, Subchapter C, Part 98, Subpart UU. Accessed May 2021
  23. ↑ "Air Pollutant Report - Oxy USA, Sheep Mountain CO2 Facility," U.S. Environmental Protection Agency, Enforcement and Compliance History Online, accessed May 2021
  24. ↑ "Environmental Assessment - OXY SMU 1–3–M and 6–4–I APDs," U.S. Department of the Interior, U.S. Bureau of Land Management, April 2015
  25. ↑ Vikara, Wendt, Et Al, "CO2 Leakage During EOR Operations – Analog Studies to Geologic Storage of CO2," U.S. Department of Energy, National Energy Technology Laboratory, Jan. 30, 2019
  26. ↑ R. Farajzadeh, A.A. Eftekhari, Et Al, [https://reader.elsevier.com/reader/sd/pii/S0306261919321555?token=380B7BA44986AA1F55E1FB5149D68E180D997BF390A63DE26F70A9D7D25A907CE5B3855A290D5149873F54C09BFC533B&originRegion=us-east-1&originCreation=20210510001340 "On the sustainability of CO2 storage through CO2–Enhanced oil recovery," Applied Energy, 261 (2020) 114467, Jan. 17, 2020
  27. ↑ P. Jaramillo, W. Michael Griffin, S. McCoy, "Life Cycle Inventory of CO2 in an Enhanced Oil Recovery System," Environmental Science & Technology, 2009, 43, 8027–8032, Sept. 14, 2009
  28. ↑ J. Sekera, A. Lichtenberger, "Assessing Carbon Capture: Public Policy, Science, and Societal Need: A Review of the Literature on Industrial Carbon Removal," Biophysical Economics and Sustainability, (2020) 5:14, Oct. 6, 2020
  29. ↑ "SACROC CO2 Treatment," U.S. Environmental Protection Agency, Facility Level Information on GreenHouse Gases Tool (FLIGHT), accessed May 2021
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  31. ↑ "Air Pollutant Report - SACROC CO2 Facility, Snyder, Texas," U.S. Environmental Protection Agency, Enforcement and Compliance History Online, accessed May 2021
  32. ↑ "Wasson CO2 Removal Plant," U.S. Environmental Protection Agency, Facility Level Information on GreenHouse Gases Tool (FLIGHT), accessed May 2021
  33. ↑ "Denver Unit CO 2 Recovery Plant," U.S. Environmental Protection Agency, Facility Level Information on GreenHouse Gases Tool (FLIGHT), accessed May 2021
  34. ↑ "Greenhouse Gas Equivalencies Calculator - Equivalency Results," U.S. Environmental Protection Agency, accessed May 2021
  35. ↑ "Air Pollutant Report - Denver Unit CO2 Recovery Plant," U.S. Environmental Protection Agency, Enforcement and Compliance History Online, accessed May 2021
  36. ↑ "Detailed Facility Report - Denver Unit CO2 Recovery Plant," U.S. Environmental Protection Agency, Enforcement and Compliance History Online, accessed May 2021
  37. ↑ "x":-102.8172,"y":32.98019,"spatialReference":{"wkid":4326}}&unit=9035&areatype=&areaid=&basemap=streets&distance=3 "EJSCREEN Report (Version 2020) - Denver Unit CO2 Removal Plant," U.S. Environmental Protection Agency, EJSCREEN, accessed May 2021
  38. ↑ "Wasson CO2 Removal Plant," Neighborhood Witness, accessed May 2021
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  41. ↑ Fraser, Catherine, "Illegal Air Pollution in Texas 2020," Environment Texas, Oct. 2020
  42. ↑ "Detailed Facility Report - Pikes Peak Gas Plant," U.S. Environmental Protection Agency, Enforcement and Compliance History Online (ECHO), accessed May 2021
  43. ↑ "Air Pollutant Report - Pikes Peak Gas Plant," U.S. Environmental Protection Agency, Enforcement and Compliance History Online, accesed May 2021
  44. ↑ "Detailed Facility Report - Terrell Gas Plant," U.S. Environmental Protection Agency, Enforcement and Compliance Online (ECHO) accessed May 2021
  45. ↑ "Air Pollutant Report - Terrell Gas Plant," U.S. Environmental Protection Agency, Enforcement and Compliance Online (ECHO), accessed May 2021
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  47. ↑ - "Air Pollutant Report - DENBURY ONSHORE LLC, 1043 MOUNT OLIVE ROAD, BOGUE CHITTO, MS," U.S. Environmental Protection Agency, Enforcement and Compliance History Online, accessed May 2021
  48. ↑ Raabe, Steve, "Huerfano County’s flat prospects," The Denver Post, March 20, 2007
  49. ↑ "QuickFact - Huerfano County, Colorado," United States Census Bureau, Population Estimates - July 1, 2019, accessed May 2021
  50. ↑ Raabe, Steve, "Huerfano County’s flat prospects," The Denver Post, March 20, 2007
  51. ↑ Whittaker, Steve; Perkins, Ernie, "Technical aspects of CO2 EOR and associated carbon storage," Global CCS Institute, Oct. 2013
  52. ↑ J.P. Brashear, V.A. Kuuskraa, "The Potential and Economics of Enhanced Oil Recovery," Journal of Petroleum Technology, Sept. 1, 1978
  53. ↑ Yancey, Royce, "Recycling CO2 reduces recovery cost," Fort Worth Star-Telegram, March 22, 1981
  54. ↑ Stewart, Steve, "Shell committed to oil recovery," Enterprise-Journal, March 31, 1989
  55. ↑ "United States Department of Interior v. Amerada Hess Corporation - appeal Denied; Order Modified" Office of Natural Resources Revenue, Sept. 13, 2016
  56. ↑ "EOR Carbon Management Workshop", CO2 Conference, Dec. 8, 2015
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  59. ↑ "Carbon Dioxide Enhanced Oil Recovery: Untapped Domestic Energy Supply and Long Term Carbon Storage Solution," U.S. Department of Energy, National Energy Technology Laboratory, March 2010

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