A CO2 Feature? A Glimpse Into Our Natural Gas Future.

NED Pipeline - Tom Shepstone ReportsTom Shepstone
Shepstone Management Company, Inc.


Turning a bug into a feature is an age-old marketing technique but, in the case of natural gas, a CO2 feature is reality combined with much future potential.

A Department of Energy “Request for Information” (RFI) issued a month ago provides a fascinating glimpse into the future of natural gas. It’s exciting. What especially caught my attention was the discussion surrounding what should be called the CO2 feature of natural gas. It has undeniably lowered CO2 emissions through natural gas fuel conversions but the future potential may be even greater.

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The RFI builds on the now well-known fact natural gas has been a God-send in reducing CO2 emissions and then moves into other CO2 feature possibilities (emphasis added):

The United States will, for the foreseeable future, continue to rely heavily upon domestically produced oil and natural gas for our national energy supply. Additionally, contributions to the national energy supply from what have become known as U.S. “unconventional” oil and gas (UOG) resources, i.e., primarily oil and natural gas from shale source rocks, continue to increase. Optimizing use of the nation’s UOG supply will require safe, efficient, and environmentally responsible UOG exploration and production technologies and processes. In addition, U.S. offshore producing areas, including prospective areas in the deepwater and ultra-deepwater sectors of the Gulf of Mexico, are expected to continue to provide a significant share of our domestic oil production well into the future.

UOG reservoirs commonly extend across large regions and therefore represent extremely large “in-place” hydrocarbon volumes. However, even with the application of advanced technologies, UOG reservoirs typically exhibit low recovery factors relative to higher permeability “conventional” reservoirs; ultimate recovery values of 10% or less are cited for liquid-rich shales and only 25 to 35% for gas-rich shales. Improving these factors is an important objective if we are to avoid wasting this valuable natural resource and reduce the environmental impact per unit of energy produced.

While science-based regulation and adherence to best practices can help achieve the goal of safe, environmentally sustainable and efficient development of both onshore and offshore resources, rapid technology advancements will be required to maximize the national energy, security, and economic benefits of UOG and offshore exploration and production activities while minimizing any negative environmental impacts.

Development of unconventional natural gas resources is an important element of our national effort to reduce carbon emissions from fossil fuels used for power generation. However, it is critical that emissions of methane (a potent greenhouse gas) associated with natural gas resource development and use be minimized in order to maximize any greenhouse gas (GHG) reduction benefit. Cost effective technologies to facilitate the capture and conversion of methane that would otherwise be flared or vented are needed.

In many areas of the country, the oil and gas production process requires the simultaneous production, handling and disposal of large volumes of salt water. Oil and gas wells that have been hydraulically fractured with large volumes of fresh water will flow back a portion of this water loaded with dissolved solids, requiring it to be safely disposed of or reused. Cost effective technologies for cleaning this water to the degree necessary for its beneficial reuse are needed, particularly in those areas of the country where supplies of fresh water are low or decreasing.

Future large-scale capture and storage of CO2 could be an important element of efforts to reduce GHG emissions and potentially reduce the impacts of climate change. One place where captured anthropogenic CO2 could be stored is in depleted oil and gas reservoirs offshore in the Gulf of Mexico. Injecting CO2 into these reservoirs could also result in enhanced recovery of residual oil.

Reuse of the hydraulic fracturing fluids in flowback and produced water is, of course, already going on in Northeastern Pennsylvania and many other places. Moreover, the use of natural gas itself (or its derivative propane) and CO2 as non-aqueous methods of fracturing wells is already underway, although it has not become standard industry practice yet. It will in many places as the CO2 feature becomes more obvious. This RFI clearly anticipates this is what should and will happen in many cases.

It’s worth perusing the RFI for some of the other ideas that are likely to the enhance the CO2 feature of natural gas. They include:

  • Reducing these emissions through efficiency improvements to boilers, combustion turbines, and engines, or fuel switching, the substitution of low-carbon energy sources (e.g., compressed natural gas/liquefied natural gas for diesel fuel, solar heating),
  • Carbon Recycle to convert CO2 (possibly along with methane and other light hydrocarbons) to liquid fuels and chemicals (e.g., methanol).
  • Improving the economics of transporting small and possibly intermittent quantities of natural gas, CO2, and various conversion products from the field to markets.

CO2 Feature extracting_shale_with_co2-218x3001There’s much more.

The Department of Energy foresees possibilities for using “novel supply-chain management strategies, technologies for densifying gases for storage and transport, and low-cost, high-strength materials for holding and transporting small quantities of liquids and high-pressure gases.”

All of this is thrust at the enormous potential of CO2 as a feature and not a bug. We’ve already seen tremendous reductions in CO2 emissions due to fuel switching to natural gas, but just imagine what’s now possible.

This is a classic case of American ingenuity at work. It’s the high road of finding new ways to make things work better, rather than the low road of trying to politically force-feed an entirely different answer based on ideology as opposed to science.

The DOE has given us a glimpse of the natural gas future and it’s as bright as could be.


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