Natural Gas - Spring 2023 - 6 slides

1/20/2023 1 Natural Gas Prefix and Number Word Review • Roman Numerals – C = 100 – M = 1000 • Metric Prefixes – Deca – 10 – Hecto – 100 – Kilo – 1,000 Word - thousand – Mega – 1,000,000 - million – Giga – 1,000,000,000 - billion – Tera – 1,000,000,000 - trillion – Peta – 1,000,000,000 - quadrillion 1 MM (millions) finance and accounting Natural Gas • 80-95% methane CH 4 • The remainder is ethane and other small hydrocarbons • Normal Units – Therm = 100,000 Btu ≃ 100 cubic feet (1Ccf) – Decatherm = 10 therms or = 1 million btu (1MMBTU) – Mcf = 1000 cubic feet = 1.025 MMBTU – *MMBTU – 1 million Btu 1 *Capital “M” is used in the SI unit system for Mega meaning 10^6 or million Natural Gas is a special case where “MM” stands for roman numerals M=1000 so MM is thousand thousand or one million Heating Value of Natural (HHV) D H c (heat of combustion in btu/lb) C + O 2 => CO 2 D H c = 14,500 btu/lb 2H 2 + O 2 => 2H 2 O D H c = 62,000 btu/lb S + O 2 => SO 2 D H c = 4,000 btu/lb Therefore, the heating value of coal with measured percentage concentrations of the three elements (C, H, S) is: HV(coal) = (14,500 x [C] + 62,000 x [H] + 4000 x [S])/100 2 Natural Gas • Natural gas is one of the cleanest burning alternative fuels available. – In light-duty applications, air emissions from natural gas vehicles are lower than emissions from gasoline-powered vehicles . Carbon monoxide and nitrogen oxides, smog-producing gases, are reduced by more than 90 percent and 60 percent, respectively. Carbon dioxide, a greenhouse gas, is reduced by 30 to 40 percent. – In medium- and heavy-duty applications, natural gas engines have shown a more than 90 percent reduction of carbon monoxide and particulate matter and a more than 50 percent reduction of nitrogen oxides, relative to commercial diesel engines. – The national average cost of compressed natural gas (CNG) was 94 cents cheaper than gasoline on an energy-equivalent basis, according the Clean Cities Alternative Fuel Price Report in June 2006. Gasoline was $2.84 per gallon, diesel was $2.98 per gallon, and CNG was $1.90 per gasoline gallon equivalent (GGE). • Source: U.S. Department of Energy, Energy Efficiency and Renewable Energy, Alternative Fuel Vehicles, http://www.eere.energy.gov/afdc/altfuel/gas_benefits.html 2 2 1 2 3 4 5 6

1/20/2023 2 Carbon Intensity of Fuel • coal (average) = 25.4 metric tonnes carbon per terajoule (TJ) • oil (average) = 19.9 metric tonnes carbon / TJ • natural gas (methane) = 14.4 metric tonnes carbon / TJ 1 Conventional vs Unconventional Natural Gas • Conventional is extracted in association with oil wells or using wells and pumps • Unconventional is extracted using advanced drilling techniques and may involve injection of heat, steam or other material to fracture rocks to release gas 1 Conventional Gas, Tight Gas, and Shale Gas http://www.wintershall.com/en/different-types-of-reserves-tight-gas-and-shale-gas.html Natural gas deposits are differentiated in terms of conventional and non-conventional reservoirs. In conventional reservoirs, the natural gas has not been created there but has migrated there and is stored there. The rock in these deposits has varying permeability. Gas from very low-permeable rock is known as tight gas. This is different in non-conventional deposits. Here the natural gas is situated in layers in which it was also created (“parent rock”). These reservoirs include both shale gas and coal gas. Hydraulic fracturing can be useful as a recovery method with bo th conventional and non- conventional deposits. Tight Gas Tight gas is natural gas that has gathered in small, poorly connected cavities between the rocks (mostly sandstone). Because this rock is not very porous the natural gas cannot flow freely to the well. The production of tight gas has been part of our energy supply for a long time. The technology for producing tight gas, called hydraulic fracturing, has been in use worldwide for 50 years. The extraction of tight gas from sandstone layers in Germany, such as in Lower Saxony, has also been tried and tested very successfully. Shale Gas With shale gas the gas has remained in the rock where it formed, the bedrock, and has not migrated to more permeable rock. The gas here is largely trapped in the surfaces of the rock particles. The production process for shale gas is much more complicated than for tight gas. More procedures are necessary to create the channels for the gas to flow through, and a much higher volume of fluids is required than with the production from tight gas deposits – since sandstone (tight gas) is naturally more porous and permeable than shale rock (shale gas). 1 Conventional vs Unconventional Gas • Shale Gas (unconventional) – Shale has insufficient permeability to allow free flow of NG. Requires advanced drilling and injection Steam or other materials to fracture rock and release • Tight Sandstones (conventional formation fracking is useful in extraction) – Similar to shale gas, NG in tiny pores, rock must be fractured or other ways to force out the NG • Coal Bed Methane (unconventional) – NG associated with coal • Methane Hydrates (conventional not currently exploited) – Frozen methane below the ocean floor 1 3 7 8 9 10 11 12

1/20/2023 4 http://dusk.geo.orst.edu/oceans/deep_curren ts.html http://soundwaves.usgs.gov/2012/06/ one cubic foot of methane hydrate traps about 164 cubic feet of methane gas 2 2 3 3 19 20 21 22 23 24

1/20/2023 5 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 Jan-2001 Jul-2001 Jan-2002 Jul-2002 Jan-2003 Jul-2003 Jan-2004 Jul-2004 Jan-2005 Jul-2005 Jan-2006 Jul-2006 Jan-2007 Jul-2007 Jan-2008 Jul-2008 Jan-2009 Jul-2009 Jan-2010 Jul-2010 Natural Gas Consumption (MMCF) U.S. Natural Gas Consumption by End Use 2001-2010 U.S. Natural Gas Total U.S. Residential U.S. Commercial Consumers U.S. Industrial U.S. Vehicle Fuel U.S. Electric Power Energy Information Administration (www.eia.gov) 2 0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 Jan-2001 Jun-2001 Nov-2001 Apr-2002 Sep-2002 Feb-2003 Jul-2003 Dec-2003 May-2004 Oct-2004 Mar-2005 Aug-2005 Jan-2006 Jun-2006 Nov-2006 Apr-2007 Sep-2007 Feb-2008 Jul-2008 Dec-2008 May-2009 Oct-2009 Mar-2010 Aug-2010 NG (MMCF) U.S. Natural Gas Consumption by End Use 2001-2010 U.S. Residential U.S. Industrial U.S. Vehicle Fuel U.S. Electric Power Energy Information Administration (www.eia.gov) 2 2 25 26 27 29 31 32