Appendix B-3: Unconventional Natural Gas Development Emissions Methodology

Transcription

1 Overview Appendix B-3: Unconventional Natural Gas Development Emissions Methodology The Marcellus Shale is a rock formation that underlies approximately two-thirds of Pennsylvania and portions of the states of New York, Ohio, West Virginia, Maryland, Kentucky and Virginia. The Marcellus Shale holds trillions of cubic feet of natural gas that had long been considered prohibitively expensive to access. Advances in drilling technology and natural gas extraction, however, have attracted new interest in this previously untapped formation. The geology and drilling trends within the Marcellus Shale suggest that areas in the southwest, north-central and northeastern regions of Pennsylvania may be especially productive. Figure 1: Marcellus Shale Formation in Pennsylvania Air pollutants are emitted from various sources during unconventional natural gas development and collection, as shown in Table 1. Table 1: Summary of Unconventional Natural Gas Emissions in Pennsylvania by Source Category, in Tons Per Year (tpy) Source Category NO X PM-10 PM-2.5 SO X VOC BLOWDOWN_VENT COMPLETION 4, DEHY DRILL_RIG 6, ENGINE 4, ,135 FUGITIVE HEATER PUMP TANK Emission Totals 16, ,

2 The counties in the Pittsburgh-Beaver Valley nonattainment area have experienced significant unconventional natural gas drilling activity since Almost all of the emissions are considered to be part of the area source sector. These area source emissions are produced by activities at the drill pad and compressor engines that pump natural gas through the gathering pipelines to a main pipeline. Gas processing plants are included in the stationary source inventory. A natural gas processing plant is a facility designed to clean raw natural gas by separating impurities and various non-methane hydrocarbons and fluids to produce what is known as pipeline quality dry natural gas. A gas processing plant is also used to recover natural gas liquids (condensate, natural gasoline and liquefied petroleum gas) and sometimes other substances such as sulfur. Drilling Activity Table 2 indicates the number of unconventional wells drilled in the Pittsburgh-Beaver Valley nonattainment counties (all of Allegheny, Armstrong, Beaver, Butler, Greene, Lawrence, Washington, and Westmoreland counties) in Drilling activity has been forecasted to remain fairly constant into the foreseeable future across Pennsylvania. Drilling activity in Allegheny County, one of the nonattainment areas largest counties, has been lower than other counties in the nonattainment area. DEP expects that drilling activity in Allegheny County will increase significantly in the near future. DEP does not expect that the drilling activity for the entire nonattainment area will increase significantly due to the increased drilling occurring in Allegheny County. DEP believes that drilling equipment will be moved from surrounding counties in the nonattainment area to Allegheny County to satisfy the increased drilling activity. Table 2: Number of Marcellus Shale Wells Drilled in the Pittsburgh-Beaver Valley Area YEAR COUNTY Allegh. Arms. Beaver Butler Greene Lawrence Wash. Westm. Total COUNTY TOTALS ,170 Current Compressor Engine Activity DEP projected compressor engine emissions from the 2013 Marcellus Shale Inventory that was submitted to the Department by natural gas producing companies operating in the state. Compressor station engine activity is expected to increase as more wells are drilled and the pressure of existing wells diminishes. As pressures at the wellhead decrease, compressor station engine activity will increase in order to pump natural gas through the network of pipelines

3 In early 2013, the DEP issued a new general permit, General Permit BAQ-GPA/GP-5, Natural Gas Compression and/or Processing Facilities (GP-5), which among other requirements, lowers the emissions rate for natural gas compressor engines used in pumping natural gas. GP-5 will serve to limit emissions because more compressors will be brought online under the more stringent GP-5 emission limits. Recent stack testing, which owners of compressor engines are required to complete annually and the results of which owners are required to submit to DEP, indicate that compressor engines in the Pittsburgh-Beaver Valley Area are operating below either the new GP-5 emissions limit of 0.5 grams of NO X per horsepower-hour or the Best Available Technology limit under the previous version of GP-5 or company-imposed emissions limits. Gas Production in the Pittsburgh-Beaver Valley Area Examination of well production data from 2010 to present in the area indicates natural gas production is increasing at a slow rate. Emissions from compressor engines will increase as more natural gas is produced. The DEP has received semi-annual gas production reports from gas producers for the last three years. It is difficult to project with a large degree of certainty gas production ten years from now based on the previous three years worth of data given all of the factors affecting production. Nevertheless, DEP based future gas production projections on growth of gas production from 2010 through mid-2014 in Indiana and Cambria counties. The projections are thought to be conservative (i.e., greater than what is likely to occur). It is important to note that emission from other source types, especially highway vehicles, have declined significantly in the Johnstown Area. Therefore, if conservative emission estimates for Marcellus Shale operations are added to the 2017 interim and 2025 maintenance year emissions inventories, the emissions in these years will not exceed emissions that occurred in the attainment year. DEP will periodically check future gas production numbers against the projected gas production in the maintenance plan revision to ensure that the projected emissions were not underestimated. Tables 3 and 4 display actual and projected well production rates for Cambria and Indiana Counties. Figure 2 shows this information graphically. As stated previously, DEP expects that well drilling activity will remain constant for the immediate future; gas production is anticipated to increase at a constant rate over the next several years, as production has increased over the last three years. In the most recent semi-annual reporting period for which data is available (January- June 2014), production increased by about 66,000,000 Mcf over the previous reporting period. Over all of the reporting periods, the gas production increased on average by 47,559,000 Mcf per semi-annual reporting period. A semi-annual growth in gas production of 55,000,000 Mcf was used to project gas production to 2017 and 2025 in order to compensate for accelerated growth in the later years

4 Table 3: Actual Well Production in the Pittsburgh-Beaver Valley Area Time Range Actual Well Production (Mcf) January June ,877,887* July December ,118,621 January June ,527,281 July December ,791,106 January June ,670,700 July December ,920,386 January June ,346,391 July December ,191,974 January June ,912,758 *July 2009 to June 2010 production which was divided by two to estimate 6-month production levels. Table 4: Projected Well Production in the Pittsburgh-Beaver Valley Area Time Range Projected Well Production (Mcf) July December ,000,000 January June ,000,000 July December ,000,000 January June ,000,000 July December ,000,000 January June ,000,000 July December ,000,000 January June ,000,000 July December ,000,000 January June ,014,000,000 July December ,069,000,000 January June ,124,000,000 July December ,179,000,000 January June ,234,000,000 July December ,289,000,000 January June ,344,000,000 July December ,399,000,000 January June ,454,000,000 July December ,509,000,000 January June ,564,000,000 July December ,619,000,000 January June ,674,000,000 July December ,729,000,

5 Figure 1: Natural Gas Production in the Pittsburgh Beaver-Valley Area Only small areas of Armstrong, Greene and Lawrence counties are included in the Pittsburgh- Beaver Valley PM2.5 nonattainment area. In addition, several townships in Allegheny County form a separate nonattainment area (Liberty-Clairton nonattainment area). Because of the uncertainty of exactly where wells may be located in the future, the Department has chosen to project emissions for all of these counties, but include emissions in the Maintenance Plan based on the percentage of area (not including water) in the nonattainment area compared to the total county area. This methodology is similar to the one that the Department has used to estimate other area sources for partial counties, although for commercial and residential sources, the estimates were based on proportionate population. Approximately 10 percent, 3 percent and 3 percent of the land area in Armstrong, Greene and Lawrence counties, respectively, is in the nonattainment area. Approximately 2 percent of the land area in Allegheny County is in the Liberty-Clairton nonattainment area. 3 These calculations have been performed only after projections were made for full counties; therefore, only Tables 5 and 6, as well as Tables show emission projections for the Pittsburgh-Beaver Valley Nonattainment Area (partial counties only where appropriate) U.S. Census TIGER ARC GIS. Includes land area only (not water)

6 Future Compressor Engine Activity The amount of compressor engine horsepower needed to pump natural gas through a pipeline is assumed to be closely proportional to the growth rate in natural gas production. The build-out of compressor horsepower may slightly lag in responding to natural gas production because when a well is completed a compressor engine may not be needed at first to transport the gas to the main pipeline because ample pressure is available at the wellhead. The effect that the lag in the buildout of compressor engines has over estimating emissions diminishes as more natural gas wells are producing. Eventually, the effect that the lag has on emission estimates vanishes for each well. DEP used the 2013 Marcellus Shale Inventory submitted to DEP by natural gas producers for compression engines. For other sources of emissions from natural gas production, the DEP used the 2012 Marcellus Shale Inventory because 2013 emissions were not available. Therefore, growth in emissions were estimated using two sets of growth factors. Growth factors used to grow inventory emissions were developed from either a base year of 2012 or In order to estimate the growth rate in natural gas production in the nonattainment counties, the amount of projected annual natural gas production in 2017 and 2025 was divided by the actual annual natural gas produced in 2012 or 2013 to obtain the growth that will occur in production between the end of 2012 or 2013 and the end of 2017 and Growth ate in roduction ( all counties) rojected Actual annual gas production annual gas production 1,643,000,000 Mcf 466,591,086 Mcf = 3.52 multiple or 252 percent increase Growth ate in roduction ( all counties) rojected Actual annual gas production annual gas production 3,403,000,000 Mcf 466,591,086 Mcf = 7.29 multiple or 629 percent increase Growth ate in roduction ( 3 all counties) rojected Actual annual gas production 3 annual gas production 1,643,000,000 Mcf 733,538,365 Mcf = 2.24 multiple or 124 percent increase - 6 -

7 Growth ate in roduction ( 3 ndiana Cam ria) rojected Actual annual gas production 3 annual gas production 3,403,000,000 Mcf 733,538,365 Mcf = 4.64 multiple or 364 percent increase Tables 5 and 6 summarize compressor engine emissions for the Pittsburgh-Beaver Valley Nonattainment Area. Table 5: 2017 Projected Compressor Engine Emissions County NO X Emission VOC Emissions PM 2.5 Emissions SO X Emissions Allegheny Armstrong Beaver Butler Greene Lawrence Washington 2, Westmoreland Area Emissions 3, , Table 6: 2025 Projected Compressor Engine Emissions County NO X Emission VOC Emissions PM 2.5 Emissions SO X Emissions Allegheny Armstrong Beaver Butler Greene 1, Lawrence Washington 4, , Westmoreland Area Emissions 7, , Other Equipment Emissions Other equipment at the wells include dehydrators, reboilers, and line heaters. Emissions from sources such as component leaks, storage tanks, and truck load-outs were also included

8 Well Drilling The number of wells drilled in the Pittsburgh-Beaver Area counties has varied from year to year. The Department used the number of wells drilled in 2012 to project emissions. Because drilling rates are estimated to be constant, the emissions associated with drilling are also constant. That is, emissions shown as reported will also be those projected to 2017 and Beginning January 1, 2015, federal regulations (40 CFR, Part 60, Subpart OOOO ) require that each well completion operation with hydraulic fracturing begun prior to January 1, 2015, or each new well completion operation with hydraulic fracturing begun on or after January 1, 2015, must use Reduced Emission Completion or Green Completion requirements. Green completion essentially requires natural gas companies to capture the gas at the well head immediately after well completion instead of releasing it into the atmosphere or flaring it off. This will significantly reduce well completion emissions. EPA estimates that VOC emissions from hydraulically fractured wells would decrease by 95 percent as a result of this regulation. Table 12: Projected 2017 and 2025 NO X Emissions Due to Marcellus Shale Drilling Activity in the Pittsburgh-Beaver Valley Area County SCC SCC Description Data Source Allegheny Prod / All / 2012 Inventory Allegheny Inventory Allegheny Inventory Allegheny Allegheny Inventory Allegheny Armstrong Prod / All / 2012 Inventory Armstrong Inventory

9 County SCC SCC Description Data Source Armstrong Inventory Armstrong Armstrong Inventory Armstrong Beaver Prod / All / 2012 Inventory Beaver Inventory Beaver Inventory Beaver Beaver Inventory Beaver Butler Prod / All / 2012 Inventory Butler Inventory Butler Inventory Butler Prod / Gas Well 2012 Inventory

10 County SCC SCC Description Data Source Butler Inventory Butler Greene Prod / All / 2012 Inventory Greene Inventory , Greene Inventory Greene Greene Inventory Greene Lawrence Prod / All / 2012 Inventory Lawrence Inventory Lawrence Inventory Lawrence Prod / Gas Well 2012 Inventory Lawrence Inventory Lawrence Prod / Fugitives: All 2012 Inventory

11 County SCC SCC Description Data Source Washington Prod / All / 2012 Inventory Washington Inventory 2, , Washington Inventory Washington Washington Inventory Washington Prod / Fugitives: All 2012 Inventory Westmoreland Prod / All / 2012 Inventory Westmoreland Inventory Westmoreland Inventory Westmoreland Westmoreland Inventory Westmoreland Prod / Fugitives: All 2012 Inventory

12 Table 13: Projected 2017 and 2025 VOC Emissions Due to Marcellus Shale Drilling Activity in the Pittsburgh-Beaver Valley Area County SCC SCC Description Data Source Allegheny Prod / All / 2013 Inventory Allegheny Inventory Allegheny Inventory Allegheny Production/Gas Well 2012 Inventory Pneumatic Pumps Allegheny Allegheny Inventory Allegheny Prod / Fugitives: All 2012 Inventory Armstrong Prod / All / 2012 Inventory Armstrong Inventory Armstrong Inventory Armstrong Production/Gas Well 2012 Inventory Pneumatic Pumps Armstrong Prod / Gas Well 2012 Inventory Armstrong Inventory

13 County SCC SCC Description Data Source Armstrong Prod / Fugitives: All 2012 Inventory Beaver Prod / All / 2012 Inventory Beaver Inventory Beaver Inventory Beaver Production/Gas Well 2012 Inventory Pneumatic Pumps Beaver Beaver Inventory Beaver Prod / Fugitives: All 2012 Inventory Butler Prod / All / 2012 Inventory Butler Inventory Butler Inventory Butler Production/Gas Well 2012 Inventory 1, , Pneumatic Pumps Butler Butler Inventory Butler Prod / Fugitives: All 2012 Inventory ,

14 County SCC SCC Description Data Source Greene Prod / All / 2012 Inventory Greene Inventory Greene Inventory Greene Production/Gas Well 2012 Inventory Pneumatic Pumps Greene Prod / Gas Well 2012 Inventory Greene Inventory Greene Prod / Fugitives: All 2012 Inventory Lawrence Prod / All / 2012 Inventory Lawrence Inventory Lawrence Inventory Lawrence Production/Gas Well 2012 Inventory Pneumatic Pumps Lawrence Lawrence Inventory Lawrence Prod / Fugitives: All 2012 Inventory Washington Prod / All / 2012 Inventory

15 County SCC SCC Description Data Source Washington Inventory , Washington Inventory Washington Production/Gas Well 2012 Inventory Pneumatic Pumps Washington Prod / Gas Well 2012 Inventory Washington Inventory Washington Prod / Fugitives: All 2012 Inventory Westmoreland Prod / All / 2012 Inventory Westmoreland Inventory Westmoreland Inventory Westmoreland Production/Gas Well 2012 Inventory Pneumatic Pumps Westmoreland Prod / Gas Well 2012 Inventory Westmoreland Inventory Westmoreland Prod / Fugitives: All 2012 Inventory

16 Table 14: Projected 2017 and 2025 PM 2.5 /PM 10 Emissions Due to Marcellus Shale Drilling Activity in the Pittsburgh-Beaver Valley Area County SCC SCC Description Data Source Allegheny Prod / All / 2012 Inventory Allegheny Inventory Allegheny Inventory Allegheny Allegheny Inventory Allegheny Armstrong Prod / All / 2012 Inventory 7.00 Armstrong Inventory Armstrong Inventory Armstrong Armstrong Inventory Armstrong Beaver Prod / All / 2012 Inventory

17 County SCC SCC Description Data Source Beaver Inventory Beaver Inventory Beaver Beaver Inventory Beaver Butler Prod / All / 2012 Inventory Butler Inventory Butler Inventory Butler Butler Inventory Butler Greene Prod / All / 2012 Inventory Greene Inventory Greene Inventory

18 County SCC SCC Description Data Source Greene Greene Inventory Greene Lawrence Prod / All / 2012 Inventory Lawrence Inventory Lawrence Inventory Lawrence Lawrence Inventory Lawrence Washington Prod / All / 2012 Inventory Washington Inventory Washington Inventory Washington Washington Inventory Washington Prod / Fugitives: All 2012 Inventory

19 County SCC SCC Description Data Source Westmoreland Prod / All / 2012 Inventory Westmoreland Inventory Westmoreland Inventory Westmoreland Westmoreland Inventory Westmoreland Prod / Fugitives: All 2012 Inventory Table 15: Projected 2017 and 2025 SO X Emissions Due to Marcellus Shale Drilling Activity in the Pittsburgh-Beaver Valley Area County SCC SCC Description Data Source Allegheny Prod / All / 2012 Inventory Allegheny Inventory Allegheny Inventory Allegheny Allegheny Inventory Allegheny Armstrong Prod / All / 2012 Inventory

20 County SCC SCC Description Data Source Armstrong Inventory Armstrong Inventory Armstrong Armstrong Inventory Armstrong Beaver Prod / All / 2012 Inventory Beaver Inventory Beaver Inventory Beaver Beaver Inventory Beaver Butler Prod / All / 2012 Inventory Butler Inventory Butler Inventory

21 County SCC SCC Description Data Source Butler Butler Inventory Butler Prod / Fugitives: All 2012 Inventory Greene Prod / All / 2012 Inventory Greene Inventory Inventory Greene Greene Greene Inventory Greene Lawrence Prod / All / 2012 Inventory Lawrence Inventory Lawrence Inventory Lawrence Prod / Gas Well 2012 Inventory Lawrence Inventory Lawrence Prod / Fugitives: All Inventory

22 County SCC SCC Description Data Source Washington Prod / All / Inventory Washington Inventory Washington Inventory Washington Washington Inventory Washington Prod / Fugitives: All 2012 Inventory Westmoreland Prod / All / 2012 Inventory Westmoreland Inventory Westmoreland Inventory Westmoreland Westmoreland Inventory Westmoreland Prod / Fugitives: All 2012 Inventory Summary For the partial counties included in the Pittsburgh-Beaver Valley Area, the maintenance plan includes emissions projected for 2017 and 2025 based on the proportion of land area in the nonattainment jurisdictions compared to the entire county. Tables show the emissions in the Pittsburgh-Beaver Valley Nonattainment Area after these percentages have been considered

23 The unconventional natural gas development emissions shown in Tables have been added to the area source inventories in the Maintenance Plan. Table 16: NO X Emissions Related to Unconventional Natural Gas Activity in the Pittsburgh-Beaver Valley Area (tons per year) SCC SCC Description 2007 NO X 2017 NO X 2025 NO X Prod / All / , , Gas , , Compressor Production / Gas Well Production/Gas Well Pneumatic Pumps Prod / Gas Well Production / Gas Well Prod / Fugitives: All Totals , , Table 17: VOC Emissions Related to Unconventional Natural Gas Activity in the Pittsburgh-Beaver Valley Area (tons per year) SCC SCC Description Prod / All / Gas , , Compressor Production / Gas Well Production/Gas Well Pneumatic Pumps , , Prod / Gas Well Production / Gas Well Prod / Fugitives: All , , Totals , ,

24 Table 18: PM 2.5 Emissions Related to Unconventional Natural Gas Activity in the Pittsburgh-Beaver Valley Area (tons per year) SCC SCC Description Prod / All / Gas Compressor Production / Gas Well Production/Gas Well Pneumatic Pumps Prod / Gas Well Production / Gas Well Prod / Fugitives: All Totals Table 19: SO X Emissions Related to Unconventional Natural Gas Activity in the Pittsburgh-Beaver Valley Area (tons per year) SCC SCC Description Prod / All / Gas Compressor Production / Gas Well Production/Gas Well Pneumatic Pumps Prod / Gas Well Production / Gas Well Prod / Fugitives: All Totals