GEOLOGY, RESOURCES, AND POTENTIAL ACTIVITY LEVELS

Transcription

1 GEOLOGY, RESOURCES, AND POTENTIAL ACTIVITY LEVELS NAS Workshop on the Development of Unconventional Hydrocarbon Resources in the Appalachian Basin Ray Boswell, US DOE/NETL Morgantown, West Virginia September 9-10, 2013 the ENERGY lab

2 Overview of Presentation Unconventional Resources Regional Geology of Appalachian Unconventional Petroleum Systems Review of Resources Terminology Recent Estimates Reserves Resources Production Future Activity Public data Needs Marcellus Shale Outcrop, Central Pennsylvania Obtained from www. gomarcellusshale.com

3 Unconventional Resources Regional, pervasive; require stimulation to obtain commercial production Continuous, basin-centered, ( tight ) gas sands Thick sand-silt sequences Free Gas in pores & fractures Limited permeability Shale Various lithologies Adsorbed Gas on organic matter and Free Gas in pores & fractures Nearly impermeable Coal-bed Methane Modified from Schenk and Pollastro (2002)

4 Paleozoic Appalachian Foreland Basin Creation of Petroleum Systems Loading on margin creates subsidence/sedimentation there, uplift on the western margin Image obtained from Central basin can become anoxic over large regions Anoxia organic matter survives to burial With time world-class source rocks expel a % of HC to the overriding sand-rich reservoirs retain a % of HC within the shale matrix Middle Devonian Paleogeography

5 Paleozoic Petroleum Systems (PS) North-central Appalachian Basin: 5 primary unconventional plays The Appalachian Basin is OLD Very Large Numerous tectonic events in the Paleozoic Late Silurian Utica- Martinsburg PS 1. Utica-Point Pleasant Shale 2. Clinton -Medina (basincentered sands) Middle-Upper Devonian Marcellus-Ohio PS 3. Ohio Shale 4. Marcellus Shale 5. U. Devonian Catskill (basin-centered sands-silts) From A. Donaldson/R. Shumaker

6 Utica Point Pleasant Petroleum System NY OIL WET GAS DRY GAS OVERMATURE IMMATURE OH PA KY WV From Ohio Department of Natural Resources

7 1. Utica-Point Pleasant Play From Ohio Department of Natural Resources CLAYS CALCITE QUARTZ Point Pleasant has high calcite low Clay: Interbedded bioclastic zones of enhanced permeability Data and images from Wickstrom, Perry, Riley and Erenpreiss, 2012 Utica is more clay and quartz rich TOC average 2.8%; high 4.9%

8 2. Clinton-Medina-Tuscarora Basin-Centered Gas Play First Production in 1887 Shoreline to shallow-marine fine-grained sand reservoir 60,000 wells in Ohio 10,000 more in NY, PA Pre-1950s Flowed naturally or abandoned Up to 50% dry holes s 1950s: drilling/stimulation tech. vertical wells: hydraulicallyfractured w/ sand proppant very few dry holes downdip limit defined by cost 2012: first horizontal well permit issued

9 M-U Devonian Ohio-Marcellus Shale Petroleum System WET GAS DRY GAS

10 3. Middle Devonian Marcellus Shale Play Central Area Thinner but more organic-rich More liquids prone Site of 2003/2004 Renz discovery well. West Virginia Geological Survey Northeastern Area Much thicker, but slightly less organic rich Dry gas Responds well to stimulation Limited clay content w/ high quartz and carbonates Fracture barriers locally ~5,000 wells thus far perhaps 5% of total potential Wang, 2012 Wang, 2012

11 4. Upper Devonian Ohio Shale Play Production began in earnest in the 1920s By 1930s: Big Sandy FIeld Huron Shale Mbr. 250,000 acres - among the largest US gas plays Through 1950s shooting with gelatinized nitroglycerin 1950s to 2000s 2000s Hydraulic fracturing w/ sand proppant 10,000 s gallons of water per well 15,000 wells.. 5 tcf gas Horizontal drilling in Huron w MHF Exploration for Burket and others in w. Pennsylvania From Range Resources Presentation Image from Harper, Penn. Geological Survey Courtesy Brandon Nuttall, Kentucky Geological Survey Cumulative U. Devonian Shale thickness (Burket, Middlesex, Rhinestreet)

12 5. Upper Dev./L. Miss. Silts and Sands Primarily tight, basin-centered gas systems Production began at the Drake well in 1859 After Harper, Pa Geological Survey Conventional reservoirs in most favorable settings Exploration now in lower quality sands and silts Potential for horizontal drilling and MHF (Eckert et al., 2013) Recent Berea horizontal drilling (186 wells) in E. KY. Courtesy Brandon Nuttall, Kentucky Geological Survey

13 Various definitions of Resources All the gas that exists: GAS-IN-PLACE (GIP) f(geology) All the gas that could be expected to be produced TECHNICALLY-RECOVERABLE (TRR) f(gip, tech., policy, reg.) f(demonstrated capability, well spacing) All the gas that should be produced ECONOMICALLY-RECOVERABLE (ERR) f(trr, market conditions) All the gas proven by drilling, available for economic production RESERVES Various categories f(data certainty)

14 Resources with Time Challenges of Assessing a Dynamic Entity PGC W. FISHER, 2006

15 Volumetrics Resource Assessment Methodology GIP = Area * H * Phi * S hc * FVF for cells; then summed ISSUE: Phi, H, S hc not readily determined from public data ISSUE: GIP is f(geology) only, but also of limited relevance Well-Performance TRR = EUR/well * Number of Remaining well locations Inherently assumes the extant technology/market situation ISSUE: EUR = f(geology, technology) AND technology = f(time). #wells = f(technology, regulation (spacing)) ISSUE: for emerging plays -- poor EUR data will analogues work? A combined approach can provide insight into recovery and impact of technology TRR: GIP x recovery factor Can use changing RF as a proxy for technology, experience

16 USGS 2002 Assessment Two Appalachian Basin Petroleum Systems

17 Recent USGS Assessments Marcellus (2011); Utica (2012)

18 EIA s Resource Estimates (AEO 2013) Utica PS = 900 MMbls, 52 tcfg: Devonian PS = 900 MMbls, 190 tcfg Utica-Martinsburg Petroleum System Marcellus-Ohio Petroleum System

19 Marcellus Shale Production Company Statements <10% of potential locations drilled to date ~4,000 5,000 laterals bcf/well Downspacing 80 to 100 ac spacing State and Federal Reports PA: 23.5 tcf ; WV 6 tcf reserves added since 2007 Continues to out-perform predictions Drilling declining but production accelerating Infrastructure constraints easing Exceeding 8 bcf/d? (~3 tcf/y) Note: too early to tell in the Utica Predictions Resource to sustain production through Wells: ~1,500+/yr for next 40 years+? EIA: ~90,000 available Marcellus well locations (but using ~120-ac. Spacing) Similar drilling intensity potential for Utica plus the other three plays U. Texas- Austin: BEG MARCELLUS SHALE Medlock et al. Courtesy (2010) Courtesy Baker Gas Gas Institute Daily Daily at 9/3/2013) Rice 9/3/13 U.

20 Summary Science Needs Related to Resources Reasonable Expectations of Activity How many wells & when & where & what type? Prudent Development Minimize impacts while maximizing the benefits Science: understand subsurface processes Matching technology to variable geology production from fewer wells less water-intensive stimulation less gas left behind Public data not readily applicable to shale resource issues Most plays are very early in their lifetimes All shales are different Logs alone don t reveal the basic res props Need detailed production and development data

21 Thank You