Fracturing wells and land cover in California

By Andrew Donakowski, Northeastern Illinois University

Land cover data can play an important role in spatial analysis; satellite or aerial imagery can effectively demonstrate the extent and make-up of land cover characteristics for large areas of land. For fracking analysis, this can be used to explore important spatial relationships between fracking infrastructure and the area and/or ecosystems surrounding them. Working with FracTracker, I have compiled data concerning land cover classifications and geologic rock areas to examine areas that may be particularly vulnerable to unconventional drilling – e.g. fracking.  After computing the makeup of land cover type for each geologic area, I then mapped locations of known fracking wells for further analysis. This is part of FracTracker’s ongoing interest in understanding changes in ecosystem services and plant/soil productivity associated with well pads, pipelines, retention ponds, etc.

Developed

First, by looking at the Developed areas (below), we can see that, for the most part, hydraulic fracturing is occurring relatively far from large population areas. (That is to say, on this map we can see that these types of wells are not found as often in areas where population density is high (<20 people per square mile) or a Developed land cover classification is predominate as they are in areas with a lower Develop land cover percentage).  However, we can also see that there is quite a large cluster of fracking wells in the southern portion of the state, and many cities fall within 5 or 10 mi of some wells.  While there may not be an immediate danger to cities that fall within this radius, we can see that some areas of the state may be more likely to encounter the effects of fracking and its associated infrastructure than others.

Forested

Next, the map depicting Forested land cover areas is, in my opinion, the most aesthetically groovy of the land cover maps; the variations in forested areas throughout the state provide a cool image.  By looking at this data, we can see that much of California’s forested land lies in the northern part of the state, while most fracking wells are located in the south and central parts of the state.

Cultivated

To me, the most interesting map is the one below showing the location of fracking wells in relation to Cultivated lands (which includes pasture areas and cropland).  What is interesting to note is the fertile Central Valley, where a high percentage of land is covered with agriculture and pasture lands (Note: The Central Valley accounts for 1% of US farmland but 25% of all production by value).  Notably, it is also where many fracking wells are concentrated.  When one stops to think about this, it makes sense: Farmers and rural landowners are often approached with proposals to allow drilling and other non-farming activities on their land.  Yet, it also raises a potential area for concern: A lot of crops grown in this area are shipped across the country to feed a significant number of people.  When we consider the uncertainties of fracking on surrounding areas, we must also consider what effects fracking could have beyond the immediate area and think about how fracking could affect what is produced in that area (in this case, it is something as important as our food supply.)

The Usefulness of Maps

Finally, as previously mentioned, mapping the extent of these land coverage can be useful for future analysis.  Knowing now the areas of relatively large concentrations of forested, herbaceous, and wetland (which can be highly sensitive to ecological intrusions) areas can be good to know down the line to see if those areas are retreating or if the overall coverage is diminishing.  Additionally, by allowing individuals to visualize spatial relationships between fracking areas and land coverage, we can make connections and begin to more closely examine areas that may be problematic. The next step will be: a) parsing forest cover into as many of the six major North American forest types and hopefully stand age, b) wetland type, and c) crop and/or pasture species. All of this will allow us to better quantify the inherent ecosystem services and CO2 capture/storage potential at risk in California and elsewhere with the expansion of the fracking industry. As an example of the importance of the intersection between forest cover and the fracking industry we recently conducted an analysis of frac sand mining polygons in Western Wisconsin and found that 45.8% of Trempealeau County acreage is in agriculture while only 1.8% of producing frac sand mine polygons were in agriculture prior to mining with the remaining acreage forested prior to mining which buttresses our anecdotal evidence that the frac sand mining industry is picking off forested bluffs and slopes throughout the northern extent of the St. Peter Sandstone formation.

A Quick Note on the Data

Datasets for this project were obtained from a few different sources.  First, land cover data were downloaded from the National Land cover Classification Database (NLCD) from the Multi-Resolution Land Character Consortium.  Geologic data were taken from the United States Geologic Survey (USGS) and their Mineral Resources On-Line Spatial Data. Lastly, locations of fracking wells were taken from the FracTracker data portal, which, in turn, were taken from SkyTruth’s database.  Once the datasets were obtained, values from the NLCD data were reclassified to highlight land-coverage types-of-interest using the Raster Calculator tool in ArcMap 10.2.1.  Then, shapefiles from the USGS were overlaid on top of the reclassified raster image, and ArcMaps’s Tabulate Area tool was used to determine the extent of land coverage within each geologic rock classification area.  Known fracking wells downloaded from FracTracker.org were added to the map for comparative analysis.

About the Author

Andrew Donakowski is currently studying Geography & Environmental Studies, with a focus on Geographic Information Systems (GIS), at Northeastern Illinois University (NEIU) in Chicago, Ill. These maps were created in conjunction with FracTracker’s Ted Auch and NEIU’s Caleb Gallemore as part of a service-learning project conducted during the spring of 2014 aimed at addressing real-world issues beyond the classroom.

Conventional, Non-Vertical Wells in PA

Like most states, the data from the Pennsylvania Department of Environmental Protection do not explicitly tell you which wells have been hydraulically fractured. They do, however, designate some wells as unconventional, a definition based largely on the depth of the target formation:

An unconventional gas well is a well that is drilled into an Unconventional formation, which is defined as a geologic shale formation below the base of the Elk Sandstone or its geologic equivalent where natural gas generally cannot be produced except by horizontal or vertical well bores stimulated by hydraulic fracturing.


Naturally occurring karst in Cumberland County, PA. Photo by Randy Conger, via USGS.

While Pennsylvania has been producing oil and gas since before the Civil War, the arrival of unconventional techniques has brought greater media scrutiny, and at length, tougher regulations for Marcellus Shale and other deep wells. We know, however, that some companies are increasingly looking at using the combination of horizontal drilling and hydraulic fracturing in much shallower formations, which could be of greater concern to those reliant upon well water than wells drilled into deeper unconventional formations, such as the Marcellus Shale. The chance of methane or fluid migration through karst or other natural fissures in the underground rock formations increase as the distance between the hydraulic fracturing activity and groundwater sources decrease, but the new standards for unconventional wells in the state don’t apply.

The following chart summarizes data for wells through May 16, 2014 that are not drilled vertically, but that are considered to be conventional, based on depth:

These wells are listed as conventional, but are not drilled vertically.

These wells are listed as conventional, but are not drilled vertically.

Note that there have already been more horizontal wells in this group drilled in 2014 than any previous year, showing that the trend is increasing sharply.

Of the 26 horizontal wells, 12 are considered oil wells, five are gas wells, five are storage wells, three are combination oil and gas, and one is an injection well.  These 177 wells have been issued a total of 97 violations, which is a violation per well ratio of 62 percent.  429 permits in have been issued in Pennsylvania to date for non-vertical wells classified as conventional.  Greene county has the largest number of horizontal conventional wells, with eight, followed by Bradford (5) and Butler (4) counties.

We can also take a look at this data in a map view:


Conventional, non-vertical wells in Pennsylvania. Please click the expanding arrows icon at the top-right corner to access the legend and other map controls.  Please zoom in to access data for each location.

Well Worker Safety and Statistics

By Samantha Malone, MPH, CPH – Manager of Science and Communications, FracTracker Alliance

The population most at risk from accidents and incidents near unconventional drilling operations are the drillers and contractors within the industry. While that statement may seem quite obvious, let’s explore some of the numbers behind how often these workers are in harm’s way and why.

O&G Risks

Oil and Gas Worker Fatalities over Time

Fig. 1. Number of oil and gas worker fatalities over time
Data Source: U.S. Bureau of Labor Statistics, U.S. Department of Labor, 2014

Drilling operations, whether conventional or unconventional (aka fracking), run 24 hours a day, 7 days a week. Workers may be on site for several hours or even days at a time. Simply the amount of time spent on the job inherently increases one’s chances of health and safety concerns. Working in the extraction field is traditionally risky business. In 2012, mining, quarrying, and oil and gas extraction jobs experienced an overall 15.9 deaths for every 100,000 workers, the second highest rate among American businesses. (Only Agriculture, forestry, fishing and hunting jobs had a higher rate.)

According to the Quarterly Census of Employment and Wages of the U.S. Bureau of Labor Statistics, the oil and gas industry employed 188,003 workers in 2012 in the U.S., a jump from 120,328 in 2003. Preliminary data indicate that the upward employment trend continued in 2013. However, between 2003 and 2012, a total of 1,077 oil and gas extraction workers were killed on the job (Fig. 1).

Causes of Injuries and Fatalities in Oil and Gas Field

Reasons for O&G Fatalities 2003-12. Aggregated from Table 1.

Fig. 2. Reasons for O&G Fatalities 2003-12. Aggregated from Table 1.

Like many industrial operations, here are some of the reasons why oil and gas workers may be hurt or killed according to OSHA:

  • Vehicle Accidents
  • Struck-By/ Caught-In/ Caught-Between Equipment
  • Explosions and Fires
  • Falls
  • Confined Spaces
  • Chemical Exposures

If you drill down to the raw fatality-cause numbers, you can see that the fatal worksite hazards vary over time and job type1 (Table 1, bottom). Supporting jobs to the O&G sector are at higher risk of fatal injuries than those within the O&G extraction job category2. The chart to the right shows aggregate data for years 2003-12. Records indicate that the primary risk of death originated from transportation incidents, followed by situations where someone came into contact with physical equipment (Fig. 2).

Silica Research

Silica-Exposed Workers

Fig. 3. Number of total silica-exposed workers and those exposed above PEL – compared across industries
Source: OSHA Directorate of Standards and Guidance

A recent NIOSH study by Esswein et al. regarding workplace safety for oil and gas workers was that the methods being employed to protect workers against respirable crystalline silica3 were not adequate. This form of silica can be found in the sand used for hydraulic fracturing operations and presents health concerns such as silicosis if inhaled over time. According to Esswein’s research, workers were being exposed to levels above the permissible exposure limit (PEL) of ~0.1 mg/m3 for pure quartz silica because of insufficient respirator use and inadequate technology controls on site. It is unclear at this time how far the dust may migrate from the well pad or sand mining site, a concern for nearby residents of the sand mines, distribution methods, and well pads. (Check out our photos of a recent frac sand mine tour.) The oil and gas industry is not the only employer that must protect people from this airborne workplace hazard. Several other classes of jobs result in exposure to silica dust above the PEL (Fig. 3).

References and Additional Resources

1. What do the job categories in the table below mean?

For the Bureau of Labor Statistics, it is important for jobs to be classified into groups to allow for better reporting/tracking. The jobs and associated numbers are assigned according to the North American Industry Classification System (NAICS).

(NAICS 21111) Oil and Gas Extraction comprises establishments primarily engaged in operating and/or developing oil and gas field properties and establishments primarily engaged in recovering liquid hydrocarbons from oil and gas field gases. Such activities may include exploration for crude petroleum and natural gas; drilling, completing, and equipping wells; operation of separators, emulsion breakers, desilting equipment, and field gathering lines for crude petroleum and natural gas; and all other activities in the preparation of oil and gas up to the point of shipment from the producing property. This industry includes the production of crude petroleum, the mining and extraction of oil from oil shale and oil sands, the production of natural gas, sulfur recovery from natural gas, and the recovery of hydrocarbon liquids from oil and gas field gases. Establishments in this industry operate oil and gas wells on their own account or for others on a contract or fee basis. Learn more

(NAICS 213111) Drilling Oil and Gas Wells comprises establishments primarily engaged in drilling oil and gas wells for others on a contract or fee basis. This industry includes contractors that specialize in spudding in, drilling in, redrilling, and directional drilling. Learn more

(NAICS 213112) Support Activities for Oil and Gas Operations comprises establishments primarily engaged in performing support activities on a contract or fee basis for oil and gas operations (except site preparation and related construction activities). Services included are exploration (except geophysical surveying and mapping); excavating slush pits and cellars, well surveying; running, cutting, and pulling casings, tubes, and rods; cementing wells, shooting wells; perforating well casings; acidizing and chemically treating wells; and cleaning out, bailing, and swabbing wells. Learn more

2. Fifteen percent of all fatal work injuries in 2012 involved contractors. Source

3. What is respirable crystalline silica?

Respirable crystalline silica – very small particles at least 100 times smaller than ordinary sand you might encounter on beaches and playgrounds – is created during work operations involving stone, rock, concrete, brick, block, mortar, and industrial sand. Exposures to respirable crystalline silica can occur when cutting, sawing, grinding, drilling, and crushing these materials. These exposures are common in brick, concrete, and pottery manufacturing operations, as well as during operations using industrial sand products, such as in foundries, sand blasting, and hydraulic fracturing (fracking) operations in the oil and gas industry.

4. OSHA Fact Sheet: OSHA’s Proposed Crystalline Silica Rule: General Industry and Maritime. Learn more

Employee health and safety are protected under the following OSHA regulations. These standards require employers to make sure that the workplace is in due order:

Table 1. 2003-2012 U.S. fatalities in oil & gas industries by year, job category, & event/exposure
Year Oil and Gas (O&G) Industriesa Total Fatal Injuries (number)b Event or Exposurec
Violence / injuries by persons / animalsd Transportatione Fires & Explosions Falls, Slips, Trips Exposure to Harmful Substances or Environments Contact w/Objects & Equipment
2012
O&G Extraction 26 0 8 6 5 3 4
Drilling O&G Wells 39 0 10 6 8 3 10
Support Activities 77 0 46 11 5 3 10
Yearly Totals 142 0 64 23 18 9 24
2011
O&G Extraction 13 0 7 0 0 0 3
Drilling O&G Wells 41 0 15 5 4 5 12
Support Activities 58 3 29 7 4 4 11
Yearly Totals 112 3 51 12 8 9 26
2010
O&G Extraction 12 0 5 3 0 3 0
Drilling O&G Wells 47 0 8 14 7 6 12
Support Activities 48 3 28 8 0 0 8
Yearly Totals 107 3 41 25 7 9 20
2009
O&G Extraction 12 0 6 0 0 0 3
Drilling O&G Wells 29 0 9 0 0 4 13
Support Activities 27 0 12 5 0 4 5
Yearly Totals 68 0 27 5 0 8 21
2008
O&G Extraction 21 0 7 4 0 0 5
Drilling O&G Wells 30 0 6 3 4 4 13
Support Activities 69 0 36 11 4 6 12
Yearly Totals 120 0 49 18 8 10 30
2007
O&G Extraction 15 0 5 0 0 0 5
Drilling O&G Wells 42 0 12 0 4 8 16
Support Activities 65 0 33 6 0 5 19
Yearly Totals 122 0 50 6 4 13 40
2006
O&G Extraction 22 0 6 7 0 3 4
Drilling O&G Wells 36 0 11 0 5 4 14
Support Activities 67 0 2 12 0 5 21
Yearly Totals 125 0 19 19 5 12 39
2005
O&G Extraction 17 0 4 5 0 0 4
Drilling O&G Wells 34 0 9 0 7 4 10
Support Activities 47 0 21 5 0 5 13
Yearly Totals 98 0 34 10 7 9 27
2004
O&G Extraction 29 0 17 0 0 0 8
Drilling O&G Wells 30 0 6 0 6 3 11
Support Activities 39 0 22 5 0 0 10
Yearly Totals 98 0 45 5 6 3 29
2003
O&G Extraction 17 0 9 4 0 0 3
Drilling O&G Wells 26 0 5 5 0 0 13
Support Activities 42 0 17 10 0 3 10
Yearly Totals 85 0 31 19 0 3 26
2003-12 TOTAL FATALITIES 1077 6 411 142 63 85 282
a Oil and gas extraction industries include oil and gas extraction (NAICS 21111), drilling oil and gas wells (NAICS 213111), and support activities for oil and gas operations (NAICS 213112).
b Data in event or exposure categories do not always add up to total fatalities due to data gaps.
c Based on the BLS Occupational Injury and Illness Classification System (OIICS) 2.01 implemented for 2011 data forward
d Includes violence by persons, self-inflicted injury, and attacks by animals
e Includes highway, non-highway, air, water, rail fatal occupational injuries, and fatal occupational injuries resulting from being struck by a vehicle.

Utica Shale Drill Cuttings Production – Back of the Envelope Recipe

By Ted Auch, OH Program Coordinator, FracTracker Alliance

Ohio is the only shale gas state in the Marcellus and/or Utica Shale Basin that has decided to go “all in.” i.e. The state is moving forward with shale gas production, Class II Injection Well disposal of brine waste from fracking, and more recently the processing and disposal of drill cuttings/muds via the state’s Solid Waste Disposal (SWD) districts and waste landfills. The latter would fall under the joint ODNR, ODH, and EPA’s September 18, 2012  Solidification and Disposal Activities Associated with Drilling-Related Wastes advisory. It occurred to us that it might be time to try to estimate how much of these materials are produced here in Ohio on a per-well basis using basic math, data gleaned from Ohio’s current inventory of Utica wells and the current inventory of PLAT maps, and some broad assumptions as to the density of Ohio’s geology.

Developing the Estimate

1) Start with a 341 Actual Utica well lateral dataset generated utilizing the ODNR Ohio Oil & Gas Well Database PLAT inventory or the current inventory of 1,137 permitted Utica wells. Generate a Straight Line lateral dataset by converting this data from “XY To Line” with the following summary statistics:

Variable

Actual

Straight Line

#

341

1,137

Minimum

186

50

Maximum

20,295

12,109

Sum

2,196,856

7,190,889

Mean

6,442 ±1,480

6,386 ±1,489

Median

6,428

6,096

2) Average Vertical Depth for 109 Utica wells utilizing data from the ODNR RBDMS Microsoft Access database = 6,819 feet (207,843 centimeters)

Average Lateral + Vertical Footage = 13,205-13,261 total feet (402,488-404,195 centimeters) (Figure 1)

Ohio Utica Shale Actual Vs Straight Line Lateral Lengths

Fig. 1. An example of Actual and Straight Line Utica well laterals in Southeast Carroll County, Ohio

3) We assume a rough diameter of 8″ down to 5″ (20-13 centimeters) for all of 1) and 14″ to 8″ (36-20 centimeters) for the entirety of 2)

4) The density of 1) is roughly 2.61 g cm3 assuming the average of seven regional shale formations (Manger, 1963)

5) None of the materials being drilled through are igneous or metamorphic (limestone, siltstone, sandstone, and coal) thus the density of 2) is all going to be
≈2.75 g cm3

6) The volume of the above is calculated assuming the volume of a cylinder
(i.e., V = hπr2):

    1. Σ of Actual Lateral Length 49,205,721 cm3 * 2.61 g = 128,180,904 g
    2. Σ of Actual Lateral Length 153,991,464 cm3 * 2.75 g = 423,476,526 g

Average Lateral + Vertical Volume = 551,657,430 grams = 1,216,195 pounds =
608 tons of drill cuttings per Utica well * 829 drilled, drilling, or producing wells = 504,113 million tons

To put these numbers into perspective, the average Ohio household of 2.46 people generates about 3,933 pounds of waste per year or 1.78 metric tons.

7) Caveats include:

    • The coarse assumptions as to density of materials and the fact that these materials experience significant increases in surface area once they have been drilled through.
    • The assumptions as to pipe diameter could be over or underestimating drill cuttings due to the fact that we know laterals taper as they near their endpoint. We assume 45% of the vertical depth is comprised of 14″ diameter pipe, 40% 11″ diameter pipe, and 15% 8″ pipe. Similarly we assume the same percentage distribution for 8″, 6.5″, and 5″ lateral pipe.

Ohio Drilling Mud Generation and Processing

Caroll-Columbiana-Harrison Ohio Solid Waste District Drilling Muds Processed (January, 2011-April, 2014)

Fig. 2. Month-to-month and cumulative drilling muds processed by CCHSWD, one of six OH SWDs charged with processing shale gas drilling waste from OH, WV, and PA.

Ohio’s primary SWDs responsible for handling the above waste streams – from in state as well as from Pennsylvania and West Virginia – are the six southeastern SWDs along with the counties of Portage and Mahoning according to several anonymous sources. However, when attempting to acquire numbers that speak to the flows/stocks of fracking related SWD waste (i.e., drilling muds) the only district that keeps track of this data is the Carroll-Columbiana-Harrison Solid Waste District (CCHSWD). The CCHSWD’s Director of Administration was generous enough to provide us with this data. According to a month-over-month analysis they have processed 636,450 tons generating a fixed fee of $3.5 per ton or $2.23 million to date (Figure 2). This trend translates into a 1,046-1,571 ton monthly increase depending on how you fit your trend line to the data (i.e., linear Vs power functions) or put another way annual drilling mud increases of 12,546-18,847 tons.

 

Unpaid Interns Sought for Fall 2014

Intern ButtonThere is always more work to do than FracTracker has staff. For the fall, we’re on the search for some unpaid interns to help out in the following offices:

  • Camp Hill, PA
  • Pittsburgh, PA
  • Wheeling, WV
  • Cleveland Heights, OH
  • Oakland, CA

FracTracker interns are current college or graduate students who aid in conducting research, gathering and analyzing data, writing articles, managing the website, and mapping geo-located data. These are unpaid positions, as our paid internships run February – August each year. Because the fall internships are unpaid, however, students can choose to seek receipt of academic credits through their academic institution. These position are not eligible for health benefits.

If interested, apply online today. Deadline: July 15, 2014.