Using Methane Conentrations in Streams to Investigate for Potential Leakage of Oil and Gas Wells in Pennsylvania > Investigating Chartiers Creek, PA for Potential Methane Sources

Investigating Chartiers Creek, PA for Potential Methane Sources

Susan L. Brantley, Jennifer Z. Williams, Seth Pelepko, Stew Beattie, Kyle Homman, and Andrew Nyblade
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Introduction

Students will use HydroClient to discover, view, and download methane data collected by the Shale Network. To further investigate the area, Students will use PA DEP Oil and Gas Mapping tool to locate nearby wells. Lastly, students will use screenshots from the Exploration and Development Web Information Network (EDWIN), to uncover potential methane sources from nearby wells.

Conceptual Outcomes

Students will be able to identify one potential source of methane
Students will learn critical thinking and data analysis skills Students will synthesize research to draw conclusions

Practical Outcomes

Students will learn how to use HydroClient and PA DEP Oil and Gas Mapping tool

Time Required

45 minutes

Computing/Data Inputs

-Methane Data from the Shale Network discovered using HydroClient

Computing/Data Outputs

None

Hardware/Software Required

Internet Browser

Instructions

To discover data in the area we will use HydroClient[1], a free web application for discovering, viewing, and downloading environmental data from multiple sources. To access HydroClient go to http://data.cuahsi.org/ by typing it exactly into the browser at the top of the screen. Before you get started working in HydroClient, please click on the Sign in with Googleat the top right of the screen as circled below. YOU MUST BE SIGNED IN THROUGH GMAIL. Signing with Google unlocks additional features in HydroClient that you will need to complete the step. When you log in, HydroClient will ask you whether it is ok to get your information from Google: please click on "Allow".

Procedure

  • Use the Enter a location search box at the top left of the screen to zoom to a geographic area. Type "Chartiers Creek Washington County, PA, United States" and use your cursor to click the option on the dropdown list as pointed out in the figure.

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The map will zoom to the location of interest as shown below (the area of the map may look different depending upon the size of the monitor). Notice the area of the map is shown at the bottom center of the map with a green "thumbs up" notifying you the area is small enough to search for data. For this particular example, the search needs to encompass a larger map area. The zoom buttons, pointed out in the next figure, allow you to adjust the map extent. The "+" sign allows you to zoom in and the "-" allows you to zoom out of the map.


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  • Click on the zoom out option (the negative sign) until you can view all of Canonsburg and Washington - an area of approximately about 3,000-6,000 square kilometers. (Alternately, use the roller on the mouse to scroll in or out.) Your map should look similar to the screenshot below but each monitor may look slightly different.


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Now you will define your search criteria in the right side tool bar to find all of the methane data from 6/1/2015 to 8/31/2015 in the area that your map is currently showing. The search will conduct automatically once the search criteria is defined.

  • Begin by clicking on the blue Select Date Range button and typing in "6/1/2015" to "8/31/2015" in the From and To boxes then click Save.

  • Do NOT Select Keyword(s),this will allow you to search for all keywords

  • Next, use the Select Data Service(s)button to pull up a list of all data sources. Use the Search box as shown below to type "Shale Network ."

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Click on the row to highlight the Shale Network data service as shown below.

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  • Click Close

After a few seconds several blue markers will pop up on the map as shown above. Each blue marker has a number that indicates how many data series exist for that location. The markers cluster dynamically; if you zoom in you will get more precise locations, while if you zoom out the locations will be more generalized.

  • To view a list of all the data series in the current map extent, click Filter Results... on the Search Bar at right.

A list of all of the data series that are displayed by the blue markers in the map above will appear.

  • Go to Selections at the top left and click Select All, this will highlight all rows as shown below.

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  • If you do not see the Select All option it is because you have not signed in with your Google account. Please sign in and complete the previous steps again.

  • Now that all rows are highlighted, click on Select Action and choose "Export # selections in combined file." All data series will download to your computer in one combined CSV file. You may see different messages at this point. You may observe a notification that says the task has started and "To complete the download, please click on the Exports button in the top right corner."

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  • The Exports tab provides information on the status of the download. Most downloads complete quickly BUT YOU MIGHT HAVE TO WAIT A BIT. When a download is complete, a pop up will appear as shown below.

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  • Click open. Then save it to your local desktop by clicking on FILE in the toolbar of Excel, SAVE AS, then choose Desktop, and save it as "Chartiers Data Values" on your local Desktop. You might be asked if you want to keep it in .csv format: click yes. Then open it up in Excel by clicking on it to begin analyzing the methane concentrations.

Questions (Write the answers on a separate sheet of paper or on this page.):

1. What is the range of methane screening values and units in the selected dataset? The methane concentrations are given in column E.

2. Vasko (2016) summarized methane concentrations in 119 sites in 4 watersheds from southwestern, central, and northeastern PA between 6/2015 and 11/2015 and concluded that streams with no known methane inputs ranged from 0.18 to 4.58 µg/L (mean = 1.47 µg/L). The limit of detection for measurements in Todd Sowers' laboratory at Penn State, where these measurements were made, is about 0.09 µg/L. How do these values in southwestern PA compare?

3. Where is the highest concentration? Record latitude and longitude for this site. This site will be the subject of our investigation.

Procedure:

We will now research nearby oil and gas well records using the PA Oil and Gas Mapping tool.

Read the disclaimer and click Continue.


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  • Display all well designations, types, and statuses by scrolling to the bottom of the left panel and clicking Select All(as shown above)or, if you want to show more refined results, click Select All and then unselect the check boxes next toORNDandPBNMunderWellStatus.BE SURE THAT BOTH CONVENTIONAL AND UNCONVENTIONAL WELLS ARE CLICKED. Click Submit Request.

Note: Conventional and unconventional wells are distinguished by their deepest producing stratigraphic interval. Wells drilled to produce below the Elk Sandstone are classified as unconventional. These wells typically are stimulated by hydraulic fracturing, have multilateral well bores (multiple horizontal well bores off a central vertical bore), or employ some other technique to expose more of the formation. While hydraulic fracturing is often associated with unconventional wells, this technology has been in use for over half a century at conventional well sites.

  • Now, we need to set our map display units to feet. Click the Set Display Unitsicon (shown below). Set the Map Display Unitsto "Feet", and click Set Display Units.

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We will now zoom to the screening sample location with the highest concentration, and then look in a circle of radius 4,500 feet around the location using the Buffer tool. Note that 2,500 feet is the regulatory distance for assumed liability for unconventional wells and also the recommended analysis radius distance in Section 78.89 related to gas migration response. However, in this case we suggest setting the buffer to 4,500 feet (1.5 km) to explore whether methane might be migrating further than the regulatory distance. A few instances in PA have reported methane migration as far as 2.5km (Llewellyn et al., 2015).

  • Scroll down on the left hand menu, and click Locate on Map,select Locate Latitude and Longitude, select Decimal Degrees, enter the sample coordinates in the popup box, and click Find to zoom to the screening sample location (shown below). You can find the latitude and longitude of the highest concentration by looking at the data file previously found in HydroClient. DO NOT CLICK THE CLOSE BUTTON. IF YOU LEAVE IT OPEN, YOU WILL HAVE AN EASIER TIME IN NEXT STEP.

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  • Next, click the Buffer icon, circled on the figure as the left circle. Note that you can create buffers around a point, line, or polygon. Because we are interested in the sample with the highest methane concentration, create a buffer (this just means to draw a region around something like a point) by selecting Point. Enter 4500 as the buffer distance and use the mouse to click the sample location on the map. Note that the flag marking your sample location disappears when you open the Buffer tool if you have closed the Locate on Map box. If you lose your flag, simply click Find again on the Locate Latitude and Longitude dialog box to replace the flag. To erase and redraw your buffer, you can use the Eraser icon, which is located directly to the right of the Buffertool (right circle on the figure).

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We show a 3500 foot buffer in the figure here: your buffer should be bigger since you chose 4500.

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Questions:

  1. Consider well density within the buffered area, and formulate some hypotheses based on density/proximity of unconventional/conventional or active/legacy wells. The red and blue dots are unconventional and conventional wells respectively.

Procedure:

Using well permit numbers, we will now select a few wells to "dig deeper" and retrieve well records and compliance records from the map viewer and Exploration and Development Web Information Network (EDWIN). EDWIN is currently not publicly available, so screenshots are provided for use.

  • Select the Identifytool as circled in the figure below. You can click on any well shown in the map viewer to see information regarding that well. For this exercise, we are interested in wells that lie within the buffer created previously. Use the Identify tool to identify a few well records. Consider well type, status, SPUD date (the date that well drilling commenced), and any documents retrievable by the "Click to display..." options.

  • Be sure to check out the William Boyce 089-1 well which is located just within the 4500 ft buffer. Note that the O and G Mapping tool says this well was permitted in 1987: however, it only has surface casing. When do you think this well was actually drilled? (Hint: Wells were not required to be permitted until 1956!)
  • Read through the completion report for the William Boyce well that was taken from the EDWIN site.

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Questions:

  1. Review documents for the wells identified above. Note the age, plug date (if applicable), well depth, cementing information, and other potentially important information. Do any of the records suggest potential issues with the wells? Be sure to look line by line in the report until you find the William Boyce 089-1 well. When was it drilled? When was it permitted? Why is this well possibly problematic?

  2. Do you think there are any problems in these stream sampling sites in Chartiers creek? Where would you suggest the Chartiers Creek Watershed Association (CCWA) should take samples for methane analysis? The Shale Network team is working with the CCWA to continue sampling.

[1] Founded in 2001, the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) is a 501(c)3 research organization representing more than 130 U.S. universities and international water science-related organizations. CUAHSI receives support from the National Science Foundation (NSF) to develop infrastructure and services for the advancement of water science in the United States. CUAHSI's free web-based application, HydroClient (data.cuahsi.org ) allows you to search for, download, and visualize physical, chemical, and biological data.

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