Existing Research & Studies

 

SAFER PA is committed to focusing on important research resulting in valuable technology development and technical analysis. Our efforts target critical technical knowledge and challenges that need solutions. The below studies and links to information sources help build the technical understanding base, identify gaps in information and enable research efforts that extend beyond the current knowledge base. 

 

Shallow Subsurface Environmental Issues Characterization and Management 

A White Paper Summarizing the Stray Gas Incidence and Response Forum

John Veil Groundwater │ Protection Council 

The white paper summarizes the information that was discussed at the Stray Gas Incidence & Response Forum from July 24-26, 2012 in Cleveland, Ohio. The Forum focused on stray gas in areas where shale gas or other unconventional natural gas is being developed. The white paper pulls material from different presentations into a more thematic narrative that covers the key topics in a coordinated way. 

 

Short-term Intra-Well Variability in Methane Concentrations from Domestic Well Waters in Northeastern Pennsylvania

Nancy Coleman, Debby McElreath  │  Chesapeake Energy

There is a natural variation in the concentration of methane and other well quality parameters. The greatest degree of variability is seen in wells with naturally stratified water quality. Excessive drawdown can result in highly elevated methane concentrations and mineralized groundwater from deeper, restricted flow zones. Naturally-occurring, highly mineralized water is associated with higher levels of dissolved methane. 

 

Real-Time Monitoring System for Evaluating Long-Term Variability of Methane In Domestic Water Wells

Charles Whisman, Richard Wardrop, Denise Good, Debby McElreath, Bert Smith  │  Chesapeake Energy

A single pre-drill baseline methane sample is not representative of the full range of natural variable of methane present.  Methane, naturally occurring throughout NE PA, has variable concentrations based on temporal and spatial sampling/monitoring. The pumping of water wells causes the highest degree of methane variability. Methane occurrence in the subsurface can be influenced by changes in air, temperature, barometric pressure, humidity, and drought conditions. 

 

The Occurrence of Methane in Shallow Groundwater from Extensive Pre-Drill Sampling 

Elizabeth Perry, Bert Smith, Rikka Bothun, Mark Hollingsworth  │  Chesapeake Energy

Methane is naturally occurring in NE PA and is highest in water wells drilled into the Upper Devonian Catskill and Lock Haven formations. When dissolved methane values are > 3 mg/L, there is a strong correlation with the occurrence of sodium-bicarbonate and sodium-chloride groundwater types (typically found in lower topographic positions along tributaries/drainages).  Dissolved methane occurrence correlates strongly with sodium, sulfate (inversely), pH, TDS, and barium concentrations.  46.5% of pre-drill baseline samples naturally exceed one or more primary or secondary EPA drinking water standards. 

 

Geologic and Baseline Groundwater Evidence for Naturally Occurring, Shallow Source, Thermogenic Methane Gas in Northeastern Pennsylvania

Brent Wilson  │  Chesapeake Energy

Upper Devonian coal is a high potential thermogenic gas source based on vitrinite reflectance and total organic carbon values.  Coal stringers are readily identifiable across the region and throughout the Upper Devonian Catskill and Lock Haven formations. Thin sections of sandstones show micro-sized coal particles throughout the sedimentary grain matrix, ranging from 1-10% in volume. Iron, manganese, and sulfur are also found in high concentrations with coal deposits, which are detected regularly in pre-drill baseline groundwater samples. 

 

Origin of combustible gases in water-supply wells in north-central Pennsylvania 

Kinga Revesz, Kevin Breen, Alfred Baldassare, Robert Burruss  │  USG

Thermogenic gas occurs naturally in the shallow aquifer system and isotopic values vary both locally and regionally with unpredictable distribution. Post mature thermogenic gases infrequently occur at shallow depths in Upper Devonian formations and are not limited to just deeper Marcellus Shale. Isotope compositions for producing gas wells are likely to change over time due to the inherent nature of adsorption/desorption properties of the shale matrix. Longer term isotopic monitoring may be warranted in alleged stray gas incidents to conclude an alleged impact or potential source. 

 

Use of Remote Sensing Technologies to Detect Surface and Near-Surface Stray Gas Occurrence and Potential Migration Pathways 

Bryce McKee, Craig Beasley  │  Shell E&P

The neoPROSPECTOR program from Shell and their partner NEOS GeoSolutions is being used in Tioga County in NE PA to detect old abandoned wells, find surface lineaments and hydrocarbon seeps, and identify surface structural features that control aquifer distribution and occurrence of hydrocarbon seeps. Remote magnetic sensing identified 67% of the documented wells, and has identified potential abandoned buried well heads. The project has been able to interpret faults/fractures and identify locations of surface hydrocarbon seeps. Shallow gas occurrence at a range of depths was interpreted with magnetic and electromagnetic resistivity data. 

 

Baseline Water Quality Sampling in Shale Gas Exploration and Production Areas

Debby McElreath, Mark Hollingsworth  │  Chesapeake Energy

Chesapeake Energy has collected more than 31,000 water well samples in areas where shale gas drilling was planned. About 25% of all the samples had detectable methane concentrations with the highest concentrations in Louisiana, Ohio, and Pennsylvania.  Dissolved methane sampling and analyses require careful consideration. There is a lack of consensus on a sampling method for dissolved methane. 

 

Design Process for Sustainable Long-Term Wellbore Integrity

Glen Benge, Deepak Khatri, Brian Lockwich  │  Baker Hughes

The core principles associated with wellbore construction include protecting the groundwater and the environment through the use of barriers and ensuring the well design and construction is environmentally sound. Successful barrier installation requires understanding the objectives of the operation, identifying the methods and materials to be used, adhering to design plans, and properly evaluating the final operation to assure the objectives have been met. 

 

Lines-of-Evidence Approach to the Evaluation of Stray Gas Incidents

Lisa Molofsky, Ann Smith, John Connor, Shahla Farhat, Tom Wagner,

Albert Wylie  │  GSI Environmental Inc. and Cabot Oil & Gas

The presence of gas-bearing strata, fault and fracture systems, and aquifer dynamics provide evidence for stray gas investigations. There are regional patterns of methane occurrence and composition. Geochemical fingerprinting analyzes the composition and isotropic signatures of gas sources. 

 

Water and Solid Waste Management  

Collection and Treatment of Flowback and Produced Waters from Hydraulic Fracturing

Edwin Pinero  │  Veolia Water

Modular approaches (package and mobile treatment plants), centralized treatment in local areas, reuse of treated water, and highly efficient treatment indicate flowback and produced water is manageable. There are various options to address differences in geography, chemistry, and producer requirements.  

 

Pennsylvania Business Opportunities 

Economic Impacts of Marcellus Shale in Pennsylvania: Employment and Income in 2009

Timothy Kelsey, Martin Shields, James Ladlee, Melissa Ward  │  Marcellus Shale Education & Training Center

This study examines how several unexplored aspects of Marcellus Shale natural gas development in PA will affect the overall economic impact occurring in the Commonwealth.  The findings suggest that the economic impact in 2009 ranged between 23,385 and 23,884 jobs, and $3.1 and $3.2 billion in that year.  This included about $1.2 billion in labor income and almost $1.9 billion in value added to the PA economy. These are large economic impacts, especially since much of this impact is occurring in relatively small counties.

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