Environmental Impact Analysis on the Hydraulic Fracture Test Site (HFTS)

Conference · Wed Jul 25 00:00:00 EDT 2018

DOI:https://doi.org/10.15530/urtec-2018-2900727· OSTI ID:1477772

Eisenlord, Sarah ^[1]; Hayes, Thomas ^[1]; Perry, Kent ^[1]

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1. Gas Technology Institute

Objective The Hydraulic Fracture Test Site (HFTS) provided a platform to test new extraction and production techniques and technologies to understand fracture geometry and increase the efficiency of shale hydrocarbon production. Eleven test wells were drilled in the Upper and Middle Wolfcamp formations, hydraulically fractured, and produced. Air quality, groundwater quality, and produced water chemistry and microbiology were monitored through the duration of the field experiment and one year into production. Methods BTEX, methane, VOCs, SOx, NOx, and PM₁₀ were measured 1,000 ft up-wind and 1,000 ft down-wind of the HFTS experiment before operations began, during hydraulic fracturing, flowback, and several months into production to evaluate operational impact on local air quality. The underlying Edward-Trinity Plateau aquifer was monitored using 5 groundwater wells within 2 miles of the HFTS pad; BTEX, methane, petroleum hydrocarbons, and a comprehensive suite of anions and metals were analyzed from samples taken before operations began, during hydraulic fracturing, flowback, and one year after production. Water produced from 3 of the 11 HFTS wells was analyzed for chemical and microbiological properties 1.5 years into production. Observations There was no significant impact to air quality from HFTS operations, although elevated BTEX concentrations were measured 1,000 ft. away from the well-pads during the flowback period. We detected no migration of hydrocarbon or fracture fluid chemical migration into the Edward-Trinity Plateau aquifer. Source waters used for hydraulic fracturing contained naturally occurring high concentrations (~500ppm) of sulfate. Rapid microbially induced corrosion was detected in several wells, leading to biocide dosing. Microbiological populations were significantly altered by biocide treatment, but still continued to increase in population size six months after application. Significance After hydraulic fracturing, detailed chemical and microbiological analysis provides evidence for microbiologicallymediated sub-surface transformations of supplied sulfate and organic carbon into sulfides. This report discusses air quality, water quality, and produced water analytical results for the HFTS experiment and further implications for the unconventional oil and gas industry.

• Research Organization: Gas Technology Institute
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• DOE Contract Number: FE0024292
• OSTI ID: 1477772
• Report Number(s): URTeC: 2900
• Resource Relation: Conference: Unconventional Resources Technology Conference, Houston, Texas, USA, 23-25 July 2018
• Country of Publication: United States
• Language: English