Reducing Freshwater Consumption in the Marcellus Shale Play by Recycling Flowback with Abandoned Mine Drainage
Open Access
- Author:
- Cavazza, Michael
- Area of Honors:
- Petroleum and Natural Gas Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Li Li, Thesis Supervisor
Turgay Ertekin, Thesis Honors Advisor - Keywords:
- Abandoned Mine Drainage
Marcellus Shale
Recycle Flowback
Barium Removal
Strontium Removal
Sulfate Removal - Abstract:
- The amount of freshwater consumed during development of the Marcellus shale play can be reduced by recycling flowback with an impaired water source: abandoned mine drainage (AMD). To use AMD in hydraulic fracturing, the high sulfate concentrations typical in AMD must be reduced to a level that it is compatible with formation fluid (<100 mg/L). Sulfate levels in the AMD can be reduced by mixing AMD with flowback fluid, which is high in metals ions such as barium and strontium, through barite and celestite precipitation. By utilizing this process, companies operating in the Marcellus shale can contribute to a cleaner Pennsylvania by reducing stream impairment from AMD and reducing freshwater consumption. The main objectives of this study were: (1) characterize AMD discharges and flowback, (2) mix AMD and flowback at various ratios to develop long-term kinetic data (2 weeks) and determine removal efficiency for sulfate, barium, radium and strontium. Eight AMD discharges of varying compositions located across the state and two recently hydraulically fractured wells in southwest PA were sampled and evaluated. Characterization included pH, alkalinity, flow rates, total and dissolved metals and sulfate. Kinetic tests showed that precipitation occurs quickly and does not continue past one day of mixing. As for removal efficiencies, barium, strontium, radium and sulfate were all removed at varying amounts. Barium and radium can be completely removed when an ample amount of sulfate is added. Sulfate can be removed completely when putting less AMD in the mixture. Strontium could only be removed up to 50%. Possible factors affecting precipitation of strontium include lack of celestite formation and the presence of organics. Results show that sulfate can be removed to level that is acceptable for hydraulic fracturing operations.