Hydraulic fracturing is perhaps the most debated form of energy production in recent years. What is well known is that over the last decade this type of unconventional oil and gas recovery has completely changed America’s energy supply from net import to net export.
pH Measurement Challenges
A hydraulically fractured well will require approximately 4 to 8 million gallons of water during its lifespan. 20 to 40% of this water will come back to the surface in the form of flowback / produced water. A retention tank is used to store this reclaimed water on-site. The driller must have a strategy to deal with this water.
Most issues with pH measurement in these applications are due to reference failure. Hydrocarbons and high particulates tend to plug the porous reference junction creating increased impedance and a noisy pH measurement. Naturally occurring sulfi des and heavy metals can attack the Ag/AgCl element in the reference leading to drift and shortened sensor lifespan.