Shale gas development relies heavily on multi-stage hydraulic fracturing (HF) to maximize the economic viability of each new well. Industry is making a concerted effort both to recycle and re-use produced brine from fracturing operations and to use alternate water sources for well operations. Some experts foresee almost all produced brines being treated and reused within the next five years. Texas A&M Global Petroleum Research Institute (GPRI) has been one of the leaders in promoting new technology to reach these goals. In the past decade we have conducted a number of field trials in different shale plays to a) identify technologies and determine their effectiveness, b) field test advanced monitoring and measurement techniques, and c) integrate the technologies into one cost-effective program for the industry.
This paper presents results from these trials that compare different types of filtration media used to remove hydrocarbons, filtration techniques to remove suspended solids and nano filtration materials to stabilize ultrahigh salinity brines making them compatible with today's fracturing fluid designs. In addition to describing cost effective brine treatment, we have provided a venue for testing advanced analytical techniques that provide rapid ways to measure the effectiveness of such water treatment. Measuring hydrocarbon content in the brines aids in selection of optimal treatment and monitoring of its effectiveness. New fluid imaging techniques characterize particulates in brines and can help to optimize filtration requirements. Biological monitoring can determine effectiveness of solids removal practices and helps in selection of appropriate bacterial control.
This paper will discuss the need to utilize on-site, real-time analysis of produced water and frac flow back brine to allow faster and more accurate characterization of the oil and gas waters being cycled back to unconventional gas development.
The benefits of the technology come from improved procedures to characterize and mitigate the risks of HF at drilling and hydraulic fracturing sites. Better monitoring and treatment can help to counter the mounting concerns of legislators, regulatory agencies, and the general public as well as aid the economic development of our natural gas resources.