The UT Bureau of Economic Geology led the study that highlights key differences in water use between conventional drill sites and sites that use hydraulic fracturing, which is rapidly expanding in the Permian. The study was published in Environmental Science & Technology on Sept. 6, with results indicating that recycling water produced during operations at other hydraulic fracturing sites could help reduce potential problems associated with the technology. These include the need for large upfront water use and potentially induced seismicity or earthquakes, triggered by injecting the water produced during operations back into the ground.
For conventional operations, the produced water is disposed of by injecting it into depleted conventional reservoirs, a process that maintains pressure in the reservoir and can help bring up additional oil through enhanced oil recovery. Unconventional wells generate only about a tenth of the water produced by conventional wells, but this “produced water” cannot be injected into the shales because of the low permeability of the shales. The study found that the produced water from unconventional wells is largely injected into non-oil-producing geologic formations—a practice that can increase pressure and could potentially result in induced seismicity or earthquakes.
The study points out that instead of injecting the produced water into these formations, operators could potentially reuse the water from unconventional wells to hydraulically fracture the next set of wells. Enough water is produced in the Midland and Delaware basins in the Permian to support hydraulic fracturing water use, and the water needs only minimal treatment (clean brine) to make it suitable for reuse.
Who’s got enough land to store and re-distribute vast quantities of water throughout the basin?
Below is a link to the study. More to come from me after I dig in.
Study: Water Issues Related to Transitioning from Conventional to Unconventional Oil Production in the Permian Basin