Where Does All the Water Go?
by R. Grant Wood
Unless you have been hiding under a rock for the past eight years, you have probably noticed the increased reporting of the Texas Energy Boom. If you have been hiding under a rock and depending on the depth of that rock, you may have encountered oilfield brine, the subject of this article. A few statistics about oil and gas underscore the importance of disposal wells within our state’s energy infrastructure. There are over 409,000 oil and gas wells in the State of Texas. Since 1936 there have been around 107,000 wells permitted for injection in Texas, with over 55,000 current injection well permits. In addition, there are over 33,000 active permits.
The occurrence of ancient saltwater in productive oil and gas formations presents a different kind of water challenge than we normally deal with in Texas. Unlike scarce surface water, energy-related water is a waste product of oil and gas production. Naturally occurring saltwater brought to the surface during oil and gas production is referred to as produced water. Production of this type of water can range from nearly zero to many thousands of barrels per day.
With the advent of hydraulic fracturing, there has been a rise in another class of water, called flowback. Flowback and produced water are similar in that they both contain high levels of total dissolved solids (TDS). The source and makeup of those TDS differ, however. In produced water, there are traces of hard rock minerals from the interval where the water was produced. Also, produced water contains dissolved hydrocarbons and naturally occurring radioactive materials, including radium isotopes. In contrast, flowback contains a “cocktail” of suspended particles, including clays, sands, chemical additives, and dissolved metals, with chemicals typically constituting 0.5% or less of the volume. Regardless of the classification of the water, we cannot simply make it go away, or dispose of these volumes on the surface.
Regulation of produced water and flowbackis predominately accomplished by utilizing Class II wells, which fall under the regulatory authority of the Texas Railroad Commission (Railroad Commission). On April 23, 1982, the Environmental Protection Agency awarded the Railroad Commission “primary enforcement responsibility” over oil and gas injection and disposal wells in Texas. Administration of this program falls to the Technical Permitting Section-Underground Injection Control (UIC) program of the Railroad Commission. Class II wells are utilized for injecting waste arising out of, or incidental to, drilling for or production of oil, gas, or geothermal resources. Other permitted uses for Class II wells include the underground storage of hydrocarbons, disposal of waste arising out of, or incidental to, the operation of gasoline plants or natural gas processing plants, enhanced recovery of oil or natural gas, and underground storage of hydrocarbons that are liquid at standard temperature and pressure.
In order to dispose of these waste streams in Class II wells, operators must register with the Railroad Commission, post a blanket bond, P-5PB(2), or sufficient surety, and have successfully permitted a Class II well. In Texas, Statewide Rule 9 requires an operator to use Form W-14 to apply for Disposal into a Non-Productive Formation. The formation is deemed non-productive if there is no production in that interval within a two-mile radius. If there is production within a two-mile radius of the proposed wellbore, Statewide Rule 46 provides for application via Form H1 and H1a to apply for Injection, or Disposal into a Productive Formation, or if there is a mix of Productive and Non-productive zones in the proposed disposal interval. In order to avoid confusion, however, an operator should engage the Railroad Commission staff and seek their assistance in satisfying all requirements listed on the instruction sheet.
The requirements are too extensive to describe for the purposes of this article, but two of the most critical requirements relate to the protection of groundwater. The Groundwater Advisory Unit (GAU) is tasked with assuring that the Base of Usable Quality Water (BUQW) is protected. Accordingly, commercial and new injection wells must set and cement surface casing through the BUQW, as determined by the GAU. Technical reviewers assure that the proposed injection interval is isolated from overlying usable quality water by at least 250 feet of relatively impermeable strata, composed of clay or shale. By assuring that these criteria are met, the GAU seeks to mitigate risks related to possible contamination of usable quality water. Once approved by the UIC, an operator has three years to obtain a drilling permit W-1 and to proceed with the drilling and completion of a Class II disposal well.
Grant Wood is a partner at the Law Office of R. Grant Wood PLLC and can be reached at firstname.lastname@example.org.