TRC updates oil, gas well construction rules

June 3, 2013
The Texas Railroad Commission (TRC) has amended well construction requirements to clarify oil and gas well construction rules related to casing, cementing, drilling, well control, and completions.

Paula Dittrick
Senior Writer

The Texas Railroad Commission (TRC) has amended well construction requirements to clarify oil and gas well construction rules related to casing, cementing, drilling, well control, and completions. The amendments take effect Jan. 1, 2014, and apply to wells drilled within Texas on or after that date.

TRC Commissioner David Porter attributed exploration and production growth to "several prolific shale plays," saying the commission was updating and enhancing its rules to continue "our agency's proud legacy of environmental protection and public safety."

Some changes involve groundwater protection measures. The Texas Legislature, the Texas Water Development Board, and TRC all have evaluated industry's demand on the state's water supplies. (OGJ Online, July 30, 2012).

TRC staffers said amendments to the TRC Rule 13 (Casing, Cementing, Drilling, Well Control, and Completion Requirements) outline the updates and also more clearly state well-construction requirements, including:

• For wells undergoing hydraulic fracturing treatments, operators are required to pressure test well casings to the maximum pressure expected during fracture treatment and to notify TRC of a failed test. Also during fracturing, operators are required to monitor the annular space between the well's casings for pressure changes (which could indicate a leak in casing) and suspend fracturing if the annuli monitoring indicates a potential downhole casing leak.

• Requires operators to verify the mechanical integrity of surface casing and intermediate casing for wells in which the drilling time for the next casing string (either the intermediate casing string or the production casing string) exceed 360 hr. This will ensure that rotation motion of the drill string did not damage surface casing integrity or other intermediate casing strings.

• Requires operators to place cement behind casing across and above all formations that have a permit for an injection or disposal well within one-quarter mile of a proposed well.

• Requires TRC approval before setting surface casing to a depth greater than 3,500 ft.

• Establishes additional testing and monitoring requirements for "minimum separation wells" where the vertical distance between the base of usable quality water and the top of a formation to undergo fracturing is less than 1,000 vertical ft. This limits the number of vertical wells that are vertically hydraulically fractured in shallow fields in the Abilene, Midland, San Antonio, and Wichita Falls areas. The provision excludes horizontally completed and fractured wells within major plays in the Barnett and Eagle Ford shale and the Permian basin.

• Requires operators to use air, fresh water, or fresh water-based drilling mud until surface casing is set and cemented in a well to protect usable quality groundwater.

• Operators are required to pump sufficient cement to isolate and control annular gas migration and isolate potential flow zones and zones with corrosive formation fluids.

• Updates references to cement quality, cementing, well equipment, well casing centralizers, and well control, and sets minimum cement sheath thickness of at least ¾ in. around the surface casing and a minimum cement sheath thickness of ½ in. around subsequent casing strings.

• Consolidates and updates requirements for well control and blowout preventers, and distinguishes between the use of well control equipment on inland, bay, and offshore wells. Main rule amendments involve the makeup of BOPs.

• Implements Article 2 of House Bill 2694 to reflect the transfer of the Texas Commission on Environmental Quality's Surface Casing Section to the TRC, where it is the Groundwater Advisory Unit. As usable quality groundwater depth varies statewide, this unit establishes the depth of surface casing required for each well to protect groundwater.