The International Association of Drilling Contractors (IADC) has released its first guidelines for geothermal well control, outlining best practices for drilling, workover, and well-service operations. The guidelines, available here, apply to geothermal projects ranging from subhydrostatic conditions to wells capable of unassisted flow and are intended to protect workers, the public, and the environment.
The IADC describes the document as a consistent framework that applies to site procedures, equipment testing, operational planning, and personnel training. Additional topics include barrier philosophy, drilling, completion, and permanent abandonment. While the document excludes nonstandard well-control operations, it provides recommended safety protocols and warning indicators for geothermal conditions involving steam or high-pressure fluids.
The guidelines note that a geothermal well may be considered “live” due to both elevated formation pressure and high temperature. It adds that a reduction in hydrostatic pressure can allow superheated water to flash into steam, resulting in rapid expansion that may lead to a blowout.
The document also highlights that geothermal well-control practices are adapted from conventional oil and gas well control but modified to address the unique challenges of geothermal environments. “A thorough understanding of subsurface reservoir behavior, fluid properties, flash potential, in-situ pressure, and temperature conditions is essential to shaping an effective well-control strategy. In most geothermal scenarios, both pressure and temperature are critical factors,” the guidelines state.
The release follows IADC’s 2025 introduction of its Geothermal Well Classification framework, which seeks to standardize classification to improve efficiency, safety, and cross-sector collaboration.
The publication of the geothermal well-control guidelines came only days before reports surfaced that Fervo Energy experienced a blowout at its Cape Station project in Beaver County, Utah. According to reports from Axios and other outlets, the incident was contained by the geothermal energy developer as of 29 May, with no injuries or environmental damage reported.