“Cabot lost control of the Huston J1 gas well for 27 hours, to which the department responded to promptly to ensure there were no significant environmental impacts,” DEP Director of District Oil and Gas Operations John Ryder said. “In this incident, mostly gas was released, which dissipated quickly to background levels within 100 feet from the well.”
The incident began the morning of Jan. 5 when a Cabot subcontractor was replacing equipment on the wellhead. The subcontractor did not follow standard operating procedures for the process by failing to first warm the wellhead prior to conducting any work in the freezing temperature. This resulted in damage to a wing valve.
A subsequent analysis of the damaged wing valve indicated that it was in the open position, allowing gas to escape. The analysis also indicated that frozen sand in the valve bore may have obstructed movement of the gate, causing a function test to indicate the valve was closed when it was open.
Cabot contacted Wild Well Control of Houston, Texas, for assistance, which installed two hydraulic valves to diminish the gas flow in the damaged valve to allow full replacement. The well was brought under control shortly before 1 p.m. on Jan. 6.
During the incident, Cabot contacted five property owners within a quarter mile of the well pad to notify them of the situation. However, it was determined that no evacuation was needed based on the results of DEP air monitoring. DEP staff used meters to detect combustible gas on and in the vicinity of the well pad, and to determine if there was an explosive atmosphere.
DEP Oil and Gas and Emergency Response program staff were on scene providing oversight throughout the incident.
The department issued a notice of violation (NOV) to Cabot on Jan. 16 for violations of the Solid Waste Management Act, Clean Streams Law and the Chapter 78 oil and gas regulations. The NOV requested a written response within 10 days, which Cabot provided.
In its response, the company said it could not determine the exact amount of natural gas or fluid released because it was not possible to safely measure the flows, but said the majority of the release consisted of natural gas.