|
Hilcorp continues gas leak assessment Evaluating Middle Ground Shoal fuel gas line repair options while monitoring situation and waiting for sea ice conditions to ease ALAN BAILEY Petroleum News
Hilcorp Alaska is continuing to monitor the situation in preparation for the repair of a leaking subsea pipeline that supplies fuel gas for its Cook Inlet Middle Ground Shoal field. Response efforts must address the leak while also maintaining the safety of the public, ensuring the safety of Hilcorp personnel and protecting the environment, said company spokeswoman Lori Nelson in a Feb. 24 press release.
The leak was discovered on Feb. 7 by a Hilcorp helicopter at a location between Nikiski on the Kenai Peninsula and the offshore field’s Platform A. The pipeline, which lies in a water depth of 80 feet, supplies dry processed fuel gas consisting of 98.67 percent methane to the A, C, Dillon and Baker platforms. The gas is used for power generation on the platforms, Nelson said.
Waiting for ice to clear Currently sea ice conditions in Cook Inlet are preventing divers from safely inspecting and repairing the line. Hilcorp has evaluated the repair options and has determined that the use of divers is the best available approach to safely fixing the leak, Nelson said. The company proposes using the divers once ice conditions enable repair operations to begin safely. In readiness for the repairs, Hilcorp has mobilized equipment and briefed personnel, Nelson said.
In the interim, Hilcorp has lowered the pressure in the gas line by minimizing the use of the fuel gas. This has involved shutting down waterflood operations in the field and cutting the use of some other non-essential equipment and activities, Nelson said. The company continues to evaluate other means whereby the line pressure could be further reduced. However, it is necessary to maintain a positive gas pressure in the line, to prevent the infiltration of seawater and the possibility of the discharge of any remnant oil in the line. Apparently, the line had previously been used for the transportation of crude oil.
The National Oceanic and Atmospheric Administration has performed calculations that indicate that the volume of gas being released to the atmosphere likely represents a low risk for humans, Nelson said.
Environmental impacts The other concern is the possible impact of the leak on the natural environment - Hilcorp has been working with environmental experts to evaluate the leak’s potential effects. Preliminary modeling of the dissolving of the methane in the seawater estimates methane concentrations in the water around one-five-hundredth of the level at which the Alaska Department of Environmental Conservation has indicated fish would be harmed, Nelson said.
Using peer-reviewed literature, including studies performed by federal agencies and a recent study relating to the Cook Inlet, environmental consultants have also concluded that the potential impact of the leak on marine life would be minimal, based on the volume of gas being released, Nelson said.
Hilcorp is developing a water monitoring plan for the area impacted by the leak. This plan includes an evaluation of the safety of the personnel who will implement the plan - the plan will be activated when the personnel safety can be assured, Nelson said.
Hilcorp continues to work with the regulatory agencies on information requests regarding the leak and will provide additional information as it becomes available, Nelson said.
| 