|
Taking new look at oil spill prevention Interior committee makes some recommendations for initiatives to prevent and contain offshore well blowouts and oil spills Alan Bailey Petroleum News
In case it wasn’t already obvious, the horrors of the Deepwater Horizon disaster amply illustrated the simple truth that containing oil inside a problematic offshore well bore is infinitely preferable to trying to clean up the oil after it has spilled into the ocean. And on Aug. 29, during its meeting in Anchorage, Alaska, the Department of the Interior’s Ocean Energy Safety Advisory Committee put some finishing touches to some new recommendations for applying new technologies to the tricky problem of anticipating a potential well blowout and containing oil from a damaged well after loss of well control.
The Advisory Committee, composed of a group of 15 representative experts from industry, government agencies, academia and environmental organizations, was formed in April 2011 to provide advice to the Department of the Interior on matters and actions relating to offshore energy safety, including drilling, well blowout containment and oil spill response.
New technologies The committee is recommending to Interior initiatives for the development of technologies for the early detection of abnormal hydrocarbon “kicks” deep in a wellbore, and for the use of downhole telemetry to continuously monitor well bore integrity. With the likely involvement of joint industry programs, in conjunction with work conducted by agencies such as the Department of Energy and the Bureau of Safety and Environmental Enforcement, BSEE, and with contributions from university researchers, these initiatives could lead to improved techniques for obtaining early warning of an impending oil well disaster, enabling timely intervention for disaster prevention, the committee thinks.
And, following the failure of the blowout preventer on the Macondo well to effectively seal the well bore and thus prevent oil spewing into the Gulf of Mexico, the committee is recommending that BSEE facilitate oil industry collaboration to develop enhanced pipe shearing technologies, to ensure that that shear rams in a blowout preventer are capable of effectively shearing and sealing any type of piping that may be used in a well. The intention is to ensure that the shearing technologies keep pace with evolving pipe designs as drilling moves into ever more challenging environments and deeper water.
Blowout preventer instrumentation BSEE should also initiate a discussion between blowout preventer manufacturers and others in the oil industry on the status of and future needs for blowout preventer instrumentation, performance monitoring and data recording, the committee recommends. And Interior should approach the Department of Energy on research into the deepwater acoustic activation of blowout preventers and other submerged well control equipment, to allow for the possibility of the primary and secondary control devices for the equipment not working in a deep-water drilling situation.
In addition, there need to be American Petroleum Institute standards for the interfaces that connect remotely operated subsea vehicles to subsea blowout preventer stacks, with the vehicles also having the technical capabilities to operate blowout preventer controls in high water pressures.
Wellbore breaches One particular concern that emerged from the committee discussions was the question of how to contain or control the flow of oil, if there is a breach in a wellbore, allowing oil to escape into the sea from, say, a crack in the seafloor. The type of well capping technology that eventually proved successful in shutting off the flow of oil from the Macondo well and that is now being implemented as part of the toolkit for offshore drilling safety and environmental protection seals the well bore but may not be able to deal with oil leaking elsewhere.
Assessing and mitigating the risks associated with wellbore breaches and seafloor oil leakage involves an understanding of seafloor mechanics and other natural systems. The committee anticipates recommending an industry and university workshop on this topic, to inform a potential future research and development program.
Loss-of-control scenarios In addition to the possibility of a wellbore breach, there are a variety of possible oil source control and containment situations that would prove challenging for the type of well capping technologies that are currently being developed. Some members of the committee are preparing probability assessments of various scenarios involving a loss of oil source control, with evaluations of which of these scenarios could be handled by well capping technologies, which may need an oil containment dome and which might only be resolved through relief well drilling. Each of the scenarios will be assigned a potential timeframe for bringing the problem well under control.
|
