Offshore Drilling in West Greenland, Relief Well Planning
1. Current Relief Well Drilling Requirements for Offshore Drilling in West Greenland
The Government of Greenland requires offshore drilling operations to be supported with
two drilling rigs to ensure that one of the drilling rigs can provide relief well drilling
services in the event that a blowout occurs while drilling with the other rig.
The two-rig policy also requires that drilling must stop with sufficient time to allow enough
time to drill a relief well in the same drilling season before ice and harsh Arctic weather
make well drilling unworkable.
The Government of Greenland’s two-rig relief well drilling policy, requiring the capability to drill
a same-season relief well is an international best practice for drilling in Arctic waters. This
international best practice is also in place in Canada and the United States.
2. Current Relief Well Drilling Requirements in the Canadian Arctic
Canada’s National Energy Board requires offshore drilling operations to have two-drilling
rigs operating offshore to ensure that at least one rig is capable of drilling a relief well to kill
an out-of-control well during the same drilling season (commonly referred to as the “sameseason-relief-capability.”)1
In 2010, after the United States Gulf of Mexico well blowout, the National Energy Board of
Canada reviewed its offshore drilling safety and environmental requirements for offshore
drilling in Canada’s Arctic (“the Arctic Review”).2 The Arctic Review reaffirmed Canada’s
requirement for a two-rig, same-season relief well capability, despite substantial industry
pressure to relieve this requirement.
While Chevron,3 BP,4 Imperial Oil,5 and ConocoPhillips6 all heavily lobbied the Canadian
National Energy Board to relax its two-rig, same-season relief well policy, no company has been
successful.
3. Current Relief Well Drilling Requirements in United States Arctic
1
Canada National Energy Board (NEB), Filing Requirements for Offshore Drilling in the Canadian Arctic, 2011.
2
Canada, National Energy Board, Backgrounder- National Energy Board Report on the Arctic Offshore Drilling
Review, http://www.neb-one.gc.ca/clf-nsi/rthnb/pplctnsbfrthnb/rctcffshrdrllngrvw/fnlrprt2011/bckgrndr-eng.html,
accessed May 2013.
3
Chevron Canada Limited, Submission to the National Energy Board Policy Hearing for Same Season Relief Well
Capability for Drilling in the Beaufort Sea, March 2010.
4
BP Exploration Operating Company Limited, National Energy Board, Hearing Order MH-1-2010, Review of Policy
on Same Season Relief Well Capability for Drilling in the Beaufort Sea, Written Submission, March 2012.
5
Imperial Oil Resources Ventures Limited, Calgary, Submission Regarding the Relief Well Policy for Offshore
Drilling in Arctic Waters, March 2010.
ConocoPhillips Canada, Letter to the Canadian National Energy Board, Re: ConocoPhillips’ Submission in
accordance with NEB Hearing Order MH-1-2010 Same Season Relief Well Capability for Drilling in the Beaufort Sea
(NEB File OF-EP-Well 05), March 19, 2010.
6
The United States, Department of Interior, requires offshore drilling operations to have tworigs operating offshore at the same time to ensure that at least one rig is available and
capable of drilling a relief well during the same drilling season.
Shell’s 2012 Chukchi and Beaufort Sea drilling campaign was the most recent approval of
offshore drilling in the United States Arctic. The United States required Shell to have two
drilling rigs located in the Arctic capable of drilling both the planned wells, and a relief
well.7 The United States also required that Shell stop drilling the planned wells, in order to
leave sufficient time to drill a relief well during the same drilling season.
In 2012, ConocoPhillips proposed to drill in the Chukchi Sea using a single jack-up drilling
rig, without a second drilling rig and without the capability to drill a same season relief
well.8 The United States Department of Interior held firm on its requirement for a second
drilling rig, and the capability to drill a same-season relief well.
4. Industry’s Request to Relax the Greenland Relief Well Drilling Policy
Recent reports suggest that the Greenland Oil Industry Association (GOIA) and/or its members
may be requesting the Government of Greenland to relax the two- rig, same-season relief well
requirement.
Canada and the United States, thus far, have rejected proposals to eliminate the two-rig,
same-season relief well requirement because there are some circumstances where surface
intervention methods are not successful necessitating a relief well. If rapid initiation of relief
well drilling is not commenced in the Arctic, and the well is not brought under control
during that drilling season, the well blowout could continue unabated during an entire winter
season. A blowout persisting through a winter season in the Arctic could be eight to nine
months long, resulting in ecological damage of catastrophic proportions.
Some operators have proposed drilling a relief well using the same rig that drilled the blown
out well. This is an unsafe, risky proposal because drilling rigs and control systems that
caused the well blowout malfunctioned, and are typically damaged by fire and explosion,
sunk or otherwise unsafe to immediately operate after a well blowout. During a well
blowout, personnel are evacuated from the rig as soon as possible. Re-boarding a rig
involved in a well blowout to move the rig to another drilling location is usually not safe.
Moreover, it would not be prudent to use a drilling rig and blowout control system that just
failed, to drill a relief well, until the rig was carefully inspected and verified to be safe and
reliable to drill another well.
For example, the two most recent well blowouts, the 2009 Timor Sea Montara well blowout and
the 2012 Gulf of Mexico Macondo well blowout both resulted in fire and explosions that
damaged the rigs. The Montara well blowout damaged the rig to the point that Australian
authorities would not authorize anyone to re-board the offshore platform until the relief well was
drilled and the well blowout was controlled. The Macondo rig caught fire and sunk to the
seafloor.
United States, Department of Interior Approval of Shell’s 2012 Chukchi Sea Exploration Plan and United States,
Department of Interior Approval of Shell’s 2012 Beaufort Sea Exploration Plan.
7
8
ConocoPhillips 2012 Chukchi Sea Exploration Plan.
In 2012, Nuka Research and Planning Group, LLC reported that it reviewed all available data
about well blowouts worldwide and did not find a single example of a drill ship drilling its own
relief well after blowing out.9 Clearly, this is not a safe or reliable plan.
5. Well Blowout Control Methods – When is a Relief Well Needed?
A relief well is the most reliable method of controlling a well blowout and is typically the last
resort for well control when surface intervention methods fail. Drilling relief wells can take
longer than well capping. However, because well capping operations are not always successful,
well capping and relief well drilling operations are typically commenced in parallel. The relief
well drilling operations can be stopped if surface intervention methods are successful before the
relief well operations are complete.
If a well cannot be controlled using surface intervention methods, a relief well must be drilled.
Approximately 90-95% of all well blowouts are solved by the well bridging on its own or by
surface intervention methods.10,11 However, historical data shows that there is a 5-10% chance
that a relief well may be needed to control the blowout and the operator needs to be prepared for
that potential situation.
9
Nuka Research and Planning Group, LLC and Pearson Consulting, LLC , Oil Spill Prevention and Response in the
U.S. Arctic Ocean, Unexamined Risks, Unacceptable Consequences, November 2010., p. 96.
10
Pidcock, G.A., and Fowler, D.R. (Gulf Canada Resources Ltd.), Relief Well Contingency Drilling Plans for Remote
Areas, SPE/IADC Drilling Conference Paper No. 21997, 1991.
11
Skalle, P., and Trondheim, J.H. (Southwest Petroleum Institute), and Nanchong, P. (UT Austin), Killing Methods and
Consequences of 1120 Gulf Blowouts During 1960-1996, Society of Petroleum Engineers Paper No. 53974, 1999.