Spill Prevention, Preparedness and Response

In fulfilling its regulatory mandate, the CNSOPB views the health and safety of offshore workers, and environmental protection, as paramount. The CNSOPB holds operators accountable for their actions and ensures that best appropriate practices are being used to prevent spills from occurring, and that operators are well prepared in the event of a spill. Nonetheless, spills are a recognized risk in the offshore area.  The CNSOPB ensures that Operators have the appropriate processes and procedures in place aimed at preventing spills from occurring and for responding to and minimizing the effects of spills that may occur.

Spill Prevention and Preparedness

The regulatory regime enforced by the CNSOPB requires operators to conduct their activities in a manner that minimizes the chance of spills.  Key requirements from a spill prevention and preparedness perspective include:

  • Requirement for an Approval to Drill a Well – Well Design and Well Control Aspects

    Every operator must apply for and receive approval from the CNSOPB before drilling a well. Ensuring that the well is properly designed, and that the appropriate well control procedures will be in place at all times, are critical to the prevention of well control incidents that could potentially result in a spill.

    In an application for an Approval to Drill a Well, operators must provide to the CNSOPB detailed information on the drilling program and well design, including the Blowout Preventer (BOP) equipment and the casing and cementing program. Operators must also submit a detailed geologic prognosis for the well that describes the geology of the area and the interpreted hydrocarbon targets.

    The application must identify and discuss drilling related hazards including matters pertaining to well control and blowout prevention. The depth and nature of formations where problems such as high pressure and other hazards are anticipated must be identified. Information about pressure testing and function testing of well control equipment must also be included. This application is reviewed by a multi-disciplinary team within the CNSOPB consisting of engineers, technicians, geologists, geophysicists and environmental scientists prior to issuing an approval.

    Additionally, the legislation and regulations puts the onus on each operator to assure the competence of their personnel in carrying out their assigned duties. With respect to well control, appropriate personnel are required to have an advanced knowledge of offshore well control equipment, techniques, and procedures and must be provided with practical hands-on training in proper well control procedures during simulated kick situations using a properly certified rig floor simulator. Properly trained personnel would be expected to react to any well control incident that may be encountered in a manner that would prevent the loss of well control. In its review of an application for a drilling program, the CNSOPB verifies the adequacy and implementation of operator training programs.

    If well control cannot ultimately be maintained, the use of the BOP would be initiated.

  • Blowout Preventers (BOPs)

    During the drilling of a well, operators are required to use BOPs. BOPs are able to seal off the top of a well that is being drilled. They are made of heavy-duty, high-pressure valves that attach to the wellhead (or “well bore”) to control well pressure and prevent any uncontrolled release from the well.

    BOPs are available for different pressure ratings and sizes. The type of BOP required for a drilling project depends on the unique factors presented by the well itself.

  • Spill Response Plans

    As part of the CNSOPB’s authorization process for exploration or production activity to be carried out offshore, operators must submit a spill response plan (SRP). These plans include a risk assessment and how an operator plans to respond to a variety of foreseeable spill scenarios. Offshore operators must also demonstrate that they have the necessary equipment and trained personnel prepared to respond to a spill. An authorization to carry out exploration or production activity cannot be issued until the SRP is accepted by the CNSOPB.

    Spill Response

    In most instances, spills that occur in the offshore are minor in nature and dissipate naturally requiring no response.

    In the case of a major oil spill, the purpose of the spill response is to reduce the environmental and socio-economic damage that may occur. The greatest extent of environmental damage occurs when oil comes in contact with marine life or the shoreline.

    When oil is spilled at sea, it normally spreads out and moves on the sea surface with wind and current while undergoing a number of chemical and physical changes. These processes, known as weathering, determine the fate of the oil.

    Some of these processes, like natural dispersion of the oil into the water, lead to the removal of the oil from the sea surface, and helps its natural breakdown in the marine environment by naturally occurring bacteria. Others processes, particularly the formation of water-in-oil emulsions, cause the oil to become more persistent, and remain at sea or on the shoreline for prolonged periods of time.

    The speed and relative importance of the processes depend on factors such as the volume spilled, the oil’s initial physical and chemical characteristics, weather, sea conditions and whether the oil remains at sea or is washed ashore.

    There are a number of different strains of bacteria in the ocean that break down the hydrocarbons into carbon and water. Ultimately, the marine environment usually eliminates spilled oil through this long-term process of biodegradation.

    For smaller spills, natural dispersion along with ongoing monitoring may be a sufficient method of spill response. However, natural dispersion and weathering cannot break down large volume spills in sufficient time to prevent the oil from reaching marine life or shorelines. In this case, further intervention is required. In the event of a spill, there are a number of technologies and methodologies that can be used to remove the oil from the ocean. Each tool has its own benefits and limitations, and therefore response to most spill events requires the use of several tools at the same time. As a part of the authorization process, operators must demonstrate to the CNSOPB that they can deploy these responses in a reasonable amount of time in the event of a spill.

    The typical types of tools and approaches include:

  • Capping Stacks

    A capping stack is a piece of equipment that is placed over a blown-out well as a “cap” to temporarily stop the flow of hydrocarbons into the environment and to allow time for engineers to permanently seal the well (see relief well drilling below). Capping stacks are very large pieces of equipment, weighing as much as 50 to 100 tons. These units are used in the unlikely event that the BOP has failed and hydrocarbons are escaping from the wellhead.

    After the capping stack is fully installed, it provides dual barrier (two rams) for containment of hydrocarbons. The stack’s valves can be closed to cap or seal the well (“cap only”) or, if necessary, the flow can be redirected to vessels on the surface through flexible pipes (“cap and flow”).

    Capping stacks are stored offsite, and preparing and installing these units is a very complex process. Before the capping stack arrives, a remotely operated vehicle inspects the seabed site and engineers are able to determine precisely what equipment is needed. Next, debris is removed and the wellhead or BOP is prepared. After this work has been completed, the capping stack is carefully maneuvered into place over the wellhead.

  • Relief Well Drilling

    Relief wells are a method that would be used in the same unlikely scenario as a capping stack. Relief wells are drilled by vessels near the existing well and provide a means to inject mud and cement into the well, thereby plugging it and stopping the flow of hydrocarbons.

    This method is considered permanent, but can take several weeks or months to achieve. While the relief well is being drilled, operators would employ other methods to stop the flow of oil (as described above) and to remove oil from the area (such as the tactics below).

  • Booms and barriers

    Booms are temporary floating barriers used to contain an oil spill. They are deployed at the site of a spill early in the process for a number of reasons. Booms can help to concentrate oil into thicker surface layers which helps other tools to collect oil more efficiently. In addition, booms can help to prevent surface oil from reaching marine life or reach the shoreline. Booms have no environmental risk on their own and are one of the most commonly used tools.

    Booms are more effective in calmer waters and have limitations with high waves or quick currents. In these cases, other tools may be more appropriate.

  • Mechanical Recovery

    Oil can be recovered from the surface using mechanical methods such as skimmers or separators. These devices are used once booms have concentrated oil in sufficiently thick layers on top of the water. Skimmers use belts, brushes, drums or suction devices to collect oil and remove it from the surface. Separators are machines that use gravity or centripetal force to quickly spin and separate oil from water.

    Much like booms, there is little to no environmental damage done by the machines themselves. However, mechanical recovery shares the same limitations in terms of sea state as booms and therefore other tools may be required.

  • In-situ Burning

    In –situ burning is a method whereby oil is burned from the ocean’s surface. In this situation, fire-resistant booms are used to contain the oil, which is then set on fire in a controlled burn. In-situ burning would be heavily monitored by highly-trained experts.

    In-situ burning can be very effective in removing oil from the ocean’s surface. However, this method is reliant on booms and as such its use is limited by sea state. Furthermore, there are risks associated with having an open fire in the presence of hydrocarbons. As such, in the event of a spill, the CNSOPB must be satisfied that the operator is taking the necessary precautions to address this risk, and that all personnel involved are appropriately trained.

  • Dispersants

    In some situations, the above tools are not sufficient to remove oil from the water’s surface. Dispersants are compounds specifically designed for use in marine environments to speed up the natural oil dispersion process. Dispersants work by attaching themselves to oil droplets. Waves   then break down the oil slick into smaller and smaller droplets which then enter the water column. When the droplets disperse into the water column, they are more quickly degraded by naturally-occurring bacteria which convert the oil into carbon dioxide and water.

  • Operators cannot use dispersants without prior approval.

    Approval Process for the use of Dispersants/Net Environmental Benefit Analysis Process

    If a major incident was to occur, and an Operator was to consider the use of a dispersant, legislation requires that a specific request for approval be made at that time to the CNSOPB’s Chief Conservation Officer (CCO).  Such a request would have to be accompanied by an incident specific net environmental benefit analysis (NEBA), also known as a spill impact mitigation assessment (SIMA).  The use of dispersants would only be considered in cases where this analysis concludes that it is better for the environment to do so.  The CCO would first consult with experts of Environment and Climate Change Canada’s National Environmental Emergencies Centre’s Science Table, which brings together relevant experts in the field of environmental protection in all levels of government, other stakeholders, and the response industry. Additionally, the CCO is obligated by legislation to consult with the federal Minister of Natural Resources Canada and provincial Minister of Energy before granting approval to use a dispersant.

    Should the use of a dispersant be approved by the Board’s CCO, the CNSOPB would closely monitor the operator’s actions to ensure the dispersant is being used appropriately and that environmental protection remains paramount.

    Reporting of Spills

    Operators are required to report all hydrocarbon spills, regardless of the size or circumstances surrounding the spill. This includes all drilling fluids, hydrocarbons, diesel and other substances used on any platform or vessel. Depending on the nature and size of the spill, an operator is required to conduct an investigation into the cause of the spill. This investigation would include a determination of the root cause of the spill, how it could have been prevented and what actions the operator will take to prevent recurrence. Each investigation report is reviewed by CNSOPB staff and must be accepted. In some cases, CNSOPB staff may visit the platforms or vessels involved to perform their own independent investigation of spills that may have occurred. In the case of a significant spill, the CNSOPB would most definitely carry out its own independent investigation.