L. William Abel
Wild Well Control Inc.
Spring, Tex.
Prepared in advance of drilling, blowout contingency plans and immediate response plans can reduce firefighting, well capping, and possible relief well costs during a blowout.
Regional and site-specific blowout contingency plans are especially beneficial for operators working worldwide, where logistics difficulties can easily bog down operations.
Multinational operators have additional operational complications because projects often vary dramatically from well to well. In foreign or remote locations, different types of wells, environmental rules, climate, politics, and reservoir characteristics complicate operations, especially during well control or blowouts.
This article is the first of an 8-part series on well control. Future articles will cover pressurized tree removal, well capping operations, techniques for killing wells after capping, snubbing operations, handling H2S, shallow gas hazards, and project management.
Because it is impossible to eliminate the potential for a blowout, the only logical and responsible position is to make plans to react before an accident occurs. Such a blowout contingency plan for operations should include information about the following:
- Immediate reaction plan (evacuations, internal and public notifications, and data collection)
- Blowout contingency plan (general logistic plans or site-specific plans with relief well details)
- Engineering modeling
- Mobilization of resources to control the blowout (first wave of equipment and personnel)
- Means for taking and verifying appropriate responses.
Many multinational operators have decentralized their operations because of current business and management philosophies and trends. Operators have assigned more responsibility to particular asset centers or business units, which may cover or overlap different geographical regions. Although decentralization can give the on-site management greater involvement in decisions, it can pose some difficulty in setting corporate standards for handling risks.
A decentralized organizational structure can create confusion about internal responsibility. For example, the business unit (asset center) has responsibility for the blowout event, but the liability may not rest entirely with the business unit. A major blowout can have enormous costs and use many resources.
Does the company's business unit or the corporation have responsibility? Which one makes the decisions about well control? Mich handles publicity? Which pays for the control effort and pollution cleanup, if necessary?
These questions are difficult to answer for domestic operations and become more difficult to answer with increasing worldwide operations for many companies. In some international regions, uncommon well types, different political environments, remote locations, and difficult logistics can complicate a company's ability to react properly and quickly during a blowout.
Another complication is that the asset center alone may not be able to cope with the problem because of a lack of staff and technical support. Because a blowout has the potential to be a huge liability, the corporation may want written assurance that the response and reactions are both effective and uniform. In other words, the corporate structure must be poised to come to the aid of the business unit with technical and operational support.
Obviously, the business unit and corporate organization must determine a coordinated effort, and this effort can be determined effectively in a blowout contingency plan. Procedures and guidelines must therefore be in place before a blowout occurs.
RESPONSE PLANS
Most operators have comprehensive emergency response plans to deal with events such as tanker spills, pipeline ruptures, and hurricanes. In some operational regions, operators have set up crisis control centers that provide staffing to deal with emergency response in these cases.
One excellent example of such a center is BP Exploration's Dyce Operational Control Center in Aberdeen. In this center, the duty manager is charged with implementing the emergency response. The center's staff comes from a variety of disciplines. This staff has access to state-of-the-art communications and computer equipment, and most importantly, they have the authority and resources to deal with the initial phases of the emergency. Computers assist participants by prompting them with checklists, phone lists, and procedures.
A video record of each facility is also maintained for review by the emergency staff, if needed. Centers like these can be very useful and effective in initiating a predetermined plan for the reaction to a blowout.
In its initial phase, a blowout can be handled by general emergency response procedures. Emergency procedures are usually designed to deal with evacuation, accountability of personnel, medical needs of survivors, and mobilization of pollution control efforts. At some time after the event begins, the emergency response team will hand over the responsibility to a team designated to organize or initiate the steps to control the blowout. This transition can be smooth and uneventful if a predetermined plan is in place (Fig. 1). For blowouts, most emergency plans conclude when the facility is abandoned and a fire watch is initiated.
The overall response should be divided into two distinct phases: the immediate response plan and the blowout contingency plan.
IMMEDIATE RESPONSE PLAN
The immediate response plan is designed to initiate an immediate reaction to a blowout and covers only the first few hours of the event. The immediate response plan intends to accomplish the following:
- Evaluate the situation by gathering accurate data.
- Mobilize the necessary experts (well control and firefighting equipment).
- Assemble key personnel of the management team to control the blowout.
- Notify the necessary authorities and insurance carriers.
- Handle initial media releases, legal requirements, and partner relations.
The immediate response plan can be initiated and controlled from a crisis center or other designated site, provided adequate, real-time communications are available. The immediate response plan must provide a consistent and predetermined reaction to all blowouts. Key personnel from inside and outside the company must be placed in the "information loop."
The immediate response plan is a means for the business unit or regional management to notify corporate management quickly and effectively that an event is occurring. This plan can also be used to bring together expertise early when a possible blowout is pending and perhaps prevent the situation from becoming uncontrolled. In some cases, taking critical action early may also mitigate the loss to a minor event rather than a major event. For example, an external source of fire water could be obtained, before a fire occurs, to prevent ignition of the flow, thereby saving the drilling facility.
The immediate response plan can be organized to have a procedure for calling out critical personnel and equipment. This first wave of mobilization could include firefighting equipment and well control personnel. In some cases, there may be a quick solution to the problem, and this window of opportunity may close within a short time. For example, some minor leaks can be stopped without great effort, but over time erosion may escalate the leak so that a complicated or difficult procedure may be required. The goal of an immediate response plan is to keep personnel in a position to take advantage of a quick solution if it is at all possible.
Certain problems can be addressed in the immediate response plan. For instance, the procedures can cover ignition of the flow, personnel safety, or pollution prevention. Serious decisions like these should be determined before the event rather than afterwards.
Guidelines as to who will make this decision (business unit or at the corporate level) can be determined as the plan is prepared.
Placing knowledgeable, experienced people at the scene is one of the most important roles of the immediate response plan. Also, a company-wide immediate response plan should produce a consistent response for all operational areas worldwide. This plan should make a smooth transition from the immediate reaction to the control effort.
BLOWOUT CONTINGENCY PLAN
For effective and efficient well control, a predetermined plan should be in place that can be activated. Well control events are best managed with project management techniques, with an organizational structure in place to control the blowout.
Capping and firefighting operations are unique; infinite scenarios exist for the conditions and the precise operation necessary for control. Therefore, it is impossible to predetermine a precise operational action plan, as it might be possible to do for a construction project.
It is possible, however, to plan the type of logistics necessary to support a firefighting and capping operation. Firefighting and capping operations do not vary notably for various reservoir conditions. These operations, however, do vary significantly for the type of operation (land, offshore, or shallow water).
Relief well plans are an integral part of the overall contingency for dealing with a blowout, even though most blowouts have been solved by capping operations and not by relief wells. In deepwater operations, a relief well may well be the only means available to control a blowout. A proper relief well design requires analyses that take into account reservoir conditions. Complicated modeling to determine kill requirements should also take into account two phase flow behavior.
Careful study of the surface conditions and weather patterns may be required before the relief well surface location is chosen. Subsurface lithology must be considered in the overall design of the relief well. Extensive engineering is required to generate a specific plan.
An operator has three options for planning before a well control event occurs:
- Use no preplanning and react only after a blowout occurs.
- Develop a general plan that is basically firefighting and capping only (logistics, operational structure, and perhaps a generic relief well plan and capping plan).
- Create a site-specific plan for a given reservoir (relief well plan, pumping requirements, and detailed capping scenarios).
The latter two options are the only responsible avenues. It is neither prudent nor acceptable for an operator to take crisis risks, no matter how unlikely, and address them only after they occur.
REGIONAL
A regional blowout contingency plan is a general or generic well control plan that addresses firefighting and capping operations for a particular geographic area (Gulf of Mexico, Alaska, Southeast Asia, northern South America, southern South America, Europe, the North Sea, the Middle East, West Africa, and the former Soviet Union).
For a regional plan, the logistical support can be predicted fairly accurately, yet exact capping procedures cannot be predetermined. Generic capping plans can include the logistical support necessary, but it is impossible to predict the exact steps and procedures that will be necessary in a capping operation.
Regional plans can group types of wells that may require similar firefighting and capping intervention techniques. In the Gulf Coast region, for example, onshore, offshore floating, inland water (shallow water), and offshore bottom supported drilling operations each require unique intervention methods.
Within a specific geographic region, well types can be subgrouped into logistical support groups, which correspond to general areas (Fig. 2). The coverage area of a regional plan is not wholly bound geographically; rather, the wells in a particular geographic region fit into a common category of well type. These well types are grouped by pressure (abnormal or normal), fluid type (oil or gas), H2S content, or other considerations that may require special equipment.
The capping and firefighting plans should be written based on well types and logistical support requirements. Logistics, rather than reservoir and formation characteristics, govern capping operations. It makes little sense to support an offshore capping operation from an onshore logistical base, yet onshore operations may be adequately supported from an offshore base.
If the wellhead is accessible following a blowout, it is often better to concentrate on a capping operation rather than immediately beginning work on a relief well.
SITE SPECIFIC
Site-specific plans match specific equipment to the reservoir conditions and parameters. For example, if the well flow is to be diverted, the diverter lines must be sized and detailed beforehand.
Capping operations, however, are very similar for all types of wells. Capping equipment may vary according to pressure ratings and specifications. But while capping procedures are generally the same, a site-specific capping plan will not vary appreciably from a generic capping plan.
The relief well plan is the major difference between site-specific and regional blowout contingency plans. A relief well plan can only be prepared in detail if certain drilling and reservoir parameters are known, which may not be the case for some exploration wells. The relief well strategy designates casing selection, casing seat design, trajectory, and well convergence.
Additionally, the plan must determine the pumping requirements to kill the blowing well, which requires, at minimum, two-phase flow modeling. Effective two-phase flow modeling requires sophisticated computer programs and many engineering man-hours. Furthermore, numerous scenarios must be investigated and analyzed completely. Thus, the cost to prepare a detailed plan can be quite substantial.
The decision to generate a site-specific plan instead of a regional plan must be determined based on the perceived risk and the potential benefit the plan will have on any control effort. If a site-specific plan can significantly reduce the time to control the blowout, its cost and effort are justifiable. Likewise, if the risk of pollution or other losses is extremely high, a site-specific plan can also be easily justified.
Marginally productive wells or wells for which a capping solution is extremely likely may not justify the cost and effort for a site-specific plan.
The site-specific plan cannot address every possibility, so certain likely scenarios must first be determined. Obviously, there is an inherent risk that the plan may not address the actual situation, and major procedural modifications may be necessary during the operation.
Site-specific plans are only justified if the risk and potential for loss are high and if capping operations have a low probability of success. Fig. 3 shows the decision process for generating immediate response plans, blowout contingency plans, and training exercises.
RECOMMENDATIONS
As an absolute minimum, blowout contingency plans should be generated on a regional basis. Immediate response plans should be created for worldwide operations.
In each region of operation there should be two blowout contingency plans created:
- One for capping operations for each type of well (onshore, offshore floating, inland water, jack up or bottom supported platform) being drilled or operated in a region
- Site-specific relief well plans should be considered for floating operations and those specific assets that represent large risks for the operator.
Once these plans are in place, the operator should consider advanced well control training courses for key members of the operations staff. These courses improve technology transfer within a company and keep the staff fresh with regard to firefighting and capping engineering and techniques.
Twice yearly, the blowout contingency plan and immediate response plan should be tested with exercises and drills that involve the operations staff, support vendors, and a well control company. The exercises should be unannounced and include full records of the responses. Each exercise should address specific scenarios that match a known potential for loss of control. These exercises can be combined with some spill drills to increase staff effectiveness and to improve procedures. Inherent weaknesses or flaws in the plans can be found if the exercises are done properly.
Table 1 lists the pros and cons of generic regional and site-specific blowout contingency plans.
The benefit of having immediate response and blowout contingency plans will only be proven if a well control event actually occurs. Experience has shown that the return on investment for such plans can be greater than 500:1.
BIBLIOGRAPHY
1. Peters, T.T., and Waterman, R.H. Jr., In Search of Excellence, Wagner Books, New York, 1984, p. 137.
2. Abel, L.W., "Blowout risks cut with contingency plan," OGJ, June 7, 1993, pp. 30-36.
3. Abel, L.W., Bowden, J.R. Sr., and Campbell, P.J., Firefighting and Blowout Control, Wild Well Control Inc., Spring, Tex., 504 pp.
4. Oberlender, G.D., Project Management for Engineering and Construction, McGraw-Hill Inc., New York, 1993.
Copyright 1995 Oil & Gas Journal. All Rights Reserved.
