'Safety of drilling systems'

To understand the 'Safety of Drilling Systems', we must first and foremost know the fundamentals that go into de?ning the specifics of the 'Drilling' discipline.

A system that is simply de?ned as a group of interconnected elements that are united to form a single 'Drilling' entity. Drilling Systems may include something as simple as a block and tackle hoisting system to a far more complex 'logging while drilling' bottom hole assembly system, with all component parts involved.

The most important thing about the 'Safety of Drilling systems' is that they can be further de?ned into subsystems, types of assemblies, subassemblies, and components. If the sub systems contain interdependent entities, they can be de?ned as further systems. For example, a draw works braking or compensation system can be de?ned as either a stand-alone system or a subsystem of a main system. Drilling has several main systems.

‘‘Drilling Safety’’ itself must be succinctly de?ned e.g. To assure that all drilling systems and processes are free from the likely-hood of failure, damage, loss, or harm.

Roland and Moriarty (1990, p. 7) state that safety in a system is ‘‘a quality of a system that allows the system to function under predetermined conditions with an acceptable minimum of accidental loss.’’

Note: In this authors experience the standard norm, is generally, even in the best wells ever drilled, a far distance from zero accident /incident free, due to all the systems, elements, hazards, risks and complexities involved.

Drilling System hazards defined as anything that can possibly cause danger, loss or harm to sub systems, tools, equipment, personnel, property, productivity loss or the environment. "It is a set of circumstances and conditions that has the potential, under the right conditions. "To result in loss"

Drilling Risks involves the probability that drilling systems accidents / incidents can result. e.g. Loss circulation in a particular region results in one of every two wellbore sections interval drilled.

The magnitude of risk, once loss circulation is determined and evaluated (inclusive of the probability, time, impact and cost of loss), the more important it is to act to mitigate this particular and other drilling hazards.

Where to assure a safe drilling system entity, a far more diagnostic and proactive (real time advisory) approach is to be viewed as preferred to a more current standard of response, reaction and cure.

‘‘Drilling System Accident’’, is a dynamic occurrence caused by the activation of a hazard and consists of a number of interrelated events that, Result in loss.

Note: It is estimated from studies, that

• 95-97% of drilling systems accidental loss are caused by tools, equipment, personnel, property, productivity, or environment damage or harm.
• <3-5% of accident loss results from injury or harm to individual(s).

'Drilling Systems Incident', A related term that commonly used to refer to accidents, but is actually a different kind of  event.  An ‘‘incident’’ is an unplanned event that may or may not have an adverse impact or loss effect. An incident is simply termed as an occurrence with No or minimal loss". Sometimes referred to as ‘‘near misses.’’

'Safety of Drilling Systems' de?ned as ‘‘A optimal degree of safety, established within the constraints of drilling operational, 'quality, time, and cost metrics'. . . achievable and desired throughout all phases of a safe drilling systems, life cycle’’

(Malasky, 1982, p. 17). The system-safety concept deals with the before-the-fact identi?cation of hazards as opposed to the after-the-fact response, react and cure implementation approach too often evident.

Considering the Deepwater Horizon disaster, a series of several accident events resulted where major problems existed that attempted to be resolved. If those involved applied a more rigorous, structured and evidence based Safer, Drilling systems approach as defined, measured managed and controlled within this memorandum.

What would have resulted is that all accident / incident loss events should have been gathered, recognised analysed and identified as safety within all planning, design, phases and also far better determined, revaluated, and acted upon during implementation.

In respect of the several problems illustrated. Even if no other solution to resolve was applied, safer instructions and individual actions may have resulted to prevent the catastrophic failures, fatalities and oil spill that resulted.

A 'Safety Drilling Systems' focus of actions and corrections taken far earlier in the accident failure chain to significantly minimize and reduce the extent impact and consequential loss that resulted.

A key learning to translate and sustain from such disasters, is that those responsible must take full notice of major findings recommended, i.e.

"There is a wide scope to improve within current processes to ensure that lessons are learned not just from major (Drilling Systems) Accidents but from every (Drilling Systems) Incident, and lost time events inclusive of all near-misses and unexpected occurrences."

References

• Ferry, T. S. 1988. Modern Accident Investigation and Analysis, 2nd ed. New York: John Wiley & Sons.
• Malasky, S. W. 1982. System Safety: Technology and Application, 2nd ed. New York: Garland STPM Press.
• Roland, H. E. and Moriarty, B. 1990. System Safety Engineering and Management, 2nd ed. New York: John Wiley & Sons.