What is Drilling Optimisation?
While there are many definitions of drilling optimisation, one I prefer can be found in the 1986 book ‘Drilling Fluid Optimisation, a Practical Field Approach’ by James L. Lummus and J.J. Azar,
“Drilling optimisation is the logical process of analysing effects and interactions of drilling variables through mathematical modelling to achieve maximum drilling efficiency. The process involves the post-appraisal of offset well records to determine the cost effectiveness of selected controllable variables, which include mud type, hydraulics, bit type, weight on bit, and rotary speed. The variables that offer the best potential for improving the drilling process are identified. A final optimised drilling programme is prepared and then will be implemented in the field. Flexibility should be built into the program allow field application changes that may be dictated when unexpected problems are encountered.”
This detailed description neatly describes the delivery process that can be easily transposed into a Plan-Do-Act-Check or similar cycle, though highly focused on the process of planning rather than the doing and there is good reason for this. Changes made in the planning and design phases of well construction present significantly less cost and risk than during the construction phase. And the statement that ‘flexibility should be built into the program’ highlights the expectation of a level of uncertainty and risk present that cannot be adequately managed by the plan alone. For this reason, teams need to be built with operational resilience in mind to maintain an optimisation approach.
Be Flexible but be Resilient
To approach delivery with a degree of flexibility in the presence of uncertainty we can introduce systems and processes to make us resilient. For example, using the six principles of long-lasting systems we can see approaches that could be taken to introduce resilience into drilling operations:
Redundancy: teams backed by trusted advisors and coaches allow the drilling process to be buffered against the shock of unexpected events. This is a common method of building resilience through experience. Examples of this would include during a complex well delivery to have drilling teams members with experience backed up by expert advisors to improve system redundancy.
Diversity: teams made up of operator, drilling contractor and service company staff already introduce a level of diversity in response to unexpected events that can reduce the risk of a catastrophic failure. Specific leadership styles are often required to leverage and act on effective insights within this diverse team, while some styles will suppress insight development and limit the ability to respond to unexpected challenges.
Modularity: the ability for individual elements to fail without collapsing the system is not always perceived to be present in the drilling systems and teams. System and team elements should be constructed to allow for continued operation with single element failures, albeit at reduced efficiency. An example of this modularoity can be seen in an example from the 2000’s; a 2 person DD crew offshore fell ill during a crucial motor kick off, by pivoting the system of operational support motor kick off was able to to be performed remotely from an office location some 340 km away for an extended period.
Adaptability: while it may be perceived that the nature of drilling risk uncertainty promotes the ability to adapt when faced with an unexpected event, this is not necessarily the situation observed. In a number of global operations it’s observed that some organisations promote a culture where adaptability is suppressed in favour of the “this is the way of we have always done it”. This presents a significant challenge to optimisation and efficiency in the face of uncertainty.
Prudence: operating on the precautionary principle is a key system design in oilfield drilling due to environmental, cost and reputational risks involved in well construction. While wellsite teams already monitor for early warning signals, their inclusion in scenario planning, early design reviews and exercises yields significant advantages. Taking this principal further not only is learning from past experiences vital to being prudent, but so is understanding the competency gaps in drilling teams particularly prior to higher risk operations.
Emdeddedness: the alignment of goals of the operation throughout the broader system. This alignment across the broader system of teams and groups indirectly involved in deliver has long been identified as critical to the success of the operation. Commonly this is reliant on wellsite teams being dependent on the connections with and between office teams to ensure operations deliver in challenging operations. An example of where this embedded alignment of goals has been eroded and had a negative individual operation impact is in some of the centralised logistics strategies that focused on cost efficiencies resulting in market competition being introduced between operations for the delivery of equipment that introduced a greater level of risk in the face of individual operation challenges.
Drilling Resilience as a Risk Focused Organisational Culture?
Reviewing the long-lasting systems approach of resilience it can be seen to be closely analogous to the characteristics of a High Reliability Organisation for drilling:
Preoccupation with Failure: the chronic unease about safety, analytic errors, unexplained failures. Alert to integrity of safety barriers, alert to data and procedure shortcomings.
Reluctance to Simplify: the simplification that is believed to be essential to ‘get the job done’ is resisted through checks & balanced, reviews etc. Technical work is rigorous and documented and independently reviewed.
Sensitivity to Operations: teams are organised so that everybody is aware of what is going on, what it means and what may happen. The organisation is focused on supporting the operations with a raised level of alertness to safety critical operations.
Cultivate Resilience: the organisation is diverse with people and skills to manage the unexpected and respond competently.
Organise around Expertise: technical decisions are referred to those with the expertise to make them.
It is from these analogous characteristics that we can draw the conclusion that resilience in and optimisation of the drilling process is an organisational culture issue more than just the technical challenge of “getting things done” (and done quickly) which optimisation is sometimes perceived as being. Therefore, drilling optimisation becomes more than the approach of delivering a programme for drilling efficiency to an encompassing risk-based approach to drilling activities that is not only delivers efficient drilling but delivers effective drilling and does not depend on luck to deliver “heroic recoveries” from unexpected challenges, as it has built a system that can pivot to these challenges in a safe, efficient and effective manner.
Where Does That Leave Drilling Efficiency?
To circle back to the originally definition of Drilling Optimisation, commonly I have taken the confrontational approach between Drilling Optimisation and Drilling Efficiency, yet this conflict only exists as a nuanced approach to how these related terms are used since the main purpose of a Drilling Optimisation process is to deliver Drilling Efficiency. As suggested in this article a resilience approach to Drilling Optimisation focused not only on the success case but the uncertainties in operational delivery encompasses more than just Drilling Efficiency yet doesn't reduce its importance to a safe and successful operation.
"Don’t just be efficient; be safe, effective and efficient: be optimised"
References
James L. Lummus, J.J. Azar, (1986): "Drilling Fluid Optimisation, a Practical Field Approach", PennWell Publishing Company
Reeves, M, Levin, S, (2017): "Building A Resilient Business Inspired by Biology", BCG Henderson Institute blog
Reeves, M, Whitaker, K, (2020): "A Guide to Building a More Resilient Business", HBR
Dekker, S, (2011): "Drift into Failure: from hunting broken components to understanding complex systems", Ashgate Publishing
Hopkins, A, (2005): "Safety Culture and Risk", CCH Australia Ltd
Reason, J, (2008): "The Human Contribution", Routledge
Perrow, C, (1984): "Normal Accidents", Princeton University Press
Thorogood, J.L, (2012): "Is there a Place for High Reliability Organisations in Drilling", IADC/SPE paper 151338, presented at 2012 IADC/SPE Drilling Conference and Exhibition, San Diego, California, 6-8 March 2012
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