Well integrity sits at the core of drilling, production, decommissioning and energy transition processes, combining technical, operational and organizational solutions to maximize containment throughout the entire life cycle of a well. In other words, well integrity is what you do when nobody's looking, and takes place in every phase of the well’s life, from design right through to decommissioning and conversion many years later.
All involved parties have a shared responsibility in maintaining well integrity, from the design engineers and service providers delivering the equipment, to well construction personnel and those operating it on site.
Failing to implement a robust well integrity management system, and employing skilled people who can operate the well safely to prevent accidental releases, can have catastrophic consequences. If the well’s integrity is compromised, this can potentially lead to a blowout which in turn can result in the loss of lives, heavily pollute the environment, and affect a company financially - all three of which were seen in the blowout from the Macondo well in the Gulf of Mexico.
In order to optimize well integrity management, it’s important to fully understand what it is and how it is implemented at every phase of a well’s lifecycle. To help you go about optimizing an existing well, or set up a robust integrity management system for the lifecycle of a new well, Terje Løkke-Sørensen, Add Energy’s Chief Technical Officer and co-author of the world-class NORSOK Well Integrity Standard, has shared insights into how you can effectively manage well integrity throughout its entire lifecycle...
1. The planning phase
“During the planning phase, the well and the well barriers, such as casing, cement and tubing, are selected to withstand worst case exposure to pressures and temperatures, as well as erosion and corrosion mechanisms which can reduce its strength. The chosen solution must be robust for the expected lifetime of the well, which can be anywhere from 10 – 30 years, with a solution for abandonment at the end of the well's life also included in the design.
“In order to optimize performance and ensure that a well is operating safely and efficiently, it’s likely that changes will take place during the formative stages of planning and design. Although these changes may be necessary, it’s fundamental that they are carefully assessed for any negative impact on well integrity, with approvals and input from the well integrity team.
“Too often we see a breakdown in communication of the operating limits during the design and production process, with key verification steps and handover information reduced in order to save costs and stay on schedule.”
2. The construction phase
“As the well is constructed on site - either onshore or offshore - consecutive hole sections are drilled and cased off with steel pipe and cement until the reservoir is reached. All these activities must be conducted with two well barriers in place, with the long term barriers in the final well verified by pressure testing and logging to ensure effective well integrity.
“A well barrier is composed of some of the same materials that create the well - with stringent performance criteria attached to prevent flow of fluids from a reservoir to the surface. This process can be further illustrated by imagining a champagne bottle – where the champagne equals hydrocarbons, while the bottle and cork is the container keeping it in place until you open it.
“To further reduce any risks, a secondary well barrier is constructed to encapsulate the primary well barrier. Using the champagne analogy – the champagne bottle is placed in a leak tight box during transport and storage to prevent any leaks.”
3. The production phase
“The production and/or injection phases constitute the longest period in a well’s life. Managing well integrity during this time involves verification of accessible barrier components, such as downhole safety valves and production trees, which are routinely pressure tested.
“Pressure inside the casing and tubing annuli must also be monitored regularly for potential leaks and corrosion, and injection of scaling inhibitive chemicals takes place if required. Replacement of downhole components, such as chemical injection valves, gas lift valves and down hole safety valves, may occur by use of wireline or coiled tubing to maintain the safe performance of the well.
“Additionally, once the well is in operation, monitoring any changes made and procedures carried out over time, such as initial clean up, shut-ins or maintenance, is crucial - whether data is collected and stored using a straightforward system or more complex software. Assessing these changes will allow for problems to be identified and resolved more quickly before they become more costly and harder to control.
“While the processes are crucial, successful well integrity management requires competent people on the job, who will work in compliance with defined standards - such as NORSOK D-010 and regulatory requirements - and document what they do for future use. At the top of the chain, you need a supportive manager who is passionate about well integrity, as it often comes down to choosing a more costly solution, rather than opting for a shortcut that will cost less financially.
“Companies who struggle to manage well integrity effectively are often those facing resource constraints, either in terms of the number of people in the team, or failing to have people with the necessary skills. When cost-saving initiatives and budget cuts sweep the industry, it is common for managers to overlook what will be more effective in favor of what will cost less in the short term, which ultimately carries a higher risk of losing control of the well, or remedial work later which will mean additional costs and lost production - so it’s crucial that you have the right team for the job.”
4. The abandonment phase
Abandonment takes place at the end of the well’s life, where components of the well are removed to allow the setting of two permanent barriers, which normally consists of cement and steel.
Robust barriers must be constructed, set and verified so they can contain any leaks from reservoirs and zones for infinity. This means that we have to consider possible pressure recharging from aquifers or injection of CO2 for that matters. Re-entering an abandoned well to fix leaks can be a very costly exercise.
5 top tips for achieving well integrity successfully
“In my experience, there are a handful of fundamental principles and practices that when implemented, result in effective well integrity:
- Understand exactly what well integrity is and how to apply it throughout the life cycle of the well
- Establish clear and concise requirements and guidelines to well integrity in place
- Have managers in place that support well integrity - even when it costs more, but ultimately reduces risks
- Ensure all changes in plans, design, materials, tools and operational execution are carefully assessed for negative impact on well integrity and get this approved
- Conduct regular training in response to unplanned situations and have workable emergency response plans.”
How can Add Energy help you overcome well integrity challenges
We have a team of well integrity experts on-hand to assess procedures and processes relating to the prevention and mitigation of an uncontrolled flow from wells to protect life, assets and the environment. We can:
- Set-up of a complete well integrity management system, compliant with applicable standards and legislation
- Conduct technical integrity assessments, to categorize the wells and identify risk mitigation requirements
- Conduct well integrity examinations, and develop programs to measure compliance, integrity gaps and propose solutions to enhance integrity
- Conduct thorough well integrity investigations of incidents, to identify the cause and provide recommended actions to prevent incident reinsurance
- Provide advisors, specialists and consultants to work as integrated members of your team, in the office, on the rig or at the well site
- Be your nominated expert witness in court and litigation cases
We have also recently launched a series of online well integrity training courses, ranging from providing learners with a deeper understanding of the basic well integrity principles, through to blowout contingency planning and operational shut-down criteria.