The complexity of drilling and producing a well today increasingly depends on more than a single-solution answer. However brilliant the individual technology or methodology utilized, it is only a part of an extended process made up of many components. Building process safety and economics into the life of a well requires orchestrating this diverse, sometimes overlapping mix of capabilities to meet very specific objectives.
Well integrity management spans all phases of well construction, from the original well engineering and planning to its completion and production, culminating in abandonment as a continuous, interrelated process.
It is vital that the well is completed in a fashion that provides effective barriers at the surface and subsurface, to safely contain and control the flow of fluids from the various formations that the well penetrates. This integrity must be maintained throughout the well’s lifetime—through well construction, completion, production, intervention, decommissioning and abandonment—regardless of changes in reservoir pressures.
Basis of design. Effective well integrity management considers the full spectrum of activities as the basis for designing, drilling and completing a secure well safely, economically, and in an environmentally responsible manner, such that well integrity can be maintained throughout the well’s life. The completed well can be considered as a secure subsurface pressure vessel with effective barriers that safely contain and control the flow of all fluids, into or out of the well. Maintaining that pressure vessel from construction through abandonment is the key objective.
As operators develop assets with increasing complexity and more demanding economics, the intrinsic value of well integrity management evolves from a thinking process that considers drilling constraints, operational efficiency, and process safety.
Asking questions. This process is driven by a series of key questions that begins with, “how can I safely and most efficiently drill this well?” From deepwater pressure management to complex wellbore geometries and formations, finding the safest, most economical way to drill and complete a well, that assures a lifetime of integrity, is a major challenge.
Increasingly, doing so requires a rather sophisticated, long-term view to the question of how to improve the well’s economics. Closely linked is the priority of how to manage and deliver both operational and process safety.
Developing answers. Well integrity management integrates well engineering, project execution, risk management, and process safety throughout the life of the well.
Equally important, the process incorporates reliable “first time” execution. This ability to make quality execution “routine” is achieved by employing rigorous project management, from well engineering through all stages of drilling and completion. The objective is that there are no surprises during well construction. Important to this process is the collaboration between key stakeholders while considering multiple options to achieving objectives.
Driving the process. The primary elements of well integrity are design, drill, construct, produce, intervene and abandon. Well design involves planning, to make certain that proper design and engineering are conducted to achieve all the well objectives. This incorporates a strong element of risk management in analyzing and minimizing risks, managing and mitigating drilling hazards, considering appropriate technology in terms of both application and availability, and establishing process safety.
In managing risks while drilling, one considers the application of a broad scope of technologies and methodologies. For example, wellbore pressure management using closed-loop drilling techniques depends on technologies, integrated with the marine riser system. Solid, expandable tubulars provide many unique solutions in planned and contingency applications, helping to conserve hole size, to reach TD and enable the optimal completion. Drilling and reaming with casing creates new drilling options for overcoming problematic hole sections and ensuring planned casing seats. While each of these technologies plays a vital role, collaborative engineering, and operations to apply and effectively execute these into the well, are the keys to delivering well integrity.
Lifetime integrity. Assuring long-term wellbore performance and stability involves several key components, of which comprehensive tubular running services is critical. This process includes tubular management services, as well as advanced technologies, including new casing running and drilling systems, and drillable casing bits. Construction must also involve best-in-class cementation equipment, from specialized casing shoes to swellable elastomer packers.
Well integrity must also be maintained throughout the production phase, which can be more than 30 years. This phase has its own unique mix of potential challenges to preserving the “pressure vessel,” but with constantly evolving technologies to address the well’s aging process challenges. Evaluation methods, such as wireline logs, need to reliably assure cement quality and provide casing inspection, and leak detection to ensure zonal isolation.
Other technologies, such as solid expandable tubulars, provide new intervention options for casing repair while ensuring HSE compliance.
The complexity of these challenges demands a sophisticated solution that orchestrates many technologies and components. This solution builds process safety and economics through well integrity management focused on long-term success.