Challenging The Industry’s Approach To Well Diagnostics

The Chorus tool, part of the Chorus diagnostic platform, reveals flow throughout the well system so the operator can use the information to elevate well system performance. (Source: TGT)

When oil prices fell in 2014, E&P companies were forced to tighten capital budgets, reduce activity levels and drive down costs. The ensuing stampede to cost reduction hit upstream oilfield service companies extremely hard.

Today, with the oil price stabilizing, operators are more inclined to push their assets harder to produce more. However, when budgets were slashed, planned maintenance and workovers were among the first to be cut or deferred, while still treading the line not to compromise on safety. Securing asset reliability is still a top priority, ensuring that wells perform at full capacity while safeguarding life and the environment.

“Wells need to perform better and last longer,” TGT CEO Mohamed Hegazi said. “Operators need to elevate well performance and need the ingenuity of oilfield service companies to do this more effectively. In today’s economic climate, we have an obligation to challenge the old way of thinking by being bold and innovative so that customers can capture more value and address well performance challenges more readily.”

For all asset managers, a key area of vulnerability lies in the happenings thousands of meters away from the surface—downhole.

A new way of thinking

Like a giant industrial plumbing system fused into the earth, wells are built using a fantastically complex assembly of tubes, barriers and cement, most of which exist around a central producing conduit. Their sole purpose is to transport valuable fluids safely, productively and profitably.

Unfortunately, it is an imperfect world where natural forces conspire to undermine the perfect functioning of the well, and despite the ingenuity of man, the well will inevitably misbehave or fail. Naturally, the industry is focused on wells and reservoirs. However, conventional definitions and diagnostics of the well tend to isolate the well completion from the reservoir, and yet the two are so inextricably linked they should never be separated because they work as one.

Therefore, a new definition of the well is needed, one that recognizes the performance attributes of the completion and the reservoir it connects to, the interplay between the two and the dynamics of the entire system. What the industry is dealing with is not just a well; it is a well system. The industry also needs to recognize the two most vital performance factors of all well systems—flow and integrity.

Flow is about the right fluids connecting to the right places, and integrity makes sure that happens without compromise. So, managing well system performance effectively means managing flow and integrity, and not much else matters.

“Diagnosing well system performance is challenging,” Hegazi said. “Flow and integrity issues can exist anywhere within the well system: beyond the wellbore, behind multiple casings to the outer reaches of the well system and in the reservoir itself—a place virtually impossible to deploy diagnostic sensors.”

Conventional diagnostics can’t provide all the answers because they either do not look far enough or don’t measure the right things; they do not look at the big picture. Rogue happenings, such as active thief zones, crossflow or the source of sustained annulus pressure lurk behind barriers and would not be diagnosed with traditional techniques.

TGT

The definition of the well system includes the man-made well completion up to and including the reservoir. (Source: TGT)

Creating a new category

Flow and integrity, and therefore well system performance, can only be properly understood and managed by assessing more than the inner workings of the wellbore. This concept is the foundation of a new and important oilfield category applicable to all wells, through-barrier diagnostics.

Diagnostic tools that “sense through barriers” have existed for decades and overlap into this category, but apart from a few exceptions, these have been primarily concerned with investigating reservoir properties, such as matrix and fluid parameters, or evaluating cement.

Acknowledging and advancing through-barrier diagnostics as a new category offers a look at the well system in a far more holistic and uncompromising way. The ability to see through multiple barriers from the wellbore into the reservoir and everything in between reveals more than ever before. Viewing the well system in its entirety provides operators with a complete picture of the goings on, both flow and integrity related. Moreover, equipped with better insights, operators are much better placed to make the right decisions to keep the entire system working harder.

Diagnostic tools versus systems

Maintaining safe, productive and profitable operations means that all well systems at some point will require diagnostic intervention, either for routine monitoring or to target a specific issue.

When it comes to diagnostics, tools tend to dominate oilfield conversations, technical forums and procurement practices, and the operational focus tends to be on running the tool in the well. If a well system is experiencing unexpected sand flow, ineffective stimulation or fracturing, or sustained annulus pressure, the operator commissions a service company to deploy a certain tool in the belief that the tool itself will provide all the answers. The reality is not that simple.

In isolation, the tool gives raw data and measurements, but revealing the truth about the well system requires more than the tool. The tool’s sensitivity and accuracy are extremely important, but many other factors beyond it contribute to the overall diagnostic result.

The synergy happens in all facets of the service, not just the tool. The diagnostic program activates the well, the method for acquiring the data, processing and modeling to refine and expand raw data, and the expertise in analysis and interpretation, which all play a vital part. The results and insights materialize from the combined effort of all these factors—an entire diagnostic system, curated and applied by human experts.

There is no doubt that advancing diagnostics to deal with today’s challenges means evolving from tools to diagnostic systems on all fronts. However, there is a need to go one step farther.

From systems come products
What the operator ultimately needs is answers. There is an interest in making sure the right diagnostic system is utilized, but the purchasing decision should be ultimately based on the clarity and completeness of the answer because this is the final product in the diagnostic workflow.

Consider the case in which a well suddenly exhibits flow issues, such as a dramatic increase in water cut, or complex integrity issues, such as sustained pressure in the C-annulus. In this case, the operator is more concerned about getting an answer it can trust to solve these issues, not what tool or system to use.

“An application-led ‘products’ approach versus a traditional ‘tools’ approach allows for improved product selection and commercial flexibility, benefiting operators on both counts,” Hegazi said. “Operators certainly appreciate technology, but they are ultimately seeking diagnostic answers that can help them make better decisions.”

He added, “A mechanism should be adopted where simpler products, such as diagnosing wellbore flow, demand fewer resources and less innovation commands a lower price. Whereas more complex products, like multibarrier diagnostics, that have years of research and development behind them, demand more extensive resources and ultimately deliver more value, [and] naturally command a higher price.”

A bright future

The old thinking cannot answer today’s new challenges. As well systems become older and more complex, managing performance will remain a priority and continue to task the industry. That is why there is a need to innovate on all levels, by building better tools and also creating better diagnostic systems and recognizing the experts that empower them. The industry needs to acknowledge the dual importance of flow and integrity as the key enablers for asset performance and the criticality
of through-barrier diagnostics as the only means to see the true picture. Finally, the need exists to adopt a product-led approach to procurement, where the answer is king and not the tool. Do all that, and the future looks bright.