Integrity and corrosion assessment for successful slot recovery and plugging & abandonment (P&A) applications Article featured in Oilfield Technology   For all plug and abandonment applications, either permanent or for slot recovery, the sealing performance of well system components needs to be assured, and remain intact.    Well systems are complex and need to work perfectly to perform safely, cleanly, and productively. Understanding the condition and sealing performance of well system barriers can be challenging once the well has been brought onstream and access to these elements and components is restricted.     Current mainstream technologies only provide partial answers, leading to an incomplete assessment. However, through-barrier diagnostics look at the well system in a far more holistic and uncompromising way. These technologies have the capability of seeing through multiple barriers to provide a more complete picture of the condition of the metal tubulars and the flow around them to see if the seals are holding, prior to plug and abandonment.     In the case of permanent abandonment, natural barriers that prevent the movement or migration of downhole fluids, must be restored. And the performance of the well system barriers  must remain intact indefinitely.     In the case of slot recovery, the well components must be in good enough condition to be used again for the upcoming production cycle.   A comprehensive integrity assessment is required for either scenario.  Optimising P&A operations Planning and executing a flawless plug and abandonment requires prior knowledge of the integrity of the well barriers, and the precise position of all downhole completion elements. Operators armed with this information can determine the location of the permanent plugs and the best depths for the casing cuts for an optimised retrieval procedure.     During the productive life of a well it may experience several operator changes, perhaps after concessions expire or following divestment decisions. This can often lead to historical data being lost which, when it comes to well decommissioning, can increase the potential for making decisions without knowing all the facts about the well system, particularly the position of the casing collars, fins, centralisers or other components that impede successful decommissioning.     Using a simple multifinger caliper or an ultrasound survey, the location of the first-barrier casing collars can be determined, but the locations of the collars in the subsequent casing strings remain unknown. This approach contains an element of risk and may result in a cut planned directly in line with a thick section of metal, like a casing collar, or fin. Cutting across a collar or a fin, would mean an increase in the rig and intervention time of several hours, or potentially days.    TGT’s Multi Tube Integrity product uses the Pulse electromagnetic sensing platform to provide accurate barrier-by barrier assessment of up to four concentric tubulars (up to 20” diameter) in one single through-tubing deployment. Pulse can also pinpoint to within 1ft the location of completion elements.    The ‘electromagnetic signature’ of each tube or metal completion component, contains information about its wall thickness. The Pulse platform harnesses this information and through 3D modeling, can decipher metal loss as well as metal gain, in multiple casing strings throughout the entire well system.     Pulse can identify the location of known completion elements, but also identify new ones, not expected including welded fins on the outer casing string, often inaccessible to other evaluation technologies.     If Multi Tube Integrity is used prior to the P&A planning, the diagnostic results would remove the uncertainty allowing operators to confirm the optimum cutting window location in all casings, thus minimising the intervention time and reducing rig time and costs.  Integrity & corrosion assessment for slot recovery Slot recovery offers operators a way of capitalising on existing assets, by providing a new means of extending a well’s productive life.     It is a robust solution which utilises the existing surface and downhole infrastructure, to create a “new” offshoot well, which would reduce the costs associated with drilling. However, before this can become a reality, the inspection of downhole completion elements such as surface casing and its cemented annulus are a must.     Limitations in current technologies have meant that barrier verification is performed while the rig is in place, and once the tubulars (production and intermediate casings) have been retrieved.     Key input parameters, such as the cement condition and the integrity of the casing are obtained at the last stage of the planning. The late arrival of this critical information results in a complex well intervention plan, with several contingent scenarios based on a range of potential outcomes from the downhole integrity assessment.     The industry is calling for a new solution. One which can determine the condition and sealing performance of the cement and the metal barriers, prior to planning the slot recovery.  Pulse data showing wall thickness, collars and completion elements in 5 ½ in., 9 5/8 in., 13 3/8 in. and 20 in. tubulars. A powerful diagnostic combination TGT’s Multi Tube Integrity product used together with the Multi Seal Integrity product is the answer. This powerful combination utilises TGT’s Pulse electromagnetic platform, the Chorus acoustic platform and the Indigo multisense platform, and it can be deployed in one through-tubing deployment.   Pulse is used to evaluate the metal thickness of multiple tubulars, including the surface casing. It also has the unique capability of being able to confirm the position of critical completion components, including collars, centralisers, and casing shoes.   Chorus is used to assess the hydraulic seal integrity of the cement barrier to determine where the cement is sealing and where it is not. Fluid flow in the well system creates a rich spectrum of acoustic energy that penetrates the surroundings. This acoustic wave is encoded with information that Chorus can convert into acoustic spectra that can locate leaks and flowpaths throughout the well system, from the wellbore to the outer annuli.   The Pulse, Chorus and Indigo platforms are part of TGT’s True Integrity System which provides a clear diagnosis of integrity dynamics throughout the well system. The key to success It is critical that before slot recovery can be executed, there is an understanding of the collective integrity of the tubes, seals and barriers of the mother well. Only in doing this can there be a guarantee of the secure passage for pressurised fluids.   The key to success for any P&A or slot recovery operation is knowing all the facts about the integrity of the well system prior to planning and execution. This delivers the potential to reduce costs, minimise schedule overruns, and ensures the integrity of the final outcome.

Total well system integrity and ‘the containment and prevention of the escape of fluids’ (ISO TS 16530-2) remains one of the biggest challenges Middle East operators face today. Article featured in Oil and Gas News   The Middle East has been the world’s most prolific oil-producing region for decades with one of the largest populations of ‘hard-working’ aging wells – many of which operate continuously in extreme environmental conditions. More than 70% of the ~800 Middle East platforms and associated well-stock are more than 25 years old.   Not surprisingly, Middle East operators are facing a constant challenge to manage corrosion and sustained annulus pressure [SAP] in their well systems, and are always on the lookout for new innovations to help. This article will provide examples of two such innovations – corrosion surveillance in chrome-based tubulars, and addressing SAP. Overcoming chrome As Middle East well conditions become more corrosive, so operators have looked to more corrosion resistant materials in the completion process, leading to a rise in chrome and nickel content in steel tubulars. However, one unintended side effect is the decrease in the effectiveness of ordinary electromagnetic [EM] well and pipe inspection systems and the tracking of corrosion in multiple barriers.   The increase in chrome and decrease in ferrous content causes EM signals to decay too quickly for such systems to be truly effective in monitoring corrosion and evaluating pipe thickness or metal loss in casing strings. So while corrosion resistance may have increased, there is now a potential information vacuum.   TGT, the market leader in through-barrier diagnostic systems, has developed a new multi-barrier integrity diagnostics system – EmPulse®. The system quantitatively determines individual wall thickness in up to four concentric tubulars, ensuring long-term well performance in the most challenging high-chromium production environments.   The EmPulse system incorporates ‘ultra-fast’ sensor technology, three independent sensors, and ‘time-domain’ measurement techniques to capture EM signals rapidly and accurately in a wide range of pipe materials before the signals decay.   In three recent Middle East deployments – an operator witnessed ‘yard test’ in 28% chrome pipe with built-in mechanical defects, and two live wells – the EmPulse system correctly identified man-made defects and quantitatively determined the individual tubular thickness.   This successful validation in high-chromium tubulars brings important reassurances for Middle East operators in protecting well system integrity – providing accurate corrosion information and addressing a crucial information gap. The case of sustained annulus pressure (SAP) Figure 2: Spectral diagnostics survey revealing source of SAP behind casing at X540m where the cement map indicates ‘good cement’. Another major challenge to Middle East well system integrity is that of SAP – pressure in any well annulus that rebuilds when bled down.   Reasons for SAP can vary but are often due to weaknesses in the cement during completion; cement degradation due to thermal and pressure loading; leaking tubing connections or wellhead seals; and corrosion. According to a 2013 SPE webinar on wellbore integrity [Paul Hopmans], out of ~1.8 million wells worldwide, a staggering 35% have SAP, with many Middle East fields facing varying levels.   Wells with SAP need to be carefully managed and production can be adversely affected or halted. SAP can also cause further damage to the well system, potentially resulting in the failure of the production casing or outer casing strings, and well blowouts.   While many operators are addressing SAP through new well designs and barriers, and better quality control over cementing – with existing wells they are having to rely on surface data – fluid sampling and bleed-off/build-up data, for example – to investigate the problem downhole.   There is also the challenge of being able to locate leaks and unwanted flowpaths behind multiple barriers, not clearly seen by conventional temperature and ordinary noise logs.   TGT’s spectral diagnostics technology locates leaks and flowpaths throughout the well system by tracking fluid movement behind pipes within several casing strings.   Spectral diagnostics utilise high-fidelity downhole sound recording systems to capture the frequency and amplitude of acoustic energy generated by liquids or gas moving through integrity breaches and restrictions such as cement channels, faulty seals and casing leaks. When coupled with surface data, the information can narrow down the range of remedial options available, and target leak repairs.   Spectral diagnostics include fast, high-precision temperature measurements to locate integrity breaches throughout the well system. High-precision temperature sensors respond more quickly than conventional sensors to the localised thermal changes caused by integrity failures, complementing acoustic measurements by providing a visual confirmation of leaks and flowpaths.   While conventional production logging measurements typically assess only high-rate first-barrier failures – the high-fidelity recording, sensitivity and clarity of spectral diagnostics enables the tracking of even low-rate leaks at very early stages behind multiple barriers, enabling timely intervention and prolonging well life. In the following example [figure 2], a water injector well experienced sustained B-annulus pressure, although the build-up rate did not exceed one bar a day – indicating a low-rate leak.   A cement bond survey indicated good cement bonding below X500m, and poor bonding above. Poor cement bonding is likely to provide flowpaths for fluid movement behind casing. Unfortunately, cement bond log indications of ‘good bonding’ don’t guarantee annulus integrity. Flowpaths can exist that remain unnoticed by the cement bond log.   A survey utilising TGT’s spectral diagnostics system was conducted and revealed fluid flow from the reservoir around X540m and channelling up the annulus through the ‘good bonding’ area.   The frequency spectrum pattern correlated with reservoir permeability and fluid-type profiles, suggesting gas being produced from these formations. The operator used the information to target a cement squeeze operation at the desired location in the well – restoring B-annulus integrity and eliminating the SAP. Evolving challenges, new technologies As Middle East operators continue to face well integrity challenges, gaining a deeper insight into both well and reservoir dynamics is vital. Advanced well diagnostics systems are now available to allow this to be achieved.

Total well system integrity and ‘the containment and prevention of the escape of fluids’ (ISO TS 16530-2) remains one of the biggest challenges Middle East operators face today. The Middle East has been the world’s most prolific oil-producing region for decades with one of the largest populations of ‘hard-working’ aging wells – many of which operate continuously in extreme environmental conditions. More than 70% of the ~800 Middle East platforms and associated well-stock are more than 25 years old.   Not surprisingly, Middle East operators are facing a constant challenge to manage corrosion and sustained annulus pressure [SAP] in their well systems, and are always on the lookout for new innovations to help. This article will provide examples of two such innovations – corrosion surveillance in chrome-based tubulars, and addressing SAP. To celebrate, TGT invited employees, customers, and business partners to an evening which relived the company’s scientific breakthroughs using acoustic, thermal and electromagnetic energy to reveal unique answers within and beyond the well bore.   Dr. Arthur Aslanyan, TGT’s Co-Founder commented, “It gave me great pride to attend the event and celebrate the company's 20th anniversary. We have come a long way since we first started the business. We are very excited about our future as the company continues to thrive”.   The event was attended by Saad Bargach, TGT Chairman and LimeRock Partners -private equity investors.   Hegazi continued, “Looking to our future, TGT is releasing several lines of new technologies and applications in coming months to further cement our position as pioneers of Through-Barrier Diagnostics. Our patent technology developments coupled with our unrivalled Geoscience organisation and global footprint, provide unique and reliable diagnostic services to our customers. This has been key in maintaining our fast growth trend and industry reputation. I am confident this foundation along with our excellent teams, will continue to fuel our growth for many years to come. Overcoming chrome As Middle East well conditions become more corrosive, so operators have looked to more corrosion resistant materials in the completion process, leading to a rise in chrome and nickel content in steel tubulars. However, one unintended side effect is the decrease in the effectiveness of ordinary electromagnetic [EM] well and pipe inspection systems and the tracking of corrosion in multiple barriers.   The increase in chrome and decrease in ferrous content causes EM signals to decay too quickly for such systems to be truly effective in monitoring corrosion and evaluating pipe thickness or metal loss in casing strings. So while corrosion resistance may have increased, there is now a potential information vacuum.   TGT, the market leader in through-barrier diagnostic systems, has developed a new multi-barrier integrity diagnostics system – EmPulse®. The system quantitatively determines individual wall thickness in up to four concentric tubulars, ensuring long-term well performance in the most challenging high-chromium production environments.   The EmPulse system incorporates ‘ultra-fast’ sensor technology, three independent sensors, and ‘time-domain’ measurement techniques to capture EM signals rapidly and accurately in a wide range of pipe materials before the signals decay.   In three recent Middle East deployments – an operator witnessed ‘yard test’ in 28% chrome pipe with built-in mechanical defects, and two live wells – the EmPulse system correctly identified man-made defects and quantitatively determined the individual tubular thickness.   This successful validation in high-chromium tubulars brings important reassurances for Middle East operators in protecting well system integrity – providing accurate corrosion information and addressing a crucial information gap. The case of sustained annulus pressure [SAP] Figure 2: Spectral diagnostics survey revealing source of SAP behind casing at X540m where the cement map indicates ‘good cement’. Another major challenge to Middle East well system integrity is that of SAP – pressure in any well annulus that rebuilds when bled down.   Reasons for SAP can vary but are often due to weaknesses in the cement during completion; cement degradation due to thermal and pressure loading; leaking tubing connections or wellhead seals; and corrosion. According to a 2013 SPE webinar on wellbore integrity [Paul Hopmans], out of ~1.8 million wells worldwide, a staggering 35% have SAP, with many Middle East fields facing varying levels.   Wells with SAP need to be carefully managed and production can be adversely affected or halted. SAP can also cause further damage to the well system, potentially resulting in the failure of the production casing or outer casing strings, and well blowouts.   While many operators are addressing SAP through new well designs and barriers, and better quality control over cementing – with existing wells they are having to rely on surface data – fluid sampling and bleed-off/build-up data, for example – to investigate the problem downhole.   There is also the challenge of being able to locate leaks and unwanted flowpaths behind multiple barriers, not clearly seen by conventional temperature and ordinary noise logs.   TGT’s spectral diagnostics technology locates leaks and flowpaths throughout the well system by tracking fluid movement behind pipes within several casing strings.   Spectral diagnostics utilise high-fidelity downhole sound recording systems to capture the frequency and amplitude of acoustic energy generated by liquids or gas moving through integrity breaches and restrictions such as cement channels, faulty seals and casing leaks. When coupled with surface data, the information can narrow down the range of remedial options available, and target leak repairs.   Spectral diagnostics include fast, high-precision temperature measurements to locate integrity breaches throughout the well system. High-precision temperature sensors respond more quickly than conventional sensors to the localised thermal changes caused by integrity failures, complementing acoustic measurements by providing a visual confirmation of leaks and flowpaths.   While conventional production logging measurements typically assess only high-rate first-barrier failures – the high-fidelity recording, sensitivity and clarity of spectral diagnostics enables the tracking of even low-rate leaks at very early stages behind multiple barriers, enabling timely intervention and prolonging well life. In the following example [figure 2], a water injector well experienced sustained B-annulus pressure, although the build-up rate did not exceed one bar a day – indicating a low-rate leak.   A cement bond survey indicated good cement bonding below X500m, and poor bonding above. Poor cement bonding is likely to provide flowpaths for fluid movement behind casing. Unfortunately, cement bond log indications of ‘good bonding’ don’t guarantee annulus integrity. Flowpaths can exist that remain unnoticed by the cement bond log.   A survey utilising TGT’s spectral diagnostics system was conducted and revealed fluid flow from the reservoir around X540m and channelling up the annulus through the ‘good bonding’ area.   The frequency spectrum pattern correlated with reservoir permeability and fluid-type profiles, suggesting gas being produced from these formations. The operator used the information to target a cement squeeze operation at the desired location in the well – restoring B-annulus integrity and eliminating the SAP. Evolving challenges, new technologies  As Middle East operators continue to face well integrity challenges, gaining a deeper insight into both well and reservoir dynamics is vital. Advanced well diagnostics systems are now available to allow this to be achieved.

New ideas that reveal a greater truth Article featured in Harts E&P   When oil prices fell in 2014 exploration and production (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 stablising, operators are more inclined to push their assets harder to produce more. However, when budgets were slashed, planned maintenance and workovers were amongst 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. Operators need to elevate well performance and need the ingenuity of oilfield service companies to do this more effectively”, comments Mohamed Hegazi, Chief Executive Officer, TGT. “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 being to transport valuable fluids safely, productively and profitably.   Unfortunately, we live in 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 obsessed with ‘wells’ and ‘reservoirs’. But 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 – they work as one.   A new definition of the well is therefore needed. One that recognises the performance attributes of the completion and the reservoir it connects to, the interplay between the two, and the dynamics of the entire system. In fact, what we are dealing with isn’t just ‘a well’ – it’s ‘a well system’.   But that’s not enough. We also need to recognise 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. The two most vital performance factors of all well systems, flow and integrity “Diagnosing well system performance is challenging. 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”, adds Mohamed.   Conventional diagnostics can’t provide all the answers because either they don’t look far enough, or measure the right things—they don’t look at the big picture. Rogue happenings, such as active thief zones, cross-flow or the source of sustained annulus pressure lurk behind barriers and wouldn’t be diagnosed with traditional techniques. A new category is born 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 chiefly concerned with investigating reservoir properties, such as matrix and fluid parameters, or evaluating cement.   Acknowledging and advancing through barrier diagnostics as a new category allows us to look at the well system in a far more holistic and uncompromising way. Seeing 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 more complete picture of the goings on, both flow and integrity related. And equipped with better insights, operators are much better placed to make the right decisions to keep the entire system working harder. Diagnostic tools vs. diagnostic 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. But 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 is extremely important, but many other factors beyond the tool contribute to the overall diagnostic result.   The synergy happens in all facets of the service, not just the tool; the diagnostic programme that activates the well, and the method for acquiring the data, the processing and modelling to refine and expand raw data, and the expertise in analysis and interpretation, all play a vital part. The results and insights materialise 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. But we need to go one step further. From systems come products When a well is exhibiting problems, what the operator ultimately needs is answers. Obviously, there’s an interest in making sure that the right diagnostic system is utilised, 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 where 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. Then 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. Operators certainly appreciate technology but are ultimately seeking diagnostic answers that can help them make better decisions”, summarises Mohamed alluding to the approach TGT has adopted.   He adds, “A mechanism should be adopted where simpler products, such as diagnosing wellbore flow, that demand fewer resources and less innovation command a lower price. Whereas more complex products—like multi-barrier diagnostics, that have years of research and development behind them, demand more extensive resources, and ultimately deliver more value, naturally command a higher price.” A bright future The old thinking can’t 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’s why we need to innovate on all levels. Not just by building better tools, but by creating better diagnostic systems and recognising the experts that empower them. We need 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. And last not least, we need 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.

New ideas that reveal a greater truth When oil prices fell in 2014 exploration and production (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 stablising, operators are more inclined to push their assets harder to produce more. However, when budgets were slashed, planned maintenance and workovers were amongst 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. Operators need to elevate well performance and need the ingenuity of oilfield service companies to do this more effectively”, comments Mohamed Hegazi, Chief Executive Officer, TGT. “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 being to transport valuable fluids safely, productively and profitably.   Unfortunately, we live in 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 obsessed with ‘wells’ and ‘reservoirs’. But 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 – they work as one.   A new definition of the well is therefore needed. One that recognises the performance attributes of the completion and the reservoir it connects to, the interplay between the two, and the dynamics of the entire system. In fact, what we are dealing with isn’t just ‘a well’ – it’s ‘a well system’.   But that’s not enough. We also need to recognise 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. The two most vital performance factors of all well systems, flow and integrity “Diagnosing well system performance is challenging. 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”, adds Mohamed.   Conventional diagnostics can’t provide all the answers because either they don’t look far enough, or measure the right things—they don’t look at the big picture. Rogue happenings, such as active thief zones, cross-flow or the source of sustained annulus pressure lurk behind barriers and wouldn’t be diagnosed with traditional techniques. A new category is born 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 chiefly concerned with investigating reservoir properties, such as matrix and fluid parameters, or evaluating cement.   Acknowledging and advancing through barrier diagnostics as a new category allows us to look at the well system in a far more holistic and uncompromising way. Seeing 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 more complete picture of the goings on, both flow and integrity related. And equipped with better insights, operators are much better placed to make the right decisions to keep the entire system working harder. Diagnostic tools vs. diagnostic 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. But 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 is extremely important, but many other factors beyond the tool contribute to the overall diagnostic result.   The synergy happens in all facets of the service, not just the tool; the diagnostic programme that activates the well, and the method for acquiring the data, the processing and modelling to refine and expand raw data, and the expertise in analysis and interpretation, all play a vital part. The results and insights materialise 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. But we need to go one step further. From systems come products When a well is exhibiting problems, what the operator ultimately needs is answers. Obviously, there’s an interest in making sure that the right diagnostic system is utilised, 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 where 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. Then 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. Operators certainly appreciate technology but are ultimately seeking diagnostic answers that can help them make better decisions”, summarises Mohamed alluding to the approach TGT has adopted.   He adds, “A mechanism should be adopted where simpler products, such as diagnosing wellbore flow, that demand fewer resources and less innovation command a lower price. Whereas more complex products—like multi-barrier diagnostics, that have years of research and development behind them, demand more extensive resources, and ultimately deliver more value, naturally command a higher price.” A bright future The old thinking can’t 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’s why we need to innovate on all levels. Not just by building better tools, but by creating better diagnostic systems and recognising the experts that empower them. We need 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. And last not least, we need 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.