Article featured in Oilfield technology   Well integrity management is a full lifecycle process adopted from the well design and construction phase right through to abandonment.   Yet, just as well diagnostics should take place at the outset of the well life – with even new completions sometimes containing flaws such as leaking connections and poor cement isolation – there is an increased focus today on routine integrity management, as well systems age and move towards abandonment. Revitalising aging wells In many regions of the world, increasing demands are being placed upon ageing well stock as operators seek to extend field life. Significant remaining reserves are the prize and technology-enabled process innovations, such as drilling multi-lateral extensions from existing wells, allow this to happen.   In the Middle East, for example, more than 70% of the ~800 Middle East platforms and associated well-stock are more than 25 years old, and in the North Sea, according to the UK Oil & Gas Authority, there remain 20 billion barrels of oil and gas resources still to be recovered on the UK Continental Shelf – a region that has been continually developed for nearly 50 years.   In such cases, whilst multi-lateral well components are new, the original wellhead, conductor and production casings have remained the same.   However, whereas previously such well stock survived through regular maintenance of the more accessible elements of the well, today more powerful well integrity diagnostics are required to monitor casing strings, tubulars and other crucial well components throughout the well system – from inside the tubing.   This article will look at how this is being achieved with through-barrier diagnostics. Through-barrier diagnostics Through-barrier diagnostics, a capability developed and perfected by TGT since it was founded two decades ago, is a valuable resource in proactive integrity management today because it evaluates critical aspects of the entire well system from inside the tubing.   Through-barrier diagnostic systems can sense dynamic well behavior and properties throughout the well, helping operators to evaluate the condition and performance of critical well components from inside the tubing.   By cleverly harnessing heat, acoustic and electromagnetic [EM] energy, through-barrier diagnostics can determine the wall thickness of individual tubulars, and locate and quantify fluid movements behind the pipe.   Two key areas where through-barrier diagnostics are having a major impact today are in tracking corrosion and sustained annulus pressure [SAP]. Tackling corrosion in the rise of chrome In some regions, downhole conditions are highly corrosive and well completions are constantly under attack from aggressive fluids, such as hydrogen sulphide, carbon dioxide and chloride. The degradation of wellbore tubulars and metal barriers is a major threat to well integrity.   On the Arabian Peninsula for example, formations such as Rus, Simsima, and Daman can cause severe corrosion of the outer well casing strings. Corrosive fluids from the aquifers can reach the outer casing surface because of integrity breaches in the outer well annulus. This is because either the outer cement sheath has degraded over time, or the initial cementing operation may have been compromised by the inability of formations to support pressure, resulting in cement losses and an imperfect seal.   In such cases, comprehensive and regular inspection is required by operators to determine whether corrosion is taking place at an acceptable rate, or if intervention and remedial action is required. To this end, the well diagnostics approach must provide quantitative information about multiple casing strings efficiently and reliably.   Yet, previously few operators were able to track corrosion to this level of detail and across all pipe strings.   To address this challenge, TGT has developed EmPulse® – a multi-barrier pipe inspection system capable of providing barrier-by-barrier visualisation of the tubulars that make up the well operating envelope, reliably and proactively. Ultra-fast EM-based sensor technology and time-domain measurements, coupled with advanced Maxwell processing, enable the system to quantify metal loss in up to four barriers independently and accurately.   In this way, it delivers sensitive and fast response measurements, bringing with it significant advantages over the frequency-based measurements offered by ordinary pipe inspection systems. Frequency-based measurements are also unable to distinguish the thickness of individual barriers and as a result provide limited information about barrier condition or the precise location of failures.   Another challenge EmPulse is addressing is that of chrome.   In a bid to pre-empt corrosion, many operators are opting for alternative steels and corrosion resistant materials, such as chrome, nickel and molybdenum. However, such materials pose even more challenges to ordinary pipe inspection systems with the decrease in ferrous content causing EM signals to decay too quickly for an effective measurement.   Yet, recent deployments in the Middle East have shown that EmPulse can again quantitatively determine the individual tubular thickness of up to four concentric barriers, even when there are high amounts of chrome in the tubulars.   In one Middle East operator-witnessed ‘yard test’ consisting of a 28% chrome pipe with built-in mechanical defects, the high-speed EM sensor technology within the EmPulse system correctly identified the man-made problems in a controlled environment.   Additional operations took place in two live Middle East wells in a very high hydrogen sulphide gas production scenario with 28% chrome tubulars. In this case, the EmPulse system again functioned as planned, and recorded the status of three concentric well barriers. A multi-finger caliper recording also confirmed the electromagnetic results for the condition of the inner pipe.   As operators endeavor to protect well integrity in challenging production environments and require versatility over tubular materials, it’s good to see that through-barrier diagnostics – backed up by many of the industry’s leading well log analysts – are meeting these challenges and providing a complete end-to-end well diagnostics solutions. Cementing and sustained annulus pressure (SAP) Two other challenges to well integrity today – both interlinked – are that of well cementing and sustained annulus pressure [SAP].   As operators look to deeper and longer reach wells, cementing techniques and sealing abilities have been pushed to the limit. According to the Society of Petroleum Engineers [SPE], at least 25-30% of wells are estimated to have annular pressure problems with cementing being one of the root causes. One outcome of this is SAP – pressure in any well annulus that rebuilds when bled down.   SAP is often the result of weaknesses in the cement during completion; or 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.   So how can well cementing and SAP be addressed?   To date, conventional means of tracking poor cementing and SAP is through surface measurements, such as fluid sampling, bleed-off/build-up data and downhole measurements such as ‘cement bond logs’, temperature and ordinary noise logs. This, however, only provides limited information and may be unable to locate leaks and unwanted flowpaths behind multiple barriers – especially when the leak rate is low.   To address this information gap, TGT’s ‘spectral diagnostics’ technology tracks fluid movement behind pipes from within several casing strings. This is achieved using high-fidelity downhole sound analysis systems to capture the frequency and amplitude of acoustic energy generated by liquids or gas moving through integrity breaches and restrictions. Complementing this, spectral diagnostic systems utilise high-precision temperature measurements to help locate integrity breaches throughout the well system.   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, thereby enabling timely intervention.   In 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, likely to provide flowpaths for fluid movement behind casing.   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 incorrectly assumed ‘good bonding’ area.   The frequency spectrum pattern correlated with reservoir permeability and fluid-type profiles, suggesting gas was 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. Figure 2 – Information from spectral diagnostics in a water Injector well Spectral diagnostics to abandon wells securely Spectral diagnostics can also play an important role in ensuring that wells are properly sealed during abandonment, especially with respect to unwanted fluid flow along the outer boundaries of the well system to surface – clearly a situation the operator wants to eliminate.   Operators perform through-barrier spectral diagnostics prior to abandonment to indicate the integrity status of the entire well system, and reveal where special remediation measures need to take place to seal the well properly and permanently. Diagnostics are also performed post-abandonment to validate that there is no unwanted fluid flow taking place and that the well is secure.   The well shown in figure 3 was part of an abandonment campaign where the operator observed sustained annulus pressure building at a rate of 0.1 bars per day in the C-annulus and 5 bars per day in the B-annulus. The maximum pressures in B-annulus were 35 bars while in C-annulus it was only 3.2 bars.   Multiple survey and plug/section milling stages were executed to abandon the well and each time through-barrier spectral diagnostics aided in targeting the plug intervals and verifying the integrity of the plug.   After the third stage, the sustained annulus pressure was eliminated in both annuli and spectral data confirmed that the unwanted flow in the outer annuli had been abated. In figure 3, one can see that the acoustic frequency-amplitude spectrum seen at stages 1 and 2 reveal zones of upward gas migration behind casing. The acoustic spectrum seen after stage 3 confirm that the gas migration had been stopped [the small acoustic response is due to residual gas].   As a result, the operator could depart from the well confident that the well was totally secure. Figure 3—Spectral diagnostics were performed during the three stages of abandonment for this well, helping the operator target special remediation measures pre-abandonment and validating integrity post-abandonment. Effective diagnostics throughout the well system Well integrity is all about ensuring that the right fluids connect safely and productively via the wellbore to the surface and don’t stray along unwanted flowpaths inside or outside the well system.   Operators select through-barrier diagnostics to deliver the crucial information they need to ensure well system integrity throughout the well lifecycle. It is these technology innovations supported by the skills and experience of TGT’s experts and others that are leading the way and reshaping well integrity management as we know it.

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.

EmPulse® multi-barrier integrity diagnostics system successfully tested on 28% chromium tubulars, ensuring asset integrity and better well performance in challenging production environments TGT Oilfield Services, the market leader in through-barrier diagnostic systems, has announced the successful validation of its electromagnetic EmPulse® well inspection system in high chromium tubulars.   In three Middle East deployments – one an operator witnessed ‘yard test’ and the other in two live wells – TGT engineers demonstrated that the EmPulse system can quantitatively determine the individual tubular thickness of up to four concentric barriers, even when there are high amounts of chrome in the tubulars.   Ken Feather, TGT’s chief marketing officer commented, “This achievement marks an important industry breakthrough as operators endeavour to protect well integrity in ever more challenging production environments. Increasing chromium content helps to protect well completions from highly-corrosive fluids, such as carbon dioxide, hydrogen sulphide and chloride—but high-chrome can cause serious problems for ordinary electromagnetic pipe inspection systems.”   He continues, “It’s essential that operators can access integrity inspection systems that work reliably and accurately throughout the well system in all environments and materials, especially where corrosive and toxic fluids are involved. This is why we created the EmPulse diagnostic platform.”   The increase in chrome and the resulting decrease in ferrous content causes electromagnetic [EM] signals to decay too quickly for ordinary EM inspection systems. Designed and manufactured completely in-house by TGT scientists and engineers, the EmPulse system combines ultra-fast sensor technology with ‘time-domain’ measurement techniques to capture EM signals rapidly and accurately in a wide range of pipe materials, including those with high-chrome content. This enables operators to evaluate pipe thickness and metal loss in multiple casing strings simultaneously, ensuring long-term well performance even in the most challenging production environments. Pulse characterisation lab, Technology Centre “The ability of EmPulse technology to make measurements when facing specialised materials in certain well tubulars marks a significant breakthrough for TGT and the industry as a whole,” said Simon Sparke, TGT integrity expert and coordinator of the high-chrome testing programme.   “That’s why today’s test results are so important, demonstrating how the EmPulse system of sensors, measuring techniques, processing and answer products can deliver fast response corrosion information, address a crucial information gap, and help protect well integrity in challenging production environments. We anticipate that EmPulse will be particularly applicable for the Middle East operators, and also some fields in the Gulf of Mexico, the North Sea and offshore Brazil.”   TGT’s EmPulse technology adds considerably to the integrity security of a well by providing barrier-by-barrier visualisation of the well operating envelope at the time of logging. The time-based measurements, enabling the system to quantify metal loss in up to four barriers independently and deliver highly sensitive and fast response measurements, brings with it significant advantages over frequency-based measurements offered by other systems. The Middle East operator witnessed ‘yard test’ consisted of a 28% chrome pipe with built-in mechanical defects where the high-speed EM sensor technology of EmPulse confirmed and correctly identified the man-made problems in a controlled environment.   The second operation took place in two live Middle East wells in a very high hydrogen sulphide gas production scenario with 28% chrome tubulars. In this case, the EmPulse system again functioned as planned, and recorded the status of three well barriers. Additionally, a multi-finger caliper recording confirmed the electromagnetic results for the condition of the inner pipe.

EmPulse® multi-barrier integrity diagnostics system successfully tested on 28% chromium tubulars, ensuring asset integrity and better well performance in challenging production environments. TGT Oilfield Services, the market leader in through-barrier diagnostic systems, has announced the successful validation of its electromagnetic EmPulse® well inspection system in high chromium tubulars.   In three Middle East deployments – one an operator witnessed ‘yard test’ and the other in two live wells – TGT engineers demonstrated that the EmPulse system can quantitatively determine the individual tubular thickness of up to four concentric barriers, even when there are high amounts of chrome in the tubulars.   Ken Feather, TGT’s chief marketing officer commented, “This achievement marks an important industry breakthrough as operators endeavour to protect well integrity in ever more challenging production environments. Increasing chromium content helps to protect well completions from highly-corrosive fluids, such as carbon dioxide, hydrogen sulphide and chloride—but high-chrome can cause serious problems for ordinary electromagnetic pipe inspection systems.”   He continues, “It’s essential that operators can access integrity inspection systems that work reliably and accurately throughout the well system in all environments and materials, especially where corrosive and toxic fluids are involved. This is why we created the EmPulse diagnostic platform.”   The increase in chrome and the resulting decrease in ferrous content causes electromagnetic [EM] signals to decay too quickly for ordinary EM inspection systems. Designed and manufactured completely in-house by TGT scientists and engineers, the EmPulse system combines ultra-fast sensor technology with ‘time-domain’ measurement techniques to capture EM signals rapidly and accurately in a wide range of pipe materials, including those with high-chrome content. This enables operators to evaluate pipe thickness and metal loss in multiple casing strings simultaneously, ensuring long-term well performance even in the most challenging production environments. ElectromagneticCalibration “The ability of EmPulse technology to make measurements when facing specialised materials in certain well tubulars marks a significant breakthrough for TGT and the industry as a whole,” said Simon Sparke, TGT integrity expert and coordinator of the high-chrome testing programme.   “That’s why today’s test results are so important, demonstrating how the EmPulse system of sensors, measuring techniques, processing and answer products can deliver fast response corrosion information, address a crucial information gap, and help protect well integrity in challenging production environments. We anticipate that EmPulse will be particularly applicable for the Middle East operators, and also some fields in the Gulf of Mexico, the North Sea and offshore Brazil.”   TGT’s EmPulse technology adds considerably to the integrity security of a well by providing barrier-by-barrier visualisation of the well operating envelope at the time of logging. The time-based measurements, enabling the system to quantify metal loss in up to four barriers independently and deliver highly sensitive and fast response measurements, brings with it significant advantages over frequency-based measurements offered by other systems.