Go with the flow Article featured in Oilfield Technology's 2022 summer magazine (pages 42-45)   As the global energy mix transitions to low-carbon sources, there may be fewer opportunities for new oil and gas field developments. As a result, many operators will shift their focus towards recovering more from existing reservoirs, and this strategy includes improving the management and performance of their Horizontal wells.   Horizontal wells generally deliver much higher levels of productivity than their vertical counterparts, but this performance can often come at a cost. Understanding the interactions between a horizontal well and the reservoir can be extremely challenging. The combination of variable well angles, extended reservoir contacts, the presence of fluid mixtures and segregated flows, formation changes, fractures and intricate completions presents a formidable challenge for analysis using conventional production-logging tools (Figure 1).   Standard production-logging technology may, under some conditions, be able to map the multiphase flows encountered in a horizontal wellbore, but it cannot quantify flows for fluids exiting or entering the reservoir behind the completion. This means that wellbore production logs do not provide a complete picture of flow dynamics across the well system. Asset teams that base development, production or remediation plans on an incomplete partial flow diagnosis may be risking lower productivity, reduced asset performance, and higher carbon overhead.   A new beginning Reservoir and production engineers have been looking to overcome the drawbacks of conventional production surveys in horizontal wells for many years. Their key requirement has been a system that could deliver continuous flow profiles across different completion and reservoir scenarios, and would also be effective in reservoirs with fractured formations.   TGT Diagnostics has been working on addressing these needs for several years and, in February 2022, launched the Horizontal Flow diagnostics product with Cascade3 technology. Specifically designed for horizontal wells, this system offers more realistic flow modelling and accurate continuous flow profiles in a wide variety of completion and reservoir settings. The insights gained from this have the potential to help companies reduce operating costs and energy consumption while increasing ultimate recovery.   The new technology uses an advanced modelling simulation engine to predict the hydrodynamic and thermodynamic behaviour of fluids and their surroundings as they flow through the well-reservoir system. This translates temperature, pressure and other well-system data into continuous reservoir flow profiles. These profiles deliver a true picture of inflow and outflow, and this is the case even for challenging wells and those that feature natural or hydraulically induced fractures.   The ability to assess flow in fractured reservoirs is important because, although fractures can boost hydrocarbon production, they can also provide pathways for early water or gas breakthrough. The new diagnostics technology can evaluate the radial, spherical and linear/fracture flow patterns commonly encountered in horizontal well systems (Figure 2). This provides an accurate assessment of linear flow occurring in the fractures and makes it possible to determine the fracture contribution. This is particularly useful when combined with the Chorus acoustic sensing system that identifies fracture locations along the wellbore.   Applications and benefits Operating companies want to maximise hydrocarbon recovery in the safest, cleanest and most economical way possible. Having an accurate picture of fluid flow in the wellbore and the immediately surrounding reservoir rock gives asset teams greater confidence in their decisions and makes it easier to enhance production, maximise recovery and rectify well problems.   The new diagnostics system provides useful input in key areas such as reservoir, well and resource management, and can even help companies enhance their environmental performance and reduce the carbon footprint of production operations.   Insights for reservoir management Effective reservoir management is a key objective for oil and gas operating companies. The development of any hydrocarbon reservoir disturbs a natural balance of rocks and fluids that may have existed for millions of years. Understanding how a reservoir will behave as new wells are drilled and fluids are extracted or injected is a daunting task. Reservoir engineers deal with huge uncertainties in their quest to maximise hydrocarbon recovery, reduce operating costs and extend the economic life of the reservoir.   At the heart of the reservoir-management process is the dynamic reservoir model, which provides a basis for all field development and hydrocarbon recovery decisions, infrastructure investments and reserves estimations. The robustness and accuracy of the model is critical to successful reservoir management, and any inaccuracies may lead to poor decisions and substantial losses.   As more data is collected, the dynamic reservoir model is updated by the reservoir engineering team using a process known as history matching. Insights from this new diagnostic system can play a critical role in history-matching, thus helping to reduce the uncertainty envelope and improve the model. A continuous flow profile provides a clear and direct quantification of the flow performance of the reservoir as it feeds the well system. In contrast to standard wellbore production surveys, which can be hindered by completion or reservoir integrity issues, Horizontal Flow can deliver a true flow profile. The continuous nature and sensitivity to low flow rates help provide a more accurate measurement of effective pay length, a key metric for making production forecasts and reserves estimates.   The new system is also effective in the presence of fractures. Predicting and preventing water or gas breakthrough is one of the most important and challenging tasks faced by reservoir engineers. Having a deeper understanding of downhole flow dynamics can help provide an early warning of locations where water or unwanted gas may be reaching the well.   The new workflow can also be used to estimate or validate other key parameters such as reservoir pressure, permeability and skin factor. This independent verification can help reservoir engineers to resolve uncertainties, improve history matching and optimise the dynamic reservoir model. Figure 1. Horziontal Flow leverages Cascade3 and the True Flow system to deliver the truest picture of inflow and outflow downhole, even in the most challenging wells. Figure 2. Flow inside the wellbore of a horizontal well can be challenging to decipher, but flow in the surrounding reservoir is equally complex. New technologies can help resolve all three primary flow patterns that surround the well system - radial, spherical and linear flow in fractures - and combines thermodynamic and hydrodynamic science in an immersive 3D fine grid modelling architecture. The result is accurate reservoir flow profiles and unique insights that help asset teams keep performance on track. A diagnostic approach to well management Horizontal wells are designed to provide optimum contact with the reservoir and so tap hydrocarbon reserves with maximum efficiency. Production engineers in the wider asset team are responsible for the well system and ensuring that it performs to expectations, thereby maintaining production targets and maximising recovery.   Well performance depends under dynamic relationship between the well completion and the reservoir surrounding it. This, in turn, depends on the performance and behaviour of completion components and the reservoir itself. To achieve their technical and business aims, production engineers need full visibility of fluids and flow dynamics downhole from the reservoir sandface to the wellbore and at all points in between. The Horizontal Flow diagnostic system helps to deliver this visibility.   Measuring real production or injection performance in the presence of complex multicomponent completions is a major challenge for production engineers. Integrity issues and zonal isolation or component failures can lead to discrepancies between the profile of fluids entering or exiting the wellbore and the profile of fluids exiting or entering the reservoir. In these situations, standard production logs could give false or misleading results. The new diagnostics system overcomes this by providing a definitive flow profile regardless of completion, integrity or zonal isolation issues. Furthermore, by identifying these issues, it can help guide maintenance or workover interventions. Vicious fluids, fluid segregation and low flow rates can also be problematic for standard production-logging sensors, leading to a false picture of flow. Horizontal Flow incorporates temperature and acoustic measurements that respond to all types of meaningful flow, thereby helping to overcome this limitation.   The new approach can also be used to assess injection compliance and the performance of completion elements such as flow control devices and swell packers. The information gained from these analysis can be used to target repairs and guide potential improvements in completion designs.   Enabling effective resource management Operating companies want to maximise ultimate recovery while minimising operating costs, thereby reducing cost per barrel produced. Horizontal Flow diagnostics can help on both sides of this equation.   Developing a field with horizontal wells represents a significant investment in time, energy and capital. Diagnostics play a key role in tracking well and reservoir performance, and steering asset team decisions. Horizontal Flow diagnostics can reveal well system inefficiencies, guide asset teams to problem areas in the completion or the reservoir, and help them act with greater certainty to achieve a positive outcome.   Horizontal well interventions can be expensive and time-consuming, and often require specialised equipment, such as coiled tubing or tractors, for well access. Diagnostic deployments of the new system can provide a complete and accurate downhole assessment and information that reduces uncertainty and quickly establishes whether remedial work is required. When a workover is deemed necessary, the ability to plan and target it with a greater precision helps save time, reduce costs and deliver better outcomes.   Reducing your environmental impact Operating companies around the world are aiming to cut their carbon-per-barrel overhead. Developing and producing oil and gas consumes enormous amounts of energy from diesel engines or gas turbines, both of which produce significant volumes of carbon dioxide (CO2). Flaring of unwanted associated gas is another major source of emissions. Combined CO2 emissions from global upstream operations are estimated at about 1 Gt CO2 per year and methane emissions at around 1.9 Gt CO2 per year. New diagnostics technology can help operators identify inefficiencies in energy-intensive operations, reduce associated gas flaring and improve the efficiency of energy-intensive intervention operations.   Water injection accounts for approximately 40% of total CO2 emissions in a typical oilfield. Operators can now assess how much of the injected water is reaching its target and identify thief zones. These diagnostic surveys often lead to a reduction in pumped water volumes and emissions, and increased field production. Water production is another source of emissions, as produced water must be managed and treated at the surface. This process requires energy, and increased water production typically means less oil, thus reducing ultimate recovery and increasing carbon per barrel.   Gas flaring is estimated to release 310 MT CO2 per year, which is about 30% of all upstream CO2 emissions. Continuous flow profiles can be used to identify sources of unwanted gas downhole and guide remediation plans, thereby reducing the need to flare.   Workovers and diagnostic interventions in horizontal wells can also have a significant carbon overhead. New diagnostics technology can minimise this overhead on two fronts when compared with the conventional approach.   Firstly, it can easily identify the crossflows, fractures and integrity failures that often confuse conventional surveys. Having this information minimises the risk of incomplete or inaccurate assessments and improves the efficiency of decision-making. Secondly, when equipped with reliable information, the asset team can plan and target its workover programmes with precision. This means equipment and operations can be optimised and executed with higher efficiency and success rates, leading to better technical outcomes and lower emissions.   Conclusion Horizontal wells are powerful tools for hydrocarbon production and represent a significant resource investment for field operators. Production engineers, reservoir engineers and the wider asset team face complex challenges in their drive to ensure that each well system performs to expectations. A new approach to flow analysis in horizontal wells could help to solve key challenges in this area, making it easier for wells and reservoirs to reach their full potential.

Article featured in Harts E&P Magazine   Today global warming is an existential crisis facing our planet and all of its inhabitants. According to the latest IPCC report, average global temperatures have increased by +1 C above pre-industrial levels, and while this may not seem like a lot, this rise is already impacting weather systems and society. At +1.5 C, climate feedback loops may lead to permanent runaway climate change. Climate science tells us that if global average temperatures rise more than +1.5 C above pre-industrial levels, the impact could become catastrophic and irreversible.   In the energy industry, we are all aware of the very real impact the climate crisis is having on society and the planet. However, here is the conundrum: Our world needs more energy so that individuals, communities and countries may attain or sustain socio-economic progress. In most situations, this energy comes at a cost, as the way energy is produced as well as consumed is ultimately leading to climate change. While we continue to develop clean energy solutions, the reality is that ~55% of the global energy mix continues to come from hydrocarbons, and it will take years, if not decades, before the balance shifts to cleaner sources. As suppliers of oil and gas, our industry has a vital role to play in taking action today to ensure a low carbon future. Reducing ‘carbon per barrel’ Every barrel of oil or gas equivalent has a carbon overhead because of the energy consumed to produce it, the flaring of gas, and the leakage or venting of methane from well infrastructure. In 2019 upstream activities released ~2.9 GtCO2e, or ~6% of the total annual greenhouse gases produced by human activity. Total hydrocarbon production in that year was ~60 Bboe, resulting in a ‘carbon per barrel’ overhead of ~48 kgCO2e per barrel equivalent. Clearly, this overhead needs to be cut drastically if we are to avoid the dystopian scenario of runaway climate change.   What can operators do to reduce emissions? One answer lies in understanding the true dynamic behavior of well systems with through-barrier diagnostics. Diagnostics that reach beyond the traditional confines of the wellbore and see more can help operators reduce energy use and resulting emissions in a wide range of scenarios. Data source Rystad Energy, EmissionsCube Energy from turbines and diesel engines accounts for more than 70% of the CO2 emissions from upstream operations. Through-barrier diagnostics can help operators identify energy inefficiencies in a number of ways. For example, one of the largest demands on upstream energy comes from powering water injection pumps to maintain reservoir pressure. Well and formation integrity issues can divert water from the target, increasing the amount of water needed and wasting resources. Through-barrier diagnostics can reveal diverted water behind casing, aiding remediation and ultimately reducing injection rates and associated emissions.   Gas flaring accounts for roughly ~30% of upstream oil related CO2 emissions. If the associated gas that is produced alongside oil cannot be utilized, it is burned. The reasons could be technical, regulatory or economic, and even though the industry is working to reduce flaring, it remains a global issue. Through-barrier diagnostics can’t provide an alternative to flaring, but it can help track sources of unwanted gas to aid remediation, enabling operators to limit unwanted gas production and flaring.   At 1.9 GtCO2e per year, methane is the largest contributor to upstream carbon emissions. Methane is a potent and insidious contributor to the greenhouse effect, partly because methane has ~30x the warming effect of CO2, and fugitive leaks from active and abandoned wells can go unnoticed for years. However, a major source of methane is intentional venting. Gas leaks inside the well system can build up in between casings, and this may be vented if the pressure exceeds safe levels. Through-barrier diagnostics can locate the source of gas within the well system, informing remediation decisions and ultimately helping to reduce methane venting. The answer for operators is simple Equipped with the right information, evasive action can be taken to improve energy efficiency, decarbonise operations and reduce emissions. Diagnostics that reveal the full extent of flow and integrity dynamics throughout the well system, from the wellbore to its outer reaches, are essential to achieving this goal. An analysis of the entire well system with through-barrier diagnostics can help oil and gas producers deliver energy through the transition, but with significantly lower environmental impact. "As suppliers of oil and gas energy to society, our industry has a vital role to play in helping it achieve a low carbon future" Ken Feather, Chief Marketing Officer

Dubai, UAE - 15 June 2021 TGT Diagnostics, leaders in through-barrier diagnostics for the oilfeld, today announced the appointment of Rizkallah Ward, as Chief Digital Officer. In this new role, he will be responsible for managing all aspects of TGT’s digital transformation.   Rizkallah will focus on expanding our capabilities in the arena of predictive diagnostics, as well as enhancing our AI data platforms and analytics, and transforming our internal systems and diagnostic workflows through digitalisation.   “TGT Diagnostics is continually advancing data intensive workflows, and evolving them to solve multiple diagnostic challenges with precision and accuracy as a priority. All industries are embracing digitalisation as a positive disruption to traditional data workflows. We intend to lead the industry in leveraging digitalisation, taking well diagnostics to a completely new level,” said Mohamed Hegazi, CEO of TGT. “Oil and gas extraction is a data-rich environment where data can be used more effectively to support operators by predicting flow and integrity challenges. I am delighted to have Rizkallah’s expertise in the executive team to spearhead our digital strategy.”   Rizkallah is a recognised leader in AI and digital transformation. He joins TGT with more than 30-years’ experience in technology and digital solutions, and has worked in a wide range of sectors including, telecommunications, military, government, utilities as well as in oil and gas. One of his most recent achievements included presenting how digitalisation is changing the oil and gas industry, at the Vienna OPEC conference.   “The company’s ambition to reshape the oil and gas industry with through-barrier diagnostics, its history, international footprint, culture and its people, are why I’m delighted to join TGT and lead its digital transformation”, commented Rizkallah. “The future of energy companies will depend on how fast they adapt to the constantly evolving energy landscape. TGT will develop multiple AI-enabled products that will feed the growing demand for predictive analytics and diagnostics. The future is exponential. The future is digital.”