bluuebunny/crossref_metadata_2025 huggingface dataset:
Unlocking the Nahr Umr Play Potential in North Oman from Regional Evaluation of the Limestone Marker Unit
Authors: Belushi Maram Al , El-Ghali Mohamed A. K.
Published: October 2023

The Nahr Umr Limestone Marker Unit (NULMU) is a relatively thin layer encased in the regional Albian Nahr Umr shale over much of the Arabian Peninsula. In Oman, Nahr Umr Formation regionally seals Shuaiba Formation and underlies Natih Formation; both are prominent carbonate reservoir in northern Oman. The NULMU often presents hydrocarbon shows in the subsurface but has never been targeted as a reservoir or studied in detail.

This study focused on understanding the lithology, facies, depositional environment, regional distribution, and reservoir properties of the NUMLU to identify potential prospective areas. The study was based on a detailed sedimentological and Gamma Ray logging of outcrops (Jebel Madar and Wadi Bani Kharus), core analysis from 2 wells, petrographic description of 17 thin sections from outcrops and the subsurface, and well log analysis of 34 well penetrations. Subsurface data allowed well correlations across the basin and creation of regional depth and isopach maps.

The NULMU in Jebel Madar is ca. 4 m thick and comprises three distinct facies in ascending order: Orbitolina wackestone (Facies A), bioclastic mudstone (Facies B) and Orbitolina wackestone to packstone (Facies C). The facies represent a proximal, subtidal ramp depositional setting. Facies A is the most likely facies to act as a reservoir due to its coarser grain size and relatively higher visual porosity (up to 15%). However, in Wadi Bani Kharus the NULMU is ca. 9 m thick and dominated by mudstones (facies D) representing deeper marine, distal ramp depositional settings. The carbonate unit presents a shallowing upwards trend with a cycle boundary towards its top followed by rapid deepening into subtidal shales of the Nahr Umr Formation.

In the subsurface, the NUMLU is present at an average depth of 1600 m and is ca. 4 m thick, except around the Lekhwair High, where it was eroded at the base Tertiary unconformity. The facies vary from Facies A to Facies B as described from cores and thin sections with average log porosity is 18% and permeability of 2 mD. The high porosity values are in areas where the erosional contact between the Shuaiba and Nahr Umr formations is more pronounced. Thus, indicating that on regional highs (Lekhwair, East Lekhwair, and Dhulaima highs), with long lived exposure the NUMLU has greater chance of reservoir properties enhancement through secondary dissolution.

The results indicate that the main control on reservoir properties is related to original depositional setting with potential enhancement by later erosional exposure. This study helps to define on a regional scale, potential prospective areas that could be further explored to open a new play potential in Oman.
Improved Waterflood Recovery for a Mature Oilfield with Challenging Reservoir Conditions and Complex Development Status
Authors: Lu X. G. , Sun S. Q. , Shan G. J. , Lin L. H.
Published: October 2023

Taking the North Saertu Development Area (NSDA), La-Sa-Xing oilfield in Daqing, China as an example, this paper presents best practices to improve mature field waterflood recovery. Placed onstream in 1963, development of the multi-layer sandstone reservoir experienced three-round infill drillings, EOR polymer flood and ASP flood. Strong reservoir heterogeneities, producing at water-cut >90% starting in 1999, various IOR/EOR activities and several well-pattern types overlapping vertically led to extreme challenges for further improving waterflood recovery. This paper first introduces the general reservoir geology, reservoir heterogeneity characteristics, fluid properties and reservoir conditions, followed by illustrating its 60-year development history and key IOR/EOR activities implemented. The focus of this paper is to illustrate the strategy, fit-for-purpose technologies, and effective reservoir management practices to further improve waterflood recovery at extra-high water-cut development stage.

The discussed improved recovery practices are based on deliberate reservoir characterization and remaining oil study by integrating wireline logging, 3D seismic, production logging, sealed core data, production performance data and various other performance monitoring data. Several pilots on water-controlling, producing by-passed thick pay sands as well as re-arranging individual well pattern were conducted, providing a basis for field-wide application. Key strategy and technologies adopted are: 1) subdivision of individual injection-production interval and reduction well spacing; 2) improving water injection at individual well pattern and single flow-unit level; 3) combining waterflood and polymer/ASP flood by utilizing the same wellbore or well pattern to develop marginal pay sands in a cost-effective way; 4) improved zonal water injection by reducing individual injection thickness and permeability contrast within the injection interval; 5) improved injection profile through profile modification; 6) integrated approach to mitigate injected water channeling in thick pay sand; 7) cyclic water injection; 8) well drilling along fault plane producing by-passed oil; and 9) horizontal wells producing poorly swept or attic oil. The IOR and reservoir management activities have successfully arrested production decline, mitigated water-cut rising, leading to an increased waterflood recovery by >2.5%.

Mainly implemented at development stage with extra-high water cut of 92%-95%, the integrated IOR and reservoir management activities discussed in this paper are all feasible, proved technically successful and cost-effective. These practices provide a road map and solutions for extending oilfield life or rejuvenation of a waterflood mature oilfield.
Towards 2030: Transforming Asset Emissions in Upstream Production Operations
Authors: Carydias Peter , Nielsen Preben
Published: October 2023

Production operators urgently need to devise credible decarbonisation strategies for their assets. This is driven by regulatory shifts and commercial goals underscored by several global initiatives. These include: the SEC's mandate for emission disclosures, the GCC's headline greenhouse gas emission reduction targets, the IEA's net zero emissions framework, and the EU's 2030 plan.

There are three main levers for integrated gas operators:Optimising existing operations to improve efficiencyDesigning sustainable developments and modificationsRebalancing portfolios towards assets with lower carbon t intensity

Large capital projects, such as carbon capture and electrification, are typically proposed as responses to the second. However, assets already in operation often offer quicker returns, with scope to reduce ~10-20% of emissions and need to develop viable roadmaps.

Through our work in the integrated oil & gas industry over the past two years, we found that the majority of CO2e operational emissions reduction opportunities can be addressed by discrete improvement programmes on rotating reliability, process optimisation and methane leak reduction.

In this paper, we discuss how asset operators can drive their operations, energy transition and digital functions to realise significant CO2e benefits in a scale of months by:Developing a value-driven decarbonisation strategy for operations, identifying benefits in production, cost, and emissions, front-loaded with high impact, rapid 20-30% reduction initiatives that can be realised in the next 1-2 years.Implementing effective and auditable real-time monitoring of plant emissions direct from existing control systems, sensors, and imaging techniquesDriving a program of tech enabled optimisation levers and bringing this into new designs for CCUS, hydrogen and electrification projects for maximum benefits.

We are having success collaborating with our client's energy transition and digital functions to solve this problem together. In this paper, we introduce:A managed approach to deriving areas of focus (SCORE – Substitute, Capture, Offset, Reduce and Evaluate)A framework of methodologies, tools, and workshop to identifying value drivers, map client pain points, identify a long list of opportunities, and then focus on the top few to build into opportunity casesValue driver trees and associated solutions to drive down emissions in these areas of focus

We introduce three case studies that showcase the power of a value-driven emissions reduction strategy, implementing effective monitoring and deriving a program of tech enabled optimisation levers: A templatised oil & gas turbine efficiency uplift solution to tackle gas driven generation lever for a major upstream producer. Deep reinforcement learning (AI) to optimise power consumption of compressors while meeting nominations and emissions constraints for a major gas transmissions operator. Templatised venting emissions solution for a major onshore unconventional gas producer
Quantification & Reduction of Methane (GHG) Emissions Though Arial Intelligence
Authors: Fahy Ronnie
Published: October 2023

This comprehensive white paper delves into the myriad benefits of utilising Aerial Intelligence and Remotely Piloted Aircraft Systems (RPAS) for methane quantification and leak detection in the oil and gas industry. Traditional methods of monitoring Greenhouse Gas (GHG) including methane emissions have proven to be time-consuming, costly, and limited in scope. However, RPAS equipped with advanced sensors and imaging technologies have emerged as a game-changing solution. By exploring the advantages, challenges, and prospects of RPAS-based GHG quantification and leak detection, this paper aims to shed light on the transformative potential of this technology in enhancing environmental sustainability and operational efficiency in the industry.

In this white paper, we delve into the wide-ranging benefits of RPAS technology for methane quantification and leak detection in the oil and gas industry. By highlighting the shortcomings of traditional methods, examining the capabilities of RPAS, and exploring real-world case studies, this comprehensive report aims to educate stakeholders about the immense potential of this transformative technology. Ultimately, RPAS-based methane quantification and leak detection can revolutionise the industry, enabling enhanced environmental stewardship, cost savings, and improved operational efficiency.
Breaking Gender Stereotypes: Advancing Women’s Careers in the Oil and Gas Industry
Authors: Banihammad B. A. , Al Shehhi K. M. , Ashraf A. A.
Published: October 2023

The oil and gas industry has historically been male-dominated, and women on site faced several challenges and obstacles. These include stereotypes and biases, safety concerns, physical demands, lack of support, and work-life balance issues. However, organizations can promote diversity and inclusion, provide education and training opportunities, create support systems, address safety concerns, offer flexibility, and challenge gender stereotypes to overcome these challenges. ADNOC, the national oil company of the United Arab Emirates, has implemented successful strategies to promote women on site. These include creating a gender-balanced work environment, investing in education and training, providing mentorship and leadership programs, addressing safety concerns, and celebrating success. Overall, these efforts have led to a more diverse and inclusive work environment, increased female representation and leadership, and improved safety and well-being for women in the industry.

Women’s contribution to field life is an essential aspect of sustainable development objectives for gender equality. Women have made significant strides in traditionally male-dominated fields such as engineering, operations, and production management. They have proven to be just as capable as men in handling the challenges of working in harsh and demanding environments. Their presence as front-liners has provided a new perspective and approach to problem-solving, leading to increased efficiency and productivity. Women in field life have also paved the way for future generations of female workers, demonstrating that gender is not a barrier to success. Their dedication to health, safety, and the environment has contributed to creating a more sustainable and responsible industry. Overall, women’s contribution to field life is a testament to their resilience, competence, and commitment to making a difference in the world.
Sand Waste Utilization for Dehydration Application
Authors: Suttipat Duangkamon , Pavasant Prasert , Sintharm Praewpakun , Sukeesan Suratsawadee , Watcharasing Sunisa , Kiattikomol Prapoj
Published: October 2023

Natural gas operation & maintenance (O&M) at the Zawtika asset is facing challenges due to the increasing volume of production sand waste obtained from the separation between sand and natural gas using a desander unit. To align with PTTEP's Sustainable Development goals and Zero waste to landfills target, PTTEP is exploring the conversion of sand waste into high-value silica-based materials. Zeolite, a versatile material with exceptional adsorption and catalytic properties, is synthesized from the high-purity silica derived from the sand. The downstream pelletization is also crucial as it enhances the handling and usability of zeolite in various industrial applications including dehydration.

The project successfully achieved a high silica purity of approximately 98 wt.% through an extraction method, resulting in the production of nanosilica particles. Zeolite, specifically Zeolite A, synthesized from the sand-derived materials demonstrated high purity and quality. The pelletization process yielded promising results, including comparable water adsorption capacity and minimal reduction in compressive strength after adsorption.
Formation Sampling in Ultra-Low Mobility Reservoirs with the Aid of Targeted Stimulation Utilizing Wireline Formation Testing Tool
Authors: Ramadan Osama , Binghaith Abdulelah , Bhat Jeelani , Soleiman Wael
Published: October 2023

Combining modern wireline formation testing technology with advanced, production enhancement products help overcome the challenging corrosive effects of stimulation fluid on downhole tools and cable. This step change opens a new frontier of formation testing and sampling technology and makes it possible to explore ultra-tight carbonate reservoirs by conducting a "surgical" intervention while maintaining the highest operational standard and efficiency.

The innovative technique presented in this paper leverages existing Test-Stimulate-Test workflows, in-depth simulations and specially designed production enhancement fluid that can control the corrosive aspect of different stimulation fluids. In a single run, the stimulation and testing are performed with an existing wireline formation tester modified to perform an in-situ acid injection matrix stimulation followed by extended pre & post-stimulation Mini-DST operations. In addition to the capture of high-quality samples, it is also possible to quantify the improvements in the reservoir permeability associated with the stimulation versus the typical production logging techniques.

This tailored engineering design is a fit for purpose solution to unlock the hidden potential of low-quality reservoirs (LQR) while exceeding the operational requirements and standards, compared to the traditional alternatives in the likes of acid stimulation and well testing techniques. More importantly, it provides a precise quantification of stimulation improvement ratio that allows the collection of "ultra-clean" in-situ hydrocarbon samples under pressure-volume-temperature (PVT) conditions enabling a more accurate characterization of the reservoir performance than it was previously possible for this type of formations. The observed operational data shows different success levels based on multiple variables such as but not limited to, borehole fluid, invasion, rock fabric and the stimulation fluids. The conclusion from the multiple tests performed in this study, recommends that a detailed job design and pre-job planning are key factors for the success of this application, as well as, revealing the potential challenges of such an advanced engineered solution for different environments either open hole or cased hole.

The innovative technique provides reservoir engineers with a clear insight into the untapped assets by revealing uncertainties that influence further development challenges, leading to an informed decision-making process, while improving the operational efficiency. A noteworthy leap forward with this technique is the improvement in the reservoir characterization for both secondary and LQR, which have been historically hard to evaluate.
Inflow Chemical Tracers: An Innovative Approach to Quantify the Zonal Contribution from Inaccessible Drains
Authors: Al Maimouni Fadwa , Keshtta Osama , Bigno Yann , Rashed Rasha , Abasher Doha
Published: October 2023

Individual zonal inflow production profiling and monitoring is very challenging in multi-lateral wells due to accessibility limitations post completion, hence, inflow chemical tracers were chosen to be deployed for this well. A transient campaign was planned and carried out with the objective of quantifying the relative inflow production from each zone in each of the three laterals.

Inflow chemical tracer systems were manufactured into a matrix and designed to provide 5 years of oil tracer and water tracer longevity (upon water breakthrough). The tracers were installed into externally vented tracer carriers which were then RIH with 3½" Inflow Control Valves in the mainbore and with 4½" in limited entry liners in the 3 laterals. The mainbore is fitted with 3 unique oil and 3 unique water tracer systems, whereas the laterals contained 7 unique oil tracer systems each, bringing the total installed tracers in the well to 24 oil and 3 water unique tracer systems.

To be able to quantify the relative inflow contribution in individual zones of each lateral, the well needed to be shut in for a duration of 24 hours to allow tracer contact with the formation fluid. Once in contact, the tracer molecules are released from the matrix and accumulate in the wellbore. The movement of these tracers to the surface gives a chemical signal that carry information on the flow – a signal that is captured during surface sampling and subsequent analysis in a high-end tracer lab.

The well was put on production with each lateral being opened sequentially, controlled by their respective ICV in the mainbore. High-frequency sampling was carried out where each ICV was kept open for an average duration of 12 hours allowing tracer production from each lateral.

The tracer signals proved the arrival of all installed oil tracers’ signatures and peaks. Results indicate that all reservoir zones in all three laterals are contributing to oil production. A quantitative interpretation was performed to determine relative inflow contribution per monitored zone.

The chemical inflow tracers were deployed in a smart multi-lateral well to enable production monitoring and surveillance of the laterals. This application is unique due to the limitation of other diagnostic methods in the market that can quantify flow inside a lateral.
Lack of Integration Between Academia and the Industry: How to Upscale Experience Through Innovative Guidelines Involving Research Outcomes
Authors: Hegazy Gehad M. , Ali Maryem. G. , Abdeltawab Bassel. A. , Ali Mena. G.
Published: October 2023

The research aim is to propose an innovative strategy that intends to crosslink different level-experience engineers and to inspect why there is a lack of integrity between industry and academia. The target groups involved undergraduate, graduate, senior, and professional petroleum engineering levels. With the help of a survey that involved participants from five different levels of experience, we identified an efficient and cost-effective process that could link academia and the industry.

In the current academic learning styles, vast theoretical concepts are being focused on. It is essential to acknowledge the importance of industrial training. The lack of integration between industry and academia can violate the meaning of engineering, which is the art of application. A way to tackle such a lack of disintegration involves including real-life experiences within the taught academic courses. This could help students develop a comprehensive vision of real-life applications and gain insight into the actual applications.

The process to investigate the reasons behind the disintegration between academia and industry was done by conducting a simple survey to investigate what we termed the "5 Cycles of Experience," which divides up experience levels into 5 sectors: undergraduates, fresh graduates, five, ten, and above ten years of experience. A hundred participants were asked different questions to investigate the reasons for disintegration and the best time for a student to get industrial training.

The results showed that most of the undergraduates questioned pointed out that having early training while pursuing their major benefitted them vastly, and the best way to receive knowledge would be by being in direct contact with someone with at least five years of experience or above, not fresh graduates. The remainder of the participants agreed to that too. The lack of integration originated mainly from the difficulty for some undergraduates to get access to training, their lack of interest, and their belief that they are being forced to do something they consider secondary. Another reason could be the overwhelm of undergraduates with the academic workload imposed by some instructors.

We intend to propose solutions to the problems that lead to the lack of connection. These include the incorporation and contribution of those in higher positions to help those in need to reach out to sites that offer training. This also includes organizing campaigns to raise awareness among new learners that such training, especially early, is relevant but complements the educational learning process. It was, finally, incorporating training within academics with lowering the academic theoretical workload.
Success Story: Selective Completion Combined with Wide-Range ESP in KOC
Authors: Shuber Hussain , Al-Watyan Abdullah , Alaryan Ali , Kishore Kunal , Aparicio Ciro , Yadavalli Sameer , Houben Cai
Published: October 2023

The objective of this paper is to demonstrate that the combination of selective completions with wide-range ESPs using Y-tools can be successfully deployed and operated. This represents a major impact in operating cost by minimizing future major workover interventions for Water Shut-off (WSO) and/or zonal changes.

The team analyzed different completion concepts (e.g., dual completions, multi-zone with ICDs/ICVs, etc), conducted a screening & ranking analysis and concluded that the conventional selective completion combined with a tubing conveyed wide-range ESP was the top ranked option which would represent the best cost/benefit among all the other options. Selective completion with flow control equipment operated by slickline tools (unlike Intelligent Down Hole Flow Control) is fit-for-purpose completion type for a large onshore oil field such as the Greater Burgan, with multiple zone reservoirs.

In selective completions, reservoir parameters such as well productivity index and bottom-hole pressure could change throughout the life of the well which shall be taken into consideration during ESP design. Multiple simulations were conducted to determine the best ESP design to cover optimal-case and worst-case scenarios at opened and closed zones. Each scenario was presented with a different productivity index and bottom-hole pressure with corresponding flowrate, motor load, and motor temperature. In which, the ESP design ensured continuous flow to the surface, minimum or no gas presence at the pump intake, and sufficient flowrate for motor cooling, within acceptable motor load ranges and pump operating ranges.

It has been shown with the results that following comprehensive ESP design modeling in selectively completed wells can potentially yield a resilient wide-range ESP system that can withstand dynamic reservoir conditions.

In KOC and in any brown field, the utilization of wide-range ESPs in combination with selective completions will reduce operational cost and deferred production, allow effective and un-expensive rig-less WSO via slickline operations, conduct well surveillance and flow performance adjustment, maximize well bore utilization and reduce requirement of workover rigs.
Industrial Operational Feedback of Solvent Acidification for a More Energy-Efficient Operation of an AGRU
Authors: Rakotoalimanana D. , Scala M. , Cadours R. , Cloarec E. , Lucile F. , Paran M.-A.
Published: October 2023

Objectives/Scope

This paper describes operational feedback from one of our Acid Gas Removal Units (AGRUs), that operates an amine-based solvent technology, in the case of high H2S content in the sour gas (20 mol%). We show that the acidification of the solvent results in energy savings and a reduction of GHG emissions.

Methods, Procedures, Process

This paper focuses on the benefits of solvent acidification in an AGRU. In practice, the solvent acidification leads to a salting-out effect and lower residual acid gas content in the lean amine, allowing the optimization of the specific reboiler duty. The approach requires a regular solvent monitoring to quantify the solvent acidity and the residual amount of acid gases in the lean amine, and the evolution of the solvent degradation products over time. Indeed, the degradation products from amine oxidation are acidic components and excessive stripping may sometimes result in corrosion- and fouling-related operational issues. This shall be supported with modelling the salting out effect.

Results, Observations, Conclusions

In our case, we observe a continuous build-up of heat stable salts in the amine-based solvent, which come from the degradation of amine solvent after oxidant ingress. This induced a reduction of the H2S residual content from 500 ppmw to less than 50 ppmw. This allowed the optimization of the AGRU specific reboiler duty of about 20% energy savings (down to 80 kg 4 barg steam / m3 solvent), which leads to 10% reduction in GHG emissions. However, this salts build-up also generates operational issues such as higher corrosion rate of carbon steel equipment and fouling issues due to iron sulphates and carbonates deposits. Thus, this paper will present the trade-off found between energy savings and unit operability, based on our industrial feedback considering the "natural" acidification of the solvent. The modelling of the vapour-liquid equilibrium of the altered solvent is a must for unit optimization, considering the impact of acidic components coming from solvent degradation or components added on purpose to improve the solvent regeneration. This concept is currently already implemented in industrial sites, especially in low pressure units such as Tail Gas Treatment Units (TGTUs), to respect specifications on Sulphur compound emissions to the atmosphere.

Novel/Additive Information

This paper will present a solvent monitoring novel strategy to optimize the amount of steam required in the reboiler of the regeneration section without impairing the unit operability.
Generating Synthetic Temperature Surveys for Wells Through Subsurface Spatial Machine Learning Modeling and Time Series Forecasting
Authors: Al-Qahtani Ahmed S. , Momtan Bayan A.
Published: October 2023

Temperature profiles are key element to ensure a healthy well life specially down-hole tubular integrity. Temperature surveys are routinely conducted and compared with a base well temperature survey, recorded soon after a well was completed. This paper demonstrates novel approach to synthesize virtual temperature surveys by data-driven meta model combining subsurface geospatial modeling and time series forecasting. The proposed model anticipates the next temperature survey profile utilizing historical temperature surveys from same well along with different wells with similar temperature behavior. Historical surveys for same well are fed as vectors into a time series forecasting model that predicts the upcoming temperature profile. While historical surveys for offset wells are fed into a 3D spatial correlation model that computes the temperature values at target well location. The final step is a probabilistic meta model trained to combine the outcomes of the two models to accurately predicted temperature profile for a target well.

This methodology has been piloted and used to predict temperature profiles for entire wells in the area using a dataset of historical surveys summing up to 29000 measurements. Predicted temperature values were evaluated using Root Mean Squared Error between predicted and actual temperature values. First step is a 3D Kriging spatial correlation which was applied to predict the temperature profile at target well location. Leave-One-Out evaluation was used where, at each round, one well survey is left out of training set, and used as evaluation. Average RMSE from all rounds was 4.43. The second step is time series prediction where LSTM RNN model was applied with 70-20-10 data division. The modeling cycle included tuning of LSTM hyperparameters in addition to optimizing the number of historical surveys used as predictor of next survey. RMSE for training, evaluation and test was 2.96, 3.6 and 4.2. In the third step, predicted temperature surveys using Kriging and LSTM were input into a probabilistic model that makes the final prediction. Final model error was 3.2 using Leave-One-Out evaluation approach. This paper includes more comprehensive evaluation of the synthetic temperature surveys’ accuracy and ability to predict abnormal behavior.

This paper presents a new approach to proactively assess the well healthiness and lower the cost of conventional temperature surveys by using data driven models to predict temperature profiles. These models not only capture historical trends of changing temperature inside the wellbore, but also address spatially distributed environmental trends that are not measured frequently such as formation properties and fluid distribution.
Tight Gas Reservoir Characterization and Comparison of PLT Methods: Micro-Seismic Monitoring, Fiber Optical Production Logging and Tracer Coated Sand Monitoring Applied in the Same Well
Authors: Yao Xiao , Qinggao Zeng , Haibo Deng , Linke Song , Xinggang Liu , Haiyan Heng , Wenjing Zhang , Geng Sun , Guangyu Wang , Belova Anna , Husein Nadir
Published: October 2023

Unconventional tight gas reservoir characterization is a complex process in continuous attempt to optimize hydrocarbon recovery. The production logging tools and formation evaluation tools currently existing in the market gained widespread adoption in conventional plays. Unconventional reservoirs are characterized with complex lithology, high heterogeneity and anisotropy. Typically, such reservoirs are developed by drilling clustered horizontal wells deploying multistage frac strategy to increase reservoir drainage and simulated reservoir volume (SRV). Accurate reservoir characterization is key to reduce uncertainties and economic feasibility of field developments. Operators are continuously looking to define reliable production logging tools for unconventional plays. This paper evaluates the comparison of three different measurement methods in the horizontal well straight after performing 15-stage hydraulic fracturing. The measurement methods in subject are: micro-seismic monitoring of neighboring wells, coiled tubing conveyed distributed acoustic sensing (DAS) and novel quantum based inflow tracers. Inflow tracer technology is fairly new solution and as such, will be elaborated in greater detail compared to the other two solutions.
Multi-Scale Drill-Core Digitalization Technique and its Applications for Reservoir Characterization: A Case Study of an Unconventional Reservoir in China
Authors: Sun H. , Liu X. , Luo L. , Ge T. , Shi W. , Li D. , Zhu Y. , Sun L. , Zhang H. , Arif M.
Published: October 2023

Multi-scale drill-core digitalization has been recognized as an efficient technique in geological survey and geophysical exploration. This technique conducts a comprehensive examination of the internal structure of rocks, and investigates the underlying mechanism of mineral and pore genesis. In this paper, a drill-core interval from an unconventional reservoir in China is selected for digitalization, aiming to address the challenge of multi-scale parameter testing and analysis in reservoir characterization. Various advanced imaging techniques, including medical computed tomography (CT) scan, hyperspectral scan, micro-CT scan, backscattered electron (BSE) image, and quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) are used to perform the analysis. These findings are necessary parameters for reservoir characterization and this comprehensive analysis resulted in a detailed understanding of favorable reservoir distribution.
Study and Application on Intelligent Carbon Emission Management System for Petrochemical Enterprises
Authors: Gong Yan , Zhang Liya , Cheng Liang , Liu Jian , Wang Hua
Published: October 2023

With the rapid development of economy in China, total CO2 emission has reached about 11 billion tons in 2022, which accounts for nearly one-third of global carbon emissions. Therefore, china government has proposed the grand vision of carbon emission peak and neutrality to prompt the low-carbon development and environmental protection. As the significant part of highly energy-intensive industries, petrochemical industry bears great responsibility for carbon emission reduction and sustainable development.

Petrochina is one of the largest oil companies in China and holds above 20 refining and petrochemical enterprises. In order to reduce carbon emission and promote green transformation of petrochemical enterprises, Petrochina has researched on not only low-carbon technologies but also digital transformation technologies in petrochemical fields during the 14th Five Year Plan period.

Since the complexity of petrochemical industry, the numerous emission sources and their close relationships with actual production process are the characteristics of carbon emission for petrochemical enterprise. Therefore, the main target of carbon emission management system is to analyze carbon emission level of the whole process effectively and identify the potential of carbon emission reduction timely by using digital and intelligent technologies.
A Magnetic Levitation Turbine Generator for Downhole Electronic Devices
Authors: Fu Tao , Yang Qinghai , Sun Wei , Liao Chenglong , Shi Bairu , Liu Yazhen
Published: October 2023

Stable and reliable power supply is essential for downhole electronic devices to fully function. A downhole generator can transform the available ambient energy in the downhole environment into electricity, which is an ideal way of downhole power supply. Turbine generators have proven useful in many different environments, but they have drawbacks such as large start-up flow rate, low energy conversion rate and short life expectancy that make them unsuitable for harsh downhole environments.

This paper presents a new method for the long-term energy supply of downhole electronic devices by using a magnetic levitation turbine generator. In this scheme, a turbine is used to convert the continuous wellbore flow into electricity and a permanent magnetic bearing is employed so that the turbine can float in the current, thus completely eliminating contact friction and allowing free rotation of the turbine, which then lead to a reduced start-up flow rate. The design of magnetic levitation structure also solves the contradiction between dynamic sealing and efficient rotation, thus achieving efficient energy conversion under different working conditions.

An experimental prototype was fabricated and tested in a closed cycle pipeline using water as the medium. The experimental results showed that the turbines can rotate smoothly at high speed and the magnetic levitation structure showed relatively high stability. At a flow rate of 20-45m3/d, the output power was 0.5-13W. With a rectifier circuit, such a generator can meet the requirements of charging the downhole electronic devices.

This magnetic levitation turbine generator has the advantages of simple structure, high conversion efficiency, easy processing and high feasibility. It is expected to offer an intriguing alternative for long-term downhole power supply, which is an important prerequisite for a wide range of future production systems and applications.
Reducing Carbon Emissions in Drilling Operations Offshore Abu Dhabi
Authors: Hinden P-M. , Farrouk H. , Innes G. , Crowther L. , Kustanto S.
Published: October 2023

This paper highlights the carbon emissions reduction associated with the thermal processing of drill cuttings. A case study is presented demonstrating how a major operator in the UAE reduced the carbon emissions of its drill cuttings treatment operation by more than 68% across three of the biggest offshore oilfields in Abu Dhabi.

The operator was utilizing a ship to shore method whereby drill cuttings are stored in skips at the wellsite before being transported 131 km by boat and 163 km by truck to a central processing site onshore for treatment. This method involves two days of travel each way, generating 30 tCO2e per trip.

To reduce the carbon emissions of the operation, the operator utilizes a thermal drill cuttings processing unit closer to the wellsite, eliminating 257,300 km of travel. This reduced the carbon footprint of the drilling waste management operation by more than 5,068 tCO2e while improving project drilling efficiency by allowing more sections to be drilled with oil-based mud.

The solution allowed the operator to recover $5,000,000 worth of base oil for reuse in the drilling operation, eliminating the requirement to ship this volume of base oil from the shore to the rig. In addition, the project has seen 80,000 work hours LTI free operations since it began in September 2021.
Potential Risk Evaluation of Biogenic Reservoir Souring for Decision Support of Water Flooding Field Development Plan in a Giant Offshore Oil Field in Abu Dhabi
Authors: Ashikawa Kota , Ikeda Koki , Iino Atsushi , Hiraiwa Takeshi , Makishima Ken , Nomura Yukito , Al Ameri Saeeda Mohamed , Dada Adedayo , Yonebayashi Hideharu
Published: October 2023

Biogenic reservoir souring is characterized by H2S generation by Sulfate Reducing Bacteria (SRB) typically after the initiation of waterflooding. An offshore oil field in UAE has been developed with dump flooding from an aquifer reservoir and peripheral seawater injection. As the future development plan (FDP), pattern seawater injection in the mid dip was selected to improve oil recovery. To assess the robustness of this development plan, the study aims to understand the mechanism of biogenic reservoir souring and predict its future risk.

Firstly, analytical investigation was conducted to assess the present reservoir souring situation. Secondly, the full-field biogenic reservoir souring simulation was performed using SourSimRL (industrial JIP's program) that works as a post-processor of reservoir flow simulators and predicts the microbial generation, scavenging, adsorption and transport processes of H2S. Lastly, sensitivity analyses were carried out to understand the limiting factors of the biogenic reservoir souring and capture the uncertainties in the prediction of the FDP.

The simulation demonstrated that the reservoir cool-down effect by injecting seawater is limited to the vicinity of injectors due to the high reservoir temperature. Thus, dominant pattern of biogenic reservoir souring is expected to be "biofilm" zone where all ingredients for SRB growth need to be supplied with the injected seawater. The sensitivity analysis also confirmed that carbon source and nutrient concentrations in the injected seawater have a larger influence on biogenic H2S generation compared to those in the formation water. The forecast simulation predicted the gradual increasing trend of biogenic H2S concentration in the produced gas at the field level, which is corresponding to the field water cut increase. However, the severity of predicted biogenic reservoir souring impact is still within the facility design limitation. Thus, the FDP is acceptable in terms of biogenic reservoir souring risk because of the robust design basis. Additional souring mitigations such as installation of sulphate removal unit is considered unnecessary. Although the field-level biogenic H2S is moderate, relatively high biogenic H2S concentrations were predicted locally in several wells. It can be managed by well surveillance at the high water cut wells.

The study managed the complicating field development history, consisting of dump flooding from the aquifer reservoir and peripheral seawater injection, and the FDP deploying pattern seawater injection in the mid-dip. Application of the full-field biogenic reservoir souring simulation significantly contributes to decision support of the water flood-basis FDP and better understanding on potential requirement to mitigate the reservoir souring risk.
Innovative Bit Body Design Unveils Manufacturing Novelty, Improves Drilling Performance and Dogleg Assurance in Rotary Steerable Applications
Authors: Gjertsen O. , Santana R. , Craigue L. , James P. , Andreasen G. , Ross J. , Boualleg R. , Tang K. H. , Li D. , Mendoza D. , Gatell J. , Durairajan B. , Mushinski R. , Karuppiah V.
Published: October 2023

The future of oilfield well drilling is incorporating the capabilities of the rotary steerable system (RSS) on a digital platform. For this capability to be successful, the RSS bottomhole assembly (BHA) must be able to drill the entire planned section and deliver an accurate actual vs. plan trajectory. This operation therefore minimizes the time spent drilling each well and subsequently the carbon footprint of that well. The drill bit plays one of the most important functions in this equation. RSS BHA's call for polycrystalline diamond compact PDC drill bits, which minimize the distance from the cutting structure to the deflection pads. By minimizing the makeup length (MUL) of PDC bits makes it possible to achieve more challenging well profiles while alleviating tool damaging shock and vibration.

To minimize the length of the PDC drill bit, innovation drove a one-piece steel body design incorporating all aspects of the application into the design. The cutting structure was designed to optimize MUL, stability, and durability to match the application requirements.  The bit body was analyzed to determine how best to reduce its length to a practical minimum while maintaining manufacturing capability and reliability. Further optimization on the cutting structure through dynamic simulation, improved cutter balancing, and backrake distribution. Removing the traditional two-piece structure and joining weld reduced the MUL by up to 2.5 in. over a baseline minimum.

The reduction in MUL from the one-piece steel body PDC architecture represented a 37% reduction in the drill-bit length. This reduction brings the cutting structure closer to the deflection point of the RSS with two results, namely an increase in build/turn rate by up to 64%, and reduction in lateral and axial shock and vibration on the average with lower peak values. Reducing the BHA and bit vibration and increasing build and turn rates ultimately reduces nonproductive time, increasing the number of sections drilled successfully in one run. Positive directional driller and customer feedback with multiday reduction drilling time has resulted. The largest impact to sustainability is seen in the reduction in RSS tool failures or prolonging time between tool replacement or maintenance.

A comprehensive design approach was undertaken to create a minimized MUL with the target of improving dogleg severity (DLS) capability and stability. The cutting structure and bit body were also designed to optimize MUL, DLS capability, and stability. Design, material analysis, dynamic considerations, and technology integration are the pillars to delivering the described solution.
Improving Injection Efficiency in CCUS Wells: A Comparative Analysis of Different Completion Designs
Authors: Bona Prakasa , Fraser Murray , Clifford Allen
Published: October 2023

Global investment has delivered a steadily increasing investment in carbon capture, utilisation, and storage (CCUS) projects for the past years. Such interest moves the petroleum industry from pioneering projects towards multi- and large-scale projects. Industrial-scale CCUS is necessary to meet the demand of climate change initiatives. Numerous subsurface studies have investigated the potential geology for carbon storage and depleted gas reservoirs are considered as appealing targets for carbon dioxide (CO2) sequestration because of their storage capacity, proven sealing capability, reservoir characterization knowledge, existing infrastructure, and potential for enhanced gas recovery.

While depleted gas reservoirs are attractive targets for CCUS, the CO2 injection process poses several challenges including extreme cooling due to gas depressurization, a potentially unstable flow regime that has consequences for tubing stress analysis, CO2 deliverability, and reservoir management. Careful well design is critical to answering these challenges. Holistic but practical simulation work is key to ensure that the well is properly designed for all types of operations along its injection lifetime.

This paper introduces for the first time, a trifecta of simulation works that links steady-state simulation, transient simulation, and advanced completion stress design. The 1D steady-state and transient analyses would feed into the meshed well-reservoir simulation which enable engineers to investigate the detailed wellbore hydraulics and multiphase flow through advanced completions. These details will be keys as input for analysing the stress and loading simulator. Streamlining these simulations will bridge the communication between the subsurface team and well design team to produce an optimum completion design based on comprehensive analysis. We investigate the behaviour of each of the completion options such as a simple monobore completion, concentric, horizontal wells with inflow control devices and intelligent completion with downhole control valves. The results are then benchmarked to each other with consistency for neutral comparison.

Effective CO2 injection entails finding methods for optimising the fluids along the pipeline and the CO2 voidage once the fluids have entered the reservoir drainage. This paper explains a proposed guideline for effective CO2 injection management. We discuss multiple gains and limitations of each completion which cover hydraulics, thermodynamics analysis, material selection, and tubing stress analysis for different scenarios. This paper also discusses phase instability of CO2 transportation within injection systems which can be avoided by maintaining the proposed guidelines.