bluuebunny/crossref_metadata_2025 huggingface dataset:
The Emergence of Maintenance as a Source of Competitive Advantage: A Sustainability Perspective from the Upstream Services Sector
Authors: Raza Mustansar
Published: October 2023

This paper aims to explore the emergence of maintenance as a source of competitive advantage in the upstream services sector, with a focus on the role of sustainability in enhancing the performance of maintenance processes. Specifically, the paper will present a conceptual framework that can be used to evaluate the sustainability of maintenance processes in services set-up, with an emphasis on the impact of external factors and the development of internal capabilities. By doing so, the paper seeks to contribute to the growing body of literature on sustainable maintenance and highlight the importance of sustainability in driving the success of maintenance processes.

The methodology adopted for this study involves a review of the existing literature to identify the common sustainability framework used in the industry. The sustainability framework commonly used is based on the Brundtland Commission report (1987) and comprises three criteria: social, environmental, and economic, with a varying number of context-specific subfactors. The impact of these external factors on the performance of organizations is analyzed to determine their influence on sustainability performance or the development of internal capabilities. Additionally, qualitative research conducted on an upstream services company identified another important criterion contributing to the sustainable success of maintenance processes i.e. technical criteria.

The evaluation of maintenance process sustainability can be based on four dimensions, namely technical, social, environmental, and economic, each with multiple criteria. The findings from the qualitative research demonstrate that the sustainable success of maintenance processes is a multi-level phenomenon that involves corporate, operational, and functional (process) levels of maintenance strategies.

While sustainable maintenance is a relatively new concept for the petroleum industry, it has been commonly used in manufacturing and production settings in other sectors over the past decade. This study assessed the factors affecting the sustainable performance of maintenance processes by reviewing existing literature and proposing a conceptual framework. The framework's factors and subfactors were refined through qualitative research conducted on an upstream services company, highlighting the external factors contributing to positive outcomes and the development of internal capabilities. The proposed framework applies to any service provider setting to enhance the maintenance process's sustainable success.
Application of Digital Twin Technology to 3D Seismic Iterative Processing and Dynamic Geological Modeling- A Case Study from China
Authors: Xia Guoyong , Li Jianhai , Lu Linchao , Ma Shaoguang , Chen Ying , Liu Yanbin , Xu Hanbing
Published: October 2023

With the continuous increase in domestic energy demand, China has increased the exploitation of domestic oil and gas resources in recent years to ensure national energy security and reduce foreign energy dependence, resulting in a significant increase in the number of wells drilling operation. In order to reduce drilling risks and achieve drilling performance, it is necessary to carry out iterative update processing of 3D seismic data. The research results can effectively reduce the uncertainty of geological cognition, and realize the efficient development of oil and gas resources. Firstly, the pre-drill geological risk and well risk analysis was carried out to clarify the types of drilling risks. Secondly, a pre-drill geological model based on 3D seismic data was established, It is used for the pre-drilling plan optimization design and well deployment; then, based on the pre-drilling 3D geological model, the real-time tracking study of the model is carried out through various kinds of data during the drilling process, the parameters such as azimuth gamma are used to predict the sand body parts encountered by the drill bit, and the geological model is constantly revised. During the drilling process, the evaluation of seismic data processing results and data iteration were guided actual drilling, and an integrated evaluation system of seismic data prediction results was formed to effectively predict risks and provide early warnings. Integrated drilling and logging data, combined with regional geological characteristics supported the drilling of horizontal well sections. Carry out seismic tracking data evaluation, summarize the advantages and application scenarios of different data, improve the target of tracking, and effectively reduce risks. Depth domain data has higher accuracy in identifying the dip angle and fracture location in the horizontal section and combined with high-resolution processing, can effectively support the implementation of well trajectory in the horizontal section.
A Conceptual Model to Maximize Project Efficiency Through Automated Scheduling Using Generative AI Models
Authors: Ali Mohamed Anwar , Mohammed Azharuddin , Saif Al Busaeedi Nasser , Saud Shah , Salem Al Sayari Amal
Published: October 2023

The study presents a conceptual model that uses generative AI to automate project scheduling for complex oil and gas capital projects. The model uses historical project schedules and expert-built process maps to generate a full-scale schedule including dependencies, resources, and duration. The study highlights the limitations of traditional scheduling methods based solely on planner ability and discusses the potential benefits of using AI, including improved accuracy and efficiency.

The conceptual model aims to address project schedule issues and the model begins by collecting data from past projects to create a historical database, which is used to train a generative AI algorithm to perfect the process maps. Process maps serve as a visual representation of the project schedule, detailing the steps and dependencies involved in a project, and are used to find potential issues or bottlenecks in the schedule and recommend solutions based on historical data. Text summarization and cataloging techniques are used to extract key information and categorize them based on project type, driver, size, stage, etc.

After examining the available literature and conducting a market analysis, it was found that the potential solutions for oil and gas scheduling requirements were not enough. The quality of the project schedule can be affected by several factors, leading to associated integrity issues, project delays, cost overruns, and other negative consequences. Addressing these challenges upfront requires a robust and reliable method that incorporates historical data, process maps, and AI-driven analysis to create accurate and transparent project schedules. Observations revealed that the model's ability to learn from historical project schedules and expert knowledge was crucial to its success. The use of expert-built process maps supplied a comprehensive and accurate framework for generating project schedules, improving the accuracy and efficiency of the generative AI algorithm. The proposed model offers a streamlined approach to project scheduling that can help reduce the potential for human error and improve project outcomes. The use of generative AI for project scheduling has the potential to revolutionize the oil and gas industry by supplying a more efficient and accurate method for managing complex projects. Further research and development of this approach can lead to continued improvements in accuracy and efficiency, ultimately leading to better project outcomes.
Impact of Diffusion and Adsorption on the Performance of CO2, CH4, and Cyclic Gas Huff-n-Puff Injection into Light Oil Reservoirs
Authors: Enab Khaled A.
Published: October 2023

The implementation of cyclic gas injection, commonly known as huff-n-puff, holds significant promise in augmenting hydrocarbon recovery from shale oil reservoirs and addressing condensate blockage in liquid-rich shale formations. The effectiveness of huff-n-puff, however, depends greatly on the composition of both the reservoir fluid and the injected gas. Particularly in ultratight shale reservoirs, where diffusion and sorption play pivotal roles, a precise understanding of their influence on huff-n-puff performance becomes crucial for accurate predictions of oil recovery and solvent retention.

To thoroughly assess the huff-n-puff process in shale reservoirs, we conducted extensive large-scale numerical simulations using a dual-porosity naturally fractured compositional model that incorporates molecular diffusion and sorption mechanisms. The Langmuir's adsorption model was employed to account for adsorption effects within the system. Rigorous grid block sensitivity analysis was performed to minimize numerical errors and enhance simulation accuracy.

By evaluating the impact of diffusion and sorption on production performance for different fluid and injection gas combinations, we established correlations between the considered characteristics and the huff-n-puff performance. To conduct this evaluation, we selected the Eagle Ford Formation, a highly developed shale with a wide range of pressure-volume-temperature (PVT) windows, from dry gas to black oil. The simulation outcomes revealed that methane (CH4) and cyclic-produced gas exhibited the highest recovery potential, while carbon dioxide (CO2) yielded the lowest production results. The performance of the solvent was notably influenced by the content of light components in the fluid and the gas-oil ratio (GOR). Neglecting molecular diffusion, especially during the soaking period, led to underestimation of recovery factors, whereas disregarding the adsorption effect resulted in overestimation of recovery. Furthermore, we observed that the adsorption of intermediate components on the surface of organic pores in shale gas condensate effectively pushed condensate out of the pores, mitigating condensate blockage around the wellbore.

This work aims to provide further insights into the huff-n-puff performance in shale reservoirs by focusing on the reservoir fluid and injection gas compositions. The results of this work will improve our understanding of the relationship between fluid compositions and diffusion and sorption. Furthermore, our findings provide insights into the optimization of the huff-n-puff process in shale reservoirs.
Design of a Novel Sensor for Circumferential Multi Casing Corrosion Measurement Through Tubing
Authors: Dutta S. M. , Ramirez M. S. , Smith A. , Olaiya J. , Friere L. , Kverneland J.
Published: October 2023

A novel sensor design is presented that uses transient or pulsed eddy current measurements to perform circumferential quantitative evaluation of corrosion, thickness, or metal loss of two or more concentric tubulars individually. Modeling and simulation studies and experimental results are presented that formed the basis, as well as provided validation, for the sensor design.

The new sensor design is based on transient or pulse eddy current technology and comprises several coils that simultaneously achieve azimuthal resolution on the tubing and the casing as well as high radial depth of investigation. The sensor is designed to induce eddy currents in multiple concentric tubulars and to measure a time-varying response from the outward-diffusing eddy currents. The full transient responses from multiple coils within the sensor can then be interpreted to obtain azimuthal information about corrosion and wall thickness of these tubulars.

Simulation studies and experimental results are presented that relate different physical features of the sensor to its performance in terms of sensitivity to channel flaws, signal-to-noise ratio, and azimuthal resolution. The results show that the sensor design has the potential to complement conventional multi-casing corrosion measurements that investigate more than three concentric tubulars but only yield average non-azimuthal wall thickness measurements of each tubular. Conventional multi-casing corrosion measurements have most recently been relegated as a precursor to pulling the tubing and evaluating the casing again with single barrier evaluation services. Measurements from the novel sensor could arm the operators with more accurate information as to the azimuthal extent of corrosion on the inner barriers and empower them to make timelier and more economical well integrity management decisions. These measurements can also complement through tubing evaluation of cement behind casing.

This paper describes the advantages, limitations, and design of a new state-of-the-art pulsed eddy current sensor that is meant to provide azimuthal measurements of the inner strings in multiple barrier completions. The novel sensor design has the potential to plug a critical gap in conventional downhole well integrity measurements during intervention or plug & abandonment which in present day only provide non-azimuthal multi-casing corrosion, thickness, and metal loss measurements.
The Accurate Emission Forecast at the Well Planning Stage
Authors: Ruzhnikov Alexey , Nifantov Aleksandr , Julaidan Mohammed , Johnson Ashley , Alharthi Rakan , Medina Diego
Published: October 2023

Well construction is necessary part of oil and gas business, and its greenhouse gases (GHG) emissions reduction is becoming important. Today, the main attention is paid to technology, minimizing drilling time and upgrading rig with low-energy equipment. However, often the changes are implemented without establishing the proper baseline. This paper provides the detailed approach how the emissions can be accurately calculated at the well planning stage, aiming to implement most effective actions to reduce it.

The conventional approach to estimate rig site GHG emissions during the well construction relies on the past data, when the average daily fuel consumption is taken. Instead, the modern workflow was developed, which included the development of the algorithm to evaluate the emission during a specific well construction activity. To ensure the accuracy of the predicted values the rig fuel consumption measured with higher frequency comparing to daily-basis-approach and processed from spud to rig release. The obtained data allowed to tune the developed algorithm to ensure the high accuracy of the prediction.

As a result, the actual GHG emissions during every operation was obtained. It was understood that between others the drilling and back reaming has the highest fuel consumption rates (as well as emission rate). The actual values were collected for different hole size at the same depth, for drilling, tripping, circulation, and flat time activities. Additionally, the carbon footprint of the auxiliaries was estimated.

The updated algorithm allows now to have 95% accurate estimation of the rig site emissions during drilling program preparation. Previous approach during any decision related to a well construction was based on 2 main pillars: the budget and the performance. Now, with this information, it is possible to add the third component into the equation – the GHG emissions footprint. And better, more balanced decision can be made at the planning stage.

The main idea of this approach is to get the low-energy, cost-effective and technically achievable well design as a baseline. It will leverage the effect of further implementation of energy transition technologies on top of this basis.

This manuscript presents a new methodology of oil and gas wells engineering bringing the well design on qualitatively new sustainable development level. The ideas, which are formulated in the manuscript, can be implemented in any drilling project worldwide.
Feasibility Study of Low-Tension-Gas Flooding Application in High Temperature High Salinity Sandstone Reservoirs
Authors: Zhou Nancy C. , Niu Fangya , Panthi Krishna K. , AlAbdullah Mohammad B. , Lu Meng , Vaughan Steven , Zhang Danhua Leslie , Mohanty Kishore K. , Mojdeh Delshad , Li Jianshen , Liu Fuchen , Yang Zhenzhou
Published: October 2023

Low-tension-gas (LTG) flooding has been demonstrated in the laboratory to improve oil recovery for tight formations with sub-20-md permeability. High temperature and high salinity (HTHS) reservoir conditions still pose significant challenges for this hybrid surfactant and gas enhance oil recovery (EOR) method. This paper presents a systematic study that includes developing low interfacial tension (IFT) surfactant formulation, investigating LTG flooding, and lab-scale reservoir simulations to evaluate the feasibility of LTG for field application in harsh reservoir conditions. The brine and crude oil analysis showed that the formation water and injection water from the interested field have total dissolved solids (TDS) up to 70,000 ppm and divalent cations, such as calcium (Ca2+) and magnesium (Mg2+) over 2,000 ppm, and the crude oil contains over 5% asphaltene and has total acid number of > 0.5 mg KOH/g. A novel synergistic blend of two commercially available long-alkyl-chain surfactants with a co-solvent was developed with ultralow IFT and acceptable foamability at 92°C. The foam injectivity core flood showed that a foam quality of 50-80% demonstrated a stable foam. The surfactant polymer (SP) core flood test using outcrop cores demonstrated the efficiency of the developed ultra-low IFT surfactant formulation. LTG core flood experiments using reservoir core plugs were performed by injecting the same low tension surfactant formulation along with gas at 50% quality followed by foam drive with the mobility control foam at 80% quality. The residual oil saturation was reduced to less than 5% by LTG flooding. The lab observed recovery was accurately modeled using UTCHEM, a chemical flooding simulator. Our experimental work demonstrates the effectiveness of LTG flooding in high temperature sandstone reservoirs with high divalent cations in high salinity formation brine. Our mechanistic models and numerical simulations for this complex surfactant and gas EOR method matched the experimental results.
Quantitative Analysis on Reducing Greenhouse Gases Emissions through the Implementation of Flare Gas Recovery Systems in Gas Oil Separation Plants
Authors: Alaskar Sarah Y. , Alsawad Turki A.
Published: October 2023

This paper explores the potential of implementing flare gas recovery systems (FGRS) in gas oil separation plant (GOSPs). During oil and gas extractions and refining stages, large amounts of ejected gases are directed to a flare network. Those flared gases increase greenhouse gases (GHG) emissions and prevent the potential of utilizing excess gas as feedstock fuel. If FGRS are used, the amounts of wasted energy and GHG will consequently decrease. In this paper, quantitative analysis was performed to explore the overall benefits of implementing FGRS in GOSPs. The pillar of this study focuses on a GOSP plant. In this study, quantified flared volumes prior and after the implementation of FGRS were analyzed. Additionally, incorporated evidence from other industry practices were also collected to support the positive outcomes of FGRS implementations. The acquired results revealed a high favorability for utilizing FGRS systems in GOSPs in comparison to conventional flaring mechanisms. This paper covers a novel quantitative analysis of utilizing FGRS in GOSPs to minimize carbon dioxide (CO2) and GHG footprint. The holistic impact and state of art of applying FGRS is recommended to be used in all GOSPs. If applied, FGRS can reduce GHG emissions hence, promoting sustainability, and aiding in power generation.
A Novel Methodology to Capture Anisotropy in Unconventional Reservoirs: A Case Study with Stress Anisotropy
Authors: Ibáñez E. , Alvarellos J. , C. Bezerra de Melo R. , Laksmikantha R. H.
Published: October 2023

The article presents the results of a case study obtained through the application of theory and methodology explained in the accompanying article submitted to this conference. Stress anisotropy determination requires material properties anisotropy as input, and the acquisition of these properties isn’t common practice. The current results clearly demonstrate how stress anisotropy could be captured in an unconventional reservoir with a simple and novel methodology. The results eventually enable efficient lateral placements and optimized hydraulic fracture design.

Rock mechanical properties were determined by compression and shear velocities; later, a 1D geomechanical model (1DGM) was built based on the poro-elasticity and effective stress principles. Subsequently, 1DGM was calibrated based on any available core, DFIT/LOT/FIT/minifrac data, and observations from DDR (daily drilling reports). The 1DGM built and the rock's mechanical properties calculated are isotropic. A regional tectonic strain value was determined based on multiple well correlations in the region. Following the theory and methodology proposed in the accompanying article in this conference, two new horizontal stresses, Shmin_tect and SHmax_tect, were determined, capturing stress anisotropy as input to hydraulic fracture design.

The play has three distinctive pay zones or shale formations: upper, middle, and lower, confined by much harder formations above and below. The area of study did not have any data for a full anisotropic characterization; however, there was production data suggesting connectivity in the staggered laterals. Thus, the objective was to determine as accurately as possible the stress anisotropy that would affect the vertical fracture growth and containment. Data from four (four) lateral/pilot wells was used to build four 1DGM in two different acreages. Results from one such well are shown in Figure 1. The results shown in Figure 1 clearly demarcate five zones with different stress gradients. In the three pay zones and shale formations, it is evident that the middle formation would potentially act as fracture containment for laterals placed in the upper and lower formations. Also, the much harder above and below formations show a higher stress gradient, as expected. Further analysis comparing microseismic and production data to substantiate the results obtained is ongoing. The results clearly show the effectiveness of the methodology, thus adding a simple but novel workflow to capture stress anisotropy that is cost-effective and has a quick turnaround.
Development and Performance Evaluation of a Novel Nano-Composite Crosslinked Fracturing Fluid for Ultra-Deep Reservoir in Tarim Basin
Authors: Xue Yanpeng , Qin Shiyong , Yang Sasa , Liu Ju , Wang Xin , Xu Hang , Hong Yinglin , Lou Erbiao , Deng Qianxing
Published: October 2023

For major ultra-deep oilwells in Tarim basin, hydraulic fracturing operation are challenged by the actual vertical depth in excess of 6000 m and the temperature at bottom hole over 160 °C. The long injection path from ground to target formation generates considerable friction, resulting in extremely high ground pressure, which usually exceed the limit of operation equipment. Moreover, traditional crosslinked fracture fluids always lost their viscosity and sand-carrying ability at high temperatures. Consequently, it is meaningful to develop and research novel fracturing fluids for hydraulic stimulation in high-temperature, ultra-deep reservoirs.

Nano-composite technology has been proven to be a potential solution to some challenges associated with crosslinked fracture fluid systems. In this work, a kind of low-cost molybdenum disulfide (MoS2) nanosheet was firstly synthesized by hydrothermal chemical method. Afterwards, the MoS2 nanosheets were mixed with polyacrylamide solution with specific molecular weight by ultrasonic dispersion, and a certain amount of organic zirconium crosslinker was added to prepare the nano-composite crosslinked fracturing fluid. Finally, a series of indoor evaluation tests were performed to compare the performance of the nano-composite crosslinked system with the similar crosslinked fluid without adding nanosheets, such as rheology properties, drag reduction efficiency, proppant suspension and retained conductivity.

The obtained experimental results have shown that the thermal stability of the nano-composite crosslinked system is much superior to that of a comparable fluid lacking the MoS2 nanosheets. The introduction of nanomaterial allows the novel fracturing fluid to operate at greatly lower polymer concentrations (0.2%-0.3%) compared with current commercial fluid systems (0.4%-0.5%) designed for 180 ℃ reservoirs. The retained apparent viscosity can be maintained above 75 mPa·s after shearing 120 mins at 180 ℃. Rheological studies have shown that the novel system has superior crosslinking properties, and the crosslinking time can be controlled within 4-10 minutes. In addition, this novel nano-composite crosslinked fracturing fluid has enough sand-carrying viscosity under high-temperature conditions, and allows for efficient cleanup by use of an oxidizer-type breaker. Little or no polymer residue and efficient cleanup are contributing to lower reservoir damage, better fluid conductivity, and improved well production.

Newly proposed nano-composite crosslinked fracturing fluid provides a new solution for fracturing stimulation of ultra-deep high-temperature reservoirs in the Tarim Basin, and hence improving the oil recovery.
Deployment of Novel Wide Dynamic Range Through-The-Bit OBM Borehole Imager Enables Logging in Challenging Environment-Implications for the Ordovician and Silurian Siliciclastic Facies Characterization
Authors: El-Khamry Ayman , Rubaie Naif , Weihua Wang , Hassan El-Saied
Published: October 2023

Acquiring borehole resistivity image logs on drill-pipe conveyance operations has some operational and data quality challenges especially in challenging hole conditions and complex well trajectories. These challenges include operation efficiency, sticking issues, proper pad contact and pads overlapping which significantly affect the produced image quality and accordingly the geological interpretation reliability. To address these, a new through-the-bit imaging technology in oil-based Mud (OBM) is introduced, the new technology design has been proven to be reliable and effective in challenging hole conditions.

This deployment technique allows acquiring high-definition micro-resistivity images in conditions where conventional wireline conveyance techniques cannot be used, such as unstable boreholes, tortuous or rugose wells, loss zones, or severe washouts. The distinctive operational advantage of the through-the-bit imaging technology is deploying the tool through the drill-pipe and reaming bit while performing a wiper trip, which saves rig time and significantly reduces fishing risk through the avoidance of cable and tool sticking. Moreover, it improved operations with full well control and the ability to retrieve logging tools at any time. In addition to the high-resolution images produced with the new technology, an inversion workflow has been developed to quantitatively interpret images. The interpretation results are compared with the analysis performed on the images acquired on tough logging conditions (TLC) operations in the same hole.

This paper evaluates the outcome of deploying two electrical borehole imaging technologies through two different conveyance techniques. The innovative through the bit micro-resistivity OBM images are proven reliable in low- and high-resistivity formations, significantly reduced sticking and eliminated the overlapping of pads towards the bottom of the logged interval due to the lighter weight of the through-the-bit technology.

The evaluation included the comparison with the existing conveyance method and covered a full range of well profiles from vertical to deviated, including highly deviated wells and long laterals. The high-resolution image produced allowed identifying various sedimentary and structural features within the target formations. These sedimentary features included thin laminations, cross bedding, soft sediment deformation and structural elements such as natural fractures and faults. Additionally, with inverted standoff images, open and closed natural fractures were identified and utilized in the fracture modeling of the field. All the forementioned identified features have been incorporated into the facies and the structural model of the studied area. The models are more reliable and can be used with confidence for well trajectories optimization and stimulation designs.
Metagenomic Sequencing of Formation Water Sample of Upper Assam Oil Fields and Its Possible Applications in Microbial Enhanced Oil Recovery
Authors: Bhattacharjee Saurav , Mech Borkha , Ahmed Naved Wasim , Khataniar Ankita , Das Aparoov
Published: October 2023

In this study, we describe a metagenomic approach which is a Next Generation Sequencing Technique (NGS) for the identification of biosurfactant-producing microbes present in the formation water sample in the oil fields of Upper Assam. This study also intends to investigate the possible use of the Bacillus subtilis OQ957160 strain (sb23) in the brown fields of Upper Assam for improving recovery of crude oil. Biosurfactant-producing strains like Bacillus Subtilis, Bacillus licheniformis, Pseudomonas Putida, and Pseudomonas aeruginosa were isolated using 16s rRNA gene sequencing and were described and examined based on their capacity to degrade crude oil to produce biosurfactants. Bacillus subtilis OQ957160 strain (sb23) was selected for further study based on its biosurfactant production capability and better interfacial tension reduction (IFT) and surface tension (ST) properties. Through changes to the growing environment, such as carbon source, temperature, pH, and salinity, the dynamics of growth research of the identified strain sb23 was done. Lipopeptide (Surfactin) was identified as the produced biosurfactant. After 70 hours of incubation under ideal conditions, the maximum biosurfactant production of 6000 mg/L and the minimum interfacial tension & surface tension of 0.98 and 23.8 mN/m were attained. At the value of 475 mg/L the biosurfactant solution exhibited critical micelle concentrations (CMC). Additionally, the biosurfactant exhibits outstanding surface activity throughout a wide temperature range of 35-95°C and at salinities ranging from 0.0-16.0% (w/v) and pH 2.0 -10.0. Under reservoir conditions, the produced biosurfactant from strain (sb23) is used in microbial flooding tests to recover an additional 7.85% of heavy crude oil. As a result, the isolated strain sb23 has the potential to significantly improve oil recovery from depleted oil fields of Upper Assam.
Experimental Investigation on Hydrate Formation and Decomposition Behaviors in Micro-Pore Channels
Authors: Zhang Jianbo , Liu Shujie , Xu Yilong , Zhang Binbin , Wang Zhiyuan , Yin Bangtang , Li Shuxia , Gao Yonghai , Sun Baojiang
Published: October 2023

Hydrate formation and decomposition are important factors affecting fluid flow in porous media. To reveal the characteristics of hydrate formation and decomposition in the pores of porous media, pore-scale experiments under different types of flow in micromodel were conducted using a visual microflow experimental apparatus. The experimental results suggested that heterogeneous hydrates were formed in the pore channels, which was mainly affected by the gas-water distribution and temperature & pressure. Compared with the gas-dominated and water-dominated flow, the hydrate formation rate was the maximum under gas-water two-phase flow, and the risk of hydrate blocking the flow channel was the maximum. Moreover, the hydrates were gradually decomposed from the pressure-reduced outlet to the inlet. The methane produced by hydrate decomposition in the pore channel would gather and form a continuous gas flow channel under pressure difference, and the methane dissolved in the water phase would also gradually precipitate out as the pressure decreases to form bubbles, which would form large methane bubbles with adjacent bubbles, thus driving the surrounding water phase flow. This paper lays a foundation for future research on hydrate formation, decomposition and flow in porous media.
Investigating the Effect of Salt, Polymer and Magnetic Nanoparticles on Critical Drilling Parameters—Coupled with Novel 3D Image Processing Technique
Authors: Khan Muhammad Arqam , Aamir Muhammad , Asad Muhammad , Junaid Muhammad , Lalji Shaine Mohammadali , Ali Syed Imran , Ahmed Hashir , Lashari Zeeshan Ali , Lv Kaihe , Li Mei-Chun , Sun Jinsheng
Published: October 2023

Drilling fluid properties have a significant impact on drilling operations. The drilling fluid system suspends and conveys cuttings to the surface using its rheological parameters within the desired operating range. To achieve this, drilling fluids require sufficient viscosity to suspend particles and control fluid loss into the formation. This study aims to address the swelling characteristics of the Middle Indus basin in Pakistan by utilizing a drilling fluid containing different classifications of additives. Eight mud samples were prepared by adding Sodium Alginate, Magnetic Bead Nanoparticles, and KCL at various concentrations to a base mud. The mud samples underwent pH and stability tests, followed by rheological properties tests, including Gel Strength, Viscosity, Shear Stress, Dynamic Viscosity, Plastic Viscosity, Yield Point, Apparent Viscosity, Flow Index, and Consistency Index. Filtration tests were performed to determine filtrate volume loss and mud filtrate cake morphology. The mud samples were evaluated by immersion in the Ranikot shale pallet. Contact angle measurements, 3D surface analysis, and intensity profile surface plots were conducted on the mud filtrate cake and samples. Results of the study reveal that all the mud samples exhibited shear thinning behavior, with dynamic viscosity decreasing as the shear rate increased. Among the tested samples, Sample 7 exhibited the highest dynamic viscosity, which can be attributed to its higher particle concentration. In terms of rheological behavior, Sample 4 performed the best among all the samples. Notably, except for Sample 4, all other seven samples demonstrated cuttings less than 1.5. The power law model provided the most accurate predictions, with the lowest mean absolute error and highest R2 value. Contact angle measurements and intensity profile surface plots highlighted the influence of the mud system on shale sample wettability and surface morphology. The results underscored the importance of KCL, Magnetic Bead Nanoparticles, and Sodium Alginate concentrations in determining the success of a drilling fluid system. These particles also modified the surface properties of the shale samples as observed through 3D image processing techniques. Magnetic Bead Nanoparticles exhibited superior performance compared to others by encapsulating the shale sample and preventing water molecule migration within it.
Track & Reduce Carbon Emission Using Planning Model to Make More Sustainable Operation for Refineries and Olefins
Authors: Jain Piyush
Published: October 2023

Balancing the dual challenge of reducing emissions while still ensuring profitable operations is top of mind for refiners and olefins producers around the world. Advancements in digital optimization technology can help industry leaders navigate the energy transition, meet sustainability goals, and optimize operations and enable companies to meet emission targets and still ensure profitable operations.

Typically, the analysis in LP models is economically focused, balance tradeoffs between different operating parameters to determine how it affects the gross margin of the asset. However, LP models can be used to make operations more sustainable by improving energy efficiency and enabling sustainability decisions such as sourcing renewable electricity for your plant.

Production Optimization using LP models can be used to predict and optimize the tradeoff between emissions and profits and help refiners to find a balance. Use of industrial AI (i.e., Hybrid model) can be a key enabler to make this decision with high confidence.
Nanoparticles Improved Sedimentation Stability of Oil-Based Completion Fluids while Drilling Ultra-Deep Wells
Authors: Yan L. L. , Wang J. H. , Ni X. X. , Sun J. S. , Zhang J. W. , Wang R. , Zhang J. Q. , Cui X. B.
Published: October 2023

The deep and ultra-deep oil and gas resources are important sources to meet the increasing oil and gas demands. But they are difficult to be explored because their buried geological conditions are extremely complex, such as high temperature (HT), high pressure (HP), thick salt and gypsum beds and borehole collapse. Oil-based drilling fluid (OBDF) is the preferred drilling fluid for ultra-deep wells due to its better wellbore stability and higher lubricity than water-based drilling fluid. Meanwhile, the oil-based completion fluid (OBCF) is also the first choice for operators because it can be turned directly by the OBDF, which is convenient and reusable. However, barite sag is often encountered because the completion fluid is required to be static for 7 to 15 days at a high temperature of more than 180°C, which results in serious problems, pipe sticking, density variation and well control problems, in ultra-deep wells. It is urgent to improve the sedimentation stability of OBCF while drilling the ultra-deep wells.

In this paper, a modified nano-silica stabilizer was prepared to improve the sedimentation stability of OBCF. Its dispersity in a water-in-oil (W/O) emulsion with an oil-water ratio of 80:20 was observed by a cryo-scanning electron microscope and the viscosity at low shear rates was also tested. Then OBCF formulations with different densities were developed and modified by the prepared nano-silica stabilizer. The rheology and sedimentation stability were evaluated on HTHP rheometer and sedimentometer, respectively. The HTHP sedimentometer can work at a pressure up to 105 MPa and a temperature up to 300 °C.

Results indicated that the novel nano-silica stabilizer could disperse stably in the water-oil interface and in the oil phase. The viscosity of the W/O emulsion at low shear rates was significantly increased after adding the nano-stabilizer. Meanwhile, the HTHP rheology and sedimentation stability of the high-density OBCF were improved by the nano-stabilizer due to its surface and size effects, and the HTHP sedimentation stability of the oil-based fluids was positively related to its HTHP rheological stability. The modified OBCF by the new stabilizer was successfully applied in a deep well with a temperature more than 200°C in China. The completion operation was smooth without downhole issues, and the casing was run to the bottom hole at once. The oil-test operation was perfectly completed for about two months, and no barite sag happened.

In a word, the modified OBCF by the new nano-silica stabilizer in this work possessed excellent HTHP rheology and sedimentation stability, expecting to be applied widely in deep and ultra-deep wells.
Application of Artificial Neural Networks in Predicting Discharge Pressures of Electrical Submersible Pumps for Performance Optimization and Failure Prevention
Authors: Mahmoud M. A. , AbuObida M. , Mohammed O. , Hassan A. M. , Mahmoud M. A.
Published: October 2023

The pump discharge pressure is a critical parameter that indicates the performance of the electrical submersible pumps (ESPs). Predicting the discharge pressure accurately can help in optimizing the ESP's performance, improving well productivity, and reducing operational costs. This paper presents a novel approach using artificial neural networks (ANNs) to predict the discharge pressure of electrical submersible pumps. The proposed model will enable early detection of possible failures and reduce downtime. Also, the effectiveness of the ANN model will be compared against the performance of different ANN models under various conditions.

In this study, a dataset of more than 12000 data points collected from 40 different wells was used to train and test various ANN models with different input parameters. The performance of ANN models was evaluated using a coefficient of determination (R2), root mean squared error(RMSE), average absolute deviation(AAD), and absolute percentage error (APE). The model inputs and ANN structure were adjusted in order to minimize the prediction errors. The results during the training and testing phases were compared to select the most accurate and efficient model. Finally, the performance of the selected model was evaluated using physical analysis of the results and error profile visualization.

The results showed that the ANN model with 16 inputs and 1 hidden layer with seven neurons is the most accurate model, with an R2 of 0.95 for training data and 0.94 for testing data, and an AAPE of 1.74 for training data and 1.84 for testing data. The model was able to accurately predict the discharge pressure of ESP under different operating conditions, with an average accuracy of 94%. In addition, anomaly detection was also performed on the predicted values to identify any failures or anomalies in the system. This helps in proactive maintenance and troubleshooting of the system to prevent any significant failures. Finally, a new equation was developed utilizing the optimized ANN model. The developed equation provides fast and reliable estimations for the ESP discharge pressure with an error of less than 3%.

Overall, the proposed approach provides novel and additive information to the existing literature by demonstrating the effectiveness of using ANNs to predict the discharge pressure of ESPs. Furthermore, the ability to accurately predict discharge pressure can lead to the early detection of possible anomalies, which can prevent costly failures and reduce downtime. Future work may explore the use of other AI techniques to further improve the accuracy of discharge pressure predictions and ESP failure prevention and explore the prediction of other important parameters in ESPs.
Estimation of Well Interference by Integrating Fracture-Driven Interactions (FDIs) and Post-Stage Fall-Off
Authors: Ibrahim A. F. , Assem A. I. , Sinkey M. , Johnston T.
Published: October 2023

Hydraulic fracturing near depleted fractured rocks is one of the main causes of fracture hits. Fracture hits damage the parent wells in addition to the loss of fracture efficiency of the child well due to the massive loss of fracture fluids and proppant to the parent well. Child well productivity typically diminishes by more than 50%. This behavior is a function of tight well spacing and the depletion time of the parent wells. The current study aims to combine real-time fracture-driven interactions (FDIs) and post-stage pressure transient analysis (PTA) to estimate an accurate fracture half-length for each stage during the frac job.

During hydraulic fracture operations, a pressure gauge is installed in the offset well(s) to measure pressure change during each stage completion in the child well to account for well interference. The connected fracture surface area (FSA) is then calculated using the post-stage fall-off pressure data. When FDI with an offset depleted zone is higher than a certain threshold, a higher stage fracture half-length is estimated, representing a lower cluster efficiency. The well interference value can then be estimated from the summation of these stages with high fracture half-length.

Actual field cases from oil and gas shale frac data are presented with live FDIs measurements for each stage followed by stage-by-stage PTA. The preliminary results showed that more than 20% of the stages experience fracture hits due to the higher fracture half-length and lower cluster efficiency. Finally, the well interference value has been validated by actual production data.

Integrating FDI measurements with PTA for detecting frac stage interference for unconventional wells presents a faster, more accurate, and cheaper fracture diagnostic tool, that will help optimize well spacing.
Achieving Accurate History Matching in Polymer-Flooded Reservoir Through Advanced Simulation of Polymer Properties
Authors: Negre A. , Suzanne G. , Charonnat S. , Delamaide E.
Published: October 2023

This study aimed at history-matching a full-field numerical model representing a mature oil field that underwent polymer flooding for several years. The main technical challenge was to account for the polymer thermal degradation and the change of polymer molecule that occurred during the development of the field. Accurately representing these changes was crucial for satisfactory oil production history matching. Advanced simulation software was used to simulate all relevant mechanisms, resulting in a successful history matching of the production data.

An innovative workflow based on an integrated approach to define geobodies and connections between injectors and producers was implemented to obtain a satisfactory model calibration on the initial water flooding phase. To model the subsequent polymer flooding phase, a single polymer model was not sufficient to accurately represent the impact of polymer injection on oil production rate, in particular towards the end of the historical period. The simulation model was therefore improved using advanced EOR capabilities involving multi-polymer simulation, advanced adsorption model and thermal degradation. Adjusting these properties supported by laboratory data yielded a robust history-match on the whole polymer flooding period.
Perspectives of Hydrogen Peroxide Injection to the Carbonate Reservoir for ISC Initiation
Authors: Askarova A. G. , Maerle K. V. , Popov E. Y. , Malaniy S. E. , Grishin P. A. , Slavkina O. V. , Cheremisin A. N.
Published: October 2023

As part of laboratory and numerical investigations, an assessment of hydrogen peroxide (H2O2) injection efficiency was performed to estimate the ability of H2O2 to increase the productivity of heavy oil field development. The combined effect can be observed, including heat release due to H2O2 decomposition and oxidative reactions with oil during the in situ combustion (ISC) process and increased oil mobility due to CO2 dissolution.

Laboratory experiments were performed on an autoclave to study the decomposition of peroxide in conditions close to the reservoir (pressure and temperature) and obtain experimental values of the kinetic parameters of the H2O2 decomposition reaction. Further, these values and experimental parameters were integrated into a homogenous numerical model representing the target oil reservoir. Also, during the laboratory experiment, the optimal value of the H2O2 concentration was determined for subsequent sensitivity analysis. The numerical model was then used to build a Tornado diagram and to estimate the effects of preheating, operational parameters, reservoir properties and kinetic parameters with or without catalysts in the system.

According to the results of the hydrodynamic modeling, efficient heating of the formation to high temperatures (over 100°C) during the injection and decomposition of H2O2 is possible only in the presence of a catalyst. The bottomhole formation zone temperature with a catalyst can reach up to 350°C. The most significant influence on the cumulative production is provided by the injection rate, reservoir permeability, initial temperature of the injecting fluid, as well as the thermal properties of the rock. When the temperature reaches 300°C, the reaction of peroxide decomposition begins to accompany the ISC of oil, which is self-initiated, since there is a sufficient amount of oxygen in the formation formed during the decomposition of H2O2.

An effective application of the technology is possible during a sufficiently fast rate of the peroxide decomposition to avoid the dissipation of the released heat due to two possible mechanisms: heating (up to ~150°С) of injected agent (effective, but it is associated with additional costs for equipment and technological risks);use of widely available and cheap catalysts.

As a result of the work, the most promising strategies of H2O2 injection technology for heating a carbonate reservoir were identified. The option of full-scale injection of the H2O2 is associated with high costs and limited development rates. This method can be applied to objects with specific conditions of elevated temperatures where the peroxide decomposition reaction will be the most active.