bluuebunny/crossref_metadata_2025 huggingface dataset:
Diesel and Emissions Tracking in Real Time: Moving Towards Sustainable Fracturing
Authors: Khan Abdul Muqtadir , Narang Rishika , Kurniadi Stevanus Dwi , Ryan Abraham , Joshi Vaibhav
Published: February 2024

Every organization in the oil and gas industry is currently focused on optimizing hydrocarbon production using innovative technologies and infrastructure to meet environmental stewardship goals. This study details a methodology to enable real-time tracking of diesel consumption during the hydraulic fracturing treatment. Diesel volumetrics can then be easily upscaled to CO2 equivalent emissions with the correct knowledge of the emission factor.

A digital dashboard is built that can stream the data with cloud or on-prem services. In the asset performance monitoring, all engine parameters such as rotations per minute (RPM) of each piece of equipment are recorded; fuel efficiency factors convert these data to the equivalent diesel totalizer. An idle time will be also recorded when the RPM is recorded outside the application's range and will be used to optimize the idle run. An effective methodology is presented to calibrate the fuel efficiency factors utilizing actual diesel measurements. The entire dataset recorded is uploaded into the operator's cloud structure. The results of on-the-fly calculations and comparisons of the performance of the assets are displayed on a dashboard with the actual diesel. Our focus in this work is on five components of emissions in hydraulic fracturing: high-pressure pumps, blender, hydration unit, and transportation of water and proppant. However, for other purposes, the dashboard and digital architecture can be expanded across the entire process from supply chain to post-treatment activities.

This methodology will enable the operators to conduct route planning and minimize diesel consumption across all activities. It provides the decision maker with real-time information on the instantaneous emissions footprint, unlike the current measurement that relies on postmortem calculation. It also provides the analysis of operations, logistics, methods, and material efficiency impact on emissions.
A Successful Case Study from China's First Self-Operated Project Using an Openhole Shunted Screen Gravel-Pack Completion
Authors: Wei Min , Cun Xihong , Liu Xiaoli , Zhao Geng , Liu Yaolan , Xu Bin , Ren Xiaoqiang , Zhang Yong
Published: February 2024

Two openhole multilateral wells (Well 1 with two laterals and Well 2 with one lateral) from China's first self-operated offshore project were completed with openhole shunted screen gravel-pack completions, which is the first application of shunted tube screens in this type of lateral well in China. The challenges of these two wells, analysis of the design of both tools and fluid, and key operational points have been documented. To date, production has doubled by use of the method in the two wells.

The project design includes the openhole shunted screen gravel-pack completion string and high-performance slurries to overcome installation challenges and provide high gravel-packing efficiency. To achieve efficiency, multiple segments and parties worked together, including the drilling, completion tools, pumping fluids, and pumping equipment teams. Each well was installed with shunted screen gravel-pack equipment, and more than 60 m3 of fluids and 17 m3 of gravel were displaced.

The project was successfully executed in Q3 2022. This is the first time this solution has been deployed in China to solve a series challenges including uncertainties regarding leakage and wellbore stability around the laterals and potential unstable shale streaks in the long openhole section.
Generative Artificial Intelligence for Geomodeling
Authors: Misra Siddharth , Chen Jungang , Churilova Polina , Falola Yusuf
Published: February 2024

Subsurface earth models, also known as geomodels, are essential for characterizing and developing complex subsurface systems. Traditional geomodel generation methods, such as multiple-point statistics, can be time-consuming and computationally expensive. Generative Artificial Intelligence (AI) offers a promising alternative, with the potential to generate high-quality geomodels more quickly and efficiently. This paper proposes a deep-learning-based generative AI for geomodeling that comprises two deep learning models: a hierarchical vector-quantized variational autoencoder (VQ-VAE-2) and a PixelSNAIL autoregressive model. The VQ-VAE-2 learns to massively compress geomodels into a low-dimensional, discrete latent representation. The PixelSNAIL then learns the prior distribution of the latent codes. To generate a geomodel, the PixelSNAIL samples from the prior distribution of latent codes and the decoder of the VQ-VAE-2 converts the sampled latent code to a newly constructed geomodel. The PixelSNAIL can be used for unconditional or conditional geomodel generation. In unconditional generation, the generative workflow generates an ensemble of geomodels without any constraint. In conditional geomodel generation, the generative workflow generates an ensemble of geomodels similar to a user-defined source geomodel. This facilitates the control and manipulation of the generated geomodels. To improve the generation of fluvial channels in the geomodels, we use perceptual loss instead of the traditional mean absolute error loss in the VQ-VAE-2 model. At a specific compression ratio, the proposed Generative AI method generates multi-attribute geomodels of higher quality than single-attribute geomodels.
Rapid Rock Properties Estimation from Micro-CT Images by Deep Leaning
Authors: Alsamadony Khalid , Alabdrabulrasul Ali , Mahmoud Mohamed
Published: February 2024

Digital rock physics (DRP) can compute several rock properties such as porosity, tortuosity, formation factor, permeability, thermal conductivity, and elasticity. To calculate these properties, the DRP workflow usually includes micro-CT imaging, processing the images (filtration and segmentation), and simulation of physical processes. These steps can be time-consuming and prone to human error.

In this study, three image datasets of a sandstone sample were used. The first dataset includes the original micro-CT images without any processing. The second dataset contains micro-CT images filtered by the non-local means filter to reduce the noise. The third dataset was created by segmenting the filtered micro-CT images. From these segmented images, porosity and tortuosity were calculated. Tortuosity was computed using pore network modeling (PNM). Three deep convolutional neural networks (DCNNs) were developed to predict tortuosity and porosity from the image datasets. The accuracy of the predictions was assessed by the average absolute percentage error (AAPE) and correlation coefficient (R).

The predictions from the three image datasets are comparable. R and AAPE of the predicted porosity by DCNNs are about 0.99 and (1%-1.8%). R and AAPE of the predicted tortuosity by DCNNs are about 0.93 and (5.9%-6.2%). The results show that simple rock properties (porosity) are more accurately predicted by DCNN than advanced rock properties (tortuosity). The predictions from the micro-CT images (without any processing) are almost as accurate as the predictions from the filtered and segmented images. This could be due to the use of deeper DCNN. Therefore, DCNN can quickly predict some rock properties from unprocessed micro-CT images without significant loss of accuracy.

This paper shows that DCNN has the potential to eliminate the need for image processing and simulation in the DRP workflow, which may allow semi-automation of the DRP workflow. Additionally, micro-CT scanner manufacturers may be able to provide end-to-end solutions. In this case, raw data (unreconstructed projections) could be used with micro-CT images to enhance the accuracy of the predicted rock properties.
Improving Underlying Image by Resolving Velocity Anomaly and Compensating for Seismic Absorption Using Q Pre-Stack Depth Migration: A Case Study of 3d Land Sukowati Indonesia
Authors: Subhan M. , Kusuma A. S. , Razi M. , Sipahutar H. , Amperianto A. , Agustina A. S. , Biramandita D.
Published: February 2024

For discovering new opportunities in the northwest of the Sukowati Field reservoir, that limited by the low-resolution images of the subsurface, especially for the target reservoir. The existence of changes in lateral velocity variations, especially in reverse-fault areas and carbonate reservoirs, necessitates the need for an accurate velocity model with validation of the well data, Q Tomography to compensate for the absorption energy, and the migration algorithm that can image the complex subsurface structure.

The final velocity model used the Tilted Transverse Isotropic (TTI) anisotropy, by adding the theta and phi (azimuth) models to the migration algorithm, which increased the focus of events, especially on faults, and reflector dips. The PSDM results are also tied to the well marker, indicating validation of the accuracy of the VMB results. The QPSDM application is used for amplitude attenuation compensation in areas with weak amplitudes, QPSDM can also broaden the frequency spectrum. During the migration process, Beam Migration can handle multi-arrival ray traces, making it suitable for application in complex areas.

All of the velocity model building processes, resulting in reasonable lateral and vertical velocities controlled by well data, and validated by understanding the geology along the survey area. The final velocity and anisotropy models follow the geological structure well and match the sonic and checkshot information contained in the well data. Beam Migration results produce a better image of carbonate body and layers under the carbonate, which become the target reservoir. This is reinforced by the results of last two drilled wells, the potential of the clastic reservoir has been proven, opening up development opportunities to the west to pursue structural closure of the Transgressive Wings Carbonate.

The limited quality of legacy seismic data to see the distribution of reservoirs and limitations in the interpretation of geological structures in the Sukowati Field can be overcome by QPSDM results that produce a more accurate map of the reservoir depth structure, higher resolution of seismic data, minimize uncertainty, and open up opportunities to seek new prospects in the northwest region.
Economic Analysis of Gas to Liquid Technology as the Solution for Stranded Gas Commercialization in Indonesia
Authors: Damayanti L. H. , Burhanudin M. , Sukmato H. , Wijaya A. , Darmawanto D.
Published: February 2024

Indonesian energy demand continuously increases in line with economic development and population growth. The average demand growth in the past ten years has been around 6% annually. The demand is supplied primarily by oil (47%). As domestic oil resource is no longer sufficient to fulfill domestic demand, Indonesia's energy policy moved away from oil by promoting the utilization of more abundantly available energy resources such as natural gas. Indonesia has natural gas reserves of 34.65 TCF in 2023. However, such reserves still have not been developed due to economic and physical reasons, called stranded gas. The development of new technology that can commercialize stranded gas is expected to fulfill the growing energy needs.

The common problem of stranded gas is when it is remote from the gas market, making the construction of a pipeline prohibitively expensive. Alternative ways of converting gas into denser energy and transporting the energy using the non-pipeline mode to the customers need to be developed. Gas-to-liquid (GTL) technology is one of the technologies currently being developed because of its ability to process natural gas to produce synthetic liquid fuels that are similar to petroleum-derived products, even with better quality so that they can reduce the portion of petroleum; both as a source of energy and as other industrial raw materials. Using Gas to Liquid technology, Natural Gas can be turned into Fischer-Tropsch synthetic fuel /FT Diesel. The FT Diesel specification matches the quality of petroleum-based diesel fuel. FT diesel is the most promising fuel as the quality requirement of diesel fuel is strengthened in the future, and it is urged to introduce FT diesel at an early date to make the most of its character of being environmentally clean while attempting to secure its demand base and creation of demand for the product in the future.

This paper presents the feasibility of GTL technology implementation to monetize stranded gas, which is assessed using the wellhead netback price of gas as a feasibility indicator. The netback price is calculated using the price of fuels to be substituted by diesel (in this case, Solar) as references. The basic question of this study is the minimum gas price at the wellhead that satisfies the GTL project investor's economic criteria when the gas is converted to GTL, and the GTL is to substitute solar consumption. The minimum acceptable rate of return (MARR) is set at 16% as an economic criteria evaluation.

In addition to feasibility analysis, this study also evaluates Indonesian regulatory viability for GTL development, including its product and benefits to the nation, as well as its implementation risk.
Reducing CO2 Emissions During Wellbore Cleanout Operations by Employing Coiled Tubing Fluid Oscillation Tool – A Case Study
Authors: Elmoneim H. , Yousuf A. , Shahzad K. , Anwar R. , Khokhar S. Y. , Saeed M. S. , Inam S. , Sana-ul-hussnain M. , Shafee I. , Haider M.
Published: February 2024

During 2022, oil and gas operations resulted in emission of 5.1 billion tons of CO2equivalent. These emissions must be reduced on the journey towards net zero emission. Wellbore cleanout operations with coiled tubing are one of the most frequent operations performed during the life of a wellbore. The coiled tubing and associated equipment used for wellbore cleanout operations is powered by diesel engines which result in high CO2 emission during operation. However, these emissions can be reduced by using a fluid oscillation tool.

A fluid oscillation tool converts kinetic energy of the pumped fluid into potential energy resulting in the creation of pulsating waves. These pulsating waves induce cyclic stress in the scale. Continuous cyclic stress induces fatigue failure in the scale which ultimately leads to disintegration of the scale present in the wellbore or critical matrix. Fluid oscillation tools can remove scales in less time and provide better fluid velocities in the wellbore even in nitrified treatments. This ultimately reduces the time of operation considerably. Furthermore, reduction in operational time corresponds to low consumption of diesel by the CT and associated equipment, leading to lesser emission of CO2.

A fluid oscillation tool was employed at multiple wells in the region of this case study to perform wellbore cleanout jobs. This paper thoroughly performs data analysis of four different wells and demonstrates the impact of fluid oscillation tool on different performance factors. Using a fluid oscillation tool led to a decrease in CO2 emission between 35-62%, reduced CAPEX between20-47% and increased production between 170-310%.

Nearly 57% of the well intervention operations performed in the region of this case study are wellbore cleanout operations. Replacing the conventional jetting tool with a fluid oscillation tool led to a decrease in CO2 emission from 1843 Tons to 924 Tons. This reduction corresponds to approximately 50% of CO2 emission during wellbore cleanout operations. The scale of this reduction would be more appreciable when adopted universally.
15K Multi-Entry Cemented Multi-Stage Fracturing System-Alternative Completion Method for Deep Tight Gas Wells
Authors: Rodoplu Rasim Serdar , Alenezi Awad , Dahlan Mohammed , Tait William T.
Published: February 2024

Multi Stage Fracturing (MSF) completion technology with a true 15,000 psi pressure rating, Multi-Entry (ME), cementable system was developed for utilization in deep tight gas wells. The new completion system brings operational and design improvements to the MSF methods utilized for these types of wells. This paper discusses the details on the development of the novel system considering harsh well conditions, its multi-entry design for creating multiple fractures across each stage, and improvements compared to the traditional open hole MSF solutions. A detailed review of the requirements for the completion installation, activation, fracturing execution and expected performance metrics will also be covered.

The new cemented MSF completion system consists of a cementable hydraulic toe sleeve and cementable fracturing ports. The toe initiator placed in the first stage is opened by applying pressure whereas multiple cementable fracturing ports in the remaining stages are opened by dropping a single size ball in each stage. Zonal isolation relies on cement behind the completion rather than mechanical, swellable or metal expandable packer as in regular Open Hole (OH) MSF systems.

To verify the completion system suitability for the target application, a thorough design of the system components and qualification testing were needed. Collaborative approach, clear project scope definition and detailed review of the solution were key factors to ensure final product met expectations.

Several wells completed and stimulated successfully with the new ME MSF system will be discussed. It is observed that the slim design, rotatable feature was mitigating the challenges, reducing the overall risk of deployment. In addition, stimulating of stages using a single ball per stage activating multiple sleeves in each stage, except for the first stage which was with cementable hydraulic sleeves, resulted with more efficient fracturing operations by reducing time, resources, and emissions.

The 15K cemented ME MSF completion system provided a third MSF option to complete deep tight gas wells in addition to the current two methods of cemented liner and open hole MSF completions. It bridges the gap between the current systems by relying on the cement for zonal isolation and allowing multiple sleeves in each stage, imitating clusters used in Plug&Perf (P&P) operations. The system eliminates isolation packers compared to open hole completions and perforation, plug setting, plug milling when compared to P&P cemented liners technique in which wireline and coiled tubing interventions are required.
Optimization of Drilling With High-Frequency In-Bit Sensing
Authors: Stolboushkin E. , Kueck A. , Pauli A.
Published: February 2024

In-bit sensing technology measures the dynamic response at the bit during drilling operations. Recently such devices have been equipped with high sampling rate sensors, advanced sensor designs, and large data storage allowing entire bit runs to be recorded. This paper will present the technology, research, and testing that has allowed the development of a data driven decision loop for the optimization of drilling operations in the field.

Data from the in-bit sensors allows the identification of drilling dysfunctions and provides actionable information from which to tailor drilling parameters to specific geologies. Additionally, drilling simulator testing, with in-bit sensors, in various geologies and with BHAs provides a database from which it is possible to create stability maps and bit performance benchmarks that can be directly used for optimization of drilling operations.

Various drilling dysfunctions, such as High Frequency Torsional Oscillation (HFTO), are detrimental to both drilling efficiency and the reliability of downhole equipment. Drilling performance also varies by geologic features. Field case studies of the successful use of this technology in actual drilling operations will be presented to demonstrate the utility and impact of this technology.

The data from these sensors is particularly useful due to their placement in the drill bit, where the fullest extent of downhole dynamic regimes can be observed. In bit sensors are showing utility in bit design, drilling optimization, and even well and field designs.
Delivering Successful Quadlateral Wells Campaign in the Middle East: Milestones & Lessons Learned
Authors: Maafri Mbarek , AlGaiar Mahmoud , Farhat Moustafa
Published: February 2024

This paper examines the successful execution of multilateral drilling and completion of complex oil wells in the Middle East, a region known for its abundant hydrocarbon resources and unique set of challenges, including wellbore stability, stuck pipe, trajectory control, drilling vibrations, downhole tool failure, and low penetration rates. The objective is to provide an in-depth analysis of the challenges faced, the best practices employed, the lessons learned, and the value added to the industry through these efforts.

The challenges of drilling and completing multilateral wells require innovative approaches and advanced technologies throughout the well construction process. The pre-planning phase includes the analysis of offset drilling events and wellbore design, wellbore trajectory design and collision avoidance, wellbore stability modeling and recommended mud weight windows, mud system design including hole cleaning efficiency analysis, drill bits design and drilling vibrations management. The paper examines each challenge and the strategies used to overcome them, including the use of advanced drilling tools, real-time data analysis, and collaboration with multidisciplinary drilling optimization teams.

The vigorous implementation of the roadmap developed by the multidisciplinary optimization teams helped achieve the pre-determined run objectives in terms of planned target depths, stuck pipe avoidance, drilling vibrations management, increased penetration rates and improved tripability. Real-time drilling parameters, torque and drag, formation evaluation, and equivalent circulating density monitoring played a critical role in the drilled sections delivery. These practices contributed to the overall efficiency and safety of the drilling process, reducing the risk of potential hazards, and minimizing the environmental impact. Lessons learned were also highlighted, including the importance of cross-discipline collaboration, the value of embracing new technologies, and the role of effective communication in managing complex projects.

This paper explores the value added by applying multilateral drilling and completion best practices and highlights the benefits of a multidisciplinary approach in such a challenging drilling environment. These include improved well performance, increased hydrocarbon recovery, reduced well construction costs, and the potential for economic growth and development in the region. By sharing these insights, this paper aims to contribute to the ongoing pursuit of excellence in the oil and gas industry and promote sustainable and responsible resource development.
Case Study: Saturation Assessment in Law Resistivity Pay (LRP) 1d & 3d Modeling (DH-Libya)
Authors: Ablil W. , Elsadawi A. , Altownisi M. , Aboelkhier M.
Published: February 2024

DH reservoir located in North Africa in the middle of Libyan dessert, Sirt Basin. This field is an immature carbonate reservoir with good Petrophysical properties, but with Low Resistivity Pay (LRP). The development of this field has encountered several obstacles to overcome the effect of micro-porosity (vugy porosity) measurements to estimate the water saturation. Standard electrical resistivity tools used widely on DH reservoir to compute the saturation with no clear vision of success. This issue effects directly the Water Saturation computation and ends up with High uncertainty of STOOIP calculation. The objectives of this study are to find a representative saturation profile and to better estimate the STOOIP for new development plans. The target of this paper is to show the wide range of the new fluid saturation assessment used to overcome the electrical bypass caused by the water bearing extents.
Capitalizing on Steady-State Multiphase Simulation to Improve Rate Measurement Process
Authors: Alhuraifi M. A.
Published: February 2024

This paper describes effective use of a multi-phase simulator software to meter the production virtually and accurately from a group of wells that are produced through a production system and have their individual rate tests measured at different conditions. In an oil production system with no metering devices installed on individual wells, multi-phase flow is measured separately for each well in the production system. To optimize well rate testing in such complicated system, steady-state multi-phase flow simulators are used to model the actual production system. A well-calibrated model can be practically utilized to get the most of the discrete measurement data. Hydraulic surface network simulation was utilized to mimic two operation modes, namely, production mode which simulates normal production conditions and rate test mode which simulates each well flowing individually to rate testing equipment for measuring its flow rate. This approach mandates the use of available rate testing and flowing pressure data to improve the fidelity of the hydraulic simulation model. The high certainty steady-state multi-phase simulation can be used to enhance rate metering accuracy and to optimize production from the modelled wells. Multi-phase hydraulic simulation is a powerful tool to thoroughly understand fluid flow from the reservoir to surface production facilities. Such an inexpensive approach is considered efficient as it could yield a continuous representation of the production system with available field data. It relies on NODAL Analysis which is an integrated analytical approach to examine the performance of the entire production system at each individual component.
Complex Well Intervention Activities to Restore the Integrity of Single Barrier High Risk Gas Well
Authors: Al Amri Y. B. , Al Bulushi Z. A.
Published: February 2024

This paper will present one of the challenging deep gas well integrity restoration within Petroleum Development of Oman (PDO). The well showed indications of parted 4 ½" tubing post frac operations. The failure resulted in compromising the well integrity and pressure communication was found on the Annulus behind the tubing (Annulus A). Moreover, access to the bottom part of the well was lost due to tubing miss alignment which made the intervention more complicated.

Downhole information were gathered using Lead Impression Block (LIB) and special Camera Runs. After Concept Design Selection utilizing engineering simulation software, an external casing patch (ECP) was found the best fit to restore the integrity of the 4 ½" cemented tubing. A specific design of the external patch including connections qualification and material selection was prepared based on gas production envelop.

Unit selection was done based on intervention simulations to select a fit per purpose unit, increase the chance of success and optimize unit technical cost (UTC)

The integrity of the wells is assured by PDO barrier policy which dictate 2 barriers at all times of the well cycle life for any flow path from the reservoir. Risk assessment to identify the integrity code of the well resulted in a code 9 (out of 10) classification which means that the well needed to be restored or abandoned as soon as possible.

Radial Cutting Tool (RCT) was used to cut the upper part which was fished out with 2 fishing assembles. Moreover, access to the wellbore was essential to isolate the reservoir. It was successfully gained by running a 4 ½" Overshot. The isolation plugs were run via slick line at different stages of the intervention for well control reasons

To verify the casing patch installation, a customized load design calculations for current reservoir conditions were performed. The integrity of the well was successfully restored and the well was put back to production after running the ECP.

The ECP design was done for the first time within similar scope of work which unlocked potential for future opportunities. As well, the intervention was done for the first time using light workover unit which minimized the cost impact.

Unique integrity repair plan with integrated risk assessment for high risk well interventions was done successfully to restore integrity of single barrier gas well.

The idea of selecting a light workover unit underwent a thorough risk assessment and detailed engineering design to prove the concept.
Protecting Boiler Feed Water Pump Against Cavitation Through Applied Mathematical Approach
Authors: Leal J. , Alkad K.
Published: February 2024

Boiler Feed Water Pumps play a crucial role in the Power Generation Blocks (PGBs) Unit at Jazan Refinery Complex (JZRC).

Frequent pump trips due to cavitation have resulted in significant financial losses and operational disruptions.

This manuscript introduces an innovative exponential solution which is mainly an equation to enhance pump protection against cavitation. This equation utilizes Factory Acceptance Tests performance curves values to precisely describe the pump's behavior, directly addressing the cavitation phenomenon.

The combination of this logic protection and the derived equation has been filed for a U.S. patent. Furthermore, this innovative approach has already been successfully implemented on 16 out of 20 Boiler Feed Water pumps at JZRC during PGB-1/2/3/4 Commissioning and Startup (CSU), with ongoing implementation on the remaining four pumps at PGB-5.

The intention of developing a better approach to protect the Boiler Feed Water (BFW) pumps against cavitation was an initiative to consider a dynamic model instead of fixed value for Net Positive Suction Head Available - NPSHA (14.7 m) based on 1 m separation margin respect to Net Positive Suction Head Required - NPSHR (13.7 m) @ rated flow provided by Pump Manufacturer, which was found very conservative protection at flowrates less than rated flow where NPSHR is less than 10 m and pump not well protected at flowrates exceeding the rated flow where NPSHR is expected to be above 20 m.

The dynamic model of protection, implemented by NPSH margin equation, has been applied successfully at Power Block Power Generation Units to avoid unnecessary trips at flowrates below rated flow and protect the pumps effectively when running at flowrates above rated flow.

NPSH margin ESD trip @ 1 m (decreasing) replaced the NPSHA trip set on 14.7 m (decreasing) to enhance the pumps reliability and availability, if the sister pump was unable to kick-in, leading to trip the Gas Turbine and loss of 220 MW of power generation.

Each power block has 02 gas turbines with 02 HRSG's and 01 steam turbine. Each HRSG has associated 02 BFW pumps, one running while the other is on hot standby. [Figure 1]
Reliability Study: Use of Chrome Plating on Special Purpose Steam Turbines
Authors: Baaqeel N. M.
Published: February 2024

An 18,000 HP special purpose steam turbine is driving a propane compressor in a Gas Treatment facility in one of Saudi Aramco gas plants. This turbine is designed with two 10-inch steam inlets, and each inlet has an independent, hydraulically actuated Emergency Shutdown Valve (ESV). The core function of these valves is to rapidly isolate the high pressure (600 psi) steam supply to the steam turbine whenever an Emergency Shutdown Device (ESD) signal is activated in a reaction time less than 200 milliseconds.

An inspection was carried out for the turbine (ESV's) by inspecting the hydraulic section drain lines through port B when actuated to open positions. The inspection revealed that oil flow through the drain line is continues at a rate of 30 ml/s. While oil flow through port B should stop when the hydraulic section is at its ultimate open position.

Initial review for the hydraulic section internal components revealed that the section was designed in a way that does not require any soft sealing components to provide oil sealing between the cylinder and piston during oil pressurization when valves are opened. It was only when valves were dismantled that it was found that the oil sealing between cylinder and piston is achieved by a very tight clearance between the two sliding components. The required Original Equipment Manufacturer (OEM) clearance was 0.9 to 1.9 thou, and the max "as found" clearance was close to 4 thou in both actuators.

A plan was set to refurbish either the cylinder or the piston in an effort to reduce the internal clearance between the sliding components.

A "weld-buildup" which is one the most common and traditional repair methodology was proposed on the internal side of the cylinder. However, due to the sheer difficulties to produce uniform manual weld on the inside surface of the cylinder, in addition to the risk of cracks formation and propagation caused by welding on cast iron were two main reasons to discard such repair proposal.

Since the objective was to decrease the clearance between the cylinder and piston it was evaluated that using a chrome plating repair methodology on the outside diameter of the piston in attempt to increase its overall outside diameter while maintaining the inside diameter of the piston. It was concluded that the use of chrome plating will produce far superior outcomes than that of the use of traditional weld-build up repair alternative.
A Sustainable Approach to Drilling in Shale Formations with Fresh Water-Based Mud System
Authors: Geri Mohammed Ba , Kauffman Demond , Almubarak Tariq
Published: February 2024

Drilling through shale formations poses significant challenges due to clay reactivity. The issues can lead to several problems, including water influx, well control issues, abnormal pressures, differential sticking, and significant formation losses. This paper presents the development of a new water-based mud that addresses these challenges. Customized water-based muds (WBMs) can inhibit shale hydration and minimize these risks. This study evaluates a novel polymeric additive for improved WBM shale inhibition. The objective is to characterize the novel WBM and demonstrate its ability to reduce shale swelling and deliver stable drilling compared to traditional WBMs.

Novel water-based muds (NWBMs) have been developed to address the limitations of conventional water-based drilling fluids in reactive shale formations. This study systematically evaluated the performance of the NWBM system using freshwater through laboratory experiments and field trials. Rheological characterization showed that the NWBM exhibited enhanced viscosity and gel strength compared to traditional systems. The NWBM increased rheological properties and lowered shale swelling by 50% versus reference WBMs. X-ray diffraction (XRD) and cationic exchange capacity (CEC) tests were conducted to characterize the shale mineralogy. Scanning electron microscopy (SEM) provided visual evidence of the dense, low-porosity filter cakes achieved with the NWBM. Successful offshore examples validated the NWBM's ability to maintain wellbore stability and avoid stuck pipe events in problematic formations. Offshore field trials exhibited 50% fewer sticking events, 30-40% faster ROP, and no wellbore instability issues through problematic shales with the use of NWBM. The integrated results highlight the NWBM's technical advantages for improved drilling performance in complex reactive shales.
Automation-Assisted and Signal-Driven Relative Geological Time Model Toward Sequence Stratigraphy and Identification of Sand Fairways in a Turbidite System: Case Study, Neuquén Basin, Onshore Argentina
Authors: Daynac N.
Published: February 2024

The Neuquén Basin is proven to be a hydrocarbon resource rich onshore region with several petroleum systems. Its depositional history was primarily influenced by changes in relative sea-level from the Triassic to the late Jurassic, leading to the occurrence of submarine and subaerial deposits (Brinkworth et al., 2018). In the study area, located in the Neuquén Embayment province, the authors performed a comprehensive seismic interpretation, focusing on the Cuyo Group (spanning from middle Lias to late Dogger Epochs). The work illustrates the benefits of using a signal driven Relative Geological Time (RGT) model (Pauget et al., 2009) to enhance the understanding of regional scale stratigraphic features, revealing a complex turbidite system. It ultimately offers the ability to draw new perspectives and insights in the evaluation of legacy data and further demonstrate the potential prospectivity of understudied deep stratigraphic traps.
The Future of Acid Corrosion Inhibitor Testing: A Machine Learning Solution
Authors: Ureiga Sulaiman , Hajri Nasser , Green Todd , Javed Muhammad Imran
Published: February 2024

The paper aims to present a machine learning virtual laboratory as an alternative to autoclave testing, which is typically utilized in determining corrosion inhibitor performance. The virtual lab aids in the optimization of acid corrosion inhibitor loading for stimulation jobs. The lowest acceptable/safe chemical dosage of the inhibitor is the optimal acid corrosion inhibitor loading. Hundreds of physical autoclave test results from a variety of settings were used to develop and test the virtual laboratory's underlying machine learning models. Metal coupons are tested with acid recipes in a laboratory autoclave under simulated wellbore conditions. The weight loss per unit area is measured in the autoclave lab test. The weight loss per unit area is measured in the autoclave lab test. Expected acid exposure period, acid strength or concentration percentage, downhole temperature, corrosion inhibitor type, corrosion inhibitor loading, and steel type are among the parameters that affects the testing. The results of the laboratory tests are categorized into two groups. One set includes 80% of the total autoclave tests which is used to train the machine learning model. The remaining 20% is used in a completely different set designated as the testing set. The testing set is used to validate that machine learning model predictions are accurate. For training and testing, several machine learning models are applied to the same data sets. Field engineers can utilize the machine learning model with the best confidence to design acid stimulation recipes with acceptable corrosion metal loss and low cost. The model can be dynamic, with updated tests being uploaded to the model on a regular basis to train it and improve prediction confidence. Eight machine learning models were trained and then tested through their tests. Each machine learning model tested the sensitivity of testing parameters using four distinct input cases to determine the best machine learning model. The outputs of two machine learning models have a 97.90 percent confidence level. The virtual laboratory will assist oilfield operators in lowering the costs of acidizing treatments while maintaining safe corrosion inhibition limits. In addition, the virtual lab would reduce the requirement for laboratory tests to determine acid formulas for each field job.
Petrophysical Properties Derived from High Frequency Drilling Vibration for Geosteering- A Feasibility Study
Authors: Al-Ofi S. , Ma S. , Ali S. , Maity S.
Published: February 2024

Drilling vibration is usually used for drilling operation diagnostic for evaluating downhole fatigue failures, severe wear of bottom hole assembly (BHA) and bit, and wellbore instabilities. This study highlights how formation petrophysical properties such as porosity can be estimated from certain range of high frequency triaxial vibration data, so that quality of geosteering may be enhanced in challenge conditions, such as ultraslim hole drilling where limited logging while drilling (LWD) data may be acquired.

In this study we explored some data sets of triaxial accelerometer measurement module, in addition to density, neutron, resistivity, and gamma ray. Although typical accelerometer measurement is sampled every 5 seconds, we customized the accelerometer recording to capture axial, lateral and tangential vibrations at 2,500 Hz sampling rates. These high frequency vibration modes were processed in frequency domain by use of fast Fourier transform and analyzed, in terms of frequency and amplitude, against other drilling parameters such as weight and torque on bit. Data regression and correlation were investigated against formation properties derived on the same drilled section of LWD logs.

Example results for a tight carbonate formation showed qualitative correlation between axial vibration average amplitude values and LWD neutron porosity. In addition, when we analyzed the high frequency vibration data and decomposed it to different frequencies, we observed higher frequency vibration peaks, 500Hz and higher, are highly correlated to LWD formation neutron porosity and bulk density. Axial and tangential vibration modes showed better correlation with formation properties than lateral mode. Taking weight-on-bit, bit size, drilling torque and rotation speed into consideration, one can use inverse correlation regression to obtain reasonable porosity values from high frequency axial vibration peak values.

These findings open the path for geosteering, and maybe even for formation evaluation, capabilities in complex drilling conditions where BHA is restricted such as in ultraslim hole under balanced coil tubing drilling.
Automation and Standardization to Accelerate Well Delivery and Resource Allocation, in a Complex Field Development
Authors: Al Abry M. , Al Mahrouqi B. , Al Farsi S. , Al Busaidi S. , Al Hosni Y. , Al Shabibi H.
Published: February 2024

The development of oil fields are becoming more complex and more challenging as the industry moving away from easy oil, the pursuit of efficiency, reliability, and consistency has become paramount. One strategy that organizations often employ to achieve these goals, especially in complex oil fields development, is automation and standardization of repetitive process.

Automation refers to the utilization of technology and software systems to perform tasks and processes with minimal human intervention, improving work quality and Standardization, on the other hand, is the process of establishing uniform templates and guidelines, and specifications across the organization. It aims to create a cohesive framework that ensures consistency in product quality, service delivery, and compliance with KPI's.

The convergence of automation and standardization in a complex field represents a transformative project that can redefine how organizations operate. Such projects involve the integration of automated features and the establishment of standardized practices to not only enhance efficiency but also improve quality during planning phase but as well as allowing time to dive deep, react and enhance the end results.

Well delivery planning and proposals are fundamental steps in the oil and gas industry, serving as a roadmap for drilling pro jects and providing stakeholders with the information they need to make informed decisions regarding investments and resource allocation. These processes require thorough analysis, attention to detail, and adherence to industry best practices and regulations. Fifteen well planning proposals were selected to implement those automated workflows via existing tool and software with standardized outputs which are relevant to production geology input. The targeted reservoir is a Fluvial system with channelized stratigraphic trap, stacked heterogenous reservoirs. The complexity of the field was captured with range of Models and scenarios. Which later used for the planning the field development. The well selection process had to reflect for the high range of uncertainty and complexity of the reservoir. The implementation trail was led to a time saving by 45%, less iterations between contributes and peer assist and improved work quality. this project was implemented during the business cycle of resource allocation in which the benefits and the values were remarkable.

The initiative of automation and standardization will be expanded in future to cover all business cycles in field development, modelling, well planning, end of well report, reservoir management activities and reserve classification and reporting.
Early Warning Method to Detect Mud Motor Stallings Incidents in Drilling Operations Using Machine Learning
Authors: Zomarah B. , Alotaibi B. , Zahrani M. , Alsaihati A.
Published: February 2024

In recent years and with the increase of complex operations such as directional drilling, there has been an increase use of mud motors to drive performance and deliver more complex well design. The challenge is that motor failures increased due to the complexity of the operation which tends to have a significant impact on the well delivery and cost. Like any equipment failure, it is impacted by the conditions the tool has been through and it often provides prior warning signs that if missed will have significant non-productive time. One of the major motor failure signs is the motor uncontrolled stalling. The objective of this paper is to present an early warning method to detect and alert of mud motor stalling to the rig crew to react before it leads to other undesired conditions. Motor stall occurs when the mud motor stops working which will cause stalls with a high-pressure reading. Using daily drilling reports (DDRs) and real-time data surface parameters, subsurface data, a dataset of incidents was created by SMEs and it is fed into a machine learning model to detect early warning signs of stalling and provide the rig crew with detailed reports in real-time. After applying the proposed data-driven method, the stalling events can be accurately detected with +80% accuracy and a low false positive rate. To ensure proper mud motor monitoring; DDR, BHA, and relevant data such as motor specifications are considered. The result of such work is impacted by the data quality of real-time data such as uncalibrated channels, improper units, and significant noise in the data. This work extends the existing literature by using surface and subsurface data to accurately detect early warning signs of motor stalling. Our work presents a complete framework for how stalling events can be detected and reported in real-time.
Elastic FWI of Surface Waves for Near-Surface Characterization of Middle East Land Data
Authors: Sedova Anna , Reinier Mathieu , Donno Daniela , Lambaré Gilles , Carotti Diego
Published: February 2024

The south of the Sultanate of Oman is characterized by very strong lateral and vertical velocity contrasts that make seismic imaging particularly challenging. In this context, full waveform inversion (FWI) appears promising. The first attempts based on acoustic FWI implementations faced difficulties in this region because the characterization of the complex near surface is critical for the success of acoustic FWI and imaging of the deeper layers. Acoustic FWI was initially coupled with near-surface characterization methods, such as inversion of the dispersion curves of surface waves, which introduces some elastic properties in the process. We take here a step further by applying elastic FWI to surface waves for an improved near-surface characterization. Since surface waves are primarily sensitive to Vs, the associated inverse problem is less prone to cross-talk with other elastic parameters. Moreover, our workflow benefits from the ultra-low frequencies recovered by interferometry. We present an application using a dataset from the south of the Sultanate of Oman that combines elastic FWI for Vs using virtual and active data and utilizes this Vs model to constrain the shallow Vp model.