bluuebunny/crossref_metadata_2025 huggingface dataset:
An Investigation on the Influence of Structural Damage on Eigenvalue Characteristics and Reserve Strength Ratio of Onshore Lattice Steel Structures
Authors: Muhaimin Wan Farra Ayesha Binti Wan , Liew Mohd Shahir , Zawawi Noor Amila Binti Wan Abdullah , Shawn Lim Eu , Sheikh Anas Khaled Al , Salim Siddique Mohd Yatim Bin , Danyaro Kamaluddeen Usman
Published: March 2022

In the study of structural strength, the reserve strength ratio provides a measure of the ultimate strength capacity of a structure. Under actual site conditions, the reserve strength ratio may vary from its design values with loss of stiffness and changes in structural integrity. Changes in the vibrational response of a structure due to loss of stiffness is observed as a form of structural health monitoring (SHM). The aim of this study is to investigate the relationship and sensitivity of the reserve strength ratio of a structure to changes in natural frequency due to damage occurrences as a measure of global structural integrity. The reduction of stiffness is simulated by the sequential removal of members according loading path within the model. To obtain the values used for comparison, a non-linear pushover analysis and eigenvalue analysis is utilized to obtain the Reserve Strength Ratio (RSR) and eigenvalue for intact as well as simulated progressive damage conditions. The pattern recognized from the analysis performed indicated that as the reserve strength ratio (RSR) is reduced with reduction of stiffness by the removal of primary and secondary members, the eigenvalues for each respective model showing similar reductions.
Integrated Well Test Interpretation Approach for Complicated Carbonate Reservoirs: A Field Case
Authors: Liu Yongjie , Sun Zhaobo , Yang Renfeng
Published: March 2022

A oilfield, located in Iraq, is a large multi-layer oil field dominated by carbonate reservoirs of cretaceous Mishrif formation and Tertiary Asmari Formation. A oilfield is located in the transition zone between Zagros orogenic belt and the eastern edge of Arabian platform, mainly in the low-angle fold belt of Zagros structure. Due to the influence of the Zagros orogeny, the fault system of the oilfield is developed, especially the Asmari formation A. It is a complex carbonate reservoir composed of dolomite, limestone and sandstone. The plane and vertical heterogeneity are very strong. The development of micro-fractures is verified by core data, logging data and dynamic analysis. And the multiplicity of well test interpretation is obvious.

The core, thin section, imaging logging and well test data (Fig.1) of A oilfield all show that fractures are developed in Asmari formation, and the production performance shows that the existence of fractures improves the production of oil wells. However, due to the serious breakthrough of edge water and secondary bottom water, the water cut of the oilfield rises rapidly, leading to the difficulty in ensuring the development effect of the oilfield. Moreover, the fracture scale in the study area is too small to characterize the parameters, the plane distribution of fractures is different and its distribution law is difficult to predict accurately, which has also become the key to restrict the efficient development of oil fields. As carbonate reservoir has developed fractures and strong heterogeneity, its pore structure is more complex than sandstone reservoir, and the uncertainty of parameter interpretation is higher. Therefore, how to evaluate and obtain the reservoir parameters of A oilfield has always been a great concern.

In general, logging, core analysis and pressure transient analysis (PTA) are used to evaluate the reservoir parameters of carbonate rocks. However, core and logging analysis can be used to get static parameters in the range of centimeter to meter, while PTA can obtain static and dynamic parameters in the range of hundreds of meters to several kilometers, such as skin coefficient, boundary conditions, permeability and cross flow coefficient. Therefore, the PTA results are more practical.
Hydraulic Fracturing to Investigate Impact of Fracturing Medium, Bedding Angle and Perforation Length on Fracture Growth in Low and High Brittle Shale
Authors: Khan Javed Akbar , Padmanabhan Eswaran , Ul-Haq Izhar
Published: March 2022

Advancements in the technique for early estimation of the hydraulic fracturing potential of fracturing fluid in different shale formations are needed to successfully stimulate reservoir volume and recover the trap hydrocarbons. The determination of fracture initiation and propagation in shale remains unclear, particularly with regard to the choice of type of fracturing fluid during fracturing operation at high confinement. Hydraulic fracturing with supercritical carbon dioxide (SC CO2) and SC CO2 foam are an encouraging technique to overcome significant use of water in shale gas production. Our study was carried out to explore the fracture propagation and fracture initiation pressure under high confinement stress. The hydraulic fracturing experiments are performed to study fracture propagation in the black shale of three different fields to generalize the scope of work using low, medium and high brittle shale: Eagle Ford, Wolfcamp and Mancos. Three different fracturing fluids were selected for fracturing tests: SC CO2, SC CO2 foam and slick water to investigate the impact of low, medium and high viscous fluids. We evaluated the fracture pressure curve, breakdown pressure (fracture initiation pressure), fracture network variation and the impact of bedding angle, perforation length, injection mediums and formation variations on fracture morphology. During hydraulic fracturing with slick water a consistent rise in the injection pressure is recorded whereas sudden fluctuations are recoded with the injection of SC CO2. With the injection of SC CO2 foam, a sudden decrease in injection pressure appears due to imbibition of SC CO2 foam in the pores matrix. Moreover, fracture initiation pressures in shale rocks varied by changing bedding angle and perforation length. Fracture initiation pressure increases with bedding angles. An appreciable difference in fracture initiation pressure with SC CO2, SC CO2 foam and slick water are 5023psi, 6456psi and 6168psi, respectively at high conferment pressure (3500psi). Comparison of hydraulic fracturing of Eagle Ford, Wolfcamp and Mancos shale with different injection medium shows that SC CO2 foam produced complex fracture networks with high aperture and length for parallel, inclined and perpendicular perforations along the bedding. With all types of shale, SC CO2 foam injection has produced dense fracture network. Thus, fracturing with SC CO2 foam can potentially enhance the stimulated reservoir volume.
Artificial Lift System Applications for Thermally Developed Offshore Heavy Oil Reservoirs
Authors: Zhang Hua , Liu Pingli , Wang Qiuxia , Bai Jianhua , Zhang Wei , Zhang Hongwen , Han Xiaodong
Published: March 2022

The total crude oil resources are approximately 9-11 trillion barrels around the world and the steam based thermal recovery processes are still the most effective methods to enhance heavy oil recovery. Due to the high oil viscosity, high fluid temperature and high fluid volume changes with time, the choice of suitable artificial lift (AL) system is one of the most important techniques in optimizing production from thermally developed heavy oil wells.

Notwithstanding the attempt by several studies in the past few decades to understand and develop cutting-edge technologies to optimize the application of artificial lift system in thermally developed heavy oil reservoirs, there remains differing assessments of the best approach, AL type for various kinds of thermal recovery methods. A comprehensive review of artificial lift systems application with specific focus on thermally developed heavy oil reservoirs across the world for offshore oilfields is conducted. The review focuses on the special designed artificial lift system with functions of both steam injection and oil production for offshore oilfield. At the same time, the purpose of this work is to apprise the industry and academic researchers on the various AL optimization approaches that have been used and suggest AL optimization areas where new technologies can be developed for thermally developed heavy oil reservoirs in the future.
Holistic Analysis, Diagnostics and Operating Philosophy for Wellhead Leak Issue for Gas Producer, Offshore Malaysia
Authors: Barat Junnyaruin , Utta Arie Muchalis , Karpaya Shaturrvetan , Maluan Lilihani Binti , Lidwin Sharon Ellen
Published: March 2022

Since the beginning of production, well NA2 and NA3 wells had issues with wellhead integrity due to thermal growth and wellhead tilting. Seepage was observed from wellhead and based on gas chromatography test, the seepage is Synthetic Based Mud (SBM), possibly from B and C annulus (intermediate and surface casing). For well NA3, seepage was observed coming out from the connection of Casing Head and Drive Pipe Housing House (DPHH) while for Well A2, seepage was found between DPHH and conductor. The issues arise from the failed elastomer seals found at the connections of leak of each well suspected due to well growth/shrink and tilting which caused the wear and tear of the seals. The seepage of both wells was rectified by injecting the failed elastomer seals with pressure activated sealant to the P-seal and grease to the elastomer. Both wells managed to produce at the capped production rate without seepage as of today. Another main issue at Field N is the leaking of metal-to-metal seal at Xmas Tree which led to production deferment. Due to the failed barrier at surface, interim philosophy was established to operate the field and rectification plan was implemented to ensure the well is producing safely at the calculated risk.

This paper describes the analysis and diagnosis, operating philosophy outline by operator which led to the well safely producing at the desired rate: (1) Standing Instruction (SI) for Well Production Ramp Up and Down based on trending of production and temperature to ensure wellhead growth and tilting will not affecting the integrity of sealant, (2) Finite Element Analysis (FEA) and Wellhead Growth Study to develop operating limit and maximum allowable growth, correlated with well production and temperature, (3) logging and survey for well leak detection and echometer survey, (4) Wellhead Seal Injection for corrective maintenance upon seepage observed, (5) manual measurement of growth and tilting and utilizing laser sensor for automation, (6) External Slip Lock Brace Support (ESBS) Installation to mitigate abnormal relative growth and (7) risk assessment for well integrity.

The holistic approach in diagnostic, monitoring and operating philosophy enabled the well to be ramped up to higher production despite the threat of losing the gas production. PCSB also avoided the utilization of rig to rectify the well which resulted in cost avoidance for the company.
Two-Phase Interference Well Testing Interpretation Method for Polymer Flooding Multilayer Reservoir
Authors: Li Peng , Zeng Yang , Tang Engao , Wei Zhijie , Cheng Shiqing
Published: March 2022

The current research on interference well test technology is based on water flooding reservoir, but the analysis method of interference well test in polymer flooding reservoir has not been reported, which leads to unclear understanding of the physical property changes between wells in polymer flooding reservoir. Considering the characteristics of polymer flow, a two-phase interference well test model of polymer flooding multi-layer reservoir is established. The pressure, water saturation and polymer concentration are all implicitly solved to improve the stability of the numerical solution, and the typical curve is drawn. The results show that: the water phase viscosity is greater during the polymer flooding process, the pressure fluctuation of the active well is later, which affects the observation well, and the pressure fluctuation received by the observation well is greater. The results show that the interference well test curve of polymer flooding is farther to the right than that of water flooding in the early stage and higher than that of water flooding in the middle and late stage. The application example shows that coincidence rate with commercial software well test interpretation is over 90% when the model is degenerated to conventional water flooding, which proves the accuracy of polymer flooding interference well test model, and provides technical support for the improvement of well test method of polymer flooding reservoir.
Bolted Flange Joint Integrity Digitalization Programme for Sustainable Flange Leak Free Operation
Authors: Saad Safari , Ekhwan Alzakri , Al-Idrus Syed M Hafiz
Published: March 2022

Loss Of Primary Containment (LOPC) due to hydrocarbon leakage from bolted flange joint has always been one of the main issues that leads to catastrophic fire and explosion in operating platforms and plants. Oil and gas companies have been putting many efforts to reduce Health, Safety and Environment (HSE) incidences due to the flange joint integrity issues. PETRONAS, which operates many oil and gas platforms, has also made series of improvement in lesson learnt and enhanced best practices to find a wholesome solution to achieve sustainable zero hydrocarbon leak from bolted flange joint. Loss Of Primary Containment (LOPC) due to hydrocarbon leakage from bolted flange joint is one of major concerns in oil and gas industry, which may cause catastrophic fire and explosion at platforms and plants. Bolted Flange Joint Integrity (BFJI) digitalization program is designed to emphasize on end-to-end digital solution addressing three main important aspects towards sustainable flange leak free operation that included correct design and specification, good quality flange joint components and correct work execution.
Towards a Multidisciplinary Approach in Play Characterisation: An Integrated Case Study from Browse Basin, NW Shelf, Australia
Authors: Ben Habel Wael , Dubey Siddharth
Published: March 2022

Stratigraphic forward modeling (SFM) is an innovative approach to subsurface facies prediction at the basin scale that augments and overcomes some of the limitations of conventional seismic, well, and analog data. As a multidisciplinary approach to play characterization, SFM improves the efficiency of current workflows, which is important given the current downward pressure on capex in oil and gas companies.

A 2D SFM study on data from Browse basin, NW Australia, was conducted to enhance the prediction of facies distribution and improve play characterization by integrating SFM with other disciplines. The work started with seismic interpretation and depth conversion. Then, a third to fourth-order sequence stratigraphy interpretation was performed to determine the main sequence boundaries, maximum flooding surfaces, and a relative sea-level curve. The sequence stratigraphy results were later used to infer some of the inputs and parameters of the SFM model. The model simulates the deposition of clastic and carbonates from the Turonian (Late Cretaceous) to the present day.

The results from the model were used to validate some of the geological concepts and the seismic interpretation. In addition, the approach enabled the prediction of reservoir quality, reservoir distribution, the presence of the seal, and the quantification of erosion. A 2D petroleum system model (PSM) covering the area from the Yampi shelf to the Seringapatam sub-basin was built using seismic interpretation, regional tectonic information, source rock geochemistry, and paleo heat flow. The results from SFM were integrated into a 2D PSM by resampling facies and erosion properties for each of the finely subdivided layers. The high-resolution 2D PSM with refined facies was simulated in geological time to model the basin evolution and its impact on all elements and processes of the petroleum system of Browse basin, which have been validated with nearby fields.

As a result of this integrated approach, the risk of charge and entrapment in prospective stratigraphic traps was better understood and quantified. In addition, this approach helped to increase yet-to-find (YTF) hydrocarbon resources by accurately predicting reservoir distribution and extent. The generation of a 2D SFM and its integration within a multidisciplinary approach to predict facies represents a novel addition to exploration workflows. Adopting such an approach can improve significantly on the understanding of hydrocarbon entrapment and further reduce exploration risks.
Nanofluids Development to Improve Oil Recovery: A Synergistic Effect Investigation
Authors: Hendraningrat Luky , Razali Norzafira , Chien Chee Sheau
Published: March 2022

Various type of nanoparticles has been studied in last decade for improve oil recovery purpose and observed its mechanisms of displacing oil concluded as disjoining pressure that involved wettability alteration, log-jamming, and viscosity effect. This paper focus on the investigation of new potential mechanism of nanoparticles to improve oil recovery with study case in an offshore Malaysian oilfield.

The silica-based nanoparticles were used in this study, and additives of polymer and surfactant were involved to improve stability of fluid and observe any potential of novel mechanism. The nanoparticles were characterized under electron microscope, dispersed, and sonicated in saline water as replicated of injected water to be nanofluids for particular concentrations. A degassed crude oil from Malaysian field was used with viscosity of 3 cP. All fluids measured their rheology and fluid properties. A polymer additive was used to improve particles stability dispersed in saline water. Meanwhile, a surfactant additive was added into the formulation to observe any synergetic effect of displacing oil. The interfacial tension (IFT), optical contact angle (OCA), and relative permeability measurement using native cores at reservoir condition to observe potential novel mechanism.

The additive showed better performance in term of stability and wettability alteration through IFT reduction and reducing contact angle to render more water-wet through dynamic OCA measurement. The synergistic effect was observed when surfactant added into the nanofluids, and classified as fragmentation. The IFT reduced significantly when nanofluids contact with crude oil from field after 10-20 minutes and oil drop started disintegration. This phenomenon was identified consistently through OCA measurement. It altered surface of rock from medium water-wet to strong water-wet. The relative permeability measurement showed consistent wettability alteration that the curve shifted from water-wet to be stronger water-wet.

This observation not only showcases the great potential of nanoparticles but also providing a new reference for synthesizing and formulating nanoparticles as a technique to improve oil recovery.
Investigation of Intermittent Loss of Electrical Integrity in Subsea Control System
Authors: Tanna Mohit Bharatbhai , Rayner Wayne
Published: March 2022

Objective/Scope

The project under consideration witnesses IR (Insulation Resistance) degradation on reconnecting the subsea system to the FPSO (Floating Production Storage and Offloading) after a prolonged period of disconnection. The IR of the system eventually regains its expected value after some time interval. The present research investigates the causes of IR degradation and the possible mechanisms behind IR recovery after system startup. The prime focus of this work is on the umbilical utilized in the field.
A Case Study of LWD and Wireline Formation Pressure Tester on Depleted Reservoir of Offshore Development Sequential Wells, Kutai Basin, East Kalimantan, Indonesia
Authors: Manurung Vinda Berlianta , Himawan Glen Ricky , Warkhaida Laila , Zulharman Ahmad , Citajaya Novrianto , Laksono Setiadi
Published: March 2022

The Kutai Basin, has been under production for more than 40 years and many wells have been drilled to develop the area. This has resulted in reservoir-induced drilling problems, like kicks and lost circulation due to depletion, while some high-pressure zones still exist. This complexity makes pore-pressure and stress analysis difficult. To address this problem, a comprehensive reservoir-evaluation program was developed by adding formation pressure testing to the planned quad-combo logging-while-drilling (LWD) program. Pressure measurements in this development stage were planned to aid the operator's understanding of the field's current hydraulic communication pathways, to relate reservoir characterization to the geological model. Emphasis was on the insight of static reservoir pressures, which are important for confirming fluid contacts and fluid density gradients.

Methods of formation pressure testing have evolved over many years. Through this paper's case study, recent LWD and wireline pressure-testing technology are elaborated in depth, in relation to two sequential wells drilled offshore in the Kutai Basin. LWD pressure-testing operations were conducted in well XX-5 in a dedicated run after completion of drilling the section. The wireline test was conducted in well XX-4 as an open-hole logging run, along with the acquisition of fluid analysis data.

Both systems were successfully utilized in the 6-inch hole sections of the subject wells, in a depleted reservoir, with the pressure overbalance expected to reach around 3100 psi in the pre-job planning stage. The average mobility was low in both sets of pressure test results, as also align with the reservoir's current depletion state. Challenges related to tight tests and lost seals in this mature field were experienced with both systems. The drilling environment and the formation's exposure conditions may have presented varying challenges; nevertheless, the same relatable quality has been achieved with both types of testing (LWD and wireline).

This paper describes in detail the planning, design, and performance of pressure testing using LWD and wireline in the Kutai Basin. Comparisons between results are displayed to highlight the current character of the subject offshore field. This study aims to enhance future drilling and logging operations, by reviewing solutions from formation pressure testing technologies and to add value to mature and depleted field planning.

Technical Categories: Geotechnical, Geoscience & Geophysics; Drilling Technology
Verticalized Sonic Measurements in Deviated Wellbore for Accurate Velocity Modelling and Seismic Well Tie in Offshore Malaysia
Authors: How Elijah Lip Heng , Donald Adam , Bettinelli Pierre , Chongrueanglap Pongsit , Hooi Woi Loon , Soh Anniza Ai Mei
Published: March 2022

Vertical seismic profile (VSP) or checkshot surveys are useful measurements to obtain accurate time-depth pairs for time-depth conversion in seismic exploration. However, in deviated wells, the standard geometry correction for rig-source VSPs will not provide reliable time-depth profiles because of ray bending, anisotropy, and lateral velocity variation effects. The accuracy of the time-depth profile can be improved by using model-based correction or vertical incidence VSP simulation with transversely isotropic (TI) data from an advanced sonic measurement. Elastic anisotropy parameters derived from sonic combined with VSP time-depth information are shown to accurately place a deviated wellbore within the reservoir to improve the drainage and productivity of a reservoir in offshore Malaysia.

For rig-source VSP in a deviated well, the source-receiver travel path is not a vertical straight line, but an oblique, refracted path. The seismic waves from the source travel along straight paths within a layer of constant velocity. On entering another layer, they undergo refraction and the direction of travel changes. The pseudo-vertical incidence VSP is simulated with a velocity model to accurately calculate the vertical traveltime.

This deviated well passes through various layers of overburden before reaching the target reservoirs. Observations from the dipole shear anisotropy, formation dip, and using dispersion analysis, indicate that these shales can be considered transversely isotropic with a vertical axis of symmetry. A single well probabilistic inversion was used to solve for the five anisotropic constants by combining the sonic measurements and prior elastic anisotropy relationships. This advanced model-based correction was the optimal solution to improve the accuracy of checkshot time-depth velocity data in combination with the anisotropic velocity model.

Isotropic model-based correction showed a 6-ms time difference compared with standard VSP geometry correction. However, the sonic data in the overburden formations showed a significant amount of layering that gave rise to significant uncertainty in the existing velocity model and thus the position of the top reservoir. The anisotropic parameters were determined at sonic scale for the shale directly overlaying the reservoir. The upscaled anisotropic velocity model showed that an 18-ms time difference with standard VSP geometry correction changed the depth of the reservoir up to 45 m. The new model now placed the reservoir at the correct position and can be used with more confidence for development purposes.
The FEL-Agile Hybrid Approach to Selecting the ‘Right’ Oil & Gas project
Authors: Nesan Ashvin
Published: March 2022

The front-end loading (FEL) project management process is a method that is trusted and ingrained into most Exploration and Production oil and gas companies worldwide. The entire FEL is modeled after the Waterfall model which is sequential in nature. The waterfall model can be construed to be too slow in adapting to changes resulting in a significant number of oil and gas projects having a high tendency of cost overruns, schedule delays and not meeting stakeholder objectives. On the other hand, the agile model employed by IT, software and technology companies offers a refreshing view to achieving the desired result in projects. However, these two industries have substantial differences between them, for example in project value and regulation. This explains the reluctance by major oil and gas companies to implement agile as part of their project management approach. Nevertheless, as the environmental and organizational factors in project management in all sectors are changing at a rapid pace, seeking alternative and workable approach is vital. The paper seeks to evaluate the concept of adapting the agile methodology for FEL in oil and gas field development projects. The paper identifies areas for integrating agile such as in FEL selection criteria and further suggests to seek a balance between the two contrasting methods. Overall, the results from a case study in the oil and gas industry indicates that by adapting agile approach into the current FEL practice, it's more likely that the right project would be sanctioned, therefore, increasing the chances of project success.
A New Insight into Smart Water Assisted Foam SWAF Technology in Carbonate Rocks using Artificial Neural Networks ANNs
Authors: Hassan Anas M. , Ayoub Mohammed A. , Mohyadinn Mysara E. , Al-Shalabi Emad W. , Alakbari Fahd S.
Published: March 2022

The smart water-assisted foam (SWAF) technology is a novel enhanced oil recovery (EOR) technique, which combines the synergistic effect of both smart water and foam-flooding methods. The smart water enables multilevel improvements, namely, stabilization of foam-lamella and wettability alteration of the carbonate rock, which leads to desirable oil relative-permeability behavior. Contact angle tests are the common approach for measurement of the preferential affinity of reservoir rocks to fluids. However, the laboratory methods for contact angle measurement are costly and time-consuming. Therefore, in this study, we propose a new approach to predict contact angle based on a machine learning technique. A model based on artificial neural network (ANN) algorithm was developed using 1615 datasets acquired from diverse published resources. The developed ANN-based model to predict contact angle was further evaluated by applying the trend analysis approach, which verify the correct relationships between the inputs and output parameters. The collected datasets were trifurcated into training, validation, and testing segments, so that the over-fitting and under-fitting issues are evaded. Furthermore, some statistical error analyses, namely, the average absolute percentage relative error (AAPRE), and the correlation coefficient (R) were performed to present the robustness and accuracy of the proposed model.

The findings from the trend analysis showed the sound relationships between the inputs and output parameters. The statistical error analyses proved that the developed ANN-based model does not have any under-fitting or overfitting anomalies, and correctly determines the contact angle with high accuracy, substantiated by the R values of 0.9988, 0.9985, 0.9967, and AAPRE values of 1.68, 1.62, 1.81, for training, validation, and testing datasets, respectively. The proposed ANN-based model for contact angle prediction has many advantages including speed, reliability, and ease of usage. This work highlights the potential of machine learning algorithms in oil and gas applications, particularly in contact angle prediction from SWAF technology. The findings from this study are expected to add valuable insights into identifying the optimal conditions (i.e., optimum smart water and surfactant aqueous solution) for the operation sequence of SWAF technology, leading to successful field applications.
The Versatile and Tunable Metal-Organic Framework MOF for Condensate Decontamination
Authors: Arayachukiat Sunatda , Pironchart Taradon , Kongpatpanich Kanokwan
Published: March 2022

Contamination of heavy metals especially for Mercury (Hg) and Arsenic (As) in condensates becomes one of major concerns in Natural Gas production due to theirs high toxicity and carcinogenicity. The key challenge to develop adsorbents for Hg/As removal is to find suitable porous materials with high adsorption capacity, long-term stability and easy to handle the toxic wastes after the adsorption process. Metal-organic frameworks (MOFs) are one of promising porous materials constructed from metal clusters and organic linkers to create the 3D framework structures. MOFs are one of the promising adsorbents for removal of Hg/As from condensates owning to their versatile structures, tunable porosity, and tailorable chemical functionalities. In this work, Zr-based MOFs have been developed for dual removal of Hg and As species owning to their chemical stability in moisture conditions, which is highly desirable for industrial processes. Zr-based MOFs with different topology and pore size distribution have been synthesized for Hg/As adsorption to understand the contribution of porous structure on the removal of Hg/As species in condensates. The performance of Zr-based MOFs results showed Hg and As removal up to 99.5% in condensates from several petroleum sources. The removal efficiencies were found to be influenced by topology of MOF adsorbents and the speciation of Hg/As in different petroleum sources. In addition, Zr-based MOFs have proposed some future trends and challenges of porous material that can be used as an alternative to the conventional metal oxides and zeolites.
Experimental Investigation, Porosity-Permeability Modelling, and Artificial Neural Network Prediction of CO2 Injectivity Change for Sequestration
Authors: Md Yusof Muhammad Aslam , Mohammad Fuad Iqmal Irsyad , Md Akhir Nur Asyraf , Ibrahim Mohamad Arif , Mohamed Muhammad Azfar , Maharsi Dara Ayuda
Published: March 2022

CO2 sequestration in saline aquifer is a promising approach to effectively secure the anthropogenic CO2 gas. Complex fluid-rock interaction processes take place during the injection of CO2 would disrupt the thermodynamic equilibrium of CO2 injectivity at near wellbore. In this study, a comprehensive investigation on the CO2 injectivity change of different injection flow rates and brine salinity was performed using core flooding experiments, permeability change prediction using (Kozeny-Carman and Hagen-Poiseuille models) and artificial neural network model (ANN). Core flooding experiments revealed CO2 injectivity impairment increased with increasing brine salinity, with Hagen-Poiseuille being the most fitted model with R2 of 0.935. However, all porosity-permeability models failed to give a good prediction at changing injection flow rate with R2 is well below 0.4. The adopted ANN model showed good agreement with the experimental data at varying brine salinity and injection flow rates. The utilization of ANN for such prediction procedure can reduce the number of experiment, operating cost and provide reasonable predictions compared to existing analytical models.
Edge Optimization Analytics and Control: A Integrated Device of Intelligent Intermittent Pumping for Tight Oil Wells
Authors: Wang Cai , Zhang Xishun , Zhao Ruidong , Shi Junfeng , Zhao Hanjun , Sun Yizhen , Xiong Chunming , Deng Feng
Published: March 2022

Intermittent pumping is an effective measure to reduce energy consumption and improve production time rate for tight oil wells with extremely low oil production. However, the intermittent pumping scheme is mainly controlled by manual timing or RTU remote timing in the cloud. The design of intermittent pumping interval lacks reasonable theoretical basis and the control efficiency is relatively low. Therefore, an integrated intelligent intermittent pumping device combining edge optimization analytic and edge control is developed.

A closed-loop integrated device containing real-time data acquisition and transmitting module, optimization module and edge control module is realized. The optimization module embeds the pump fullness calculation model and intermittent pumping scheme optimization model. Instead of using dynamometer cards, a deep learning model of transferring power curves to dynamometer cards named PTD (Power to Dynamometer) is established through deep learning in order to lower the oilfield IoT cost. The average single well area error of predicted dynamometer card is less than 3%. To transfer the PTD to untrained new wells, a parallel model is established by parallel connection of PTD and transferring learning model. The parallel model is embedded into the edge computing device to realize the dynamometer card real-time prediction and pump fullness calculation. The calculated data is transmitted to scheme optimization model where a reasonable intermittent pumping scheme can be optimized. Then the optimized pumping scheme is transmitted back to the edge control device to adjust the pumping scheme to realize loop control.

This technology was applied to 100 wells in the oilfield, the monthly energy consumption reduced by 30%, and the average pump efficiency increased by about 17%. The application of this technology is insightful to promote the IoT and intelligence of oilfield artificial lifting system.
Qualification of Mechanical Interference Fit Connection for Offshore Pipeline Application
Authors: Eka Putra I. Wayan , M. Adnan Mas Nazli Aziah Bt , Badaruddin M. Fauzi B
Published: March 2022

Subsea pipeline is still considered a major cost contributor for offshore oil and gas field development. One of the major factors which affect this high cost is expensive installation cost due to expensive pipelay barge mobilization/demobilization cost, daily charter rate, as well as low speed for pipelay using welding. Several technologies were being considered to further optimize capital expenditure (CAPEX) for subsea pipeline installation. Mechanical Interference Fit Connector (MIFC) is currently being considered as an option to optimize the cost for rigid offshore pipeline installation. However, this technology is new in Malaysia, and the normal regulatory requirement for the application is still based on welding. There was a requirement to demonstrate the design and integrity of the MIFC to meet the conventional requirement for pipeline welding as part of the regulatory requirement for a permit to install (PTI) and permit to operate (PTO). This paper presents the approach to assess the design and performance of the MIFC joint. The assessment includes design verification using finite element analysis (FEA), and subsequent validation by full-scale testing. Several cases have been analyzed and tested to simulate the full-life cycle loading of the pipeline, starting from joint preparation, offshore installation loading, hydrotest loading and in-place loading during operation. The outcome of the modeling and verification by full-scale testing concluded that the MIFC was able to meet and even exceed the minimum requirement of the joint integrity during the full life cycle of the pipeline loading from installation until operation. As a result, the joint acceptance criteria envelope can be designed as acceptance criteria for regulatory purposes and for offshore application quality assurance and control purpose in-lieu of the acceptance criteria by welding. This approach has then been accepted by Malaysian Regulatory for PTI/PTO requirement and successfully applied for one of the pipeline projects in one of PETRONAS subsidiary as first application in Malaysia and the world longest MIFC application for a single subsea pipeline. This successful application opens the possibility for replication to other fields and other pipeline operators in Malaysia.
Challenges and Mitigation Strategies for High-Rate Gas Well Testing in High-Pressure-High-Temperature DST Operation
Authors: Hemaprasertsuk Jakpakorn , Ratawessanun Watanapong , Bandyopadhyay Parthasarathi , Chia Boon Shin , Thanudamrong Suphawich , Hamdan Mohamad Kamal , Kongpat Nitipong , Akbayev Beibit , Ngan Arthur Cheng Ho
Published: March 2022

Well testing provides useful data for reservoir characterization during various stages of field life, from exploration, development to production. The key information that are typically can be obtained are, information on reservoir properties, deliverability, and pressure data. However, if the data acquisition during the well testing is compromised it can also lead to incorrect data and could lead to a wrong understanding of the reservoir and could results in sub-optimal field development. Therefore, it is important to emphasize on the quality of the data being acquired.

This paper captures the experiences gained for a high-pressure-high-temperature (HPHT) exploration well DST where data acquisition was compromised in the 1st well drilled in the structure. A combination of temperature transient effect and tubing movement in the well during shut in resulted in data quality which can't be interpreted with confidence. The lessons learnt from the same was captured and addressed successfully in the subsequent well which enabled quality data acquisition.

The objective of this paper is to share the challenges and mitigation strategies for a HPHT DST with the help of two DST operation where the challenges resulted in less-than-optimum data quality and the one where they were mitigated. The range of challenges came from planning, to gauge placement, to identify potential problems early, and even having proper contingency plans to cater for unplanned events.

The paper also deals with some of the best practices which can help with any DST program. Key examples are pre-job modeling, accurate temperature measurement and modeling, real-time data acquisition, and a special focus on sampling as a part of a successful DST program.

Disclaimer

All parameters cited in this paper are purposely made in ambiguous manner to maintain confidentiality of the data.
Mortality risk factors in febrile ulceronecrotic Mucha- Habermann disease: a systematic review of therapeutic outcomes and complications
Authors: Tasouli-Drakou Vasiliki , Nguyen May , Guinn Hannah , Hassan Omron , Butala Sneha , Phan Sheshanna
Published: March 2022

Febrile ulceronecrotic Mucha-Habermann Disease (FUMHD) is a variant of Pityriasis Lichenoides Et Varioliformis Acuta (PLEVA). Although rare, the condition may progress to involve serious complications and even lead to fatal outcomes if diagnosis and appropriate treatment is delayed. A PubMed search following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIMSA) guidelines was performed to find cases of FUMHD from the earliest records to October 2021. Treatments, complications, and patient outcomes were extracted from the literature and summarized, while a review of quality was also performed. A total of 63 publications with 68 patients were found. Successful treatment modalities for FUMHD included antibiotics, antivirals, systemic steroids, methotrexate (MTX), cyclophosphamide, cyclosporine (CYA), intravenous immunoglobulins (IVIG), pentoxifylline, and ultraviolet B phototherapy. Out of 68 patients, 55 patients had their condition fully resolved and 13 cases were fatal. Increased age, systemic involvement, and monoclonal T-cell receptor rearrangement were associated with worst prognosis, but mucosal involvement did not affect mortality risk. Overall, the publications had low risk of bias, but most lacked adequate follow-up periods. FUMHD is a diagnostic and therapeutic challenge due to the lack of clearly defined diagnostic criteria and optimum treatment. Further studies with larger patient populations and longer follow-up periods may lead to refinement of diagnostic criteria, establish an optimum treatment regimen, and better estimate the likelihood of recurrence.
Disparities in COVID-19 health outcomes among different sub-immigrant groups in the US - a study based on the spatial Durbin model
Authors: Jung Jihoon , Ahn Yoonjung , Bommarito Joseph
Published: March 2022

Immigrants may be more vulnerable to coronavirus disease 2019 (COVID-19) than other sub-population groups due to their relatively low socioeconomic status. However, no quantitative studies have examined the relationships between immigrants and COVID-19 health outcomes (confirmed cases and related deaths). We first examined the relationship between total immigrants and COVID-19 health outcomes with spatial Durbin models after controlling for demographic, biophysical and socioeconomic variables. We then repeated the same analysis within multiple subimmigrant groups divided by those with original nativity to examine the differential associations with health outcomes. The result showed that the proportion of all immigrants is negatively associated with the number of confirmed cases and related deaths. At the continent and sub-continent level, we consistently found negative relationships between the number of confirmed cases and the proportion of all sub-immigrant groups. However, we observed mixed associations between the proportion of sub-immigrant groups and the number of deaths. Those counties having a higher prevalence of immigrants from Africa [Eastern Africa: –18.6, 95% confidence interval (CI): –38.3~–2.9; Northern Africa: –146.5, 95% CI: –285.5~–20.1; Middle Africa: –622.6, 95% CI: –801.4~– 464.5] and the Americas (Northern America: –90.5, 95% CI: – 106.1~–73.8; Latin America: –6.8, 95% CI: –8.1~–5.2) mostly had a lower number of deaths, whereas those counties having a higher prevalence of immigrants from Asia (Eastern Asia: 21.0, 95% CI: 7.7~36.2; Western Asia: 42.5, 95% CI: 16.9~68.8; South- Central Asia: 26.6, 95% CI: 15.5~36.9) showed a higher number of deaths. Our results partially support that some immigrants, especially those from Asia, are more vulnerable to COVID-19 than other sub-population groups.
Dental Students and COVID 19
Authors: Koppolu Pradeep , Tanvir Syed Bilal , Lingam Amara Swapna , Noor Muhammad Zakir , Barakat Ali , Alwahibi Mohammed Saleh , Almoallim Hesham , Aqerban Ali , Noushad Mohammed , Niazi Fayez Hussain
Published: March 2022

Background:

Coronavirus is an emerging respiratory pathogen that causes coronavirus disease-2019 (COVID-19), as per the Chinese Center for Disease Control and Prevention.

Objective:

This study aimed to assess the state of awareness and extent of knowledge about COVID-19 among dental students from India, Pakistan, and Saudi Arabia.

Materials and Methods:

The present descriptive cross-sectional study was conducted on 872 participants from December 2020 to January 2021. Random sampling was performed using an electronic questionnaire. One-way analysis of variance and independent sample t-test were performed to assess and compare the mean knowledge score between different demographic data.

Results:

Approximately 60% (n = 520) of the responders were women and 40% responders were men (n = 352). The responders were from Saudi Arabia (36.9%; n = 322), India (34.2%; n = 298), and Pakistan (28.8%; n = 252). The difference within the subgroups was statistically nonsignificant (P > 0.05), indicating that dental students of all subparameters possessed equal knowledge on COVID-19.

Conclusions:

Dental students possess sufficient knowledge about COVID-19, qualifying them at least to work in a medical ward. However, more emphasis must be placed on infection prevention and control policies such as hand hygiene, personal protective equipment, and pre- and postexposure prophylaxis.
Comparative Study of Acute Coronary Syndrome in Postmenopausal Women and Age-Matched Men
Authors: Kodliwadmath Ashwin , Nanda N. , Duggal Bhanu , Kumar Barun , Mondal Debopriyo , Bhat Shashikantha
Published: March 2022

Background:

Acute coronary syndrome (ACS) differs in women and men with respect to risk factors, clinical presentation, complications and outcome. The major reason for the differences has been the effect of estrogen which protects women from coronary artery disease (CAD) till menopause. Women develop CAD one decade later than men. Hence, we compared the profile of ACS in postmenopausal women with age-matched men to see, does the difference still exist.

Materials and Methods:

Comparative prospective study of 50 postmenopausal women as study group and fifty age-matched men as a control group diagnosed with ACS, who were admitted in a medical college hospital from December 2013 to September 2015. Chi-square test and Student's t-test have been used to find the significant association of study parameters between women and men.

Results:

Chest pain was the main complaint in the majority of the women (76%) and men (88%). Radiation of chest pain (60%) and sweating (72%) were significantly present in men compared to women (24% and 26%, respectively), whereas breathlessness was significantly present in women (40%) compared to men (16%). Women had later presentation to the hospital after symptom onset compared to men. Women had a higher respiratory rate (22.02 cycles/min) compared to men (20 cycles/min) and more crepitations compared to men. Men had more ventricular tachycardia (14%) and intracerebral hemorrhage (4%), whereas women had all other complications more than or same as men and higher in-hospital mortality (14%) compared to men (8%).

Conclusion:

Postmenopausal women with ACS had more atypical presentation of symptoms, later presentation to hospital, more tachypnea, more crepitations, more complications, and higher in-hospital mortality compared to men of the same age group. The difference in the profile of ACS continues to exist even after menopause and age matching.