bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and Validation of AM Metals/CFRP Joints Based on Patterned Surfaces and Fibers Engagement
Authors: De Pasquale Giorgio , Plos Sara , Zappulla Letizia
Published: March 2022

The fabrication of co-cured metal/CFRP joints offers some relevant advantages as the elimination of adhesives and the simplification of building process. In this view, the additive manufacturing (AM) of metal parts is suitable for expanding the potentialities of co-cured AM metal/CFRP joints where patterned surfaces are introduced. This paper presents a methodology to fabricate the joint, based on matrix patterns of 3D features on the metal surface, which is able to improve the polymer matrix adhesion and to provide carbon fibers engagement. Both FEM simulations and experiments show significant enhancement of the global mechanical strength.
Optimum Percentage of Fly Ash as Cement Replacement and Effect on Mechanical and Durability Properties of Self-Compacting Concrete
Authors: Hameed Asif , Rasool Ali Murtaza , Hassan Javed Muhammad , Afzal Abrar , Elahi Khizar , Munir Daniyal
Published: March 2022

Self-compacting concrete (SCC) is a type of concrete that does not require vibration and undergoes compaction under its own self-weight. Cement being the major constituent of self-compacting concrete is very expensive. Thereby incorporating fly ash, a by-product obtained by burning coal in coal power plants, the percentage of cement can be reduced. Thus in this study, class C fly ash in varying percentages from 0 to 30% has been used as a partial replacement of cement. The main purpose is to study the effects of fly ash on mechanical behavior and durability properties of self-compacting concrete and to choose the optimum dosage of fly ash. To determine the mechanical behavior, fresh properties of self-compacting concrete were studied by performing Slump flow, J-ring, V-funnel, and L-box tests. Hardened properties were evaluated by performing the Compressive strength and Split tensile test. The durability was determined using the volume of voids and sorptivity test. Tests to study mechanical behavior were performed by casting cylinder, whereas, concrete discs were cast to perform durability tests. Finally, it was observed that the replacement of 25% Fly ash with cement was found to be the optimum percentage.
Numerical Investigation of Openings on Lateral Strength of Masonry Walls
Authors: Mughal Ubaid A. , Qazi Asad Ullah , Hassan Fizza , Rasool Ali Murtaza , Hameed Asif
Published: March 2022

The study investigates the reduction in masonry walls' strength with different opening sizes and aspect ratios using simplified micro modeling. Calibration of the numerical wall model was done by following an existing wall model from the literature. Springs (COMBIN39) were used to model the compression and shear strength of mortar, whereas contact elements (CONTA178) were used to model the bond between mortar and bricks. The load was provided in two phases; first, the gravity load was applied in the vertical direction to compress the wall then the lateral load was applied. Five walls with an opening size 0%, 1.85%, 3.66%, 10.91%, and 16.5% of the total wall area have been modeled in this study. The analysis results showed that up to an opening area of 4% masonry wall showed approximately 50% reduction in strength and stiffness. Beyond 4% opening size, strength and stiffness drop almost linearly. Such modeling can save cost, time, and know beforehand the type of failure of a masonry wall to avoid life loss.
Dimensional Accuracy of 3D - Printed Acrylonitrile Butadiene Styrene: Effect of Size, Layer Thickness, and Infill Density
Authors: Robles Gerald Sanqui , Delda Ray Noel M. , del Rosario Renz Lui B. , Espino Michaela T. , Dizon John Ryan C.
Published: March 2022

The adoption of Additive Manufacturing (AM) is continuously growing due to its capability to produce complex shapes which leads to the dependence of manufacturers on AM to replace conventional manufacturing processes. One important focus of research now is on the accuracy of 3D printed products produced via the Fused Deposition Modeling (FDM). These products have great potential to be applied to tooling and other rapid prototyping applications. The aim of this study is to assess the accuracy of 3D printed Acrylonitrile Butadiene Styrene (ABS) through manual measurements of dimensions. Several sets of samples with cubic shapes were printed and measured using a digital micrometer to evaluate the dimensional accuracy of the 3d-printed parts. A 22 full factorial design was employed to investigate the effects of infill density and layer thickness on the dimensional accuracy of ABS parts.
Additive Manufacturing of Supercapacitor Electrodes – Materials, Methods and Design
Authors: Nargatti Kiran , Ahankari Sandeep
Published: March 2022

Fabrication of supercapacitor (SC) electrodes plays a vital role in enhancing the electrochemical performance of SCs. Conventional fabrication techniques have limitations in fabricating the complex SC electrodes. The three-dimentional (3D) printing technique has several advantages over conventional manufacturing techniques that includes patterning capability, contact-less high-resolution, controlled material deposition, design flexibility, and multi-material compatibility. Due to these excellent qualities, considerable research efforts have been made in developing 3D printed SC electrodes. This review offers a literature update on the recent printing materials employed and the design aspects in making of SC electrodes. It also discusses the impact of critical parameters involved in various techniques of 3D printing of electrodes. Finally, the paper concludes with the scope and challenges in material/manufacturing of electrodes and the performance comparative analysis of various 3D printed structures.
Comparison between Sediment Material and Natural Subgrade Material for Road Construction
Authors: Ibrahim Osama Ragab , Al Maqbali Laila Ali , Al Shaqsi Mahmood Sulaiyam
Published: March 2022

This paper presents the comparison between sediment and natural subgrade material for road construction to check its stability to improve soil properties. Two samples were investigated which are sediment and subgrade construction material which were taken from Wilayat A’seeb, Oman. Sediment was collected from Alkhoud dam, Muscat, and subgrade construction material was collected from Al Mubilah construction site, Muscat. Elemental analyses and mechanical tests were conducted to achieve the purpose of the study. According to the AASHTO classification, the result of the sediment samples shows that it was silty and clayey gravel A-2-4 and clayey sands or sandy clay mixtures according to USCS classification. Also, investigations on the subgrade construction material show that it was silty and clayey gravel and sand A-2-7 according to AASHTO classification and well-graded sands, gravelly sands according to USCS. The result of grain size distribution curves shows that subgrade soil is applicable to be used but sediment is not applicable as pavement construction and. The maximum dry density (MDD) and optimum moisture content (OMC) of the sediment sample are 1.422 g/cm3 and 20.3% respectively. Also, the maximum dry density (MDD) and optimum moisture content (OMC) of the subgrade construction material are 1.634 g/cm3 and 15.5 % respectively. As compared between the two materials, it found that the result of maximum CBR value of subgrade material was 16.13% and the maximum CBR value of sediment material was 16.07% and that means both materials are very close in strength and sediment has the power to be used in road construction with some improvement. According to the experimental results, it shows that the investigated sediment and natural subgrade soil are suitable to be used in the subgrade layer because it is corresponding to the range of Omani standards but it is not suitable to be used as subbase and base layers. Other standards might be compatible with the results to be effective use in subbase and base layers.
Challenges in Implementing an Integrity Operating Window IOW Program in Offshore Operations
Authors: Ahmed Rehan , Jaafar Rohana , Ab Rahman Alia Rashiqah , Sabturani Mohd Fikhri Fikhri , A. Khairudin Ahmad Naim
Published: March 2022

Objectives/Scope

Highlights the challenges faced by matured Offshore Operating Oil and Gas Asset during implementation or enhancement of the Integrity Operating Window (IOW) monitoring and proposed solutions to address the challenges. PETRONAS Upstream has embarked on an exercise of upgrading its IOW reporting in light of the increased number of Loss of Primary Containment (LOPC) incidents and premature equipment breakdown which has resulted in Unplanned Deferment (UPD) and Health, Safety and Environment (HSE) incidents.

Methods, Procedures, Process

IOWs are sets of limits used to determine the different variables that could affect the integrity and reliability of a process unit. Comparative analyses are made between the implementation of an automated online system with Artificial Intelligence capabilities versus a moreconventional manual system. We explore the advantages and disadvantages of each of these approaches including the element of cost. Integration of Pi historian and laboratory information management system (LIMS) to the IOW module will help provide real-time data and analysis to the Online and Manually implemented risk-based inspection (RBI) system.

Results, Observations, Conclusions

Since this is currently an ongoing exercise, the results will be based on the achievement of key performance indices, including a marked change in equipment uptime andavailability. The expectations are to upskill operations and Engineering teams in implementing andadjusting the IOW to the needs of the facility, extending asset life, and adjusting the parameters based onmachine learning or manual adjustments. Note that upgraded IOW manuals have been developed and rolled out for this pilot study, and all lessons learnt will be incorporated into any future enterprise rollout.

Novel/Additive Information

The implementation of IOW monitoring and reporting are interfacing with other digital solutions to achieve a seamless and autonomous work process. Among digital solutions interfacing with the IOW database are Predictive Revitalization of Instrument to Maximize Efficiency (PRIME), LIMS and other in-house digital solutions such as online Corrosion Management Program and Risk-based Inspection (RBI).
Improved Drilling Performance in Asia Pacific Formations Through Digitally Augmented Design Process for Shaped Cutter Drill Bits
Authors: Duffy Stephen , Wasuthalainunt Nick , Wongnang Chanikarn
Published: March 2022

The objective of this paper is to demonstrate the improved drilling performance achieved by operators in the Asia Pacific region by implementing shaped Polycrystalline diamond compact (PDC) cutter technology. The success of these PDC bit designs is achieved using a design process augmented by advanced drilling simulations to optimize cutter placement specifically for the formations present in the region. For decades the drilling industry has been aware of the potential performance gains, in certain targeted formations, by forming cylindrical cutters into other geometrical shapes. These early generation shaped cutters had limited success due to diamond technology, along with the high manufacturing costs associated with shaping the cutters. Recently, PDC drill bits with shaped cutter designs are becoming more prolific in particular formation types. A number of these formations targeted for improved drilling performance are present in the Asia Pacific region.

This paper describes a unique advanced drilling simulation software that has been calibrated with data recorded from various pressurized drilling tests in specific rock types in the drilling lab. It also explores the new design processes that integrates these advanced drilling simulations against historical drilling data and aids in the down selection of design concepts. This new process has been used by application engineers in the Asia Pacific region and supported by a global service delivery team to optimize shaped PDC cutter bit designs.

Improved drilling performance is achieved with the correct application of shaped PDC cutter technology. Case studies from the Asia Pacific region demonstrate how shaped cutter PDC designs allowed operators in China and Brunei to improve drilling performance. For example, a Brunei operator doubled the rate of penetration previous seen in these targeted applications. In South West China, longer footage and rate of penetration (ROP) improvements have been achieved. In North West China, 30% ROP improvements have been observed.

This novel design process enables performance driven design decisions with minimal need to iterate in the field, providing the operator with an optimal design to suit their needs.
Improvement Drilling Efficiency by Using Mud Motor and Agitator Bha in 6 1/8-in. Hole: Gulf of Thailand
Authors: Toasudjai Natsuda , Lordkratok Chanya , Fecho Kelly , Tipdontree Poppoom
Published: March 2022

In the Gulf of Thailand (GOT), deep directional drilling wells are planned with two runs using motor and adjustable-gage-stabilizer (AGS) bottom hole assembly (BHA) in the 6-1/8-in. hole section or the rotary-steerable-system (RSS) BHA. However, the cost of the RSS is not economical for some wells. The paper discusses the challenges of drilling in the high temperature environment and explains the engineering and analysis that resulted in a one run hole section with a motor BHA.

The extreme temperature elastomer (XT) motor was paired with an agitator system to facilitate the transfer of BHA weight for effective weight-on-bit (WOB) while sliding in long tangent or curve for great depths and temperature more than 150 degree Celsius (⁰C) well. Exhaustive BHA analysis, namely hydraulics, drill-string torque-drag and various sensitivity studies were performed for optimal placement of the agitator and shock sub in the BHA for the best friction reduction and least damaging vibration effect on BHA components. The simulation capabilities were enhanced by trail runs, analyzing historical performance and empirical data to implement step change improvements in the next BHA.

The XT motor with agitator-system BHA enabled smooth sliding and fast rate of penetration (ROP) across the entirely true vertical depth (TVD) range of the 6-1/8-in. hole. There was no BHA hanging up when sliding in deep sections of the well, demonstrating stable tool-face control while sliding, which translated to an overall efficient penetration rate. The 6-1/8-in. hole sections drilled with the XT motor and agitator-system BHA demonstrated 30 percent (%) faster ROP than similar TVD sections drilled with a motor without an agitator-system BHA. For example, a 6-1/8-in. hole with 1360-meter (m) drilled in long tangent at 41degree (°) inclination was successfully drilled in one run from shoe to 2584m MD of the well TD in 27 hours, with an average on bottom ROP of 51 meter per hour(m/hr).
Enhancing Oil Recovery in a Brown Oilfield of Offshore South China
Authors: Liu Wubo , Gao Xiaofei , Li Qingquan , Guo Yi , Yu Lei , Wang Chao , Chang Botao , Wang Fei , Li Shuzhong , Shim Yen Han
Published: March 2022

Located in offshore South China, XJ oil field entered the mature development phase after more than 20 years of production, with the water cut of the field increasing to 93%. A new strategy was executed starting in 2018 that targeted the remaining oil column, which was being squeezed by a strong bottomwater. One of the biggest challenges was the high uncertainty of the oil/water contacts in the current reservoir state. After reviewing the technical and geological challenges encountered, we will describe the successful approach taken to optimize the remaining reserves recovery using innovative horizontal well placement strategies.

Using a few case studies, we will illustrate how we executed this innovative well placement strategy. This includes landing the horizontal wells at the upper part of the reservoir with low incident angle, drilling the horizontal sections close to the top of target zones using a reservoir boundary detection tool, and using a continuous packer for the well completion to reduce the water cut. In addition, we will describe how the team evaluated and selected logging technologies in the planning phase for proper well placement.

The two cases discussed in this paper are based on horizontal wells completed using the following new strategy: maintaining a long lateral section in the upper layer of a predefined target, following the undulating structure while mapping the thin sandstone, keeping the trajectory in the target zone, etc. To ensure that each horizontal well could meet the target productivity index planned, real-time data were used in reservoir modeling to determine the required lateral length of each horizonal well. With the purpose of controlling water cut and improving oil recovery in these laterals, a new completion assembly, including a perforated liner with special completion material that prevented water from entering the liners, were installed in selected intervals according the logging data interpretation. Several observations will be highlighted, including:

Real-time logging data can effectively evaluate the reservoir properties and structural changes along the lateral Optimum well placement in the lateral section is critical for draining the remaining oil column An optimized completion design based on real-time reservoir evaluation.

The performance of the wells drilled to date shows that the production increased from 1,000 to 3,000 BOPD with zero to very low water cut. A reversing production trend from a declining trend to a growth trend is recorded. The successful implementation of the new strategy and the application of fit-for-purpose technologies in mature oil fields lead to improved production and increased oil recovery.
Weathering Uncertainties in Oil & Gas: Challenges and Design Optimization of High Contaminant Gas Field
Authors: Mustaffa Norlelawati , M Norpiah Rohaizad , Awang Bakar Dyg Amalina Azzyati , M Nazori Qurratuaini , Agus Muliadi
Published: March 2022

Typically, for a high volume, low condensate-gas ratio offshore gas production field having high content of carbon dioxide (CO2), hydrogen sulphide (H2S), mercury and solid particulates having to meet Liquified Natural Gas (LNG) inlet specification would require an enormous facility exceeding the largest available floatover vessel capacity. Aside from an enormous and complex processing facility, it would also require a large emergency disposal system and sour service pipeline material to cater for start-up and process excursion scenarios. In order to obtain a commercially attractive solution while meeting technical integrity and designing for operational excellence in mind, several innovative design approaches were implemented. The scope of this paper will cover major optimization implemented at gas treatment system, emergency blowdown system, export gas pipeline, and venting system at receiving platform.
Fine Characterisation of Remaining Oil Using Time-Varying Numerical Simulation: Experimental Study, Characterisation in Model, and Application in QHD Oilfield
Authors: He Yifan , Liu Yingxian , Cai Hui , Chen Xiaoming , Chen Jing
Published: March 2022

For water-flooding oilfields, both indoor experiments and mine field practices have confirmed that long-term water flooding can change physical properties, wettability, and fluid parameters. The comprehensive performance of these changes is that the relative permeability curve of oil and water changes dynamically. Usually, numerical simulation does not consider the change of reservoir properties, which will cause the mismatch of history matching. This error is especially obvious in the high water-cut period. It further affected the understanding of remaining oil and the prediction of subsequent production. Therefore, time-varying numerical simulation is required for fine numerical simulation in high water cut period to improve the accuracy and reliability of model prediction.

In order to solve the above problems, a set of fine reservoir numerical simulation process integrating core experiment, logging, dynamic and geological knowledge was established. The specific workflow is as follows:

The data of core particle size analysis, X-ray diffraction and cast thin section were used to study the change law of reservoir physical properties and wettability after water flooding, which confirmed that the reservoir was re-stimulated under long-term water flooding. The relative permeability curves before and after water flooding were compared using natural cores. After water flooding, the relative permeability curves shifted to the right and the residual oil saturation decreased. It is confirmed that the relative permeability curves will change with water flooding. Carried out 500∼2000PV water flooding laboratory experiment, determined the oil displacement efficiency under high multiple flooding, calculated the residual oil saturation changes with the displacement multiple and physical properties. Using pore cross-sectional area flux to continuously characterize the temporal changes of properties during the simulation process. In this way, the accurate conversion of the attribute change law from the laboratory core to the actual model is realized, and the deviation caused by the change of the mesh size is avoided. In the simulation process, the changing laws of the attributes are defined separately according to the partitions, and the iterative modification of the attributes is realized in each time step.

When time-varying numerical simulation is applied to the QHD oilfield, the matching degree of history matching has been improved.

Time-varying simulation is an important means to improve the history matching effect of high water-cut water drive oilfields, and can help oilfields understand the true remaining oil distribution. This method has been extended to Bohai SZ, BZ and other oil fields.
Non-Contact Magnetic Tomography Method MTM Inspection for Re-Instatement of a Decommissioned Buried Pipeline
Authors: Lam Choong Meng , Jasni Nur Akmal Hakim
Published: March 2022

The Magnetic Tomography Method (MTM) has been introduced as a non-intrusive inspection technique capable of inspecting ferromagnetic materials such as carbon steel pipeline without any contact. A buried main pipeline in one of PETRONAS's operating countries that had been out of service for more than 8 years needed to be inspected prior to being re-instated. This paper discusses in detail how this innovative MTM technology was used to successfully inspect a decommissioned buried pipeline and safely re-instated the pipeline operation. The MTM inspection covered 172 kilometres of buried pipeline, including the calibration work which involved direct assessment methods. The danger degrees such as Rank 1, 2 and 3, as well as the safe operating pressures, Psafe along the entire pipeline were determined using the MTM results of Risk Factor F in accordance with MTM technical approach. Direct assessment findings were consistent with the MTM inspection findings, as the technology detected all of the anomalies discovered by the direct assessment methods. MTM inspections of decommissioned buried pipelines are proven since they are reliant on the residual self-magnetic leakage field (SMLF) in the pipeline and do not require any intrusive works. Being a non-intrusive inspection method, this technology was not affected by the low pressure & low flowrate, and no changes to the pipeline operation mode was required during the inspection. Further, this MTM inspection method was not affected by the stalled pigs inside the pipeline, as this inspection method was non-intrusive. The inspection results serve as major input to the Pipeline Integrity Management System (PIMS) to effectively manage the integrity and risk level of the pipeline.
Remediation of A Complex Blockage for Gumusut-Kakap Subsea Flexible Flowline from a System Perspective
Authors: Gwee Yong Chin , Chin Grace , Chan Chee Hou , Chua Lee San , Ling Jason , Wu Yvonne
Published: March 2022

A subsea production flexible flowline in Gumusut-Kakap field was found blocked in March 2021 during a routine production well-flowline switching/alignment operation. Further evaluation showed that the blockage was caused by the formation of hydrate and gel over the 1.3km length of the flexible flowline, as the live crude and water were left stagnant and untreated in the flowline over a prolonged period. This paper covers the remediation strategy and the associated challenges from a System perspective, which successfully unblocked the flowline within a relatively short period of time.

The condition of the blockage in the flexible flowline was simulated using a commercial multiphase dynamic software to ascertain the phase distribution and hence allowed the estimation of the location and length of hydrate, gel, and emulsion in the flowline which has a downward inclination of circa 50 meters height. Heating (from production well), methanol (MeOH) soaking and flowline depressurization were planned and executed. In addition to the technical methodology, the System-wide aspects were also considered for the effective and optimum execution of the remediation activities which include attempting to fulfill the production commitment, abide by the subsea hardware and flexible flowline integrity envelope, and consider the impact of the remediation operation on other operations at the Gumusut-Kakap installation.

The MeOH soaking, flowline depressurization and pressurization successfully remediated the blockage over the period of weeks. Positive results were observed at the start of the remediation when the targeted location for MeOH contact and depressurization were identified via field trial. One of the key challenges is the time factor in which to ascertain the "appropriate" waiting time for the flowline depressurization, as the remediation involved partial shut-in of the prolific production wells.

A holistic System engineering approach is critical to the successful remediation of the blockage, integrating the key technical requirements as well as the soft and non-technical aspects to deliver optimum and net positive value for the asset.
Fish Anchor Testing in the Swan River
Authors: Hossain Muhammad Shazzad , Kim Youngho
Published: March 2022

OTC-28901-MS proposed the novel dynamically installed "fish" anchor in 2018, adopting a geometry taken from nature, for potential economic and safer tethering of floating facilities in deep water. Every cross section of the fish anchor shaft is elliptical, leading to very low drag resistance during free fall through the water column, and also low resistance in penetrating the seabed sediments. The padeye is fitted on the widest part of the shaft to mobilise the maximum resistance area under operational loading. The fish anchor embedment depth during dynamic installation, and capacity under both monotonic and cyclic operational loading in calcareous silt were assessed through centrifuge model tests and large deformation finite element analyses. During dynamic installation, the normalised tip embedment depth of the fish anchor was typically three times that for the torpedo anchors and 50% greater than that for the OMNI-Max anchors. Under operational loading, the fish anchor dove deeper, reaching penetrations 20 to 60% greater than achieved during installation. By contrast the torpedo anchors (for all mooring mudline inclinations) and the OMNI-Max anchors (apart from a single test with mooring mudline inclination of 0°) pulled out directly without diving, reflecting insufficient free-fall penetration in calcareous soil.

This paper provides a follow up reporting the performance of the fish anchor through field tests in the Swan River, Perth. A 1/15th scale model fish anchor was fabricated with dry weight being 0.304 kN. The anchor was tested at five different locations. At two shallow water locations (water depths 1.1 and 1.9 m, respectively), the tests were performed from the Burswood and Maylands jetty. At relatively deeper water depths of 2.91∼4.73 m, the tests were performed from a barge. The riverbed soils consisted of clay, silty clay, silt and sandy silt. The impact velocities were 5.9∼11.7 m/s. The normalised tip embedment depths were even greater compared to those achieved from centrifuge tests in calcareous silt. Under operational monotonic loadings, the fish anchor dove, as opposed to pull out of the riverbed, for mooring angles ≤ 37∼47°. Interestingly, in contrast to non-diving torpedo and suction caisson anchors, the diving fish anchor resulted non-elliptical failure envelopes, which have been expressed mathematically. The ultimate capacity was 3.5∼15 times the weight of the anchor submerged in water for taught and catenary moorings.
Standardization and Carbon Footprint Reduction of Subsea Manifolds – Is Ready and Now!
Authors: Ali Mohammed Hasan , Galli Caterina , Freire Machado Jose Felipe , Martinelli Giordano
Published: March 2022

There has never been a more challenging time for the energy industry. In the subsea sector, the search for optimised costs, minimized carbon emissions, and maximized performance is set to intensify as oil prices continue their unpredictable trajectory.

At the same time, the risks to equipment, to people, to the local terrain and seascape will remain. What the industry needs in the face of all this is cost certainty and reduced CO2 output, derived not just from technical certainty but also execution certainty.

With these concerns front of mind, it is no surprise that research into the performance of subsea equipment and service suppliers published by [1] Kimberlite LLC in May 2020 showed some concern about the capability of suppliers" offerings to meet those future requirements.

45% of those surveyed said that more advances were needed in subsea trees, citing reliability, cost, lead times, and size as areas for improvement. In addition, subsea manifolds were separately cited by another 12%, as a technology area that could be advanced.

As part of the goal to achieve carbon net zero status, every single aspect of subsea operations is an opportunity to drive improvement. Through the work undertaken as described in this paper to drive standardization across the industry around the world, it can be shown that even equipment like manifolds – that come with some entrenched design and operational philosophies behind them – can deliver substantial improvements to the areas that matter most such as reduction of carbon footprint.
Effect of Silicon Carbide on the Surface Tension and Adsorption of SDS on the Sandstone Formation
Authors: Pandey Anurag Pandey , Roy Vishnu , Kesarwani Himanshu , Mittal Govind , Sharma Shivanjali , Saxena Amit
Published: March 2022

Oil recovery in modern fields is challenging due to the reservoir complexity and heterogeneity. The need is to improve the efficacy of additives used in oil mobilization under higher pressure, temperature, and salinity conditions. The nanoparticles provide improved and sustainable solutions for improving oil recovery. Silicon carbide nanoparticle exhibits negligible agglomeration and impart higher thermal stability to the displacing fluid for oil mobilization at higher salinity. The SIC nanoparticles are being used in EOR Applications for the first time owing to their adsorption reduction potential and thermal stability at elevated temperatures. The study estimates this nanoparticle's enhanced oil recovery potential using electrical conductivity, surface tension reduction, and crude oil mobilization. The concentration of SDS was varied from zero-4000 ppm and that of SIC from 100 ppm to 300 ppm. The solution's surface tension and critical micelle concentration (CMC) conductivity were measured at elevated temperatures (30°C, 50°C, and 70°C) with and without nanoparticles. The adsorption studies were performed for 72 hours with 10 wt% of sand added to the solution. The loss of surfactant onto the sand was calculated by studying the variation electrical conductivity before and after adsorption. Surface tension reduces from 70.15 to 28.5 mN/m with increasing SDS and nanoparticles concentrations in the solution. The CMC values of the SDS+SIC solution were lower than that of the independent surfactant system, even at higher temperatures of 70°C. SDS adsorption increased from 0.80 to 6.27 mg/g as the surfactant concentration increased up to 4000 ppm. It was reduced by about 10% and 20% for 100 ppm and 200 ppm of the nanoparticles. However, at 300 ppm, the agglomeration of nanoparticles renders them ineffective in controlling adsorption.
Sand Erosion Mitigation for Offshore Pipeline and Riser – Erosion Prediction by Computational Fluid Dynamic CFD Analysis and Experimental Testing
Authors: Putra I Wayan Eka , Chien Tan Chin , Badaruddin M Fauzi , Isa M Hilmi , Hou Cheong Xiang , Dongjie Liu , Dalin Sun
Published: March 2022

Late life production of oil & gas facilities are faced with significant challenge especially when sand is produced along with the production fluid. It can cause premature failure of the equipment, for example piping and pipeline. Mitigation by adding sand removal facility is limited by space, available load, and handling at satellite wellhead platform. It also introduced additional pressure drop which limit the production that already in low pressure. One of the measures to mitigate sand erosion issue for the offshore pipeline and riser is by flow assurance, to reduce the flow velocity so that the sand velocity will be less than the erosional velocity. This mitigation comes with drawback where reducing velocity will require bigger size pipeline, higher cost, and introduce higher liquid dropout along the pipeline which will create severe slugging issue in the pipeline. Next mitigation can be done by increasing bend radius along the pipeline, to reduce impact angle of the sand to the internal surface of the pipeline. Last mitigation will be increasing resistance of the material to the sand erosion. Combination of those methodology is required to achieve the most optimum solution to mitigate sand erosion. This paper present sand erosion mitigation on one of the existing pipeline replacement projects in PETRONAS by application of unbonded flexible pipe. Modeling of the of the erosion due to sand particle solution in the pipeline was done using computational fluid dynamic finite element analysis simulation. Experimental test with samples positioned at various orientation of the riser bend location were also investigated. Concerning the exceptional balance between results efficiency and simulation time, a grid sensitivity test has also been included. Various parameters were used to verify the sensitivity of the simulation including materials properties for various fluid composition data obtained from production forecast and fluid velocity as modeled in the pipeline steady state hydraulic analysis and transient flow assurance analysis. As result, the thickness of internal carcass is found sufficient to withstand the erosion threat generated by sand particles for the entire design life of the pipeline. The results obtained from finite element analysis and erosion experimental test were then correlated, and the comparison were illustrated in graph of velocity against erosion rate for each of sand concentration. The result of the modeling and experimental testing may improve prediction model of the sand erosion in the offshore pipeline especially for flexible pipeline and riser application.
Hybrid Pipeline Fit for Purpose for Multiphase Gas and Condensate Transportation
Authors: Mukhtar Nur Izyan , A Razak M Hasbi , Jamil Zurina
Published: March 2022

Corrosion and materials degradation factors during normal and abnormal operating conditions are among the essential criterion in evaluating materials suitability for an offshore pipeline transporting treated gas and condensate with contaminants i.e. CO2, Materials resistant to wet H2S damage in accordance with ISO 15156 requirements and mercury. A thorough study was conducted to ascertain the pipeline section that will be exposed to sour service conditions due to substantial Materials resistant to wet H2S damage in accordance with ISO 15156 requirements level along the pipeline during certain transient scenarios. The study was conducted in view of fit-for-purpose solution and CAPEX optimization initiatives for the project. During certain transient scenarios, there is potential exposure to substantial H2S level under wet conditions for a certain pipeline length which increases materials susceptibility to wet H2S damage such as Hydrogen Induced Cracking (HIC)/Stepwise Cracking (SWC) and Sulfide Stress Cracking (SSC). Flow assurance modeling with compositional tracking module was used to determine the level of H2S along the pipeline where few potential scenarios leading to sour conditions were considered. Risk assessments were also conducted to ascertain the impact and mitigations for the scenarios. Based on studies, exposure to sour service conditions is expected at a partial length of the pipeline as the H2S level exceeds the sour service limit during specific transient scenarios. Specific mitigation measures involving chemical injection, process control and safeguarding and operating procedures were outlined. The study successfully demonstrated an optimized materials selection approach for the pipeline.
Determining Long-Term Fate of a CO2 Sequestration Project Utilizing Rigorous Well Integrity Risk Assessment Strategy
Authors: Patil Parimal Arjun , Hamimi Asyraf M , Bakar M Azuan B Abu , Das Debasis Priyadarshan , Tiwari Pankaj Kumar , Chidambaram Prasanna , B A Jalil M Azran
Published: March 2022

Depleted hydrocarbon reservoirs are considered inherently safe for carbon sequestration, but high well density penetrating the CO2 storage reservoir could compromise the containment performance in a carbon, capture & sequestration (CCS) project. Based on the available well data, it is crucial to understand the age of the well, materials used for wellbore construction, cement quality, barriers performance, and well integrity. A risk management methodology can be incorporated to evaluate primary and secondary barriers in existing plugged and abandoned (P&A) and development wells to ensure long-term fate of CO2 sequestration project.

Existing P&A wells and development wells in a depleted field were drilled 3–5 decades ago. The wellbore construction utilized non-corrosive resistant materials. Health of all wells that ever penetrated the CO2 storage reservoir need to be analyzed from long term perspective of storing CO2. Throughout the lifespan of wells, subsurface barriers should maintain hydraulic isolation to prevent leakage happening from subsurface to environment of reservoir fluids and injected CO2. Deterioration of strength of wellbore construction material due to corrosion, induced by downhole pressure and temperature conditions, should be considered. This study investigated 3 exploration and 21 development wells. Risk register was developed for each well describing causes and CO2 leakage risks, impacts and consequences. Metrics were defined for parameters such as well age, well head materials, wellhead functional test and leak test, sustained casing pressures for risk determination. Wells were risk rated individually based on the assessment. Wells with low risk can be utilized for well conversion. While for high-risk wells, an opportunity risk matrix was developed to mitigate risks in all the wells.

This study evaluates the well integrity and CO2 leakage risk along the wells that penetrated the CO2 storage reservoir. The improved rigorous risk assessment exercise evaluates well barrier failure causes and impacts along with estimating the risk number per well. The well risk assessment score calculated was between 9.24 and 13.35 for 21 development wells. Out of these 21 wells, 4 wells with risk score <10 can be utilized for wells conversion. Specific barrier restoration process by additional scope of work such as lower completion removal including packer milling, intermediate casing removal, or installation of downhole permanent barriers with remedial cement is discussed for designing the well abandonment process to minimize leak potential of high-risk wells for ensuring long-term containment security.

Improved rigorous well integrity risk assessment for CO2 storage field is decisive for any CCS project economics that utilizes barrier identification process and remedial actions.
Reduction of Residual Oil in Oil-Wet Carbonate Formations by Application of Hybrid Smart Water/Silica Nanofluid Enhanced Oil Recovery Method
Authors: Mahmoudpour Maziar , Pourafshary Peyman , Moradi Babak , Rasaei Mohammad Reza , Hassani Kamran
Published: March 2022

Smart water flooding has recently been considered as an attractive EOR method due to its lack of expensive chemicals. Alterations in oil/brine/rock interactions in porous media, such as wettability by smart water, affects oil recovery. Different mechanisms, such as wettability alteration, changes in the viscosity, changes in the interfacial tension and control of small particle migration, make nanofluid injection an effective method. In this study, the injection of a combination of smart water and silica nanoparticles is investigated for EOR. Different characterization measurements, such as contact angle, interfacial tension, zeta potential, X-ray diffraction, viscosity and core flooding are performed to investigate the effect of the developed method on oil recovery and the mechanisms changing sweep efficiency. Our results show that the highest oil recovery is achieved by the injection of smart water with a high concentration of sulfate ions combined with silica nanoparticles with a concentration of 0.1 wt.%. The addition of silica nanoparticles to smart water improves the wettability alteration mechanism, as well as increasing the fluid viscosity and affecting the sweep efficiency. Therefore, the application of the developed hybrid method exhibits distinct advantages compared to stand-alone smart water flooding.
Research and Application of Comprehensive Adjustment Technology for Offshore Polymer Flooding Oilfield
Authors: Kang Xiaodong , Zhang Jian , Li Peng , Zeng Yang
Published: March 2022

During the implementation of polymer flooding, high injection pressure and water cut return occur in the later stage. The early polymer flooding in offshore oilfields is more sensitive to the change of injection and production rate, so it is necessary to explore a new early polymer injection development mode suitable for offshore oilfields. By considering the impact factors of early polymer flooding development in offshore oilfields, such as large well spacing, thick oil layer, early polymer injection timing, limited platform life and space, the "pan type" development mode of polymer flooding water cut in offshore oilfields is established based on experimental research and numerical simulation and achieved the polymer flooding overall infill, polymer/surface binary flooding, unstable polymer flooding technology which has been applied in 3 oilfields in Bohai bay, providing support for the polymer flooding technology development in offshore oil fields in China.
Corrosion Management of Wet Gas Sour Gas Carbon Steel Pipeline with Corrosion Inhibitor and Mono-Ethylene-Glycol in NACE Region 3
Authors: Leow Chun Ho , Ong Hock Guan , Lee Rachel , Khoo Cheng Ai
Published: March 2022

This paper will present corrosion management of a wet sour gas carbon steel export pipeline using continuous and batch corrosion inhibitors with mono-ethlene-glycol (MEG) as hydrate mitigation strategy in NACE MR 0175/ ISO 15156 region 3 (severe sour). The wet sour gas carbon steel export pipeline corrosion management via continuous CI and batch inhibitors with closed loop MEG regeneration system is rare worldwide. This is especially challenging when the case study may potentially be the longest wet sour gas, large diameter carbon steel pipeline (approximately 207km × 32 inch) in the world thus far. Pipeline corrosion management and hydrate management aspects when being reviewed holistically, it could provide significant cost savings yet safeguarding the overall technical integrity of the pipeline. The overall corrosion management leverages on Shell's many years of JIP and operating experience in sour service including the pipeline material specification, corrosion management, inspection, and maintenance philosophy. Reliable correlation between reservoir properties and uncertainties severe sour service, flow assurance, chemical behavirous, operating experiences etc were considered to best represent the operating envelope for this wet sour gas carbon steel pipeline. This includes the testing and selection of continuous CI and batch inhibitor, corrosion monitoring, operational pigging, maintenance, and inspection requirements throughout the field life.
Encapsulating Complex Carbonate Facie Heterogeneity into Static Reservoir Model through Seismic-Based Characterization, Lang-Lebah Field, Central Luconia, Offshore Sarawak
Authors: Suwannasri Krongrath , Yaw Peng Cheong , Asawachaisujja Sirada , Uttareun Ratchadaporn , Limpornpipat Orapan , Suphawajruksakul Apichart , Chongrueanglap Pongsit
Published: March 2022

Capturing the reservoir heterogeneity is crucial for optimizing field development. Lang-Lebah field is a Miocene carbonate platform with approximately 5 sq.km. in size and over 1 km in height with a high degree of heterogeneity in both vertical and horizontal directions. In this study, we conducted a seismic-based characterization to capture reservoir heterogeneity and then ran sequential gaussian simulation with a data from wells to build a static model for field development purpose.

The method mainly comprises of four steps. The first step is to establish a relationship between reservoir properties (such as facie and porosity) to elastic properties (such as P- and S-wave impedances) to build conditional probability. The second step is running pre-stack inversion to derive P- and S-wave impedances as inputs for the third step. The posterior probability of each facie is determined through Bayesian classification using inverted impedances and the derived conditional probability as inputs. The last step is employing sequential gaussian simulation to build a static model using derived posterior probability of each facie and porosity cube.

The static model encapsulates heterogeneity in terms of carbonate facie and reservoir properties. The observed heterogeneity is highly consistent with the understanding of geological model of this carbonate platform. The result shows lateral heterogeneity in each zone of high energy facies (such as reef margin) at the windward flank of the platform and low energy facies (such as lake) at platform interior. Thus, this result was elaborated for geological concept beyond the using well data alone. The result also shows a vertical succession from different carbonate reservoir deposit regarding to accommodation as carbonate build-out to a typical carbonate platform build-up continue to carbonate build-in. In addition, flooding event or surfaces, which is part of reservoir barrier, was also identified and included in this static model.

The details of this successful novel study lay a fundamental work process for battling the challenge of gigantic carbonate characterization for field development. Because of this sophisticated model, we can properly plan the sequence of production and producing well targeting based on the derived reservoir heterogeneity resulting in enabling several Tscf of reserves and minimizing development costs.