bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Lab-to-Field Approach and Evaluation of Low-Salinity Waterflooding Process for High-Temperature High-Pressure Carbonate Reservoirs
Authors: Sarma Hemanta Kumar , Singh Navpreet , Belhaj Ahmed Fatih , Jain Adarsh Kumar , Gopal Giridhar , Srivastava Vivek Raj 
Published: October 2022

Abstract
Low-salinity waterflooding (LSWF) process has gained great attention over the years as a promising enhanced oil recovery (EOR) method with its superior performance over high-salinity water waterflooding. This study presents a rigorous and systematic lab-to-field approach involving research, discovery and validation using experimental and simulation components. Impact of various ionic compositions on LSWF was determined including a fundamental understanding of water geochemistry and likely geochemical reactions. The roles of crude oil/brine/rock (COBR) interactions and resulting rock-surface charges were investigated as well. Both experimental and simulation components were treated as complementary to each other. Experimental components included: reservoir-condition high-pressure high-temperature (HPHT) displacement tests in composite cores using brines of different salinities and specially-designed ionic compositions; investigation of wettability alteration - presumably a key LSWF mechanism - in a unique and specifically-designed HPHT imbibition cell; Zeta potentiometric studies were conducted using a Zeta potentiometer capable of more representative evaluation in brine-saturated whole cores rather than with pulverized samples. Simulation involved: proposing likely geochemical reactions during LSWF; incorporating oil/brine/rock interactions, and then, simulation studies linking laboratory data to data from the candidate reservoir on complementary basis. The findings of the coreflooding experiments proved conclusively that LSWF with certain specific ionic composition yield a higher oil recovery. HPHT imbibition tests yielded both visual and quantitative estimations and monitoring of how the wettability alteration took place during LSWF and how it was impacted by the degree and magnitude of both temperature and pressure as the vivid variations in the contact angles were clearly captured. Using a whole reservoir core rather than pulverized samples, Zeta potentiometric studies enabled an investigation of the charging behavior at the rock-water interface at various salinities. A new method to estimate Zeta potential in high-salinity environment was developed and validated, and it conclusively proved that rock-surface charge played a vital, if not a more dominant role, in the LSWF process. The simulation studies included incorporation of experimental data generated during the study, identification of a set of likely geochemical reactions during the process and complementary field data to study the LSWF performance under various conditions and constraints. A conceptual "lab-to-field" approach that can contribute to designing a more efficient LSWF process with optimized ionic chemistry has been proposed based on results and analysis from this study.
New Approach for Reducing Investment Risk Through the Development of a Permeability Delineation Strategy in Coal Seam Gas Reservoirs
Authors: Caro Diana Olarte 
Published: October 2022

Abstract
The intrinsic heterogeneous nature of Coal Seam Gas (CSG) reservoirs can significantly diminish the expected return. This paper presents a new method to decrease inherent investment risk by delineating permeability and provides illustrative case studies. The approach identified riskier reservoir areas to effectively place delineation wells and optimise the number of fracture wells, all with an aim to reach economic gas rates with minimum expenditure and maximum value during development phases.
This work characterises high-mid-low permeability and coalbed gas saturation areas through a novel methodology that uses normalised production rates and net coal measurements. As a result, a comprehensive risk map is generated, from which new development locations near high-risk areas are proposed for permeability delineation. The data acquired from delineation defines which development wells need to be fractured to minimise risk. Additionally, the effect of dewatering on gas production is investigated, along with the impact of fractured wells on mitigating risk. The approach also incorporates a decision trees analysis to predict incremental value resulting from applying the new approach.
A reliable qualitative characterisation of permeability and coalbed gas saturation was obtained after using normalised production rates and net coal measurements in a particular CSG reservoir. Probabilistic distributions of actual production trends show a detrimental effect of low permeability in dewatering and, subsequently, gas recovery. This condition worsens as gas saturation decreases. The above findings are crucial to categorising risk and generating a risk map. An effective delineation well placement is determined based on the existing high-risk area's size and location. Overall, this methodology provides an effective placement of delineation and fracture wells to identify and mitigate risk, respectively. According to economic risk assessment in an illustrative case, the expected return is projected to increase by more than five times from implementing the new delineation approach.
This approach fits the current industry needs very well, as it is reliable, maximises return and can be easily integrated into the development strategy of any CSG reservoir. The novelty of the methodology relies on the qualitative identification of permeability and gas saturation to capture reservoir heterogeneity and categorise risk, all to optimise delineation and fractured wells placement. It can be applied to reservoirs where heterogeneity characterisation through traditional tools is not economically feasible.
Assessment of CO2 Emission and Reduction Technologies in Offshore Oil and Gas Fields
Authors: Mohd Pangi Syahirah , Md Yusof Muhammad Aslam 
Published: October 2022

Abstract
The offshore oil and gas industry is an energy-intensive process that contributes to one of the prominent carbon dioxide (CO2) emission sectors in Malaysia. The CO2 is obtained from the hydrocarbon (HC) flaring, HC venting, fuel gas and diesel combustion and CO2 venting. The pressing need to achieve net zero carbon emissions by 2050 goal, has encouraged the implementation of more energy-efficient and CO2 emission reduction solutions, of which four are assessed in this paper: (i) implementation of surge gas recovery, (ii) application of flare gas recovery, (iii) conversion of vent to flare, (iv) re-injection of CO2 for enhanced oil recovery. This paper provides a comprehensive assessment to evaluate the ongoing initiatives to reduce CO2 emissions from offshore oil and gas fields and address the pain points that need to be solved to ensure that the net zero carbon emission can be achieved in 2050. Data from 18 offshore fields in South China Sea is taken as the case study. This study started with the analysis of the overall CO2 emissions trend and narrowed it down to each type of emission and field to analyse the impact of the technologies implemented while modelling the efficacy of the solutions. Finally, the developed model was used to predict the possibility of the current approach to achieving the desired goal of net zero carbon emissions by 2050. Overall CO2 emission analysis highlighted that fuel combustion contributes the most with an average of 1.3 MMtCO2e per year which takes up 53% of the total emission followed by HC flaring and HC venting that takes up the remaining 24% and 23%, respectively. The results indicate the benefits of all the implemented technologies. The surge and flare gas recovery projects have started to reduce the emissions significantly since 2020 and will prohibit any CO2 release from flaring and venting in 2025 once the project is fully completed. Moreover, the vent to flare conversion technology gives a positive impact to the total flaring with a drastic reduction from 2024 onward where there will be only 6 fields that will continue to flare beyond 2035 but with low emissions. However, there is an urgent need for a cleaner technology to solve the continuous emissions by fuel gas combustion because it remains high even after 20 years of forecasting. This paper is the pioneer to address the impact of implemented CO2 reduction technologies in offshore oil and gas fields in the Southeast Asia region.
High Performance and Recyclability of WBM on the GWF-3 Project
Authors: Nasiri Zahed Masoud , Punler Alastair , Purkis Clare , Boase Aaron , Smillie Steven , Duff Mark , Park Fraser , Cobb James 
Published: October 2022

Abstract
The four well GWF-3 development project offshore Western Australia has used Water Based Mud (WBM) in the 12 ¼ in. section to drill through the same reactive clay formations which, on off-set wells, were historically drilled with Synthetic Based Mud (SBM).
The GWF-3 project well design was based on the learnings from the GWF-2 development project completed in 2017. The typical well design required a 36 in. conductor, 13 ⅝ in. casing, highly deviated 12 ¼ in. section through the Muderong shale interval and then completing the well in an 8 ½ in. hole section.
This paper describes the approach to the drilling fluids design and reviews the performance of the WBM on these wells, focusing on its salinity and recyclability.
As part of the change from SBM to WBM, a fundamental re-design of the Solids Control Equipment on board the drilling rig was also carried out. The SBM cuttings treatment system was removed from the rig, a Big Bowl Centrifuge was installed, and modifications were made to the surface flow lines. The installation of the Big Bowl Centrifuge was a waste minimisation initiative, and the surface flow line modifications were made to assist in the reduction of rig time spent on the displacement and re-conditioning of the drilling and completion fluids.
Swelling Mechanisms Assessment of Water-Based Drilling Mud by Polyvinyl Alcohol
Authors: Poungui Danielle , Sugai Yuichi , Sasaki Kyuro , Nguele Ronald 
Published: October 2022

Abstract
Swelling control is an elaborated balancing of solid-liquid ratios in the mud, influencing crucial physio-chemical features. Mechanical swelling control methods showing limitations drove recent researchers to consider chemical agents, including polyvinyl alcohol (PVOH). PVOH is known to have a swelling ability to improve mud rheology. The present study investigates the synergy of PVOH and Bentonite in an aqueous environment by analyzing the effluents samples. Three types of PVOH were selected: a standard PVOH and two modified PVOHs (a non-ionic group PVOH and a cationic group PVOH-3 attached to the carbon backbone. Except for the control sample (sample without polymer), PVOHs were added to different mud samples at ranging concentrations of 0.1 wt.% to 0.5 wt.%; each has a bulk volume of 400 ml. Each mud sample was filtrated at room temperature under an applied pressure of 1.28 MPa for 5 hours. The samples’ effluents were then analyzed for polymer adsorption. Preliminary filtration tests revealed further effluent production reduction with increased PVOH concentration. Compared to the control sample, samples containing standards PVOH-1, Non-ionic PVOH-2, and Cationic PVOH-3, respectively, had their mud cake mass increase of 48%, 36%, and 38%, while respectively having filtrate recovery reduction of 21%, 19%, and 43%. Adsorption tests showed mud swelling owes primarily to hydrogen bonding which is counteracted by the presence of a charged group. Mud swelling is, therefore, dependent on the rate of hydrogen bounding in a system.
Influence of Activators and Admixtures on Rheology of Geopolymer Slurries for Well Cementing Applications
Authors: Omran Mohamed , Khalifeh Mahmoud , Saasen Arild 
Published: October 2022

Abstract
Geopolymers are considered an alternative to Ordinary Portland Cement due to various reasons regarding some of its shortcomings and the high carbon dioxide footprint associated with its production. Superplasticizers are admixtures that plasticize and fluidize the cementitious slurry by means of steric electrostatic mechanisms that apply repulsion forces between the slurry particles. They are commonly used to improve the workability of cement and geopolymer pastes. However, the most developed superplasticizers are for Ordinary Portland cement. Electrokinetic potential measurements of the ingredients can be used in the evaluation of superplasticizers. Therefore, the effect of the utilization of two hardeners and the effect of the electro-kinetic potential of four admixtures, on the rheological properties of a rock-based geopolymer slurry are presented. These four admixtures are examined to investigate their applicability to being superplasticizers for conventional geopolymers. The results show that naphthalene-based admixtures could be considered effective superplasticizers for the rock-based geopolymer slurry. Although they reduce the slurry's yield stress and API gel strength by showing the highest absolute zeta potential value, the viscous behaviour of the geopolymer slurries showed an increase. Hence, electro-kinetic potential measurements could be used to evaluate the applicability and performance of the admixtures on the rheological properties of the geopolymer slurry.
Reliability Improvement of Auxiliary Boiler Feed Water Pump Caused by Vibration Issue and Capacity Oversized by Pump Upgrading Using Frequency Response Function Inspection Test Method Basis
Authors: Permadi Kemal , Firdauzi Athena Anatolia , Syamsuddin Syamsuar , Waluyo Sabdo 
Published: October 2022

Abstract
Two Auxiliary Boiler Feed Water Pump (ABFW) serve as a fluid supplier into the boiler to support the operation for steam system in Floating Storage and Offloading (FSO) Gagak Rimang. During FSO Gagak Rimang operation, steam system is produced through 2 unit boilers to run Cargo Oil Pump (COP) intermittently during lifting activity. In order to maximize boiler operation, the fluid has to be inside the envelope of design parameter specification. Therefore, the reliability of the ABFW pumps are very essential to ensure smooth and stable lifting operation.
Historically, the performance of this ABFW pump was degraded due to vibration issue and capacity oversized resulted from changing boiler operating mode.
This paper will explain how to improve pump reliability by solving the 2 factors mentioned above by redesigning the impeller which reduced pump vibrations and return the pump condition back into desired operating points.
Estimation of Rock Permeability Scores Using Machine Learning Methods
Authors: Qalandari Roohullah , Zhong Ruizhi , Salehi Cyrus , Chand Nathaniel , Johnson Raymond Leslie , Vazquez Gonzalo , Mclean-Hodgson Jack , Zimmerman Joel 
Published: October 2022

Abstract
Permeability is an important parameter that describes the flow characteristics of rocks (hydrocarbons in the oil and gas reservoirs or groundwater in aquifers). Currently, laboratory experiments using cored samples and well testing are the main methods to determine rock permeability. However, these methods are time-consuming and/or resource-intensive. This paper proposes a novel machine learning approach to predict permeability scores. Field drilling and wireline data are acquired from 80 wells in the Surat Basin, Australia. The permeability scores are based on petrophysical interpretations from wireline logs. Before applying machine learning modeling, some preprocessing steps are conducted, including the elimination of non-numerical values and outliers. In this study, artificial neural network (ANN) and extreme gradient boost (XGBoost) are used to predict the permeability scores. There are 7 permeability scores in the original data and additional groupings (3 or 4 permeability groups) are conducted. As the data is highly imbalanced (i.e., almost 90% of samples are labeled with permeability score 0), the undersampling technique and oversampling technique (SMOTE) are used to enhance the model performance. Finally, the confusion matrix is used as an evaluation metric to quantify the model performance of this multiclass classification task.
Results show that machine learning models have skewed performance (predicted permeability scores are lower than actual permeability scores) due to imbalanced data and have the best performance on the 0 permeability score samples (&gt;99% accuracy). The implementation of undersampling and oversampling techniques can balance the model performance and improve the performance on high permeability score samples. Among all simulations, XGBoost with undersampling technique can achieve over 80% accuracy for the 3 permeability classes. The proposed machine learning approach provides a fast and cost-effective way to estimate rock permeability. It can be used to identify high and low permeability zones (e.g., identification of sweet spots).
Drilling Riser Affecting Shallow Water Wellhead Fatigue
Authors: Lee Jia Hui , Lim Tze King , Young Laurence , Porter Mika 
Published: October 2022

Abstract
The use of a semi-submersible drilling vessel in relatively shallow water (&lt;100m) wells, can expose the wellhead, conductor and surface casing to significant wave-induced fatigue loading. A short length of drilling riser connecting the drilling vessel and the subsea well allows for a significant portion of the vessel and riser motions to be transferred directly to the wellhead and conductor system. Thus, screening of drilling vessel and drilling riser parameters that reduce the transfer of wave fatigue loading to the subsea stack is critical to ensure that the well has sufficient fatigue performance to accommodate expected drilling and completion operations, as well as provide margin for future workover and P&A operations. This paper provides the effects of drilling riser system parameters such as riser tension, BOP stack size and weight, riser joint hydrodynamics and flex-joint stiffness on fatigue accumulation. A parametric study is performed to determine the individual effect of each parameter mentioned above, on the fatigue performance of a shallow water well. Values considered from each parameter are selected based on drilling vessels that are available in the Australian region. The analysis is performed using irregular wave analysis with an industry standard riser analysis software. Based on wave fatigue analysis performed for the subsea wells, the riser telescopic joint hydrodynamic diameter and stiffness of the upper and lower flex-joints are identified to have significant effect on fatigue performance of the wellhead and conductor system in shallow water depth. This differs from wells in deeper water, where riser tension and BOP stack size and weight have a larger effect. Learnings from the parametric study will benefit future wells by allowing screening of acceptable drilling vessels and riser systems to be performed up front to ensure acceptable fatigue accumulation at the shallow water wells. In addition, it is envisaged this information can be fed back to drilling contractors to enable equipment configuration to be selected that is suitable for various water depths.
A Case Study of Design and Installation of Upper Completion System for a Deepwater Gas Field in South China Sea
Authors: Huang Yi , Meng Wen Bo , Jiang Dong Lei , Wang Xue Peng , Chen Hai Ning , Su Jian Bo , Ruescher Nigel , Xu Fei , Diao Huan , Wang Heng , Xiao Tan , Wang Ying Hao , Yu Yi 
Published: October 2022

Abstract
The urgent demand to replace the rapidly declining conventional reserves is driving China's operators to accelerate the development of deepwater reservoirs. SHENHAI Project is the first deepwater project operated by CNOOC China Ltd., locates in water of 1220m to 1546m in South China Sea.
Deepwater completions differentiate themselves not only by unique technical challenges, but also by their high cost, risk, and long project cycles. A sound project management process is essential to ensure flawless execution. By reviewing the key steps of the SHENHAI deepwater completion campaign, such as upper completion design, critical equipment selection, interface management, workshop preparation, and final project execution, lessons learnt, etc., this paper provides both a job cycle of completion design-to-execution and a methodology to manage a complex project by addressing the challenges inherent in the deepwater completion process.
As a result, the well completion campaign was completed ahead of schedule. A total of 11 deepwater wet-tree wells were successfully delivered as designed including two dual-zone hydraulic controlled intelligent wells. The upper completion design has been proven to be safe and reliable with first applications of several critical upper completion tools in the region, such as Nitrogen-Charged Surface Controlled Sub-surface Safety valve (SCSSV), Hydrostatic-Setting production packer and quartz-based permanent downhole pressure gauge.
This success demonstrates the completion design and practices are applicable for this deepwater project and can be extended to further offset deepwater projects in this area. This paper describes case details of successful upper completions of SHENHAI project aiming to provide information and experiences for engineers who may face the similar challenges.
Impact of Hydrogen Sulfide Scavenger Residuals on the Fluorescence Behaviour of OiW Discharges from Gas-Condensate Production
Authors: Lehmann Marc , Vamvounis George , Bloom Sarah , Prout Jake , Gordon-Wright Henry , Das Sambit 
Published: October 2022

Abstract
The oil-in-water (OiW) contaminants in produced water discharges arising from offshore oil and gas production systems are required by global regulatory bodies to be monitored in order to limit the environmental impacts of such releases. The level of these contaminants is commonly measured using online analyzers that utilize UV fluorescence to target the luminescent properties of OiW components.
It is known that the nature and variability of the fluorophores in the OiW fractions may influence the response of these type of analyzers. In particular these readings can also be affected by chemical residuals used in oil and gas treatment, that may also be present in the produced water. This study reports on the impact of the reaction products of a monoethanolamine based hydrogen sulfide scavenger, used in gas treatment to remove hydrogen sulfide (H2S), on the fluorescence behavior of OiW discharges, and its implications on the OiW reporting levels that may be expected from deep-UV and near-UV based analyzers.