bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Minerals in Drilling Fluids Using Synergy in X-Ray Fluorescence and Fourier Transform Infrared Spectra Realized with Machine Learning
Authors: Atheaux I. , Medvedev A. , Makarychev-Mikhailov S. 
Published: May 2024

Abstract
Analysis of solid contents in drilling muds is part of the API mud testing protocol performed daily by the mud engineer during drilling operations. This is carried out with the laborious manual retort analysis where high-gravity solids (HGS) and low-gravity solids (LGS) are detected. With the vision to improve the process and potential toward online measurement, monitoring of HGS and LGS in water-based mud (WBM) using two fast and reliable analytical techniques, X-ray fluorescence (XRF) spectrometry and Fourier transform infrared (FTIR)-attenuated total reflection (ATR) spectroscopy, have been evaluated. While information on total LGS content in a drilling fluid is useful, understanding the LGS minerology is also undoubtedly valuable, particularly when reactive clays are present and wellbore stability and integrity are at risk. In the present work we describe the dataset of XRF and FTIR-ATR spectra of a series of multicomponent water-based drilling fluids loaded with up to eight dispersed minerals. The minerals were barite (HGS) and LGS as clays (bentonite, illite, and kaolinite), carbonates (calcite and dolomite) and siliceous minerals (quartz and soda feldspar). Machine-learning (ML) analysis techniques such as partial least squares (PLS) and advanced modern PLS methods were applied to XRF and FTIR combined data to analyse these complex multicomponent samples.
In this paper, a detailed discussion of the data workflows will cover the spectra preprocessing, ML algorithm selection and results on individual spectra, concatenated data, and data fusion. While quantification of barite (HGS) in drilling fluids with either XRF or FTIR was straightforward (the coefficient of determination, R2, at ~0.99), analysis of some LGS was more challenging. For example, the best soda feldspar and calcite PLS models based on FTIR spectra showed poor performance (R2 ~0.75 and ~0.48, respectively). Interestingly, PLS models based on different combinations of concatenated spectra (joined side-by-side) demonstrated even worse results compared to the single spectra models. Extensions of the PLS method designed to deal with multiblock datasets were then explored, and the sequential and orthogonalized PLS (SO-PLS) was found to be the best, realizing the synergy between spectrum types. SO-PLS models for calcite and soda feldspar gave R2 of 0.97 and 0.77, respectively. Detailed error analysis for all minerals is finally presented in the paper, with prediction errors varied from 1% for barite to 11% for soda feldspar.
The two spectrum types, when smartly processed together using data fusion and ML techniques, demonstrate synergy, and provide significantly better mineral quantification accuracy, achieving a comprehensive minerology analysis of solids in drilling fluid.
Numerical Investigation on Energy Loss Characteristics in Irregular Annulus Based on Entropy Production Method
Authors: Zhou Y. S. , Qu C. F. , Jiang L. , Zhang H. W. , Zhang X.B. , Huang Z. , Li J. P. , Zhou C. Y. , Cheng S. D. , Li Y. 
Published: May 2024

Abstract
The actual downhole annulus is irregular, a variable cross-section geometry, due to the difference between the diameter of tool joints or downhole tools and the inner pipes. With the increasing of well depth, inevitable energy loss caused by contraction or expansion geometry is high in irregular annular flow. However, the energy loss generation mechanism for such irregular annulus flow is still unclear. The entropy production theory is considered as an excellent method for energy loss analysis, which is widely used in fluid machinery flow field.
Therefore, the main purpose in this work is to reveal the energy loss generation mechanism caused by contraction and expansion geometry in irregular annulus based on entropy production method. In this paper, the spatial distribution of entropy production rate in irregular annular flow was depicted first. Then the inlet velocity and contraction-expansion ratio influence on different entropy production were discussed. Finally, we identified the high entropy production area and its main energy loss sources by quantitative analysis.
The results show that 1) The high entropy production was mainly occurred at the entrance, downstream of the variable cross-section structure and near the wall. The proportion of time-average entropy production rate was relatively small and can be ignored. 2) The main energy loss areas were in narrow annulus and downstream of the variable cross-section structure, which the entropy production portion was about 55.8%~62.0% and 23.4%~26.4% separately. The main energy loss were wall and turbulent entropy production in these two areas. 3) The energy loss generated in downstream of the variable cross-section in annulus was more than that in upstream.
Study of Surface Complexation Modeling on Low Salinity Polymer Flooding in High-Temperature High-Salinity Carbonate Reservoirs
Authors: Hassan Anas M. , Sebastian Anoo , Al-Shalabi Emad W. , Kamal Muhammad S. , Patil Shirish 
Published: May 2024

Abstract
The low salinity polymer (LSP) injection is a hybrid enhanced oil recovery (EOR) technique, which synergistically enhances the displacement and sweep efficiencies through compounding the advantages of low-salinity water (LSW) and polymer floodings (PF). While an appropriate LSP-flooding field-scale design typically requires a predictive mechanistic model for capturing the polymer-brine-rock (PBR) interactions, few studies have focused on this issue till date. Therefore, the present study investigates the impact of water chemistry on polymer behavior in porous media using a surface complexation model (SCM), with the purpose of refining our understanding of the PBR-system. In particular, this work examines the effect of salinity and hardness on polymer viscosity and adsorption in dolomite formations during LSP-injection with the use of our in-house developed coupled MRST-IPHREEQC simulator. Hence, to comprehensively capture the geochemistry of the LSP process, the coupled MRST-IPHREEQC simulator included the chemical reactions, such as aqueous, mineral dissolution and/or precipitation, along with the surface complexation reactions.
The findings of this study showed polymer viscosity losses of 82% and 63% for the 10-times spiked salinity (6230 ppm) and 10-times spiked hardness (110 ppm) cases, respectively. Thus, the base case low-salinity (LS) brine of 623 ppm was more effective in reducing the risk of polymer viscosity loss for the dolomite model (i.e., viscosity loss of 55%). The polymer viscosity losses calculated for the various potential determining ions (PDIs) concentrations of 10-times spiked Mg2+ (40 ppm) and 2-times spiked SO42- (156 ppm) were 61%, and 46%, respectively. Moreover, investigating the impact of salinity on polymer adsorption revealed that dynamic polymer adsorption increased from 53 μg/g-rock to 68 mg/g-rock and 64 mg/g-rock, when the salinity and hardness were increased from the base case (623 ppm) to 10-times spiked salinity and 10-times spiked hardness cases, respectively. Furthermore, the analysis showed that the 10-times spiked magnesium case exhibited higher polymer adsorption (87 μg/g-rock) compared to the 2-times spiked sulfate case (64 mg/g-rock), which is related to the formation of Mg-polymer surface complexes as a result of surface complexation processes between polymer molecules and magnesium surface species at the surface of dolomite rock. Overall, the surface complexation model has demonstrated that during LSP-injection, the stability of the water-film is enhanced, suggesting a significant alteration in wettability towards a more water-wetting state. This wettability alteration plays a crucial role in increasing oil production. Consequently, our findings underscore the effectiveness of LSP-flooding in enhancing oil recovery processes by modifying the wettability of the reservoir rock surfaces, leading to a more efficient displacement of oil.
A Method for Predicting Formation Pore Pressure in Carbonate Rocks
Authors: Tao Zhenyu , Liu Yuhan , Ye Yuguang , Fan Honghai , Sun Lewang , Shang Heya , Wang Lihao 
Published: May 2024

Abstract
Formation pore pressure refers to the pressure of the pore and the fluid in it, which is an important parameter in drilling engineering, related to well depth structure design, drilling fluid preparation, and casing matching. Accurately predicting formation pore pressure helps to reduce drilling accidents and achieve safe drilling. Due to the complexity of the causes of abnormal pressure in carbonate rock formations, it is difficult to predict the formation pore pressure. Taking Block M in Qaidam Basin of Qinghai Oilfield in China as an example, this paper proposes a prediction method for formation pore pressure in carbonate rock formations based on analyzing the causes of abnormal pressure. Firstly, based on core analysis and well-log interpretation, this paper analyzes the causes of abnormal pressure in Block M; According to the causes of abnormal pressure, the Fan comprehensive interpretation method is selected as the calculation method for the formation pore pressure. The model is modified based on well-log data and experimental data, and the BP neural network is used to correct the prediction error. Based on this model, the formation pore pressure of two wells is predicted. Compared with the measured points, the error is less than 5%, which meets the engineering requirements.
Pore-Scale Modeling of Hydrogen-Brine Relative Permeability in Underground Hydrogen Storage
Authors: Dorhjie D. B. , Cheremisin A. 
Published: May 2024

Abstract
Hydrogen is poised to become one of the most promising alternative clean sources of energy for climate change mitigation. The development of a sustainable hydrogen economy depends on the global implementation of safe and economically feasible intersessional hydrogen storage and recovery. However, the current body of literature lacks comprehensive numerical characterization of the multiphase flow of hydrogen-brine and how geological parameters at the pore scale influence the multiphase flow. This study presents a pore network simulation of hydrogen-brine and cushion gas-brine relative permeabilities. Initially, the generated pore network model was validated against the characteristics of the core sample, such as porosity, permeability, and pore size distribution. In addition, the model was adapted to replicate the results of the drainage capillary pressure curves and relative permeability curves observed in the laboratory experiment. Furthermore, a sensitivity analysis was conducted to quantify the effects of fluid and rock properties on the relative permeabilities of the fluids. The results indicate that the capillary pressure and the relative permeability of the hydrogen and brine are sensitive to the distribution of the surface contact angle. The relative permeability of hydrogen phase decreases as the frequency of pores with stronger water-wet contact angle values increases. The relative permeability endpoint (residual saturation) was also significantly influenced by pore and throat shape, pore and throat size distribution, and pore connectivity. Simulations of different cushion gases revealed that the relative permeabilities of CH4 and N2 are similar to hydrogen. This research offers a comprehensive pore-scale prediction of the relative permeability of hydrogen and brine systems and presents the parameters and cushion gases to consider in the selection of geological storage sites for hydrogen storage.
Application of NMR Relaxometry in Petrophysical Properties Determination and Pore Structure Characterization for Clastic and Carbonate Rocks
Authors: Samokhvalov N. , Kovalenko K. , Skibitskaya N. , Ponomarenko O. , Zaripova L. , Muminov A. 
Published: May 2024

Abstract
This paper discusses the use of Nuclear Magnetic Resonance (NMR) relaxometry to effectively determine the porosity and irreducible water saturation of rocks. The rapidity, efficiency and lack of influence on the core sample integrity actualizes the development of methodological approaches for experiment procedures and interpretation of measurement results in order to increase the information content of the method [24].
The paper presents the results of NMR investigation of clastic and carbonate rocks at full water saturation, irreducible water saturation and residual gas saturation, trapped during spontaneous imbibition. The first section of the paper presents possibility of NMR to evaluate separated distribution of pores and throats by size, which provides characterization of pore space structure of the reservoir and distribution of fluids by different types and the degree of bonding with rock surface. The second section presents results of suggested "subtractive distributions" of transverse relaxation time (T2) for characterizing various elements of the pore space and obtaining their distributions according to the volume ratio. The third section presents technique for determination of the irreducible water saturation and gas saturation trapped during spontaneous imbibition based on the T2 cutoffs. And fourth section presents review and consideration regarding possibilities and limitations of the NMR method in determination throat size distributions and capillary pressure curves modeling. In the conclusion the future research directions from current conducted researches have been suggested. The matters concerned in this research provides an insight into mechanism of fluid displacement through the drainage and spontaneous imbibition processes. Suggested techniques of investigations and data interpretation intended to improve understanding of rock pore space structure and reservoir properties.
Upstream Data Project Portfolio Benchmarking as a Novel Approach for Strategy and Value Realization
Authors: Mohd Nasir Amir Ikhwan Haniff , Chan W. 
Published: May 2024

Abstract
PETRONAS Upstream has been executing multiple data projects each year with different level of complexity and risk comprising of a myriad of project categories such as data delivery, stranded data recovery, system development and data governance. The imperative requirement in delivering the projects to ensure business success and continuity calls for a strategic decision to produce and design a methodology to benchmark the projects for a comprehensive data portfolio management, which is crucial for maximizing the value of data projects to the organization. This paper outlines a novel approach on how Upstream Data innovate a portfolio benchmarking process to quantitatively assess the complexity of the projects by utilizing a modified Diamond Framework Model referred to as the Pentagon Model with the following objectives in mind: Improve resource planning and allocation efficiencyConduct a thorough project risk assessment and value realizationAnalyze project benefits and assess possible business impactIdentify appropriate project management approaches and styles
Implementation of Machine Learning Approach in Pore Size Evaluation Workflows for Carbonate Reservoirs
Authors: Alward W. , Al-Jubouri M. 
Published: May 2024

AbstractThe petrophysical evaluation of carbonate reservoirs presents a significant challenge due to complex diagenetic processes that alter reservoir properties. Advanced log measurements, such as NMR T2 relaxation time and borehole images, are often necessary to evaluate the carbonate pore systems (micro, meso, and macro pores), and permeability and infer the impact of diagenesis on reservoir properties. The absence of these measurements may lead to inappropriate estimation of reserves and inadequate development strategies. To address this challenge, we propose a novel interpretation method that utilizes machine learning algorithms to perform carbonate porosity partitioning (micro, meso, and macro) using standard log measurements (e.g., resistivity, density, neutron, sonic, and gamma-ray). We trained the machine learning model in key wells with NMR and/or borehole images to establish relationships between standard logs and carbonate pore partitions. Subsequently, we applied the model to other wells to predict the target pore volumes. Standard ML model workflow (data cleaning, feature engineering, train/split, hyperparameter tuning) was followed. We present a comprehensive workflow for accurate evaluation and characterization of carbonate reservoirs where NMR measurements are not available. We successfully applied this workflow to datasets from heterogeneous carbonate reservoirs in South Iraq to obtain reliable carbonate pore partitions. These pore volumes were then used to estimate permeability and variable cementation exponent to improve water saturation and perform carbonate rock typing. Our proposed methodology provides a reliable and efficient approach (if applied with domain knowledge and reservoir considerations) for the petrophysical evaluation of inter- and intragranular, vuggy carbonate reservoirs, particularly in cases where advanced log measurements are not available, overcoming challenges with the traditional interpretation methods in such complex reservoirs.
Phased Installation of Fixed Offshore Wellhead Platforms for Drilling and Production in Shallow Water Risky Marginal Fields with Moderate Environment
Authors: Chatterjee Prabir Kumar 
Published: May 2024

AbstractThis paper proposes a minimum structure to drill and appraise four oil/gas wells without installing a structural jacket. A structural template with conductor guides will be installed on seabed. The well conductors may be driven into the seabed by a hammer fitted to the jack-up rig-based crane. The conductors will support a small, prefabricated two-level deck (9m × 12m). The template is supported by customized mudmats to withstand the environmental loads without piled foundation. In case of a positive drilling outcome, a riser and a pipeline will be added to connect with the nearest subsea/onshore tie-in point to carry out well testing by flowing the wells. Based on the outcome of a prolonged well testing, installation of the remaining facilities will be undertaken. In Phase-2, a structural jacket will join the template and piles will be driven through the legs. The deck of the second phase will have internal opening to clear the existing topside (installed in Phase-1) during installation. The existing and the new decks will be joined at offshore. The platform has a provision for two future wells.Numerical studies show that the Phase-1 structure can withstand omnidirectional environmental forces due to 10.4m high waves and Phase-2 structure can withstand 15.4m waves at 35m water depth. Structural design is performed using API RP2A working stress design method. The results show adequacy of the structure with required minimum reserve strength and prove that large amount of initial CAPEX can be avoided by carrying out well appraisal before installing full production facilities.
Preparation and Mechanism Study of Ternary Resin-Nano Silica Copolymer Lost Circulation Additive for Oil-Based Drilling Fluid
Authors: Dai Liyao , Sun Jinsheng , Lv Kaihe , Bai Yingrui , Li Mei-Chun 
Published: May 2024

AbstractDue to the development of shale bedding and micro-fractures, it is very easy to induce complex downhole accidents such as leakage during the drilling of horizontal Wells, and the leakage of oil-based drilling fluid is serious, resulting in great economic losses. Aiming at the problems of poor compatibility and insufficient temperature resistance between chemical plugging materials and oil-based drilling fluids. In this paper, butyl acrylate, octadecyl methacrylate and sodium p-styrene sulfonate were selected as the copolymer, dibenzoyl peroxide as the initiator, divinylbenzene as the crosslinking agent, nano-silica as the toughening agent, and water as the dispersed phase. A ternary resin-nano silica copolymer lost circulation additive was prepared by suspension polymerization. The results showed that the molecular structure test of the resin lost circulation additive indicated that the unsaturated groups were grafted and the interpenetrating three-dimensional mesh structure was formed, with oil-absorbing and swelling properties at high temperatures and good mating properties. Under the condition of 140 ℃, the sealing experiment was carried out on the sand plate with a pore size of 1 mm, and the pressure capacity was up to 10.6 MPa. The particles compact and seal the leaking strata by deformation compaction and filling action. Compared with conventional plugging materials, resin lost circulation additive has good thermal stability and self-adaptability, easy to enter the pore space, micro-fracture, oil-based drilling fluid loss is effectively reduced.
Agnostic Tooling: A Modular Approach to Producing Fields Tooling Needs
Authors: Bouillouta F. , Narozanski M. , Yuill L. , Silva A. 
Published: May 2024

Abstract
The aim of this abstract is to demonstrate an innovative methodology used to maximize tools adaptability reducing risk exposure and cost with an attractive lead time. Furthermore, it will highlight the past project successes and lessons learned. A key challenge within life of field operations is securing tooling sets across different well types from various original equipment manufacturer (OEM), a timely and costly process. Recognizing that despite different OEMs, there are common mating features for tooling to interface with, the "Swiss Army Knife" of agnostic tools targets an operator’s total requirement with the minimum number of tools needed. This innovative approach to tooling uses a modular design, whereby tooling can be adapted to multiple well types and the functionality targeted to specific operational requirements.
The methodology presented reduces the quantity of tools required, improves capability, and lowers CO2 emissions. By design, the agnostic tools are not limited by the original OEM specifications as they can be simplified and modularized resulting in an efficient and economically beneficial process. For example, one area of simplification is to use a standardized guiding and landing of the intervention tooling on the subsea equipment.
In addition, given the operational challenges when planning offshore campaigns on multiple wells, working with just one supplier of the intervention tooling package, allows for more flexibility in case re-prioritizations or re-scheduling shall be required. One key area of success for this approach is in support of decommissioning offshore oil and gas infrastructure which will hit an average of US$15 billion a year to peak in 2035 and is the subject of increasing regulation to comply with end-of-life plug-and-abandonment. A recent case study for a multi-OEM well P&A campaign in Brazil benefited greatly from this approach; the modular design reducing the total number of tools from 62 to 23 within a 12-month lead-time.
The novelty in agnostic tooling is the modular approach to tooling from different OEMs subsea equipment, reducing the total number of tools needed via tooling standardization and therefore the overall campaign cost with a single point of contact.