bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Ultra-High Temperature New Microemulsion Technology for Deep Drilling Wells: Lab Study
Authors: Al-Saqer Qassem , Alabdulmohsen Zainab , Anioke Chidiebere , Al Qunis Mohamed 
Published: February 2024

Abstract
Formation damage caused by reservoir drill-in fluids or completion fluids could be minimize by microemulsion fluid system in an average reservoir temperature. However, in deep drilling wells the formation temperature can reach up to 380 °F, which requires a new design that can tolerate this level of temperature with minimum formation damage.
This paper presents an engineering approach on overcoming the formation damage in ultra-high temperature reservoirs. The new microemulsion fluid design contains a low organic acid concertation, and a surfactant blend that can stand for high temperature formation. The surfactant blend has a high capability of removing the filter cake residues and water wets all solids surfaces. Extensive laboratory work conducted to demonstrate this approach by studying the properties of the new fluid design on both drill in fluids and oil-based muds with high and low gravity solids through filter cake removal efficiency test and multi – stage back flow test.
For both fluids type, drill in fluid and oil-based mud with high and low gravity solids, results showed more than 60% filter cake removal efficiency and 83% improvement in return to flow value for OBM with high gravity solids and more the 90% filter cake removal efficiency and 96% improvement in return to flow value for drill in fluid when using the new surfactant in comparison with current used surfactant. The organic acid in the microemulsion blend removes the formation bridging solids, while the high gravity solids are dispersed and mobilized when circulated. This blend shows a high capability of removing the filter cake residues and water-wetting solid surfaces, which leads to reduce the near wellbore damage and increase well productivity in both oil and gas production formation.
The new microemulsion solution has an ultra-low interfacial tension property that helps with the diffusion of the project into the rock matrix and lead to solubilizing the oil in the filter cake emulsion while converting the solids and surfaces in a water-wet state.
Innovative Method to Predict H2S Concentration from Advanced Mud Logs
Authors: Qubaisi Enter: Khalid , Meridji Yacine , Rubaie Naif , AlAkeely Abdullah 
Published: February 2024

Abstract
Hydrogen Sulfide (H2S) presents a hazardous environment while drilling. Measuring H2S concentration real-time while drilling will provide early indication and allows the operator to the necessary safety precautions at the rig site and ensures proper execution of rig operations. There were several attempts in the oil and gas industry to estimate hydrogen sulfide, yet there's no proven methodology to accurately measure H2S concentration real-time while drilling. Mud Logging services, also known as surface data logging can be utilized to predict H2S concentration while drilling. Although Mud Logging does not actually measure H2S directly, some of the actual measurements can be used as proxies to predict H2S concentration.
Common practice is to acquire PVT samples and/or perform Drill Stem Test (DST) to quantify fluid properties and have an accurate measurement of H2S volume. Our innovative methodology that will be discussed further revolves around building a predictive model that can estimate H2S concentrations prior to sample acquisition to ensure proper and safer sampling or testing procedure. The model is trained on few wells where DST tests were performed and an actual H2S concentration is known, then the model is deployed on few blind tests to investigate model validity and accuracy. Several iterations were made to select the best inputs from Advanced Mud Logging (AML) logs to best predict H2S % in the reservoir rocks. Furthermore; multiple regression methods were tested to achieve optimum modeling. The CNN (Conventional Neural Networks) model delivered the lowest RMSE (Root Mean Square Error), therefore was identified as best modeling technique.
Several inputs from AML logs were selected to build the predictive model: Methane, Total Normalized Gas, Volume of Calcite, Volume of Dolomite and CO2 (Carbon Dioxide). The model indicated that there was a very strong correlation between AML outputs and H2S concentration with Normalized total gas showing the highest correlation followed by C1 gas (Methane). Interpreting potential in-situ H2S can lead to taking the necessary precautions at the rig site. Using advanced mud logging can not only identify zones of interest but can also act as an early warning system for potential drilling hazards. Workflows are placed to identify these potential H2S accumulations that can pose a risk to operations, downhole tools, and forward testing procedures can be planned accordingly.
Emphasis of High Order Stratigraphic Sequences Enabled by the Relative Geological Time Modelling Method: Application to Fractured Thin Reservoirs in a Pre-Salt Gas Field, Offshore Netherlands
Authors: Daynac N. 
Published: February 2024

Summary
The author describes the method and results of a global and automated approach for seismic interpretation (Pauget et al, 2009), applied to a pre-salt gas field of the Dutch Cleaver Bank High platform, offshore Netherlands. A sequence stratigraphic framework called ‘Relative Geological Time (RGT) model’ is built from the seismic data to emphasize structural and stratigraphic features. Basin and reservoir characterizations are thus enabled by RGT-derived advanced attributes, rock physics modelling, Wheeler diagrams and sub-sample stratal slicing. Several fault networks related to different tectonic phases are emphasized, key stratigraphic surfaces are delineated, and major facies trends of the pre-salt reservoir level are discriminated. Those outputs are finally used to assess the impact of fault networks and subsequent subsidence on the eustasy-controlled thin beds succession. The author ultimately demonstrates the potential of the global RGT modelling method to revise hydrocarbon fields and identify pre-salt siliciclastic carbon storage sites.
Rock Physics Modeling and Iterative Petrophysics Driven Inversion Results: Estimating Subsurface Petrophysical Properties and Characterizing Reservoirs - A Real-Time Case Study of Clastic Gas Field in Pakistan
Authors: Azeem Adil , Hameed Ali , Ali Virk M. Muneeb , Awan Faheem Razzaq , Mathur Akash , Abid M. Faraz 
Published: February 2024

Abstract
Rock physics modeling (RPM) using iterative petrophysics is a vital tool in the oil and gas industry for predicting subsurface properties and characterizing reservoirs. This technique has revolutionized the way in which analysis and interpretation of seismic inversion data has been performed and provided better understanding of the subsurface geology. The main scope of this work was to highlight the importance of using RPM logs data as opposed to using directly recorded and linear regression based corrected logs for seismic inversion input.
The approach that was followed for this study started with building a consistent RPM based upon the iterative petrophysics. The results of RPM data were compared with recorded and multi-linear regression (MLR) data-set. The main quality check for the health of the well log data was set to see which data will provide a closer correlation to the original seismic amplitude versus offset (AVO) response. Using well to seismic tie of RPM and recorded well logs data, the well based wavelets were extracted and compared. Moreover, the pre-stack inversion was performed with the optimized parameters. Furthermore, consistent well based probability density functions (PDFs) for two different facies were generated and implemented on the inversion results. Finally, the results were quality assured on the blind wells.
It was concluded that, the well based elastic logs response were improved dramatically using RPM and iterative petrophysics approach. The modeled AVO response (intercept and gradient) of the RPM based data was much closer to the original conditioned seismic data as compared to data from Multi-linear regression (MLR) and original recorded logs data. RPM data provided a far better well to seismic tie, an average cross-correlation improvement from 50 to 70%, resulting in a consistent well based wavelet. In addition, this led to improved PDFs and implementing them to the pre-stack inversion results. Furthermore, the correlation of the predicted litho-facies at the blind wells were consistent with the encountered petrophysical properties.
This study highlights the importance of RPM and iterative petrophysics as a vital tool for oil and gas industry. Current study not only highlights their importance but also highlights importance of effective reservoir characterization with enhanced seismic data interpretation, robust well-ties and accurate porosity and litho-facies away from wells. These insights not only have a huge impact on reservoir monitoring and management but also crucial for strategic decision in the industry.
A Study in Ultra-Thin Cement Sheath Evaluation
Authors: Li B. , Olaiya J. , Garcia M. , Kamgang S. 
Published: February 2024

Abstract
Reliable evaluation of the cement-bonding and identification of isolation zones of a cased-hole well are challenging problems. The CBL tool can provide a cement map for identifying cement top and cement channels of a well. Ultrasonic tools have been developed and deployed to conduct pitch-catch and/or pulse-echo measurements for cement evaluation at high spatial resolutions. However, there are limitations in tools based on pitch-catch or pulse-echo measurements, particularly for ultra-thin cement sheath.
This paper presents a systematically study of effects on responses of sonic and ultrasonic cement evaluation tools caused by cement sheath thickness and propose a workflow for the reliable evaluation of ultra-thin cement sheath. To quantify limitations of these types of cement evaluation tools, a systematically study has been conducted to evaluate effects caused by casing annulus spacing on tool responses. The test fixtures with varied annulus spacings were designed, constructed, and cemented. Multiple tests were designed and conducted to verify the annulus spacing effects on amplitudes of arrival wave peaks, the inverted acoustic impedance of casing annulus, attenuation rates of waveforms and quantify the annulus spacing size limits that cause the failures of tools. The tests results confirmed the attenuation rates of shear horizontal wave measurements will not be influenced by casing annulus if it is greater than 0.4 inch. The cement sheath must be greater than 0.75 inch if a CBL tool is utilized. For the first time, different types of cement evaluation tools are evaluated on the same test fixtures. This experimental study provides a guideline for selecting tools to conduct cement evaluation.
Development of Powder and Fiber Temporary Plugging Agent System to Improve Fracture Complexity in Slickwater Fracturing
Authors: Cao D. , Kalgaonkar R. , Huang T. , Baqader N. 
Published: February 2024

Abstract
Increasing fracture complexity by temporary plugging agent (TPA) in slickwater fracturing is getting great attention due to the huge difference with conventional fracturing. A powder and fiber TPA system was developed for narrow and long fractures in slickwater fracturing. Additives were optimized to improve the performances in both near wellbore and far field applications for unconventional reservoir developments. Three different powder and fiber systems with similar size were evaluated. For all the three systems, blocking efficiencies increased with injection flow rates. Weight ratio of 4:1 between powder and fiber showed much higher blocking efficiency than that with less fiber component. Samples S1 and S2 showed better performances than sample S3. The dispersibility of powders and fibers in slickwater was found critical to its plugging performance by a cross-sample test. Accordingly, two additives were developed to adjust the dispersibility of TPAs for improved performances. One additive improved migration ability of TPA system at high flow rate and plugging ability at low flow rate, which helped the TPAs flow through high flow rate near wellbore region to plug fractures in deep position. The other one was developed for near wellbore applications with enhanced plugging performance at both high and low flow rate regions. This work provides some insights of powder and fiber types TPAs to increase stimulated reservoir volumes for unconventional reservoir developments.
High-Resolution Characterization of Carbonate Source Reservoir Heterogeneity for Enhanced Production Optimization
Authors: Von Gonten W. D. , Ali S. , Ali M. , Eichman S. , Gupta A. , Kias E. M. C. , Mesdour R. , Al-Bassam M. , Degenhardt J. , Cordes M. , Suarez-Rivera R. 
Published: February 2024

Abstract
Carbonate source rock reservoirs often exhibit pronounced lamination, resulting in fine-scale facies and rock property variations that are not adequately captured by open hole logs. Precise characterization of reservoir heterogeneity across multiple scales is essential for accurate hydraulic fracture design, landing zone optimization, and ultimately enhancing well productivity. This paper presents a comprehensive workflow that utilizes specialized core-logging equipment to precisely define the thinly layered nature of the cored section, enabling centimeter-scale resolution analysis of vertical heterogeneity. The acquired data allow us to define distinct rock classes with unique and characteristics behaviors, based on multi-dimensional data patterns that mirror their unique and characteristic behaviors in rock properties. The rock classification facilitates the quantitative definition of vertical heterogeneity, capturing the fine-scale property variations within the core section. It also informs the selection of core samples for laboratory rock property characterization, ensuring that the representation of the observed variability is maximized. By integrating the multidimensional core-logging data with the discrete laboratory rock property results, we construct centimeter-resolution petrophysical and geomechanical models that result in higher fidelity reservoir characterization of thinly layered carbonate source reservoirs and more representative numerical simulations, thereby enhancing our ability to optimize hydraulic fracturing and well productivity. The workflow also includes upscaling the resolution of downhole wireline log measurements, utilizing image log measurements as structural constraints to the process, thereby enabling the derivation of high-resolution petrophysical and geomechanical properties in non-cored sections of the same well and in neighboring wells without core data. The study revealed cyclic reservoir and mechanical property variability, particularly in intervals with higher organic content, which were critical for understanding productivity, evaluating the in-situ stress, and for hydraulic fracture modeling. This level of detail in reservoir characterization is not achievable when using conventional resolution wireline logs.
A Novel Approach for Carbon Capture & Sequestration Pilot Study in the Western Desert of Egypt
Authors: Eleoni M. , Dredge J. , De Boer Y. , Mansour K. , Ismail A. , ElSayed R. , Merghany I. , Ellamey C. , Agam A. , Taqey A. , Gomes R. , Stojic S. , Nasiri A. , Bouchet F. , Nasreldin G. 
Published: February 2024

Abstract
Egypt, as the host for the previous UN COP27 in 2022, has committed to emissions reductions in support of limiting global warming. Carbon capture and storage (CCS) offers the potential to significantly reduce point source CO2 emissions in the country. Accordingly, the Egyptian operator BAPETCO, along with partners Cheiron and Capricorn, is exploring the potential for carbon capture and storage to sequester more than 350,000 metric tons of CO2 per annum.at two fields in Egypt’s Western Desert. Storage candidates comprise 20 stacked geological formations starting from Apolonia till Lower Safa, The objective of this paper is to present the novel methodology implemented to screen technically feasible and economically advantageous subsurface storage sites.
The applied approach is divided into three phases.1. The first phase is site screening, ranking, and selection to identify the best possible sites for CO2 storage. Through detailed geological characterization and modeling of all potential reservoirs within the two fields, specific sites are selected and ranked based on a scientific scorecard that is developed based on extensive experimental simulations worldwide.2. The sites with the highest rank pass to phase 2, the feasibility study. In this phase, selected reservoirs are reviewed in detail to quantify the reservoir capacity, optimize injection scenarios, confirm the required well count, and propose injection points. The study will forecast the evolution of the CO2 plume over time, by modeling the injected supercritical CO2 plume movement within the formations while honoring advanced trapping mechanisms such as CO2 trapping due to residual trapping, dissolution in saline water, and mineralization. Then, dynamic reservoir simulation models are fully coupled to 3D geomechanics models to study the impact of the injection on the well integrity, cap rock integrity as well as fault reactivation and integrity.3. Once the subsurface sites successfully pass the feasibility study, risk assessment, and mitigation, phase 3 is implemented to propose reasonable and economical surface facility configuration and pipelining scenarios that fit the subsurface sites’ requirements in terms of the number of wells and distance between them, depth of injection, required wellhead pressure, and proximity from CO2 source of emission.
the followed scientific approach resulted in concluding four feasible sites in the two fields to be deployed for a long-term and safe sequestration of more than 350,000 metric tons of CO2 per annum.
In this case study, we present the details of this integrated approach to account for the complex surface and subsurface nature of the western desert of Egypt during other CCS studies in similar environments.
Future Development Path of China's Fossil Energy under the Background of Carbon Peak and Carbon Neutrality
Authors: Jing Yu , Bo Zhou , Bing Li , Pingliang Fang , Hongyuan Zhang , Hongchun Huang , Changchang Chen 
Published: February 2024

Abstract
This research focuses on two main lines: national energy supply and demand security under the goals of carbon peak and carbon neutrality, as well as national energy green and low-carbon development. The research conducts quantitative prediction on the total demand and energy structure of national fossil energy under low-carbon transformation goals, providing reference for the country to implement green and low-carbon energy transformation and build a new energy system. Based on the national energy security and carbon peak and carbon neutrality strategic objectives, this study uses grey relational analysis to conduct multi-factor analysis and innovatively builds a fossil energy development potential prediction model under the "dual carbon" goal constraints. Three scenarios of robust-sustainable transformation, active-CCUS technology breakthrough, and radical-renewable energy technology breakthrough are designed to analyze the energy development paths under different scenarios, outlining the national energy development path and defining the quantitative targets for the fossil energy development phase. Through multiple model calculations, it is found that in the three scenarios, China's primary energy consumption will peak around 2030, with a peak value of approximately 5.99-6.01 billion tons of standard coal. The total energy consumption demand will slowly decline from 2030 to 2040, and maintain basic stability from 2040 to 2060. In the three scenarios of robust, positive and radical, China's energy consumption in 2030 is respectively 6.01, 5.99 and 6.01 billion tons of standard coal, of which non-fossil energy accounts for 24.9%, 27.0% and 28.3% respectively. By 2060, China's energy consumption will be approximately 5.63, 5.8, and 5.87 billion tons of standard coal, with non-fossil energy accounting for 73.6%, 80.0%, and 85.2% respectively. In response to the challenges facing the adjustment of the national energy supply and demand structure, this research has proposed corresponding development strategies from the three aspects of policy system, industrial layout, and technological innovation. The research results of this project have strong forward-looking, strategic and guiding significance, providing a theoretical basis for the country's energy transformation and development under the background of carbon peak and carbon neutrality, with significant comprehensive benefits.
Predicting Mud Weight Window from Well Logs by Integrating Deep Neural Networks and Physics Models
Authors: Phan Dung T. , Liu Chao , AlTammar Murtadha J. , Abousleiman Younane N. 
Published: February 2024

Abstract
The selection of an appropriate mud weight is important in drilling operations, as it plays a pivotal role in mitigating the potential for costly wellbore instability issues. The safe mud weight window is typically computed through analytical solutions that necessitate detailed rock properties as integral inputs. Conventionally, these rock properties are estimated based on well logs through empirical correlations. This paper introduces a wellbore stability analysis workflow that makes two changes to the conventional methodology. First, microporomechanics models are used to upscale the nano and micro properties of the mineral constituents to the macro rock properties. Unlike the correlation methods, this scientific approach can explain the origin of the rock properties. To help get the mineral composition data, a deep neural network (DNN) is trained on 15,979 data points to predict the volume fractions of silt inclusions, clay, and kerogen from gamma ray, resistivity, density, neutron porosity, and photoelectric logs. Second, another DNN is used in the workflow to speed-up the analytical solution for mud weight window computation. This DNN is trained to predict the mud weight window from in-situ stresses, pore pressure, well trajectory, and the rock properties. Its prediction is used as the starting point in the analytical wellbore stability solution to quickly determine the correct mud weight window. To demonstrate the practical application of this workflow, evaluations were conducted using a 480-foot shale well segment comprising 961 depth intervals. The results show that the hybrid approach can calculate 961 mud weight windows 5 times faster than the purely analytical solution.