bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acquiring Real-Time Data in Under Balanced Coiled Tubing Drilling for Geosteering: The Current Success and Factors Limiting Physics Boundaries
Authors: Ibrahim Mohd Azizi , Enezi Faisal Naif , Alnasser Fatimah Mohammed 
Published: February 2024

Abstract
The objective of this article is to share the current success of real-time logging while drilling (LWD) data acquisition in under balanced coiled tubing drilling (UBCTD) that enables petrophysical evaluation and precise depth control in identifying layers targeted for geosteering a well. In addition, the paper will generally discuss the trial results of technologies tested in UBCTD operations, the success and limiting factors. A future outlook to acquire more advanced logging technology to assist a precise geosteering are discussed later as challenges for further development in UBCTD
The method of tool testing procedure and analysis of the acquired data addressed the then current tools potential and, in some cases, directed the research towards the improvements required before the tool is operationally viable for further testing. The tools trials were conducted in multiple environments from controlled to simulation of the actual UBCTD conditions. In most of the cases, an ideal environment was created to acquire the desired data in order to prove the viability of the concept. The data acquired from the trial runs are treated carefully to avoid missing information and overlooking of the hidden potentials. UBCTD conditions challenged the current LWD tool physics especially for porosity measurements due to a couple of factors, such as the borehole size and the multiphase condition of fluids used in the process.
With the aim of assisting geosteering in complex environments, multiple conceptual tools were tested in UBCTD in attempt to acquire LWD data. The tested LWD tools are GR, Acoustic and Resistivity where the trial was simulated in a real coiled tubing drilling environment. Such tools consist of a set of devices dedicated to obtain certain measurements, these are developed for Gas/Water velocity measurement; electrical/resistant probes for water holdup and optical probes for gas holdup; and pulsed neutron. The aforementioned tools were tested in controlled environments to prove the concepts. There were mixed results indicating that there are real challenges associated with developing LWD for UBCTD
The value of sharing these trial tests is to ensure the concepts and practicality for developing a logging tool are captured before proceeding to tools manufacturing. Some concepts are mere theories therefore require further enhancements to be viable before the actual LWD tools were built. Sharing such information could help the industry to focus on certain critical aspects in developing super slim LWD tool in the ever-growing UBCTD operation in future.
Diagenesis of Platform Carbonates Flanking the Tazoult Salt Wall (High Atlas, Morocco)
Authors: Travé A. , Chaves A. , Moragas M. , Baqués V. , Martín-Martín J. D. , Saura E. , Cofrade G. , Cruset D. , Munoz-Lopez D. , Cantarero I. , Playà E. , Carola E. , Vergés J. 
Published: February 2024

Abstract
The Central High Atlas of Morocco is a double verging major diapiric province encompassing SW-NE trending salt-related ridges and Lower to Middle Jurassic deposits over synclines (minibasins) in between them. Typically, Pliensbachian and Bajocian platform carbonates flanking diapirs exhibit partial dolomitization in the vicinity of the diapir wall. The interpretation of the diagenetic products and diagenetic evolution of these dolomitized carbonates may be complex due to different fracture patterns, brecciation, fluid pathways, heterogeneities, localized uplift associated with diapiric activity, among others. The present work focuses on the dolomitization affecting Late Aalenian-Bajocian platform carbonates flanking the Tazoult salt wall, localized in the center of the Central High Atlas. Analytical work includes standard microscopy, cathodoluminescence and 𝛅13C–𝛅18O isotopic analyses. A paragenetic sequence is discussed to reconstruct the diagenetic evolution of the flanking platform carbonates. The results highlight the major influence of diapirism and igneous intrusions on the fluid circulation. Moreover, the present work complements a previous work related to the Liassic successions flanking the Tazoult salt wall.
Designing Matrix Acidizing Treatments with Particulate Diverters—Part I: Model and Predictions
Authors: Tardy Philippe M. J. , Ziauddin Murtaza , Vidma Konstantin , Khan Abdul Muqtadir 
Published: February 2024

Abstract
While particulates are often used in the field to optimize reservoir coverage by diverting the injected treatment fluids into lower injectivity zones, the optimal job design may be difficult to reach without the proper models. In our study, we detail models for particulates transport, bridging, plugging, diversion and degradation, which are the tools required to provide reservoir and completion specific design guidelines for various scenarios. Each model is built using dedicated experimental procedures. Experimental data are presented together with their correlations.
The efficiency of particulate fluids depends on multiple factors including the magnitude of the injectivity contrast present in the reservoir, how much flow resistance may be achieved by accumulating particulate filter cakes in perforations and how quickly the accumulation can start. The onset of diversion requires perforation plugging and, potentially before that, perforation bridging. The onset of bridging depends on parameters such as particulate loading, rate through perforations, and size of perforations and of particulates. Once the cake forms, diversion may start depending on the permeability of the cake, the permeability of the zone connected to the plugged perforation, and the perforation type. Particulate and cake degradation rate is also an important aspect to consider. This paper elaborates on the models relevant to quantify diversion efficiency of particulate-based fluids in the field. The paper also provides new and useful insights on the important factors that should be considered during the design phase.
Testing the Robustness of Quadruped Robots for Unmanned Inspection Activities in the Energy Industry
Authors: Pencelli Manuel , Bonacchi Luigi Bono , Fiorucci Marta , Schillaci Guido , Youssef Ali , Politano Andrea , Bettini Alessandro , Porciani Daniele , Salusti Lorenzo , Cioncolini Stefano , De Magistris Giovanni 
Published: February 2024

Abstract
The energy industry is witnessing a growing interest in adopting robotic technologies for unmanned operations, such as asset inspection. Robots performing inspection tasks are safer, cost-effective and can help minimize risks, especially when assets are in extreme environments. Although different studies highlight the positive impact that the adoption of robots may have in the energy industry, there is little evidence of the robustness of such tools during operation. This is mostly due to the limited access for the scientific community to operational sites and corporate data, and to the limited availability of robust robotic platforms certified to - and thus allowed to - operate under specific conditions. This study aims at filling this literature gap by testing one of the few robot platforms available in the market that are well-suited for the energy industry, as they can be released with an ATEX certification (ATmospheres Explosibles) for operation in environments with explosive atmospheres.
This paper tests the robustness of a quadruped robot in autonomous inspection activities on a mineral lube oil console used to lubricate gas turbines and available at the Baker Hughes site in Florence (Italy). A qualitative analysis of robot performances in critical tasks for mission accomplishment - such as locomotion, step climbing, visual inspection, recharge, and docking - has been conducted and discussed.
Innovative Non-Conventional LCM Solution for Total Losses across Fractured Formations
Authors: Olivares Tulio , Al-Zahrani Walid , Al-Dossary Fahad 
Published: February 2024

Abstract
Curing total losses of drilling fluids in fractured formations is one of the most challenging fluid loss scenarios to control. Loss zones are unpredictable due to large vugular zones, extended and connected fracture structures formations. However, based on proper evaluation of the offset wells data, losses events can be anticipated to customize a Lost Circulation Material (LCM) solution. Non-Conventional LCM solutions typically are used to go beyond and be more aggressive, aiming to cure the losses, reduce non-productive time and resume programmed operations. We worked to locally develop an Innovative Non-Conventional LCM solution, which involves pill trains combinations to cure the losses across fractured formations. After successful lab testing verification, those formulations were implemented at the field with satisfactory results.
Well A was identified with total losses across fractured formation. Previously lab tested Non-Conventional LCM solution was recommended. At Well A location, the first pill was made with blend of organic polymers with super absorbent materials, specifically designed to impart viscosity and swell as it fills the fractures. producing a viscous slurry designed to flow into downhole loss zones, where it will swell and seal large fractures providing a base for the second pill pumped to rapidly de-water, leaving behind a drillable plug. The second pill pumped consisted on a blend of sealants which form a stable, high solids, high fluid loss LCM slurry. Upon contact with a thief zone, this second pill will rapidly de-water, leaving behind a drillable plug-in fracture, voids and vugular spaces across the loss zone. A soft squeeze was hold for several hours. The resulted plug was easy drilled through without the danger of unintentional sidetracking. As conclusion, we were able to customize an Innovative Non-Conventional LCM solution to regain the circulation on well A, allowing them to continue with the programmed operations and eliminating non-productive time in this well.
This paper discusses how this innovative customized Non-Conventional LCM Solution was designed, lab and field tested with successful results curing total losses scenarios across fractured formations, resulting in considerable non-productive time mitigation while drilling across losses zones.
Automated Estimation of Mechanical Specific Energy as a Tool for Stratigraphic Interpretation During Real-Time Drilling Operations
Authors: Peña-Gutiérrez John , Sabirov Airat 
Published: February 2024

Summary
Limitations in volume and quality of geological and geophysical data result in challenges for lithostratigraphic interpretation in shallow sections of many development wells. Correct interpretation of key formation tops is critical for the recognition of casing points and for the early identification of geological units that imply drilling hazards. This study describes how Mechanical Specific Energy (MSE) curves can be used as a complementary tool for lithostratigraphic interpretation where petrophysical logs and rock descriptions are not available, particularly in shallow well sections. This work shows that MSE delivers high resolution curves that represent changes in drilling conditions and mechanical rock properties (often associated with lithostratigraphic markers). Lastly, this MSE driven lithostratigraphic interpretation method was successfully employed in a highly variable and complex stratigraphic succession of clastic, carbonate and evaporitic sedimentary rock succession.
Development and Application of an Annular Electronically-Controlled Packer
Authors: Yang Qinghai , Hou Ze , Jia Weite , Qu Jingxue , Wu JiLei , Wu Xi 
Published: February 2024

Abstract
Electric control packers have the characteristics of simple and fast setting and unlocking processes, and are commonly used for short-term testing operations that require reservoir sealing. At present, electrically controlled packers are generally driven by electric hydraulic pressure, which has disadvantages such as complex structure, low reliability, and no large diameter liquid passage, and cannot meet the needs of rapid underground operations. This article proposes and develops a fully electrically controlled annular packer, which is driven by an annular motor with a driving torque of 8N. m. After being amplified by a reducer, the driving force of the rubber cylinder can reach 6KN. The packer has a 25mm center liquid passage, which can meet the needs of high-flow liquid flow; In order to improve reliability and avoid downhole accidents that cannot be unsealed, the innovative design of four protection mechanisms, including magnetic coupling torque transmission, rubber cylinder stroke position monitoring and limit protection, motor driven current limit protection, and forced unsealing structure, has greatly improved the reliability of the packer. This packer has been successfully applied in the stratified sampling and testing operations of PetroChina Jilin Oilfield, achieving rapid sealing of underground reservoirs. The packer adopts a modular design concept and has the ability to pass through cables. It can be combined with other electronic control tools to meet the layered sealing requirements of other layered process measures and has good application prospects.
Intelligent Optimization of Drilling Parameters Based on Multiple Drilling Agents
Authors: Pei Zhijun , Song Xianzhi , Hu Zhijian , Pan Tao 
Published: February 2024

Abstract
Drilling parameter optimization is one of the important ways to improve drilling efficiency and reduce drilling cost. Multi objective intelligent optimization technology has the characteristics of comprehensive consideration of factors and fast solution speed, and is suitable for drilling parameter optimization scenarios. Based on the drilling data of a vertical well in Tarim Oilfield, the rate of penetration (ROP) prediction agent, pipe string friction calculation agent and bottom hole cleanliness agent are established by using artificial intelligence or mechanism methods. Based on non-dominated sorting genetic algorithm II(NSGA-II), several established drilling agents are combined, and intelligent optimization model of drilling parameters is established. The evaluation function of the drilling scheme is set up to select the optimal drilling parameter optimization scheme from numerous Pareto solutions under the condition of ensuring operation safety, and the scheme is applied and verified in this well for Kangcun Formation and Jidik Formation with low ROP. According to the optimization results of drilling parameters, under the condition of ensuring the bottom hole cleaning and normal drilling, compared with the previous drilling plan, the ROP of Kangcun formation is increased from 3.43m/h to 7.72m/h; The ROP of Jidik formation is increased from 4.76m/h to 8.84m/h. The ROP of the two formations has been increased by 125.1% and 85.7% respectively, which can shorten the drilling cycle and reduce the drilling cost to a certain extent.
Case Study of Appraisal Well to Unlock STOIIP in High Pressure, High H2S Environment
Authors: Mahrooqi Alkhattab , Siyabi Rashid , Hinai Nasser , Balushi Hamid , Hadhrami Abdullah 
Published: February 2024

Abstract
This case study demonstrates the value of appraisal well in high pressure/ H2S stringers in the south of Oman. The appraisal objective is to narrow down the high uncertainty in ODT, Structure and reservoir properties to unlock the full STOIIP of the field. A comprehensive and integrated evaluation of different data, such as production data, pressure data and high uncertainties triggered the need to appraise the field. Planning and execution of appraisal well was associated with many challenges and risks. However, the integration between different disciplines led to a safe delivery of the well. The results of the new appraisal well unlocked 7% STOIIP that confirmed the MBAL STOIIP scenario of having higher volumes. The outcome of the appraisal well opened an area for adding two extra oil producers. Additionally, the appraisal results triggered the need of reprocessing the seismic data to reduce structural uncertainty and hence better estimating the in-place volume.
At-The-Bit Look-Around 3D Inversion; Key Milestone Achieved with Innovative Close to the Bit Ultra-Deep Azimuthal Resistivity Sensors
Authors: Elkhamry A. , Maimani A. Al , Fouda M. , Taher A. 
Published: February 2024

Abstract
Efficient well placement profoundly depends on early geo-steering decisions to maximize reservoir contact. In highly undulated thin target zones, this can be more concerning as the formation dip changes abruptly. Such environments present a significant challenge where geo-mapping instruments are placed farther behind the bit in the bottom hole assembly, leading to relatively late decision making and more aggressive well path corrections. This paper presents the advantages of placing geo-mapping tools close to the drilling bit position leading to enhanced reservoir contact (Net-to-Gross) and less tortuous well bores.
Deep and ultra-deep azimuthal resistivity measurements have historically provided a step change for proactive geo-steering, yet the challenge has always been the proximity of the sensors to the bit opposed to other less sophisticated near bit sensors. Well placement with conventional configurations have been regularly utilized to ensure maximum reservoir exposure with varying results due to unforeseen geo-structural changes such as the formation dipping regime (1D environment), lateral boundaries (2D environment) or channels (3D environment). A new tool design was introduced in which the ultra-deep resistivity transmitter was embedded into the rotary steerable system allowing 1D and 3D inversions to be closest to the bit position, offering at-the-bit visualization of the reservoir, hence, earlier, and less aggressive well path corrections could be made to optimize well placement and increase reservoir contact. Geo-mapping formation boundaries while drilling high angle sections with a near bit ultra-deep azimuthal resistivity inversion minimized potential reservoir exits while also minimizing wellbore tortuosity. This is critical for efficient well placement, minimizing drilling risks and smooth completions deployment. Horizontal wells were placed in thin reservoir targets that are successfully resolved by integrating 1D and 3D inversions to improve reservoir mapping, remote lithology and fluid identification to optimize well placement and reservoir evaluation. The accuracy of reservoir visualization from the near-bit resistivity inversion has been validated by other logging while drilling measurements in the drill string, such as triple combo and azimuthal images from several sensors.
This paper presents the global first at-the-bit look-around inversion utilizing an ultra-deep resistivity sensor embedded in a rotary steerable system for horizontal well placement in two target sand packages. The proximity of the ultra-deep sensor to the bit enabled quicker decisions to optimally place the well in the target zone while reducing well tortuosity leading to a higher net-to-gross and a smoother well trajectory. This also facilitated the deployment of the completion equipment saving costly rig time.
Continuous Bottomhole Pressure Estimation Using Machine Learning and Physics-Based Methods – A Field Case Study
Authors: Zalavadia H. , Sabharwal V. , Sankaran S. 
Published: February 2024

Abstract
Bottomhole pressure (BHP) has been increasingly integrated into modern workflows in characterizing subsurface reservoir, evaluating well production performance, and optimizing artificial lift designs for unconventional reservoirs. The increasing need for agile asset development planning demands robust and continuous well performance evaluation, for which bottomhole pressure lays the foundation. However, there are several challenges that most of the unconventional operators are facing. It is uneconomical to install permanent downhole pressure gauges and have continuous measurement throughout the entire life span on all wells across the entire asset. A practical approach is to estimate BHP from wellhead pressure by using physics-based multi-phase flow correlations. However, since various multi-phase flow correlations were developed with limited field datasets and assumptions only applicable for certain flow conditions, these empirical or mechanistic models are not generalized to fully characterize the fluid flow behaviors that are applicable for various flow patterns without constant manual selection and tuning. Finally, there is a need for robust estimation of BHP with various changing wellbore configurations under different artificial lift designs and types through the life of the well.
In this work, we propose a hybrid methodology integrating physics-based and machine learning models to provide BHP with high accuracy. Five different candidate multi-phase flow correlations were selected for physics-based models to estimate BHP from routine daily production data and consider any change of artificial lift designs and types. With the availability of some downhole pressure gauges to calibrate BHP estimates, we propose to improve BHP estimation in two major steps – first, selecting the best physics correlation for each producing day based on dynamic criteria using a classification method and second, improving the physics-based BHP estimate using a physics-informed machine learning (PIML) approach.
The machine learning models were trained based on historical downhole gauge pressure data and validated with data hold-out in history and data measured. The results of model performance showed that this hybrid pre-trained model can be leveraged as a ‘virtual downhole gauge’ to continuously provide high-accuracy BHP estimation in a robust and consistent manner in the absence of physical downhole gauges.
In this paper, we present a field case study to demonstrate the deployment and usage of continuous BHP estimation integrating physics-based and machine learning models. This framework has been successfully deployed for one of the largest U.S. unconventional shale basins with over 3000 producing wells. By leveraging this hybrid methodology, high-accuracy and continuous BHP estimates can be provided at field or asset level to streamline well performance analytics workflows for unconventional reservoirs and facilitate better asset development decision-making.