bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep Chandra Observations of A2495: A Possible Sloshing-regulated Feedback Cycle in a Triple-offset Galaxy Cluster
Authors: Rosignoli L. , Ubertosi F. , Gitti M. , Brighenti F. , Pasini T. , O’Sullivan E. , Gastaldello F. , Gaspari M. , Temi P. 
Published: February 2024

Abstract
We present the analysis of new, deep Chandra observations (130 ks) of the galaxy cluster A2495. This object is known for the presence of a triple offset between the peaks of the intracluster medium (ICM), the brightest cluster galaxy (BCG), and the warm gas glowing in Hα line. The new Chandra data confirm that the X-ray emission peak is located at a distance of ∼6.2 kpc from the BCG, and at ∼3.9 kpc from the Hα emission peak. Moreover, we identify two generations of X-ray cavities in the ICM, likely inflated by the central radio galaxy activity. Through a detailed morphological and spectral analysis, we determine that the power of the active galactic nucleus (AGN) outbursts (P
cav = 4.7 ± 1.3 × 1043 erg s−1) is enough to counterbalance the radiative losses from ICM cooling (L
cool = 5.7 ± 0.1 × 1043 erg s−1). This indicates that, despite a fragmented cooling core, A2495 still harbors an effective feedback cycle. We argue that the offsets are most likely caused by sloshing of the ICM, supported by the presence of spiral structures and a probable cold front in the gas at ∼58 kpc east of the center. Ultimately, we find that the outburst interval between the two generations of X-ray cavities is of the order of the dynamical sloshing timescale, as already hinted from the previous Chandra snapshot. We thus speculate that sloshing may be able to regulate the timescales of AGN feedback in A2495, by periodically fueling the central AGN.
Red Asymmetry of H
α
Line Profiles during the Flares on the Active RS CVn-type Star II Pegasi
Authors: Cao Dongtao , Gu Shenghong 
Published: February 2024

Abstract
Stellar coronal mass ejections (CMEs) have recently attracted much attention for their impacts on stellar evolution and surrounding exoplanets. RS CVn-type stars could produce large flares, and therefore may have frequent CMEs. Here we report the capture of a possible CME or chromospheric condensation on the RS CVn-type star II Pegasi (II Peg) using high-resolution spectroscopic observation. Two flares were detected during the observation, and the low limits of the flare energies are of the order of 1033 erg and 1034 erg, respectively. Using mean spectrum subtraction, the H
α
residual shows red asymmetry during the flares, and the redshifted broad emission components are probably caused by chromospheric condensation or coronal rain. Moreover, a far redshifted extra emission component with a high bulk velocity of 429 km s−1 was observed during the second flare and is probably due to a prominence eruption. The velocity greatly exceeds the star’s escape velocity, which means that this eruption can develop into a CME. The CME mass is estimated to be 0.83–1.48 × 1020 g, which is slightly larger than the value expected from solar flare-CME extrapolation. The kinetic energy of CME, derived to be 0.76–1.15 × 1035 erg, is less than the kinetic energy extrapolated from solar events. Additionally, we could not completely rule out the possibility of chromospheric condensation resulting in the far redshifted extra emission. Finally, there is a blueshifted broad component in the subtracted H
α
profile derived using synthesized spectral subtraction when no flare happened, and its behavior is associated with the H
α
activity features.
La répartie : place et enjeux dans les Discours des misères de ce temps de Pierre de Ronsard
Authors: Ndong Sangoul 
Published: February 2024

Dans sa Responce aux injures et calomnies des predicans et ministres de Geneve sur son Discours et Continuation des misères de ce temps (1563), Ronsard promet de ne rien cacher de sa vie lorsqu’il entame sa réponse à Bernard de Montméja sur quelques points le concernant. Le mensonge devient ainsi non envisageable dans la Responce. Il est repoussé avec force. Mais faut-il croire tout ce que Ronsard dit dans sa polémique contre les protestants ? Les formules d’attestation ne relèvent-elles pas dans sa Responce d’un artifice rhétorique ? Faut-il aussi voir les huguenots tels que Ronsard tente de les faire voir ? C’est autour de ces interrogations que s’articule cette étude sur la répartie dans les Discours des misères de ce temps.
A Comprehensive Testing Program of Flexible Pipe Armor Wire Against CO2 and H2S Towards Excellent Flexible Pipe Integrity Management System
Authors: Aziz Mohd Faisal B , Razak Siti Aishah Ali Noor , Karim Khairul Anuar , Hussien Hayati 
Published: February 2024

Abstract
This paper explains PETRONAS’ effort to establish partial pressure limits of CO2 and H2S and SN-curve of flexible armor wire through a comprehensive testing program. This is following an incident in 2020 where PETRONAS suffered more than RM 500mill of production losses alone excluding the cost to remove and replace with new flexible riser to resume production. By stablishing these limits, it assists the operator to plan necessary procedure to deal with elevated CO2 and H2S during operation, hence avoiding future recurrence of incidents.
Application of Autonomous Outflow Control Devices to Optimise Three Simultaneous Operations in Monobore Wells, Case Study of Offshore China
Authors: Xiong S. , Cheng J. , Ren F. , Moradi M. 
Published: February 2024

AbstractIn a recent intervention campaign, improved field recovery was targeted by CNOOC through redesign of completions of several wells at Offshore China. This was to maximise the production and injection capacity of each platform with limited available wells per platform. Therefore, a new completion design was suggested that could accommodate performing three operations using one single completion wellbore simultaneously. The new completion comprises a system that allows oil production from the deepest reservoir (operation 1) while the string is used to produce water from the shallowest reservoir (operation 2) and re-inject the water down to the deeper reservoirs without bringing water up to the surface (operation 3).However, the control of fluid influx and outflux for each section of the wells was key to the success of the campaign especially since the reservoir management plan requires maintaining prescribed injection profiles. Focusing on injection operation and considering the risks associated with reservoir uncertainty and the likelihood of development of thief zones, it was recognised that the challenges could be mitigated by deploying autonomous outflow control devices (AOCDs). The device allows the flow of a certain amount of fluid toward the reservoir while autonomously closing after reaching a designed flowrate.As mentioned above, the wells usually pass through a water-bearing zone vertically where the water would be produced and pumped down to be injected into a middle reservoir. This middle reservoir section normally comprises a few separate sub-layers. This section of the wells was then divided into several completion zones separated by swellpackers with an appropriate number of AOCD installed on the screens in each zone. An integrated workflow was followed to deliver successfully the AOCD application for these complex wellbores. The workflow comprised performance evaluation of the basecase completions and sensitivity analyses to determine the best AOCD completions for the wells.The performance of one of the wells equipped with AOCD completion shows the devices have managed to achieve the prescribed outflow injection profile to these sub-layers supporting the nearby wells based on the reservoir management plan.This study demonstrates the possibility of maximizing the net value of each well drilled using new technologies. The AOCD completion enabled the operator to implement an optimum reservoir drainage strategy that uses downhole control which autonomously control the flow based on well dynamic conditions.
Optimising the CO2 Storage Potential in Deep Saline Aquifer by Creating Pressure Sink
Authors: Razali Nur Myra Rahayu , Khanifar Ahmad , Das Debasis P , Yakup M Hamzi , Majidaie Saeed 
Published: February 2024

Abstract
Malaysia has pledged to reduce the intensity of Green House Gas (GHG) emission by 45% based on Gross Production Product (GDP) in 2030 and ultimately net-zero carbon emission in 2050 during UNFCCC-COP 26 in Scotland. However, the growing energy demands need some of the high contaminant (CO2) natural gas fields in the region to be developed. To mitigate the negative climatic impact of such developments and manage the huge quantities of produced CO2, Carbon Capture and Storage (CCS) is the only viable technology in the current world. In this paper, a multidisciplinary subsurface study is conducted to unlock the potential containment for CO2 storage and estimate the effective volume in deep saline aquifer.
A fit for purpose 3D geological model was built for K reservoir in Z field. A range of porosity was tabulated from well log data and permeability was estimated from available poro-perm cross plot. Then, a compositional dynamic model with appropriate CO2 storage features is established using CMG-GEM simulator. The initial formation pressure and temperature were estimated from available well tests, and PVT and SCAL data are considered from an analogue field. The base case model was initialized, and several scenarios were run to estimate the optimum effective CO2 storage capacity for injection period of 25 years.
The CO2 gas injection started on the January 2025 with 60 MMscf/d injection rate and maximum water withdrawal was set at 30 kbbl/d. The prediction ran until 2050. An effective CO2 storage capacity for non-voidage case is estimated at 4.9 Bscf for a commingled injector with no producer case. This contributed only 3% of the theoretical storage capacity that can be sequestered due to high pressure build-up in the reservoir. For voidage case, one injector and one producer (commingled) case predicted to effectively sequestered 80.13 Bscf, which is approximately 51% of the total theoretical storage capacity. The simulation was further optimized with two injector and one producer (commingled) case where a total of 95.44 Bscf gas is predicted to be sequestered in the reservoir. This contributed to the highest effective CO2 storage volume, approximately at 61% of the total theoretical storage capacity.
This study presents the feasibility and optimization of CO2 sequestration in saline aquifer zone for one of Malaysia pre-development fields that can be as part of forecasting the CO2 injectivity and behaviour in storage reservoir during containment. Based on the study outcomes, it was well understood that the small, restricted saline aquifers may not present the greatest avenue for sustainable and economic CO2 sequestration due to their limited size and the requirement of water production to create additional voidage/pressure sink. In such a scenario, extensive and open aquifer systems in the region may be analyzed for their containment integrity and effective storage capacities.
Full Rigless Cable Deployed ESP System-Truly Eliminate Dependence on a Rig for Installing and Retrieving ESP String
Authors: Zhao Mengpan , Li Qijun , Hong Yuandong , Zhu Lisha , Zhang Li , Lei Xing , Xue Fan , Dai Rui 
Published: February 2024

Abstract
Over the past decade, Nova Rigless ESP has been at the forefront of research and development in the field of rigless electrical submersible pump (ESP) solutions. The dedication to Rigless ESP Solution has earned significant acclaim within the industry, manifested through numerous achievements, such as a record-breaking operational run life of 10 years and an average increase of 2-3 times in ESP run life. Traditionally, the majority of applications have involved the conversion of existing ESP wells to the Wireline Deployed Rigless ESP systems.
However, in response to evolving market demands that emerged in 2018, operators expressed a need for solutions capable of transforming naturally flowing wells to ESP-assisted production without the use of a rig. In answer to this challenge, the team developed the Full Rigless Cable Deployed (FRCD) ESP system, a groundbreaking innovation in well intervention technology. Currently, the FRCD suite boasts three distinct configurations of wellhead equipment, each designed to accommodate a variety of operational scenarios and maximize adaptability.
This paper delves into the operational principles of the FRCD system, detailing its design, implementation process, and the value it offers. Furthermore, this paper will present a comprehensive case study that showcases a collaborative effort between operators and suppliers to successfully integrate the FRCD system into their well architecture. This case study will not only demonstrate the practicality and effectiveness of the FRCD system but also underscore the commitment to client-centered innovation and tailor-made solutions in the oil and gas industry.
Successful Application of Novel Low Density High Temperature Resistant Cement in Bohai Bay Steam Recovery Wells
Authors: Feng Ying tao , Tian Jin , Puspitasari Melinda , Zhang Hao , Cui Ce , Li Yi , Geng Li Jun , Han Dong Dong , Tang Yu Tong , Wang You Wei , Feng Qing Hao , Zhao Dong Hui , Zhao Hu , Yu Bin , Xiao Wei , Fang En lou , Dan Lian , Zhao Jun 
Published: February 2024

Abstract
In Bohai bay, heavy oil reserves account for 70% of the total proved oil reserves. Most extensive enhanced oil recovery technique is cyclic steam stimulation, which would poses significant challenges to cementing operation. Cement integrity under multi-cyclic steam stimulation limits conventional cement slurry systems, especially when the steam injection temperature is as high as 350 °C. Besides, leakage formation, shallow gas and acid corrosion also increased the complexity of the cementing jobs. A novel lightweight, high-temperature-resistant cement system had been developed in order to ensure long-term effective isolation of the layer when exposed to ultra-high temperature(350 °C) due to cyclic steam stimulation. This paper will describe the design and evaluation of cement slurry in details. With the novel cement system, cementing operation in steam recovery wells had been successfully carried out over 20 wells. CBL logging tests showed excellent bonding result. Advanced long-term zonal isolation for 3 years under constant steam injection had been achieved. This successful cement operation has great reference in the cementing industry.
Revisiting Production Outlook in a Mature Offshore Field: A Case Study on Exploring Opportunities to Increase Production Using Rigless Techniques
Authors: Devsali S. , Unial R. , Gunwant D. 
Published: February 2024

Abstract
Field Delta located 95 Km North West of the city of Mumbai is producing through 13 wellhead platforms through approximately 60 oil wells mostly operating on gas lift. The recent flowing gradient surveys recorded in the wells have indicated drop in liquid level thus resulting in de-optimized gas lift system. Many wells in the field have also ceased to flow due to liquid loading and gradual drop in liquid level below the last operating gas lift valves.
Recompleting the wells with smaller tubing sizes and Gas Lift Valves upto the bottom of the well using workover rig in offshore is cost intensive and time taking and may not be economically viable for all the wells. Therefore various revival strategies which do not require workover and can be used for extending the operating life of mature wells have been discussed in the paper through various case studies. These technologies provide a sustainable & reliable means to retrofit gas lift to reach the deepest point.
Methodology adopted to carry out the designing by matching the existing valve depths and possibility to go deeper considering the system limitation has been discussed in the paper with few examples. Simulation indicated that in 6 wells scope exists for enhancing production by replacing dummies at deeper depths with CVs with the available gas injection Pressure. 19 wells have been identified in which scope exists for deeper injection below current injection depth (last Gas Lift Mandrel) through rig-less applications like single point gas lift and rigless coiled tubing gas lift system below the packer.
A comparative analysis of different technologies to revive production from liquid loaded wells have been brought out in the paper through various case studies.
Rising Above Bitumen Challenges in Exploratory Wells, Mexico
Authors: Moncayo S. 
Published: February 2024

Abstract
The present paper showcases the solutions implemented to overcome the challenges of encountering bitumen while drilling exploration wells in Southern Mexico land fields.
Specifically, while drilling exploration well Actul 1 Exp, located between Tabasco and Veracruz province in Cuichapa Basin, Mexico South. Offset fields are Arroyo Blanco, Soldados and Rabasa at a range of 3 to 10 kms from the exploratory well separated by a major fault.
New-Generation Nuclear Magnetic ResonanceT1-T2 Logging–Derived Formation Evaluation in Jurassic Shale Oil Reservoirs of China
Authors: Zhou Cong , Wang Yue , Yan Wei He , Zhao Xian Ran , Wang Yu Hua , Wu Jin Long , Jiang Bao Yan , Qu Chang Wei , Yang Xue Feng 
Published: February 2024

AbstractChina is accelerating the exploration and development of tight sandstone and shale reservoirs in the Jurassic Lianggaoshan Formation for oil and gas. The formation evaluation is challenged by complex mineralogy, low porosity, and unknown formation water salinity. In addition, the operator needs a technique for underground fluid typing and sweet spot identification of the shale oil reservoir to optimize their development strategy.We introduce a new method that uses nuclear magnetic resonance (NMR) T1-T2 logging for the formation evaluation and underground fluid typing of the shale oil reservoir. The measurement of continuous 2D NMR T1-T2 logging enables the quantitative estimation of the bound and movable fluid volumes in the pores. The integration of wireline NMR, induced gamma ray spectroscopy, and borehole imaging provides insight into the potential sweet spot of the shale oil reservoir in the Jurassic Lianggaoshan Formation.In a case study from tight sandstone and shale reservoirs in the Sichuan Basin, China, spectroscopy-derived mineralogy is calibrated by X-ray diffraction, which lowers the uncertainty in porosity and water saturation estimates from logs. An artificial intelligence methodology derived from the concept of blind source separation for extracting signals from 2D NMR T1-T2 measurements is proposed. Clay-bound water volume and porosity derived from cluster volumetric analysis of NMR T1-T2 match well with those from spectroscopy and core experiment results. The movable hydrocarbon saturation proves to be effective and robust in sweet spot identification.We discuss an integration of NMR T1-T2 logging methods from a new-generation wireline NMR tool in the unconventional reservoir. This tool helps operators to understand the potential of their reservoirs. The shale oil sweet spots identified by the new method are encouraging to secure the gas and oil productions for operators.
Technical Challenges in the Development of Deepwater Subsea Multi-Functional Manifold System
Authors: Shi Lei 
Published: February 2024

Abstract
This paper introduces the technical challenges of the research and development of a subsea multi-function manifold system at 500m depth. According to the characteristics of the first engineering application of subsea multiphase flowmeter, subsea hydraulic gate valve, subsea connector and other products, will focus on the integrated design technology of control, distribution and monitoring system to manifold module, assembly integration and precision control technology of manifold system, manifold system test and full-cycle reliability risk analysis technology.
Evolution of Non-Routine Integrated Well Works for North Sabah
Authors: Rahim K. Zainul , Kasim M. , Liew T. , Ghaffar M. , Ling Y. M. , Hakimuddin M. , Zamir A. Abu 
Published: February 2024

Abstract
A description on the approach taken by the operating company to increase quantity and complexity of non-routine well intervention activities while maintaining cost effectiveness in an offshore mature brownfield asset in Sabah waters, which had been producing under another operator since 1979. Due to the age of the asset, the four producing oil fields in the asset have severe pressure depletion, relatively low production rates, organic and inorganic scales and sand production challenges to be overcome.
The operator first focused on improving well integrity management while simultaneously seeking to increase the company knowledge and experience on less complex well intervention activities before building up to more complex activities over a four-year period. The well integrity management strategy was optimised by implementing one comprehensive and one condition-based maintenance cycle conducted annually with corrective maintenance planned out in between the preventive maintenance activities. The operator conducted a comprehensive review on the production enhancement opportunities and selected the most easily achievable ones for fast execution, mostly those which could be conducted through slickline intervention alone, before expanding intervention operations to more complex opportunities.
After two years of the revised well integrity strategy implementation, a trend of the typical integrity failures and their frequency had been established, which was then used to update the critical sparing philosophy and internal well integrity management systems. Once the asset well integrity had been improved, more complex non-routine intervention was planned and executed, this started with chemical pumping and slickline services supported by a vessel for additional bedding for organic and inorganic scale remediation. Due to significant logistical challenges, subsequent campaigns utilised a larger vessel with a crane to avoid reliance on the jacket cranes with limited and derated capacities. Starting from the third year of operating the assets, the operator successfully planned and executed Coiled Tubing, Pumping and Slickline interventions supported by an Accommodation Workboat for acid stimulation, coiled tubing sand clean out and most recently for coiled tubing and slickline fishing activities.
This paper may be used as a guide on how an operator can successfully approach building up well intervention activity frequency and complexity in a mature oil producing asset.