bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi-Field Integrated Rock Type Framework Optimisation in Thrusted Carbonates of The Thamama Group to Reduce Modelling Uncertainty and Improve Reservoir Characterisation
Authors: Robert Matthew James , Saradva Harshil , Obaid Shams , Jain Siddharth , Jha Bhawesh Chandra , Salter Tim 
Published: October 2022

AbstractObjectives/ScopeThis study aims to use modern techniques to re-characterise the diagenetically altered Thamama Group reservoir units of multiple gas-condensate fields in Sharjah, UAE and determine robust rock-typing framework from the full dataset and recent core analysis program. This would be used to reduce mismatches observed in static and dynamic properties and demonstrate that a matched-outcome can be achieved with less model manipulation by focusing on textural variances within the units.Methods, Procedures, ProcessResults, Observations, ConclusionsFour petrophysical rock types were identified and found good equivalence to the identified petrographical rock types; the algorithm separated mono-modal micritic packstones from highly diagenetically altered grainstone-wackestone rudstone facies, with the rock-type clusters also being defined by Winland-r35 and Lucia poro-perm threshold lines. A single rock-typing framework, suitable for all studied fields with observed differences being explained by variability in the rock type proportions.When compared to the previous rock typing framework and reservoir models, better matches were achieved between predicted properties and core data in QC wells. Static model property distributions were more realistic in achieving a volumetric match with produced gas. Better saturation distribution with realistic Swcr and Socr were observed by using the new Rock Typing Sw equations. Rel-perm modification for increasing water production to match the observed data was negligible due to presence of more water saturation in the crest of the reservoir. Multipliers for permeability and porosity were significantly reduced to match the well productivities and tubing head pressure estimations were improved due to less mismatch with liquid production rates.Novel/Additive InformationThis work represents the first time petrophysical and petrological rock typing was conducted for several gas-condensate fields in Sharjah, UAE. Newly acquired core data, petrographical information and core descriptions were integrated in the study.The previous workflow, established in 1993, was updated using modern machine-learning techniques incorporating new data and a wider range of data than the previous rock typing model that was based solely on porosity measurements, remaining consistent to pore-scale and textural changes.
A Marginal Field and a Thin Saturated Lower Cretaceous Reservoir Development Through Integrated Seismic Reservoir Characterization - Onshore Case Study - Al Dhafra Petroleum – UAE.
Authors: Hassan Hany Mohamed , Elsadany Karim Mostafa , Abd El-Karim Walid Abd El-Mawla , Aly Omar , Elasrag Ramy Moahmed , Moahmed Yassien Hemdan , Sabry Yehia , Mihaljevic Ivica 
Published: October 2022

Abstract

Objectives & Scope
The objectives of this study are to determine new sweet spots & fluid content of the current discovery. Where, the Lower cretaceous carbonate reservoir units (Thamama) are among the most important hydrocarbon producing reservoirs in onshore Abu Dhabi. However, the studied field is considered as a marginal field, where the several cycles which affect the oil industry have emphasized the role for full integrated control of technical solutions for the development of such fields. Thus, an integrated feasibility study has been carried out to investigate the adding value of the seismic inversion and reservoir characterization. The area of study is located in southeast onshore Abu Dhabi. The studied field has been discovered and tested oil in Thamama carbonate units and is currently preparing for the first oil production.

Challenges & Procedures
Carbonates rocks are strongly modified by diagenetic process which influence the petrophysical properties to varying degrees. In carbonates, the influence of geological attributes is biased towards depositional properties in case of the use of texture and towards diagenetic attribute when using pore type.
The main challenge is to locate new save optimized candidates for infill wells securing the production plateau and minimizing the risks behind the reservoir facies/quality and seismic resolution.
To meet the objective, an integrated seismic reservoir characterization study was carried out by first a careful conditioning of the well logs and the seismic gathers data, followed by preserved AVO angle stack generation. Then, the rockphysics, fluid substitution, and wavelets estimation. The information was then used to conduct pre-stack AVO simultaneous inversion to generate several elastic attributes such as Acoustic & Shear Impedances, VpVs, and density. This was followed by detailed Litho-Porosity prediction as well as water saturation.
4D Seismic Feasibility Study for Monitoring Complex Carbonate Reservoir in Onshore, Abu Dhabi
Authors: Singh Nepal , Celma Rafael , Rappin Didier 
Published: October 2022

Abstract
Development of complex Upper Cretaceous carbonate reservoir of a mature onshore oil field in Abu Dhabi has been challenging because of higher pressure depletion, water cut and reservoir heterogeneities. 4D seismic reservoir surveillance technique is always challenging in carbonate reservoirs due to weak signal, therefore a feasibility study is carried out with the objective of identifying pressure depletion and the bypass oil zones subjected to different duration of production/water injection (WI) interval. Monitor seismic surveys are modeled from elastic properties derived from reservoir properties simulated at different periods using a calibrated Petro-elastic model. Seismic data acquired in 2007 is taken as base survey for monitoring field depletion during 14 years of production and future production/WI over a period of 2 to 9 years. 4D seismic amplitude attribute, "Envelope (monitor)-Envelope (base)" and "time-shift" are found above the repeatability noise (~10%) and detectability limit of 0.149ms respectively over a period of 14 years of production and 9 years of production/WI period. Technique is not found feasible over 2 years of Pilot WI period because of poor 4D signal to be detectable. 4D signals are dominantly controlled by accelerability law taken from the worldwide analogue and hence a pilot 4D monitor survey is recommended for the calibration of pressure law thereby consolidating the concept before implementing it on full field scale for optimizing the infill producers as well as water injectors.
Lower Jurassic Tight Gas Exploration Potential in Offshore Abu Dhabi
Authors: Taher Ahmed A. , Al Hammadi Mariam K. , Al Shuwaihi Muna H. , Vantala Aurifullah 
Published: October 2022

Abstract
The Lower Jurassic, Izhara and Hamlah formations, evaluation study has been conducted to provide an understanding of the hydrocarbon exploration potential of these formations in offshore Abu Dhabi. This objective was accomplished by evaluating the data from legacy reports and analysis the available drilling and testing results of wells that were penetrating Izhara and Hamlah reservoirs. Also, the regional well log correlation, structural settings, lithofacies variations, depositional environment models, source rocks potential were incorporated into this study. These were resulted in better understanding of the facies variations, porosity development and hydrocarbon charge system.
The timing of structural growth, the presence of indigenous source rocks, the hydrocarbon shows while drilling and the presence of high hydrocarbon saturation in the interpreted logs concluded that both the Izhara and Hamlah formations are hydrocarbon-bearing reservoirs.
The Lower Jurassic section is comprised of sequences of shallow marine mixed carbonates intercalating with shale and anhydrite streaks. These formations, although exhibits a gradual thickening from the northwest towards the southeast direction, yet they show remarkable lateral consistency, both in lithology and log response. Primary and secondary porosity are generally moderate to poor in these formations, reflecting the deep burial compaction and reflecting the terrigenous shale and anhydrite nodules with the carbonate reservoirs.
The Upper Izhara comprises of lime-mudstone and wackestone, cryptocrystalline, slightly argillaceous and occasionally dolomitic. This type of lithofacies is reflecting a similar depositional environment to that found in the Middle Jurassic Lower Araej formation, which characterized by low porosity and relatively high permeability. While, the Lower Izhara intervals is mainly comprised of shale with high hydrocarbon saturations and high porosity values. This lithology represents an unconventional potential for shale gas accumulation.
The Hamlah Formation is comprised of a variety of carbonate lithologies that are characterized by relatively low permeability which, has been deteriorated due to the precipitation of minerals from the thin streaks of terrigenous shales and the anhydrite nodules.
The evaluation of the Izhara and Hamlah formations resulted in defining high prospective areas for future exploration activities. The tightness of the reservoirs in these formations can be overcome by using multi-stage acid fracturing and long horizontal drain holes. This new technology will turn tight reservoirs of the Izhara and Hamlah formations into attractive targets for future exploration activities.
The evaluation of reservoir properties, hydrocarbon charge system, trap development and seal integrity has resulted in defining significant hydrocarbon accumulations in the Izhara and Hamlah formations in most of the prominent offshore structures.
Reservoir Characterization, Bridging the Scale from Micro to Macro
Authors: Bouzida Yasmina , Cazeneuve Eduardo Adrian , Mavromatidis Angelos , Al Ali Khalfan , Leythaeuser Thomas 
Published: October 2022

Abstract
This paper describes the reservoir characterization of a carbonate formation using acoustic and borehole imaging log in a novel way. Interpretation of the interplay between stratigraphic and structural reservoir elements allows additional understanding of the hydrocarbon trapping mechanism and informs decisions on the well testing program and future well placement.
High-resolution Borehole Images (BHI) have historically been one of the most widespread geological evaluation tools and they continue to be a cornerstone for providing precise data on the facies and fractures intersected by the well. The shallow depth of investigation of wellbore imaging tools can now also be usefully augmented by the acoustic, Dipole shear processing.
Patented Deep Shear Wave Image (DSWI) methodology allows identification of geological interfaces with a depth of investigation up to 110 feet away from the borehole. The processed data bridges the gap between wellbore images and field scale seismic data and so can guide meaningful reservoir descriptions and fracture characterization at the geo-cellular mode scale.
Combination of the two separate imaging measurements compensates for the limitation of each logging tool's capabilities and helps increase the range of feature detection from near borehole to as much as 110 or more feet away from the well. The statistically rich borehole imaging data can be used to help confirm the detailed characteristic of these features and how the facies/lithology affect the fracture properties. BHI also calibrate the DSWI features true azimuth, while the DSWI data can help confirm fracture hierarchies and fracture bed interaction away from the borehole.
The current study highlighted that the different scales of measurement allow additional quantified analysis of the fracture hierarchy and leads to proposal of conceptual fracture models that recognize bed-bound and non-bed-bound fractures sets. The reservoir itself is highly stratified with intercalations of limestone, mudstone and evaporite. Hydrocarbon (HC) presence, defined by an acoustic derived HC Index (but validated with conventional resistivity logging), suggests that oil is preferentially trapped in successive porous layers, but enhanced in some intervals by the additional presence of fractures. The Reservoir pressure points have indicated that only main faults-oriented NNW-SSE could potentially compartmentalized the reservoir. Additional wells and data integration are needed to confirm it.
The DSWI is also useful to calibrate the poor to moderate seismic data in this field by detecting sub-seismic features that have an impact on the reservoir and helps in updating the geological and reservoir model.
Drilling with Casing to Address Formation Troubles in Surface Hole
Authors: Alexeyenko Alexey , Han Kyungnam , Petrenko Maxim , Chutchev Eduard 
Published: October 2022

Abstract
Subsurface anomalies can present complex well construction challenges. These anomalies to name a few are irregular wellbore stress profiles, low fracture gradients that require complex mud programs and, in some cases, total fluid losses while drilling. Poor wellbore stability is a common result of such anomalies and service companies serving the industry develop technologies to address, mitigate against and overcome these issues.
A gas well encountered such a challenge. While drilling the 17″ section complete fluid losses were encountered. These losses generally uncommon in the field and were attributed to a seismic anomaly. This resulted in poor wellbore stability and led to multiple lost BHAs and sidetrack attempts. The surface casing design did not allow for extensive remedial options so rather than continuing recovery operations it was decided to suspend well construction and spud an offset well 50 meters away.
Equipped with the knowledge of the drilling problems from the direct offset, the potential problems they represent and considering the proximity, it was decided to introduce two engineered solutions to mitigate against these challenges and secure successful well construction. First, the surface casing design was modified and the 18-5/8″ casing was set deeper and second, casing while drilling (CWD) technology was introduced to drill for 13-3/8″ intermediate casing from the 18-5/8″ shoe to 13 3/8″ casing point (CP). During planning it was concluded that casing drilling technology would allow to simultaneously keep every foot drilled behind casing, under total losses conditions. Furthermore, CwD would minimize the open hole time compared to conventional drilling practices, an important factor when mitigating against risks from poor wellbore stability.
Approximately 4.5 days after setting the 18-5/8″ surface casing, a 16″ CwD drill bit made-up to 13-3/8″ casing successfully drilled 1575 ft with total losses and cemented in place across an interbedded formation. This was a starkly different result compared to the direct offset where operations were suspended after many more days between setting the 18-5/8″ to decision to suspend.
Analysis, Comparison, and Results of the Effectiveness of a PDC Bit Containing Fracturing and Shearing Elements When Drilling Challenging Heterogeneous Section Containing Massive Cherts
Authors: Nunez Ygnacio Jesus , Ruiz Fernando , Al Mutawa Ahmed Abdulla , Al Shamisi Eisa Daban , Al Rahma Rahma Ahmed , Hamdy Ibrahim , Jawadekar Rohan Vijay , Lari Aliya Mohamed , Connelly Nicola , El-Hafez Hany , Fierro Juan Carlos , Atallah Lama 
Published: October 2022

Abstract
A new PDC Bit design containing fracturing and shearing elements which can deliver improved ROP in a single trip to drill a challenging heterogeneous section containing massive chert compared to previously used conventional hybrid or roller cone bit designs. The demonstration is supported by a real field case from an unconventional gas exploratory field project in Abu Dhabi.
In this unconventional field, 6 wells have been drilled using 4 Bits on average to complete the 12 ¼″ section (Tricone and PDC) where the presence of chert has resulted in additional trips due to Bit life. The massive content of abrasive cherts is approximately 2,000 ft thick, reason why it was decided to think of a new customized PDC Bit design and use it in well # 7. Plan is to prove that is possible to introduce an alternative option to complete the section in one trip and stablish a comparison with previous wells where Hybrid Bits were used.
The new unique PDC design features dual row cutters, new shaped cutters, advance elements to reduce vibration and sensing at the bit technology to increase the efficiency in rock interaction. It will be used in the ongoing exploratory project to demonstrate its advantage in terms of cost saving and rig time reduction. Reduction target at least 15% is anticipated while increasing the ROP and eliminating a trip across the chert formation. The study will compare the data with previously used Hybrid Bit and create a basement for the exploratory field in 12 ¼″ section. A strong hypothesis is that this bit will complete the well in this particular area and optimizing drilling cost in development studies. All the analysis, studies and design have been done and completed during Q2 and Q3
Where such non-homogenous formations containing massive abrasive cherts can be crossed and have detrimental impact on the bit life, the novelty is to bring to the stage a new PDC bit, which will be able to offer a different alternative by reducing torque, having healthier wells, and optimizing drilling cost in this unconventional field where drilling CAPEX reduction are paramount.
A New Workflow to Study the Impact of Artificial Maturations on the Petrophysical Properties of Unconventional Shale Rocks
Authors: Hassan Amjed M. , Elsayed Mahmoud K. , Oshaish Ali A. , Al-Ofi Salah M. , El-Husseiny Ammar Ammar H. , Abu-Mahfouz Israa S , Mahmoud Mohamed A. , Abouelresh Mohamed O. , Attia Hussein M. 
Published: October 2022

Abstract
Multiple challenges are associated with the characterization and development of unconventional shale reservoirs. The petrophysical properties play significant roles in hydrocarbon production from unconventional reservoirs. Several techniques can be used to determine the petrophysical properties such as routine core analysis, nuclear magnetic resonance (NMR), and dielectric techniques. This study presents an effective workflow to characterize the petrophysical properties of unconventional shales at different maturation stages.
In this study, the conducted measurements are X-ray diffraction (XRD) analysis, Rock-Eval pyrolysis, helium porosity, NMR, and dielectric experiments. The rock samples were prepared for the measurements by drying the samples under a vacuum. In addition, the samples were artificially maturated using a muffle furnace at different temperatures and heating times. The impact of shale maturation on the petrophysical properties was captured by evaluating the rock properties after each maturation stage. Results show that the shale samples have a TOC of 17.5 wt.% on average, and a hydrogen index (HI) of 809, indicating that the samples are belonging to kerogen type I. The mineralogical analysis indicates that the used shale samples have a calcite percentage of around 59.9%. Moreover, the artificial maturation led to reducing the total organic content, due to the conversion of organic matter into hydrocarbon fluids. NMR and dielectric measurements showed that the shale porosity system was altered due to artificial maturation. The real dielectric constant was reduced indicating a reduction in the kerogen percentages. The cumulative probability density was increased after the maturation, revealing the shale porosity was increased which could be attributed to the dissolution of kerogen during the maturation process.
Ultimately, this study improves our understanding of characterizing unconventional shale formations. Also, a reliable workflow is proposed for a better characterization of the unconventional formations by integrating routine core analysis, Rock-Eval, NMR, and dielectric techniques. Such workflow can pave the way to introduce a downhole technique to characterize unconventional resources more effectively.
Cloud-Edge Combination: A Novel Intelligent Intermittent Pumping Optimization and Control Method for Tight Oil Wells
Authors: Zhang Xishun , Wang Cai , Sun Yizhen , Shi Junfeng , Zhao Hanjun , Zhao Ruidong , Jiang Weidong , Li Jinya , Zhou Xiang , Liu Xiang , Yi Ran 
Published: October 2022

AbstractMore than 100,000 oil wells with liquid production less than five cubic meters per day in the target company will be converted to intermittent pumping by the end of 2025. That has a broad application prospect. In order to avoid network delay, improve pumping efficiency and realize unattended operation, an intelligent intermittent pumping optimization and control method based on cloud-edge combination is proposed.Firstly, intelligent edge modules with data acquisition and transmission, analysis and calculation and automatic control were configured into the intelligent pumping cabinets. An evaluation model of pumping effect aiming at stable production and minimum energy consumption was embedded into the intelligent edge module.Secondly, an intelligent management and control cloud platform for intermittent pumping wells was built. By using the production big data of intermittent pumping wells, a cloud prediction model of the optimal intermittent pumping scheme was built so as to provide a plan for each single well. In the execution stage, the cloud prediction model of the intermittent pumping system is used to formulate a one-day intermittent pumping scheme for every single well, and the optimized scheme signal will be sent to the edge module from the cloud. The edge module executes the corresponding intermittent pumping system according to the cloud order and monitors the intermittent pumping effect through the effect evaluation model by analyzing the real time production data. If the output and energy-saving effect meet the expected indicators, the optimized one-day scheme will be carried out at the edge until a new optimized scheme signal comes from the cloud 24 hours later. Otherwise, the pumping scheme will be switched to the power frequency mode and edge module will feed back the abnormal data to the cloud. After receiving new instructions from the cloud, the edge module will switch the pumping mode from power frequency mode to intermittent mode again.This technology has been applied into 2000 wells in two oilfields in China with a power saving rate of more than 30%. The joint control method of cloud-edge combination avoiding negative effect caused by network delay, basically realizes the unattended operation for intermittent pumping wells, greatly improves the management efficiency, and highly promotes the intelligent construction of the oilfield.