bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Capillary Condensation on the Geomechanical and Acoustic Properties of Tight Formations: An Experimental Study
Authors: Albannay Aamer , Bui Binh , Katsuki Daisuke 
Published: December 2021

AbstractCapillary condensation is the condensation of the gas inside nano-pore space at a pressure lower than the bulk dew point pressure as the result of multilayer adsorption due to the high capillary pressure inside the small pore throat of unconventional rocks. The condensation of liquid in nano-pore space of rock changes its mechanical and acoustic properties. Acoustic properties variation due to capillary condensation provides us a tool to monitor phase change in reservoir as a result of nano-confinement as well as mapping the area where phase change occurs as well as characterize pore size distribution. This is particularly important for tight formations where confinement has a strong effect on phase behavior that is challenging to measure experimentally. Theoretical studies have examined the effects of capillary condensation; however, these findings have not been verified experimentally.The main objective of this study is to experimentally investigate the effect of capillary condensation on the mechanical and acoustic properties of shale samples. The mechanical and acoustic characterization of the samples was carried out experimentally using a state-of-the-art tri-axial facility at the Colorado School of Mines. The experimental set-up is capable of the simultaneous acquisition of coupled stress, strain, resistivity, acoustic and flow data. Carbon dioxide was used as the pore pressure fluid in these experiments. After a comprehensive characterization of shale samples, experiments were conducted by increasing the pore pressure until condensation occurs while monitoring the mechanical and acoustic properties of the sample to quantify the effect of capillary condensation on the mechanical and acoustic properties of the sample.Experimental data show a 5% increase in Young's Modulus as condensation occurs. This increase is attributed to the increase in pore stiffness as condensation occurs reinforcing the grain contact. An initial decrease in compressional velocity was observed as pore pressure increases before condensation occurs which is attributed to the expansion of the pore volume when pore pressure increases. After this initial decrease, compressional velocity slightly increases at a pressure around 750 - 800 psi which is close to the condensation pressure. We also observed a noticeable increase in shear velocity when capillary condensation occurs, this could be due to the immobility of the condensed liquid phase at the pore throats. The changes of geomechanical and acoustic signatures were observed at around 750 - 800 psi at 27°C, which is the dew point pressure of the fluid in the nano-pore space of the sample at this temperature. While the unconfined bulk dew point pressure of carbon dioxide at the same temperature is 977 psi. Hence, this study marks the first measurement of the dew point of fluid in nano-pore space and potentially leads to the construction of the phase envelope of fluid under confinement.
Stiff String Casing Design: Tortuosity and Centralisation
Authors: Nobbs Benjamin , Aichinger Florian , Dao Ngoc-Ha , Studer Regis 
Published: December 2021

AbstractThe forces and stresses along casing strings are modeled using a stiff string torque and drag model. The effect of wellbore tortuosity and centralization are quantified in preplanning phase in addition to the effect of 3D orientated casing wear. A realistic case study is presented to show the resulting effect on axial, burst, collapse and Von Mises equivalent (VME) safety factor as well as VME body and connection design envelopes.While running a tubular downhole, a smooth wellbore is normally assumed when performing a torque and drag calculation. In reality, the inherent tortuosity of the wellbore which is caused by the drilling process can cause significant local doglegs. When applying a soft-string torque and drag model, the stiffness, radial clearance and high frequency surveys needed to fully model local doglegs are rarely modeled. The stiff string torque and drag and buckling model can model these effects, as well as the addition of rigid and flexible centralisers. This study involves the comparison of different casing design load cases, under different centralizer programs and tortuosity taking into account a 3D orientated casing wear.The results show that there can be significant differences in overall axial stress depending on the centraliser program and tortuosity used. The soft string model doesn't directly account for bending stress, normally this is estimated using a Bending Stress Magnification Factor (BSMF). In contract the stiff string model can directly calculate the additional bending stress. This additional stress can be particularly prevalent while RIH casing with centralisers and high tortuosity. The reduction in American Petroleum Institute (API) and VME stress envelope is also quantified using a 3D orientated casing wear model. A better understanding of axial stress state reduces risk of well integrity issues.This paper will show the benefits of using a stiff string model, considering additional contact points, bending stress as well as the benefits of modelling tortuosity and centralizer program early in the design process. During extended reach drilling (ERD) and high-pressure, high temperature (HPHT) wells, this information can be critical when correctly assessing the axial stress state.
Wellbore Cleanness Under Total Losses in Horizontal Wells: The Field Study
Authors: Ruzhnikov Alexey , Echevarria Edgar 
Published: December 2021

Abstract
In the Middle East many of the matured fields have fractured or vugular formations where the drilling is continued without return to a surface. This situation has been commonly interpreted as lack of hole cleaning and high risk of stuck pipe. The manuscript describes a study performed to analyze the hole cleaning while blind drilling horizontal sections.
Most of the losses while drilling across fractured or vugular formations happen sudden, and this represents a risk of formation instability and stuck pipe. Additionally, the cuttings accumulation may lead to a potential pack off. To understand the hole cleaning the annular pressure while drilling was introduced in different sections, what via change of the equivalent static and dynamic densities describes the cutting and cavings accumulation in the annulus. Additionally, the hole cleaning behavior with different fluids pumped through the drillstring (i.e. drilling fluid, water, water with sweeps) was studied.
The proposed study was performed in 4 different fields, 9 wells, across horizontal 6⅛-in. sections with total lost circulation. It was identified that while drilling with full returns ECD vs ESD variations are within 1.5 ppg, those variations are matching with the modeling of hydraulics. Once total losses encountered the variations between ECD and ESD are very low - within 0.2 ppg - indicating that annular friction losses below the loss circulation zone are minimal. This support the theory that all the drilled cuttings are properly lifted from bottom and carried to the karst into the loss circulation zone and not fluctuating above the loss zone. Additionally, minor to no relation found in hole cleaning while drilling with mud or a water with sweeps. This finding also is aligned with the stuck pipe statistics that shows higher incidents of stuck pipe while drilling the with full circulation due to pack off.
The manuscript confirms the theory of the hole cleaning in total lost circulation and application of different hole cleaning practices to improve it. The results of the study can be implemented in any project worldwide.
Unconventional Waste & Flare Gas Recovery System UFGRS in New Circular Economy
Authors: Soliman Mohamed Ahmed , Salu Samusideen A , Al-Aiderous Abdullah Y , Ansari Nisar Ahmad , Al-Hajri Khamis , Mecikar Ellyes 
Published: December 2021

Abstract
Keeping pace with the rest of the world on reducing the greenhouse gas emission, Saudi Aramco embarked on an aggressive program to minimize or cut routine flaring and energy resources used in producing oil and gas through policies, standards and inhouse innovations. The innovative Unconventional Waste & Flare Gas Recovery System UFGRS has supported the corporate strategy to minimize or eliminate routine flaring with minimum CAPEX and OPEX.
This paper present in detail the innovative Ejector Based Unconventional Waste/Flare Gas Recovery System (UFGRS) without using gas compressors. The objective of the project is to eliminate the hydrocarbon gas release to atmosphere for any upset flameout scenario from GOSP-A massive flare & relief system and continuously recover 1.825 Billion Standard Cubic Feet per year (1.825 BSCFY) of valuable purge gas with the lowest CAPEX and OPEX.
Conventional Flare Gas Recovery System (FGRS) using gas compressors is the normal choice deployed in many facilities to recover the routine gas flaring but it was found to have high CAPEX and OPEX (maintenance, high power consumption & labor intensive) compared to the value of the recovered gas. Also, the compressors based FGRS is more complex and less reliable than the ejector (static) based FGRS. In addition, the innovative FGRS is capable of handling high turndown ratios compared to convention compressor based FGRS. Also, additional innovative parts of this idea is the integration with the existing compression system and the use of only static equipment like ejectors, pipes, valves and water seal drums to recover the waste/flare gas. The idea has very low operating cost compared to conventional flare gas recovery systems, apart from significant gas savings.
The unconventional FGRS system was proven successfully in December 2020. The system is currently in operation for 8 months without any interruption and managed to eliminate the total design routine gas flaring rate of 1.825 BSCFY GOSP-A producing facilities. Also, the project resulted in reducing CO2 emission by 106,000 ton/year which positively contributed to the kingdom circular economy initiatives.
To further enhance the ejector based FGRS, a US Patent No. 10,429,067 was granted in October 2019 to utilize the Ejector based FGRS concept for Emergency flare gas recovery. The innovative idea includes utilizing multiple ejectors in parallel with provision of different ejectors operating at different pressures that will allow the system to be used to recover flare gas over a range of different flow rates corresponding to different emergency release scenarios. Also, two new patents are under filing to utilize the liquid as motive fluid instead of the gas.
Crude Oil Storage Tank Refurbishment Duration Optimized by 40% Through Advanced Techniques
Authors: Al Yammahi Saeed Mubarak , Al Kaabi Mohamed Obaid , Al Zaabi Rashid Hamad , Shendge Sachin Ashok , Dizon Manly Vista , Sarkar Ananda 
Published: December 2021

Abstract
Crude storage tanks are an important asset in every oil company. Having adequate storage capacities is important economically and ensure steady supply of oil in the market. Hence, taking a huge tank out of service for refurbishment is technically and safety critical, and as much as putting it back into service on time.
This paper presents an advanced methodology and assessment of tank refurbishment process of large capacity Crude Storage Tanks, in compliance with the International Codes and Standards resulting in optimization of the project schedule by approximately 40% as compared to conventional methodology of refurbishment. By deploying the advance techniques, detailed assessment, and dynamic planning we have been able to accelerate the completion of the project, improve tank availability time without compromising with the Integrity and HSE.
Single-Phase Production Profiling in Conventional Oil Producers Using Fiber-Optic Surveillance
Authors: Panhuis Peter in ‘t , Al Shidhani Lujaina , Al Bahri Sultan , Hemink Gijs 
Published: December 2021

AbstractThe objective of this paper is to demonstrate how both Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) data, acquired using a fiber-optic cable installed and cemented behind a 7" production casing, could be used for single-phase production allocation in two conventional oil producers in the South of the Sultanate of Oman.DAS data can be processed, time-averaged, and filtered to specific frequency bands, to identify and monitor the acoustic frequencies that are excited by the flow through the perforation tunnels. It will be shown that under certain assumptions, the flow-induced acoustic amplitudes at the perforations can be calibrated and converted into actual flow rates, which allows for continuous production profiling across all intervals of interest.DTS data, acquired under transient conditions, can also be analyzed using a thermal simulation model, to allocate production to specific perforation intervals, provided an appropriate logging program is followed. DTS is not as good as DAS in capturing dynamic changes to the inflow profile, but does have a deeper depth of investigation and is less sensitive to the geometry of the perforation tunnels or possible flow obstructions in the wellbore. The two technologies are therefore complimentary and are best acquired simultaneously.This is the first case study in the Sultanate of Oman, where both DAS and DTS data sets were successfully acquired and interpreted for single-phase production profiling in a conventional oil producer with perforated casing. Moreover, it was also the first time in Oman that oriented perforation was achieved with full shot density, through a double perforation run with a slight offset in orientation angle between the two runs.
Application of Artificial Intelligence and Machine Learning to Detect Drilling Anomalies Leading to Stuck Pipe Incidents
Authors: Bimastianto Paulinus Abhyudaya , Khambete Shreepad Purushottam , Alsaadi Hamdan Mohamed , Al Ameri Suhail Mohammed , Couzigou Erwan , Al-Marzouqi Adel A/Rahman , Ameri Fahed Salem Al , Aboulaban Said , Khater Husam , Herve Philippe 
Published: December 2021

Abstract
This project used predictive analytics and machine learning-based modeling to detect drilling anomalies, namely stuck pipe events. Analysis focused on historical drilling data and real-time operational data to address the limitations of physics-based modeling. This project was designed to enable drilling crews to minimize downtime and non-productive time through real-time anomaly management.
The solution used data science techniques to overcome data consistency/quality issues and flag drilling anomalies leading to a stuck pipe event. Predictive machine learning models were deployed across seven wells in different fields. The models analyzed both historical and real-time data across various data channels to identify anomalies (difficulties that impact non-productive time). The modeling approach mimicked the behavior of drillers using surface parameters. Small deviations from normal behavior were identified based on combinations of surface parameters, and automated machine learning was used to accelerate and optimize the modeling process. The output was a risk score that flags deviations in rig surface parameters.
During the development phase, multiple data science approaches were attempted to monitor the overall health of the drilling process. They analyzed both historical and real-time data from torque, hole depth and deviation, standpipe pressure, and various other data channels.
The models detected drilling anomalies with a harmonic model accuracy of 80% and produced valid alerts on 96% of stuck pipe and tight hole events. The average forewarning was two hours. This allowed personnel ample time to make corrections before stuck pipe events could occur. This also enabled the drilling operator to save the company upwards of millions of dollars in drilling costs and downtime.
This project introduced novel data aggregation and deep learning-based normal behavior modeling methods. It demonstrates the benefits of adopting predictive analytics and machine learning in drilling operations. The approach enabled operators to mitigate data issues and demonstrate real-time, high-frequency and high-accuracy predictions. As a result, the operator was able to significantly reduce non-productive time.
Eco Friendly Lighting Options for Offshore Installations and Related Design Challenges
Authors: Pragasam Sathishkumar 
Published: December 2021

Abstract
The impact of artificial lighting on birds and animals has been a subject of research for many decades. These studies have established that light pollution from offshore facilities result in disturbing effects on migratory birds and marine animals.
It is understood from the various studies that light emanating from offshore structures attract birds at night and disorient them during their migratory flight. As they are distracted from their flight path, they are either found trapped by the light that they keep circling around the installations or make them to take shelter in the installations, ultimately making them miss their migratory journey. This results in reduced winter survival and reduced reproduction success. Many birds are also found to die eventually because of bird strike or by getting themselves incinerated in flares. Congregation of birds in offshore installations also lead to risks related to helicopter landing / take-off.
It is also observed that artificial light attracts marine species like turtles and fishes, which result in adverse effects like alteration of feeding habits, impacted circadian rhythm and interference with their reproductive function.
From the knowledge of aforementioned disruptive effects of artificial lighting, significant efforts have been made to develop lighting systems for offshore installations that are eco-friendly. Various means of mitigating the undesirable effects of artificial lighting in offshore installations are being tried in the last couple of decades.
Gas Deviation Factor Calculation Made Easy and Accurate Using an IR 4.0 Tool
Authors: Al-Hajri Nasser M. , Barghouti Akram R. , Ureiga Sulaiman T. 
Published: December 2021

Abstract
Gas deviation factor (z-factor) and other gas reservoir fluid properties, such as formation volume factor, density, and viscosity, are normally obtained from Pressure-Volume-Temperature (PVT) experimental analysis. This process of reservoir fluid characterization usually requires collecting pressurized fluid samples from the wellbore to conduct the experimental work. The scope of this paper will provide an alternative methodology for obtaining the z-factor. An IR 4.0 tool that heavily utilizes software coding was developed. The advanced tool uses the novel apparent molecular weight profiling concept to achieve the paper objective timely and accurately.
The developed tool calculates gas properties based on downhole gradient pressure and temperature data as inputs. The methodology is applicable to dry, wet or condensate gas wells. The gas equation of state is modified to solve numerically for the z-factor using the gradient survey pressure and temperature data. The numerical solution is obtained by applying an iterative computation scheme as described below:A gas apparent molecular weight value is initialized and then gas mixture specific gravity and pseudo-critical properties are calculated.Gas mixture pseudo-reduced properties are calculated from the measured pressure and temperature values at the reservoir depth.A first z-factor value is determined as a function of the pseudo-reduced gas properties.Gas pressure gradient is obtained at the reservoir depth from the survey and used to back-calculate a second z-factor value by applying the modified gas equation of state.Relative error between the two z factor values is then calculated and compared against a low predefined tolerance.The above steps are reiterated at different assumed gas apparent molecular weight values until the predefined tolerance is achieved.
This numerical approach is computerized to perform the highest possible number of iterations and then select the z-factor value corresponding to the minimum error among all iterations. The proposed workflow has been applied on literature data with known reservoir gas properties, from PVT analysis, and showed an excellent prediction performance compared to laboratory analysis with less than 5% error.
Coiled Tubing Workflow Leads to Successful Completion of Multistage Fracturing in Extended-Reach Wells of Aishwarya Field, Barmer, India
Authors: Jahn Felix , Dehingia Madhurjya , Singh Ishaan , Bandyopadhyay Bholanath , Agarwal Arpit , Singh Atul 
Published: December 2021

Abstract
Coiled tubing (CT) was used to perform multistage fracturing treatments from the CT-tubing annulus in extended-reach wells of Aishwarya Field, Barmer, India. The wells were completed with chrome completion and included multiple fracturing sleeves. With peculiar challenges faced, solutions and lessons learnt are herein captured. In particular, casing deformation was observed in transverse wells, for which the workflow was developed so the wells with post-fracturing casing deformation could be completed and delivered for production.
During the initial phase of the campaign. CT got stuck eight times after fracturing due to casing deformation. In three instances, the bottomhole assembly was left in the hole, and twice the CT was cut for recovery. After the workflow was implemented, no CT stuck incidents occurred due to casing deformation, and all 16 transverse wells in the campaign were delivered successfully.
This study highlights the importance of differentiating between transverse and longitudinal wells while understanding their implications. In wells where casing deformation can occur, the workflow for CT-assisted multistage fracturing (MSF) operations must be adjusted. A smaller outside diameter (OD) shifting tool needs to be used without a packer assembly, and the CT cannot stay in the well during fracturing.
Lessons Learned From the World's Largest Continuous Onshore and Offshore 3D Seismic Survey
Authors: Al Mesaabi Saif Ali , Cambois Guillaume Marie , Cowell James , Arnold David , Boukhanfra Mohamed Fawzi , Al Karbi Saeed Hamad , Mahgoub Mohamed , Obaid Khalid 
Published: December 2021

AbstractIn 2017 ADNOC decided to cover the entire Abu Dhabi Emirate, onshore and offshore, with high- resolution and high-fold 3D seismic. Acquisition of the world's largest continuous seismic survey started in late 2018 and is around 77% complete at the time of writing. Data processing is well under way and interpretation of the first delivered 3D cubes is ongoing. Now is an opportune time to review the status of this gigantic project and draw preliminary lessons.Comparison with legacy data shows a massive improvement in deep imaging, which was one of the main objectives of this survey. The basement can clearly be interpreted, while it is hardly visible on legacy data being covered with high energy multiples. A thorough analysis demonstrated that increased offset is the main reason for the uplift. The large fold and the low frequency sweep also help recover signal down to 3 Hz. This extends the bandwidth in the low frequencies by one to two octaves compared to legacy data, which tremendously benefits structural interpretation and stratigraphic inversion.