bluuebunny/crossref_metadata_2025_split huggingface dataset:
Post Frac Cleanout and Plug Milling Optimization Strategy. Successful Implementation in Extremely Depleted Wells in the Sultanate of Oman
Authors: Nunez Alvaro Javier , Sayapov Ernest , Benchekor Ahmed , Al Husaini Nasser Khalfan , Al Kendi Al Muntaser , Khalil Mohamed Amin , Al Awaisi Asma Ali Salim , Al Kharusi Sharifa Saif 
Published: September 2021

Abstract
Post frac cleanout and milling operations are considered some of the most critical activities that leverage on the operational benefits of coiled tubing. Therefore, they deserve the highest focus on continuous improvement and planning since the associated efficiency gains are often immediately quantifiable. This paper will focus on the improvement and optimization of post frac cleanout and milling strategies in extremely depleted wells in the Sultanate Of Oman. The gains from such optimization helped improve wells delivery and overall performances.
Plug and perf methodology is still the preferred placement method of hydraulic fractures. One of the main challenges in depleted wells is the need for cleanout and plug milling after each stage to avoid risk of CT becoming stuck either differentially due to depletion or mechanically with plug cuttings in case circulation is lost. For years the frac and mill concept was adopted to complete those wells, resulting in frequent delays to frac operations and huge cost impact to the overall project. An efficiency improvement plan was agreed upon to address this particular challenge. A step-by-step strategy improvement plan was developed via in-depth analysis of frac initiation and reservoir characteristics in order to combine together multiple stages of post-frac cleanout and milling activities. This was done through unique software simulations and fluid selection criteria to achieve the lowest possible bottom hole pressure to minimize the losses in addition to the highest possible lifting velocity and best carrying medium conditions. Moreover, the utilization of engineered fluid solutions with foaming agent and foam generator have demonstrated significant added value through enhancement of carrying fluid properties while achieving the lowest possible settling velocity, which in turn lead to the highest possible velocity factor.
After completing the agreed optimization plan, a post frac cleanout with 6-plug milling was performed in a single combined stage instead of multiple individual stages. This improvement reduced the overall frac operation for 6 stages from nearly 30-35 days to 19-20 days. Understanding the field and reservoir pressures in addition to fluid selection for both post frac cleanout and milling operation is crucial to successful implementation of this methodology. This achievement was delivered through a collaboration between many different business units from design to execution and it will help Petroleum Development Oman PDO on the future planning of hydraulic fracturing activity. The completion of the entire wells (well delivery) was achieved in a significantly shorter period of time compared to previous wells; this is reflected on actual cost reduction of more than 20% of total cost/AFE.
Well Cutting Without Explosives with Multiple Cuts on a Single Run
Authors: Ghannam Hanan , Mourani Houssam , Schwanitz Brian Joseph 
Published: September 2021

Abstract
Pipe cutting operations are often a critical part of stuck pipe situations, well interventions and plug and abandon operations which all need to remove cut sections of pipe from the well. Unlike traditional ‘blade’ style e-line cutters, which can jam under pipe compression or explosive pipe cutters, which need to dress-over the jagged cut by the rig, a new electric line mechanical cutter's unique design enables performance even if the pipe is under compression, in tension or is neutral. It can also perform multiple cuts in the same run, while creating a clean and machined cut with tool-entry friendly shape.
This paper will describe the technology of the new generation cutter, present two case histories; one of multiple cuts of stuck drill pipe, per each run in hole, from Germany and one of a critical tubing cut from a subsea well in Nigeria, using electric wireline and tractor conveyed services for many tasks traditionally performed with coiled tubing in highly deviated wells. These "light vs heavy" solutions can often be done off-line from the rig.
Stranger Things 2: Unconventional Deployment Method of High Performance Lightweight Cement Enables Success in Complex Wells
Authors: Shine Joe , Qasmi Urooj , Gbemiga Ilesanmi 
Published: September 2021

Abstract
There are advantages to using high performance lightweight cement when encountering low bottomhole pressures. The most notable are maintaining wellbore stability during cement placement and the isolation of potential flow zones to achieve the wellbore construction objectives. Several complex wells sought these advantages for similar situations. A review of the deployment process for using high performance lightweight cement conventionally, including the quality assurance measures, initially deemed it as not a viable option. As the complex wells needed a technical solution, an unconventional deployment method for high performance lightweight cement enabled its use while simplifying and improving quality assurance; allowing achievement of the isolation requirements.
Manuscript Title: Mechanical and Microstructural Studies of Volcanic Ash Beds in Unconventional Reservoirs
Authors: Acosta Juan C , Curtis Mark E , Sondergeld Carl H , Rai Chandra S 
Published: September 2021

Abstract
Volcanic ash beds are thin layers commonly observed in the Eagle Ford, Niobrara and, Vaca Muerta formations. Because of their differences in composition, sedimentary structures, and diagenetic alteration, they exhibit a significant contrast in mechanical properties with respect to surrounding formation layers. This can impact hydraulic fracturing, affecting fracture propagation and fracture geometry. Quantifying the mechanical properties of ash beds becomes significant; however, it is a challenge with traditional testing methods. Common logging fails to identify the ash beds, and core plug testing is not possible because of their friability.
In this study, nanoindentation was used to measure the mechanical properties (Young's modulus, creep, and anisotropy) in Eagle Ford ash beds, and to determine the contrast with the formation matrix properties. Two separate ash beds of high clay and plagioclase composition were epoxied in an aluminum tray and left for 48 hours curing time. Horizontal and vertical samples of ash beds were acquired and mounted on a metal stub, followed by polishing and broad beam ion milling. Adjacent samples were also prepared for high-resolution Scanning Electron Microscope (SEM) microstructural analysis.
The Young's modulus in ash beds ranged from 12 to 24 GPa, with the horizontal direction Young's modulus being slightly greater than that of the vertical samples. The Young's modulus contrast with adjacent layers was calculated to be 1:2 with clay-rich zones and 1:4 with calcite rich zones. The creep deformation rate was three times higher for ash beds compared to other zones. Using Backus averaging, it was determined that the presence of ash beds can increase the anisotropy in the formation by 15-25%. SEM results showed a variation in microstructure between the ash beds with evidence of diagenetic conversion of rhyolitic material into clays. Key differences between the two ash beds were due to the presence of plagioclase and the occurrence of porosity within kaolinite. Overall porosity varied between the two ash beds and adjacent carbonate layers showing a significant increase in porosity.
Understanding the moduli contrast between adjacent layers can improve the hydraulic fracturing design when ash beds are encountered. In addition, the presence of these beds can lead to proppant embedment and loss in fracture connectivity. These results can be used for improving geomechanical models.
Combining Capacitance Resistance Model with Geological Data for Large Reservoirs
Authors: Davudov Davud , Mabadeje Ademide O. , Malkov Anton , Venkatraman Ashwin , Dindoruk Birol 
Published: September 2021

Abstract
Capacitance resistance models (CRM) are amongst more popular reduced physics-based models that provide quantitative first order estimate of inter-well connectivity using production and injection data (without geology). However, application of these models to mature fields with large number of wells along with historical data and varying operating conditions is challenging and computationally expensive. In this study we present a novel hybrid approach that combines CRM with geological data for application to large reservoirs.
CRM models are used to obtain interwell connectivity values from production and injection data. These models assume that all well pairs are connected and this increases number of unknowns especialling when applying to larger domain (larger mature fields with over 500 wells) get To overcome this limitation, we obtain radius of investigation (ROI) for every injector using Fast Marching Model (FMM) that characterizes the field based on the geological data. Specifically, FMM is used to determine unrelated producer-injector pairs and ROI for each injector that reduce the number of unknowns and hence computational complexity. This hybrid model approach is validated by comparing results with a standalone CRM model for both a synthetic case and field case study.
We use numerical simulation to validate results from the proposed method using synthetic data for a producing field with 5 producers and 4 injectors. The FMM accurately identifies unrelated injection-production pairs to reduce the number of unknowns in CRM model by 35% (20 to 13). After a conceptual validation, we apply this hybrid approach to a mature field with 29 injectors and 46 producers where the number of unknowns are further reduced by 57% after identifying non-related pairs using FMM. This results in significant speedup of computations as compared to a standalone CRM approach.
In summary, a hybrid model of geology and CRM is proposed and has been validated using synthetic and field data. This combination of two reduced-physics models (CRM and FMM) decreases computational speed. Large mature field operators can use this hybrid approach to address shortcomings of deploying a standalone CRM approach for the entire field. The deployment of a hybrid CRM approach is greatly beneficial to continuously optimize mature fields based on the data being collected given the increasing focus of digitization to deliver ROI.
Miscible Flooding for Bitumen Recovery with a Novel Solvent
Authors: Mathews Tanya Ann , J.Cortes Alex , Bryant Richard , Hascakir Berna 
Published: September 2021

Abstract
Steam injection is an effective heavy oil recovery method, however, poses several environmental concerns. Solvent injection methods are introduced in an attempt to combat these environmental concerns. This paper evaluates the effectiveness of a new solvent (VisRed) in the recovery of a Canadian bitumen and compares its results with toluene. While VisRed is selected due to its high effectiveness as a viscosity reducer even at very low concentrations, toluene is selected due to its high solvent power.
Five core flooding experiments were conducted; E1 (Steam flooding), E2 (VisRed flooding), E3 (Toluene flooding), E4 (Steam + Toluene flooding), and E5 (Steam + VisRed flooding). Core samples were prepared by saturating 60% of the pore space with oil samples and 40% with deionized water. The solvents were injected at a 2 ml/min rate, while steam was injected at a 18 ml/min cold water equivalent rate. Produced oil and water samples were collected every 20 min during every experiment. The oil recovery efficiencies of the core flood experiments were analyzed by the emulsion characterization in the produced fluids and the residual oil analysis on the spent rock samples.
The best oil recovery of ~30 vol % was obtained for E2 (VisRed) in which VisRed was injected alone. Although similar cumulative recoveries were obtained both for E2 (VisRed) and E3 (Toluene), the amount of VisRed injected [~1 pore volumes (PV)] was half the volume required by toluene (~2 PV). The produced oil quality variations are mainly due to the formation of the water-in-oil emulsions during mainly steam processes (E1, E4, and E5). The increased amount of the polar fractions in the produced oil enhances the formation of the emulsions. These polar fractions are namely asphaltenes and resins. As the amount of the polar fractions in the produce oil increases, more water-in-oil emulsion formation is observed due to the polar-polar interaction between crude oil fractions and water. Consequently, E1 and E5 resulted in more water in oil emulsions. The cost analysis also shows the effectiveness of solvent recovery over steam-solvent recovery processes.
An Investigation on the Process of Re-Imbibition of Oil and its Impact on Oil Recovery in the Yates Field
Authors: Jin Xiao , Phatak Alhad , Sanders Aaron , Friesen Dawn , Lewis Ed , Valdez Raul 
Published: September 2021

Abstract
In mixed- to oil-wet reservoirs characterized by intense natural fracturing where the dominant displacement mechanism is gravity drainage, surfactant injection can lead to a shift in wettability and incremental oil production. In some cases, oil can also re-imbibe back into the rock matrix after the oil saturation has been reduced upon initial exposure to surfactant, suggesting limited permanence in the wettability shift. The re-imbibition phenomenon is investigated in this paper utilizing Amott cells.
Three cationic surfactants (C12-, C12-16-, C16-based) solutions with interfacial tensions (IFT) between 0.18 to 0.95 mN/m were pre-selected to be evaluated. Current applications of the C12- based surfactant in the Yates field is considered successful based on incremental oil recovery seen during the treatment. Silurian dolomite rock samples were flooded with Yates crude oil before being aged at 140 °F for 6 weeks. For the imbibition tests, synthetic brine was set as the external phase within the Amott cell and the recovery of oil was recorded periodically. After the imbibition tests ended, the rock samples were placed in an inverse Amott cell with the Yates oil as the external phase.
Baseline tests were first conducted to show that without a surfactant in the oil or brine, no imbibition occurred. With a surfactant concentration of 3,000 ppm, oil recovery at the end of the imbibition tests varied from 34% to 64% of the original oil volume in the core sample. During the re-imbibition test, a large amount of oil was able to re-imbibe into the rock, displacing the brine. Most of the displacement occurred within the first two weeks. The net oil recovery, taken as the final volume of oil recovered in the imbibition test minus the final volume of oil re-imbibed into the rock, ranged from 0% to 18%. Given the possibility of surfactant dilution in field applications, another set of tests were conducted with 1,500 ppm. A reduction in oil recovery during imbibition was observed for both the C12- based surfactant and the C12-16- mixture. Partition coefficients were determined for each of the tested surfactants and the ion pair mechanism was used to explain the net oil recovery results. Lastly, the impact of rock permeability on re-imbibition was investigated. Results show increasing permeability may lead to a linear response in oil re-imbibition,therefore minimizing the permeability range when selecting rock samples may be necessary when conducting the re-imbibition test.
The importance of oil re-imbibition is demonstrated in the experimental study and we make an argument for conducting both the imbibition and re-imbibition tests to better evaluate surfactant efficacy. The improved understanding of wettability alteration should lead to advancements in chemical enhanced oil recovery designs for field treatments.
Evaluation and Modeling of Asphaltene Deposition in Oil Wells
Authors: Al-Safran Eissa , Al-Ali Batoul , Alrashidi Hessah 
Published: September 2021

Abstract
Asphaltene deposition in oil wells is a challenging flow-assurance phenomenon that affects the well production, project economics, and operational safety. While asphaltene precipitation is governed by the hydrocarbon mixture thermodynamics, Asphaltene deposition is governed by the complexity of flow hydrodynamic behavior and characteristics. This study aims to evaluate and compare the performance of the existing asphaltene deposition models and improve the current theoretical understanding of the deposition phenomenon by developing better predictive asphaltene deposition model. A large experimental database is collected, including aerosol and asphaltene particles deposition in air and crude oil systems, respectively, to carry on the evaluation. The results of this study revealed that Kor and Kharrat (2017) model of transport coefficient, which accounts for both diffusional and inertial deposition mechanisms outperformed other models in matching the transport coefficient from aerosol/air data. In addition, an improved sticking probability model is proposed in this study, and curve fitted using corrected deposition flux data to obtain the model constant. The improved model is not only physically sound, i.e. SP≥1, but also it requires less input data than other models. A validation study of the improved model shows a slight over prediction of experimental data with an absolute average error of 6.8% and standard deviation of 11.4%. The significance of this work is to provide theoretical predictive tool for asphaltene deposition in pipes to enable prevention, mitigation, and management of oil field asphaltene deposition strategies.
A Computational Fluid Dynamics Protocol for The Hemodynamic Analysis of a Microfluidic Model of Thrombosis
Authors: Zhao Yunduo Charles , Keogh Sarah Elizabeth , Vatankhah Parham , Preketes-Tardiani Renee Ellen , Ju Lining Arnold 
Published: September 2021

Abstract
Thrombosis is both attributed to biochemical agonists and mechanical stresses applied to platelets. Whilst the effect of biochemical agonists has been extensively studied, the mechanosensitive factors remain poorly defined. Stenotic microfluidic channels mimic the narrowing vessels, providing the real-time observation of platelets under disturbed flow. Though the experimental analysis of platelets in disturbed flow confirms the mechanosensitive behavior of platelets, it cannot explicate detailed thresholds for platelet activation. Computational Fluid Dynamics (CFD) could be utilized alongside experimental analysis to characterize thresholds for platelet behavior under imposed shear stress. CFD simulations, however, are prone to uncertainties and errors which should be minimized to obtain compelling results. Hereby, we have presented a CFD protocol for researchers in the field of microfluidic and hemodynamic studies.
EZR Promotes Pancreatic Cancer Proliferation and Metastasis by Activating FAK/AKT Signaling Pathway
Authors: Xu Jian , Zhang Wei 
Published: September 2021

Abstract
Introduction: As a member of the ERM (ezrin-radixin-moesin) protein family, EZR has been recognized as a regulator of adhesion signal pathways by researchers. Moreover, EZR was thought to play irreplaceable roles in invasion and metastasis of versatile cancers. In this study, we managed to undermine the effect of EZR on proliferation and metastasis in pancreatic cancer (PC).Methods: To analyze the impact of EZR expression on overall survival and free diseases survival of PC patients, we screened abnormally expressed EZR in PC using the Gene Expression Omnibus database(GEO database) and The Cancer Genome Atlas (TCGA) database. Following, Gene Ontology (GO)-based functional analysis and Gene set enrichment analysis (GSEA) was performed to predicate the possible biological processes in which EZR were involved. The clinicopathological characteristics and prognosis of PC patients were analyzed according to clinical data. Further, immunohistochemistry, western blotting and real time PCR analysis were conducted to analyze the expression level of EZR in PC and paired paracancerous tissues. The effect of EZR on proliferation of PC cell lines were detected by Cell Counting Kit-8 assay, and meanwhile, Transwell assay was performed to detect the effect of EZR on invasion and migration of PC cell.Result: EZR exhibited higher expression level in pancreatic cancer tissues and cell than paracancerous tissues and cell, and its expression level was positively correlated with poor overall survival and diseases-free survival in PC patients. CCK8 assay indicated that EZR facilitated the proliferation of PC cells, meanwhile, Transwell assay showed that EZR promoted the migration and invasion of PC cells. The GO analysis predicated that EZR was involved in biological processes including cell adhesion, ameboidal-type cell migration, cell junction assembly. Through GSEA analysis, pancreatic cancer pathway, and the adhesion junction pathway were screened as the mostly enriched pathways in EZR-regulated pathological process. The inhibition of EZR suppressed proliferation and migration of PC cells. Western blot experiment revealed a positive correlation between EZR and FAK, the proliferation invasion and migration ability of PC cells were significantly decreased after knockdown of EZR.Conclusion: Our finding revealed EZR accelerated the progression of PC via FAK/AKT signaling pathway.
Mixed Methods Evaluation of Simulation-Based Training for Postpartum Hemorrhage Management in Guatemala
Authors: Parameshwar Pooja S. , Bianco Katherine , Sherwin Elizabeth B. , Meza Pamela K. , Tolani Alisha , Bates Paige , Sie Lillian , Enríquez Andrea Sofía López , Sanchez Diana E. , Herrarte Edgar R. , Daniels Kay 
Published: September 2021

Abstract
Background

To assess if simulation-based training (SBT) of B-lynch suture and uterine balloon tamponade (UBT) for the management of postpartum hemorrhage (PPH) impacted provider attitudes, practice patterns, and patient management in Guatemala, using a mixed-methods approach.
Methods

We conducted an in-country SBT course on the management of PPH in a governmental teaching hospital in Guatemala City, Guatemala. Participants were OB/GYN providers (n = 39) who had or had not received SBT before. Surveys and qualitative interviews evaluated provider knowledge and experiences with B-lynch and UBT to treat PPH. In addition, a retrospective chart review was performed to evaluate management of PPH over a 2-year period before and after the introduction of SBT.
Results

Multiple-choice surveys indicated that providers who received SBT were more comfortable performing and teaching B-lynch compared to those who did not (p = 0.003 and 0.005). Qualitative interviews revealed increased provider comfort with B-lynch compared to UBT and identified multiple barriers to uterine balloon tamponade implementation. Chart review demonstrated an increased use of UBT after the introduction of simulation-based training, though not statistically significant (p = 0.06) in contrast to no change in B-lynch use.
Conclusions

Simulation-based training had a stronger impact on provider comfort with B-lynch compared to uterine balloon tamponade. Qualitative interviews provided insight into the challenges that hinder uptake of uterine balloon tamponade, namely resource limitations and decision-making hierarchies. Capturing data through a mixed-methods approach allowed for more comprehensive program evaluation in low and middle income countries (LMICs).