bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling of Stimulation Fluid Placement and Flow in Carbonate Reservoirs
Authors: Wilson Sam , Hammonds Paul , Graham Gordon M. , Nichols David , Bellio Hanen Ben Abdallah , Azuddin Farhana Jaafar , Sazali Yon Azwa , Sauri Ahmad Shalabi M 
Published: February 2022

Abstract
We report the development of a model to support matrix-based stimulation treatments in limestone reservoirs that takes information directly from data obtained during core flooding, such that the model can be calibrated against a variety of novel stimulation fluids under conditions directly representative of the candidate field. The model builds on an earlier stimulation model developed for clastic reservoirs, which primarily addressed stimulation as a formation-damage-removal phenomenon; it maintains the 3-dimensional aspects of the earlier model but incorporates the substantially greater complexity required in coupling the damage-dissolution reactions to the hydrodynamic phenomena associated with the formation of wormholes. Wormholes are an ideal method of stimulating carbonate reservoirs (in the absence of massive hydraulic fracturing) but their formation is stochastic, anisotropic, and involves greater morphological changes. Hence, successful stimulation depends on formulation chemistry, application rates, rock morphology, pressure, and temperature. This initial model has been calibrated to describe the behaviour of a selection of non-standard stimulation fluids, which have been evaluated in part through core-flood performance. The reaction-rate data for these novel fluids was abstracted from a series of core flood experiments with effluent and morphological analyses. The user interface provides easy condition input and selection and provides a clear output of results. Future developments will expand the model to a broader range of conditions and chemical formulations.
New Single-Step Acidizing Technique Treats Severe Fines Damage Over a Wide Range of Temperatures and Mineralogies
Authors: Houchin Lanne R. , Granizo Dorian , Conine Joseph 
Published: February 2022

Abstract
Most sandstone reservoirs in shallow water continental shelf fields are fully mature and require economical low-risk stimulation treatments to achieve maximum recovery. The once characterized "New Fronter" developments in Deepwater and Ultra Deepwater are also entering the mature, end of life status. 2019 had the largest increase in acid stimulation treatments ever in the Deepwater Gulf of Mexico. This study focused on identifying a HF acid derivative treatment that could be used as a single-step sandstone acid treatment, with all the associated benefits, but would not require acid flowback services. Five commercially available buffered, retarded, and HF derivative acid chemistries were tested to determine the risks of facility upsets. Laboratory tests showed that these HF derivative acid chemistries had varying levels of potential facility upset risk in either viscous emulsion formation or overboard water quality noncompliance. A new Fluoroboric Acid (HBF4) chemistry was developed building on 80 years of well-known performance history. This chemistry has all the benefits of HBF4, is compatible with most sensitive minerals and does not cause facility upsets. Ninety-three treatments were done in the eastern and central US GOM without the expense of flowback equipment. These treatments resulted in an 88% economic success rate and only 2 short term oil and grease noncompliance instances in the facilitie overboard water discharge.
Time Lapse Wear Study Yields New Design Features to Improve the Erosion Resistance of Stand-Alone Screen Completions
Authors: Malbrel Christophe A. , Kale Rakesh 
Published: February 2022

Abstract
As operators focus on harvesting stranded reserves from existing infrastructures, specific technical challenges and ROI calculations are affecting sand control completion selection and putting screen design requirements in a new light. In-fill drilling and completion of sidetracked wells in depleted reservoirs are not favorable to gravel packing because low hydraulic frac pressures and small wellbores make conventional gravel packing operations incredibly challenging, if not downright impossible. Furthermore, gravel packing is selected when operators are looking for a long-term sand control solution warranted by significant reserves, something that is not necessarily present in brown field redevelopments. As a result, there is a need to improve stand-alone completions, and particularly improve the erosion resistance of screens that have been known to fail by hot spotting, where localized high flow situations erode the screen and lead to completion failure.
A series of time lapse erosion tests was conducted to identify critical damaging mechanisms and evaluate solutions, including mesh materials and design features to improve the erosion resistance of mesh screens. The test program included detailed examination of the test coupons in frequent intervals to identify wear features and trends over time. This approach to testing was instrumental in characterizing damaging backward eddies inside the screen and developing solutions to mitigate their impact.
From this test campaign, two new features were found to substantially improve screen erosion resistance. A hardening process to treat meshes commonly used in screens increased the Mean Time to Failure (MMTF) by 50%. Furthermore, a novel shielding concept aimed at preventing direct line-of-sight flow to the basepipe perforations (while maintaining the filter surface area and good flow distribution over the screen length) reduced mesh weight loss by 75% and maintained the original maximum pore size beyond the 72hour success criteria, for an estimated MTTF improvement well over 300%.
Matrix Stimulation Treatments Using Non-Corrosive and Environmentally Friendly Systems: A Decade of Experience Across a Variety of Romanian Fields
Authors: Panait Emil , Zecheru Mihaela , Dragomir Alexandru , Dos Santos Auribel , Lopez Fabian 
Published: February 2022

Abstract
Because of the challenges commonly associated with matrix acidizing, chelating agents are increasingly reinforcing their good reputation as standalone alternative treatments in oil and gas wells worldwide. Systems based on GLDA and DTPA have been extensively used in tens of limestone and sandstone Romanian reservoirs over the past decade. This paper offers useful insights, design criteria and best practices based on substantial field experience that led to remarkable productivity boost in more than 50 wells.
From deep and high temperature sour-wells, to shallower heavy oil plays. From inland oil producing assets to offshore gas condensate fields. Field applications included wells in sandstone, limestone and dolomite and placement involved foam and plain injection both via coiled tubing and bull-heading. The different stimulation campaigns involved a comprehensive laboratory evaluation, structured damage assessment followed by detailed treatment designs and execution. Experiments included both core-flood tests through limestone cores at 120 deg. C and solubility evaluation of mineral deposition at downhole conditions after scale characterization showed presence of sulphate-rich minerals like CaSO4 and BaSO4.
Results of experimental evaluation showed creation of highly conductive wormholes without signs of face dissolution despite low injectivity. Solubility of challenging scales achieved dissolution from 43% to 78% in formulations containing DTPA and GLDA. Fully compatible with well completion components including sensitive equipment and jewelry like ESP was found. Bottle tests using challenging heavy crude oil demonstrated not only complete compatibility without signs of sludge, emulsions or precipitates but it also exhibited unexpected benefits in viscosity reduction during lab evaluation and field implementation. Experimental evaluations were followed by field execution that covered over 60 matrix stimulation treatments across 10 fields using chelating agent-based formulations of Glutamic-Acid-Diacetic-Acid (GLDA) and Diethylene-Triamine-Pentaacetic-Acid (DTPA). The outcome was a substantial increase in wells productivity with 2-3 times of improvement (TOI) in average and 30 % reduction of downtime without safety, environmental or asset integrity issues.
Field results achieved and summarized in this paper demonstrate the efficacy of the methodology employed for productivity diagnosis. In addition, the numerous benefits of using chelating agents as standalone stimulation systems were corroborated. Described criteria and lessons learned represent a concise and useful tool to facilitate fluid selection and matrix treatment design in challenging field conditions with multi-functioning, non-corrosive, biodegradable and safe chemicals.
Rapid Curing Environmentally Degradable Polymeric Pill for Loss Circulation Treatment
Authors: Magzoub Musaab , Salehi Saeed , Hussein Ibnelwaleed , Nasser Mustafa , Ghalambor Ali 
Published: February 2022

Abstract
Loss circulation is frequent while drilling in naturally fractured or depleted reservoirs, which is usually associated with high non-productive time (NPT). Moreover, naturally pre-existing fractures may propagate when fluid pressure inside the fractures exceeds the minimum principal stress. The primary objective of this paper is to investigate the operational performance of a quick applying polymeric pill to treat severe loss circulation in highly fractured formations. To strengthen the wellbore in the presence of large fractures, proper size and concentration of loss circulation materials (LCM) are required. In this paper, a crosslinked polymer comprised of inorganic crosslinker (Aluminum-Acetate) is used to cure severe loss circulation by completely sealing fractured or high permeable formations. To achieve this, the project investigated the rheological behavior, mechanical properties, gelation mechanisms, and the filtration of the crosslinked polymer through an artificial fracture. The effect of concentration, temperature, pH, and salinity on the stability and gelation process was also assessed.
The rheological properties of polyacrylamide/Aluminum-Acetate (PAM/AlAc) in aqueous solutions, with concentrations varying from 1 to 3 wt.%, were highly affected by pH, time, and shear rates, while temperature changes have less impact. The Aluminum-Acetate has a broad operational window and can form a strong gel in temperatures ranging from 75°F to 260°F. Nanosilica (NS) in small quantities less than 1% was found to enhance the stability and strength of the polymer. The results revealed that the gelation time of the Aluminum-Acetate is controllable at pH conditions between 3.5 and 8.5, and the most stable gel was formed in the temperature range from 65°F to 212°F. Fracture sealing experiments demonstrated the ability of (PAM/AlAc) to form a strong plug with sealing pressure of up to 700 psi. In general, the Aluminum-Acetate reinforced with nanosilica has great potential applications in curing severe loss circulation in high fractured formations under a wide temperature range. This paper describes a detailed method of mixing and preparing stable and functioning polyacrylamide/Aluminum-Acetate pill for curing a severe loss of circulation. The new proposed aluminum-based salt was investigated as a potential environmentally friendly replacement for the conventional chromium acetate as crosslinkers for polyacrylamide. The paper provides a good understanding of the rheological, mechanical properties, and gelation characteristics, which are important factors affecting the spotting of these pills.
Completion Damage
Authors: Fleming Niall , Taugbøl Knut , Mathisen Anne-Mette , Braadland Ove , Kaarigstad Håvård 
Published: February 2022

Abstract
Formation damage has received significant attention over many years as one of the primary reasons for well productivity impairment, to the detriment of completion damage. The objective of this paper is to redress this imbalance and to focus on the central role that completion damage has on well productivity. Formation damage is a reduction in inflow performance due to damage of the near wellbore, while completion damage is an increased pressure drop effecting the lower completion, e.g., plugging of sand screens. A completion damage classification system is presented for the first time that relates this damage type to lower completion design throughout well lifetime. In addition, a review of some of the fluid qualification tests has been performed.
Fluid compatibility. Computational fluid dynamics (CFD) was used to determine the displacement efficiency from drilling to completion fluid in a candidate well, and hence the mixing ratio of drilling fluid to completion fluid to be used in compatibility tests. Furthermore, CFD simulations provided an indication of the likely shear rates occurring during displacement that were later used in the testing. Fluid stability. To determine the influence of sag on fluid displacement efficiency, CFD was used to model the worst-case situation where all the weighting agent came out of suspension.
Using the displacement efficiency and shear rates obtained, a new dynamic completion damage test was devised to determine the potential for screen plugging. Finally, an overview will be presented of how Equinor's approach to completion damage has changed because of this study, with increased focus on achieving a better balance in the evaluation of formation and completion damage.
Evaluating the Performance of Fluid Placement Approaches on Well Stimulation Results
Authors: Kumar Sanjiv , Davidson Brett , Abouakar Ahmed Hassan 
Published: February 2022

Abstract
Oil and gas production or water injection is sometimes hampered by wellbore scales and fills (i.e., inner well flow impediments) as well as formation damage (skin) that impedes flow. Formation damage may reside in the near wellbore region but could also extend deep into the formation. While the severity of the skin may vary from well to well the mechanisms of damage are generally mechanical, chemical, biological, or thermal in nature. Whereas a formation with no damage would have a skin factor of zero a well with serious damage may have a skin factor of 20 or greater. Formation damage impairs rock permeability which directly impacts oil and gas production or water injection operations hence the economics of the oil and gas field.
Well stimulations to address formation damage are accomplished through a variety of techniques but most commonly through chemical (acid) treatments to restore a wells productivity or injectivity. Often, due to permeability heterogeneity, common stimulation approaches do not provide maximum volumetric contact of treatment fluids with the formation. To maximize volumetric contact of the treatment fluid with the formation and across the entire completed interval, it is of utmost importance to employ a technique that can overcome the challenges of permeability heterogeneity to improve post-stimulation outcomes.
Investigation of Parameters Controlling Equivalent Circulating Density ECD in Managed Pressure Drilling MPD
Authors: Ashena Rahman , Bahreini Hossein , Ghalambor Ali , Sahraei Eghbal , Ahmad Loi Darab Majid 
Published: February 2022

Abstract
In Managed Pressure Drilling (MPD), it is possible to drill holes that simultaneously expose formations with narrow safe mud windows and with pore pressures close to the fracture pressures of other exposed formations with minimal formation influx or mud losses, and also minimal future formation damage during production. In Continuous Circulation Systems (CCS), as a sub-class of MPD, the dynamic or circulating pressure is adjusted to control formation pressures. Therefore, the key factor in success of CCS and prevention of unprecedented formation damage is Equivalent Circulating Density (ECD). This is because a small error in calculation of the ECD can cause a kick influx or drilling fluid loss. Therefore, there is a strong need to investigate the effects of various parameters affecting ECD, which is the objective of this work.
In this study, a section of a vertical annulus was simulated using Computational Fluid Dynamics (CFD) in 3-D and 2D to determine the effects of different affecting parameters on ECD. The seven investigated parameters in this section consist of DP rotational speed, eccentricity, rate of penetration (ROP), cuttings size, drilling fluid density, rheological parameters, and radius ratio (of drill-pipe OD to wellbore diameter).
The CFD simulation results show that the ECD of MPD may be significantly affected by the aforementioned parameters. The ECD shows to change due to unprecedented change of the aforementioned affecting parameters. This can potentially jeopardize the MPD drilling operation success. Among the parameters, in laminar flow, radius ratio Yield Point and ROP showed the greatest effect on ECD whereas in turbulent flow radius ratio, PV and mud density showed to have the greatest effect with the other parameters to have minimal effects.
Dimensionless Artificial Intelligence-Based Model for Multiphase Flow Pattern Recognition in Horizontal Pipe
Authors: AL-Dogail Ala , Gajbhiye Rahul , AlNajim Abdullatif , AlNaser Mustafa 
Published: February 2022

Summary
Multiphase flow analysis attracts a lot of attention from researchers from diverse disciplines. There are several studies including experimental, theoretical modeling, and numerical analysis that were carried out to investigate the multiphase flow. However, many facets of multiphase flow are still unresolved owing to the extremely complex nature of the multiphase flow. The complex interactions of the different phases are leading to different flow regimes that are difficult to predict but essential for developing the computational model. The identification of the flow pattern is still a challenging task. One of the growing fields is the machine learning approach, which can address such complex problems. This study aims to use machine learning to develop models that can identify the flow patterns in multiphase flow.
To achieve the objective, a large set of experimental data was collected. The effect of fluid properties, such as density, viscosity, and surface tension, on the flow pattern was introduced by changing the fluid properties. The wide range of data was processed by applying a machine learning technique for predicting the flow regimes. The models were built using dimensionless parameters to extend their validity for various design and operational conditions. This approach enables to capture the main flow pattern as well as subcategories of flow patterns in the horizontal pipe. Comparison and analyses of the different machine learning tools were carried out to investigate classification of multiphase flow patterns.
The results showed that different artificial intelligence (AI) methods can predict the flow pattern in horizontal pipes with high accuracy. The results of using Reynold’s number for liquid (ReL) and gas (ReG) as an input to predict the flow patterns are deficient in accuracy for the support vector machine (SVM) and discriminant analysis (DA). However, the prediction capability of the model was improved by introducing Weber’s number for liquid (WeL) and gas (WeG) along with the Reynolds numbers (ReL and ReG). The improvement in the flow pattern prediction owing to the introduction of Weber’s number is speculated because of the capturing hydrodynamic phenomenon (inertia and surface tension) owing to change in fluid properties. It infers that capturing hydrodynamic phenomena affecting the flow pattern and their transition is essential for the prediction of flow patterns in multiphase flow.
Intraneural Ganglion Cyst of The Ulnar Nerve Causing Cubital Tunnel Syndrome: Two Case Reports.
Authors: Casula Ilaria , Gras Mathilde 
Published: February 2022

Abstract
We present two cases of cubital tunnel syndrome caused by intraneural ganglia of the ulnar nerve at the elbow. This is a rare presentation for this type of ganglia, much more frequent at the peroneal nerve. An association between a history of trauma and the development of the synovial cyst is observed, therefore adequate preoperative imaging such ultrasound or MRI should be prescribed to better plan surgical treatment, in case of identified trauma. Drainage of the cyst and excision of its envelop under loupes magnification appears to be a correct and sufficient treatment when no articular nerve branch is found.
mecA-gene detection and MDR profile of S. aureus isolates from patients attending the Referral Hospitals of Amhara Reginal state, Ethiopia
Authors: Moges Feleke , Tamiru Tadele , Amare Azanaw , Mengistu Getachew , Eshetie Setegn , Dagnew Mulat , Feleke Tigist , Gizachew Mucheye , Abebe Wondwossen 
Published: February 2022

Abstract
Background: Staphylococcus aureus causes different types of human infections and has the ability to develop resistance to many antibiotics. There is a scarcity of data on the mecA gene and MDR profiles of this organism in developing countries, like Ethiopia. The aim of the present study is, therefore, to investigate MDR profiles and the mecA-gene profile of S. aureus from Referral Hospitals of Amhara Reginal State. Methods: Of the total of 110 isolates collected from Amhara Region Referral Hospitals, 70 MDR isolates were further processed for isolation of S. aureus mecA gene. Genomic DNA was isolated using SIGMA ALDRICH genomic DNA isolation Kit for Gram positive bacteria. Amplification of S. aureus mecA gene was done using amplicon size of 533 bp. Agarose gel electrophoresis was prepared with 1.5% agarose by TAE solvent and 0.5μg/mL of ethidium bromide. Electrophoresis was carried out for 1 hour and a half (7 Volts/ cm²) in 1X tris acetate EDTA (TAE) buffer. Data were analysed by using descriptive statistics.Results: The Majority of the isolates were recovered from patients aged less than 5 years, 51 (36.7%) and least from age greater than 60 years, 6 (4.3%). Most of the isolates were from blood, 61 (43.9%), followed by wound, 45 (32.4%). High resistance rate was observed in penicillin 81 (73.6%), followed by cotrimoxazole 78 (70.9%), ceftriaxone 76 (69%), erythromycin 66 (60%) and tetracycline 65 (59.1%). Phenotypically, considering cefoxitin as a surrogate marker, 38 (34.5%) of the isolates were methicillin-resistant. The overall MDR isolates were 92 (83.6%). The PCR amplification result of mecA gene was 14 (20%).Conclusions and recommendations: There is a high rate of MDR and MRSA isolates of S. aureus. PCR amplification result indicates 20% of MRSA isolates are mecA gene producers. Largescale study for detection of MDR strains of S. aureus including MRSA using molecular techniques should be encouraged in the Amhara region.
Case Report: A Rare Case of Brain Metastases in an Elderly Patient with Primary Pancreatic Cancer
Authors: Rajpal Sharad , Taha Hash Brown , Kvascevicius Lukas , Burneikiene Sigita 
Published: February 2022

Abstract
Pancreatic adenocarcinoma is an extremely aggressive cancer with a low survival rate. Common sites for metastases include the liver and lungs while brain metastases are considered extremely rare, especially in elderly patients. We present an elderly female patient who developed brain metastases 51-months after the initial diagnosis of pancreatic cancer and was treated with gross tumor resection, chemotherapy, and stereotactic radiosurgery. The treatment completely resolved her neurological symptoms but did not result in improved survival for this patient. The patient developed generalized tonic-clonic seizures and was diagnosed with leptomeningeal carcinomatosis and died 5.5 months after tumor resection.