bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well Cementing in an Abnormal Pressure Zone of the Talara Basin: Overcoming Engineering Challenges
Authors: Pingo Abraham , Vera Christian , Soriano Victor Hugo , Villanueva Jaime , Ahmed Ramadan , Hilario Poma Juan , Paredes José Luis 
Published: July 2020

Abstract
The Talara Basin in Perú is a mature oil field where production is extremely marginal, and well-construction designs are tailored to this condition to optimize well costs. However, one well recently drilled in this area was identified with the original reservoir pressure, and the well design was not based on this pressure. As a result, drilling issues such as fluid loss and lost circulation were carefully monitored while trying to control reservoir pressure in a long open-hole section. The challenges faced while cementing a high-pressure zone with controlled fluid losses and achieving well objectives in terms of safety, reliability, and lifetime zonal isolation of the well are discussed.
At the planning stage, a mud density of 13 lbm/gal was considered adequate to control downhole pressure (overbalanced); however, before reaching total depth, signs of high pressure were observed while drilling through a low-permeability formation. Mud density was significantly increased to control the well while monitoring the fluid return. When the mud weight reached 15.5 lbm/gal, losses were reported. Finally, the well was stabilized at 15.8 lbm/gal using different lost circulation pills. This event complicated the cementing operation because it substantially increased the necessary slurry density (16.1-lbm/gal lead and 17-lbm/gal tail). Nevertheless, proper cementing design and effective slurry placement using conventional techniques resulted in successful cementing operation with full cement return to the surface.
High-density cement slurries were successfully mixed and pumped regardless of their highly viscous property. The cementing unit and personnel were able to manage this vital operation without facing major problems. Before bumping the plug, circulating pressure was close to the theoretical value, confirming that the cement slurry column was as per the design without noticeable losses into the formation. Full cement returns confirmed a successful cement placement. Final circulating pressure was 2,370 psi, and it increased to 2,900 psi when the plug was bumped. The cement evaluation log obtained after 24 hours indicated good bonding, effective mud displacement, and a successful cement operation. The well was then fractured and put on production. Neither corrective work nor a well-integrity remediation operation was necessary.
Drilling the abnormally pressurized well was extremely challenging because of unexpected high pressure and associated problems, including working with high-density slurries and using various fluid additives to achieve adequate zonal isolation for future stimulation works. Techniques involved and experiences gained while undertaking this considerably challenging project are discussed in this article.
Stimulation Applications for Carbonate Reservoirs: An Overview of Acidizing Technologies and Methods Used in Pre and Post Salt Reservoirs in Brazil
Authors: Jardim Abrahão , Costa Alberto , Boldrini Alberto , Colbert Felipe , Garcia Fernando , Gachet Raphael 
Published: July 2020

Abstract
Pre and post salt carbonate reservoirs are becoming the main source of hydrocarbon production in Brazil. One of the reasons behind this success is the development of many fields located on pre salt areas along the Brazilian shore. Production optimization is vital for sustainability, which requires efficient methods and technology to stimulate these reservoirs.
The main cost-effective approach used in Brazil to improve the production in carbonate reservoir areas is matrix acidizing. Stimulation fluids are pumped into the formation below the fracture pressure to create wormholes that can bypass near wellbore damage and increase the drainage radius along the wellbore. This study offers an insight of the most common methods and technology used to perform matrix acidizing on offshore carbonate reservoirs in Brazil. The main aspects of the study are fluids selection, pumping strategies, completion design and pressure behavior analysis.
Before 2012, most of the offshore stimulation operations in Brazil were performed on sandstone reservoirs. With the advent of pre salt development this scenario changes drastically leading to a high volume of matrix acidizing on carbonate reservoirs in both post and pre salt zones. The main challenges to designing and executing matrix acidizing on carbonate reservoirs in Brazil are the long reservoir intervals combined with high permeability contrasts, high formation temperature and the need of large fluid capacity to accommodate the required treatment designs. Additionally, super duplex stainless steel metallurgies must be considered for corrosion inhibition protection. To overcome these challenges: first, a proper fluid diversion technique must be employed to distribute the treatment fluid across all targeted zones; next, a proper fluid selection must be made to avoid carbonate face dissolution; and finally, corrosion protection is required for the well bore completion components from the corrosion rates increased by the high temperatures downhole.
The lessons learned and best practices captured over the past decade on more than 250 offshore carbonate matrix acidizing operations has led to much success in the post and pre salt zones of Brazil.
Fluid and Reservoir Characterization from Wireline Formation Tester: Field Examples from Santos Basin Reservoir
Authors: Bertolini Andre , Monteiro Jacyra , Munoz Rodrigo , Colacelli Santiago 
Published: July 2020

Abstract
The objective of this study is to dynamically characterize the reservoir and fluid distribution in a Santos Basin field by using well data including in-situ fluid properties and dynamic reservoir properties from wireline formation tester (WFT), openhole logs, and a simplified structural model of the field. Reservoir pressure measurement, pressure gradients, and fluid identification and sampling are part of the routine wireline suite service to evaluate offshore wells. The ability to extract high-quality reservoir properties from interval pressure transient tests (IPTT) and to measure fluid properties in real time are critical to characterizing laminated reservoirs in early stages, before production tests.
The challenge of characterizing the reservoir and downhole fluid in different intervals of the reservoir as well as assessing reservoir connectivity in early stages of the field evaluation is ably addressed by deploying the latest WFT technologies, including radial probes entry for higher-quality interval IPTT and downhole fluid properties measurement. These measurements and methodology using a dissolved-asphaltene equation of state (EOS) enabled the investigation of compartmentalization or lack of thermodynamic equilibrium in some of the reservoir intervals, providing information for future well data acquisition and field planning decisions. Among downhole fluid measurements, optical density of the formation fluid linearly correlates with reservoir fluid asphaltene content, which in combination with a gas-liquid-asphaltene equilibria modeling enables operators to reduce uncertainty in reservoir connectivity assessment. Different fluid units were identified, on top of each other and most probably disconnected from each other. The technique used is based on comparing the fluid coloration of different collected samples that could be in communication to establish if they could be in equilibrium (same fluid unit) or not.
From an understanding of the fluid distribution and permeabilities of the field, reservoir scenarios are developed to optimize and design future well data acquisition and to improve field development plans.
EOR Screening Methods Assisted by Digital Rock Analysis: A Step Forward
Authors: Manrique Eduardo , Delgadillo Claudia , Maya Gustavo , Gelvis Javier 
Published: July 2020

Abstract
The screening of chemical EOR technologies for a Colombian field was performed using two different screening tools (weighting averages and artificial intelligence). The Alkali-Surfactant-Polymer (ASP) pilot results were compared with the initial screening studies identifying some weaknesses that are addressed in this paper. Additionally, the use of Lattice Boltzmann pore-scale flow simulation approach to support EOR screening studies is also presented.
The screening study was developed using the same input data (e.g. pressure, temperature, porosity, permeability, oil gravity, and viscosity). Screening results and potential reservoir analogs identified using both systems were compared, including the evaluation of the geological parameters that are normally missing in most of screening studies. The results are compared with the ASP pilot performance to validate the effectiveness of conventional screening studies overlooking geologic information. In addition, the results were also confirmed evaluating ASP field cases reported in the literature. Finally, the use of digital rock analysis using micro CT scan images to support ongoing screening results is presented.
Screening results obtained using different screening tools were similar identifying the EOR recovery process (e.g. Chemical EOR). However, the screening results excluding the evaluation of geological parameters such as rock cementation (e.g. sandstone formations with carbonate cement) did not prevent the selection of ASP flooding as an EOR recovery process for the field under study. This was confirmed with the severe scaling problems observed during the ASP pilot test implemented in Colombia as well in Canadian ASP floods. This paper describes the main steps for conducting robust EOR screening studies, including the use of Lattice Boltzmann pore-scale flow simulation to evaluate preliminary performance of oil recovery processes (e.g. waterflooding, polymer and surfactant injection) that contributes to field evaluations and experimental lab design.
The proposed screening approach will contribute identifying the technical and economic EOR potential (from exploratory appraisal to mature field rejuvenation) under conditions of limited information and time constraints.
Static-Fractal Analysis in Petrophysical Model, Field M Case of Success in Cased Hole Completions
Authors: Castellanos Luis 
Published: July 2020

Abstract
The objective of this work is to generate an effective selection of cased-hole completions that contributes to increase the production of M field, contemplating all the necessary technical criteria to ensure that the evaluation formation and static fractal analysis could be advantageous for the reservoir characterization and the determination of well productivity parameters.
We used the Statistic-Fractal analysis inside of petrophysical model known as fractal and geostatistical models whose main purpose is to analyze data for reservoir characterization. That is, through separating data from production log tools and resistivity logs, it is possible to have an accurate picture of the hydrocarbon path through the identification of the repeatable marks of data along the selected well logs from cased-hole completions of the field in study. That representative mark, associated with the knowledge of the internal characteristics of the reservoir (porosity, permeability, fracture systems and faults, Water-Oil Contact) help to obtain better results.
For this scrutiny we analyzed 12 wells (1, 11, 51, 62, 61, 3A, 3Are, 21, 21are, 31,32, 64), from M field in Southeastern Mexico, deep onshore carbonates (average reservoir depth is 6,493 m) producing light oil, with different completions, which include slotted liner, cemented liner with selective perforations and open-hole completions.
This paper describes the process of analysis and selection of new potential intervals to complete and explains the workflow used during the design stage. Statistic-fractal analysis in petrophysical model techniques are discussed together with lessons learned from the wells in terms of production behavior. The importance of this work lies in improving the selection of new locations and completions in mature fields.
Water Source Wells: Challenges to Produce Water. Field Experiences from a Waterflooding Project
Authors: Vasconez Danilo , Farag Sherif , Meneses Alba , Rodriguez Omar , Pastrana Wilmar 
Published: July 2020

Abstract
A water flooding project was initiated in a mature field in the Oriente basin. The shortage of water production for the implementation required the identification of the water source, an infinite aquifer located at the base of existing wells. Next, well integrity, well schematics, well status, water quality and water demand were used to define the best candidates to be converted from oil producers to water source wells. As part of the operational process several issues were solved by the evaluation and implementation of different solutions. To isolate shallower producing intervals, three technologies were applied: traditional cement squeeze, scabliner and casing patch. The latter resulted to be the best technical solution followed by scab liner and cement squeeze. To avoid residual oil zones at the top of the water source reservoir, it was necessary to create a new operative bottom by drilling out cement, landing collars and float collars at the base of the production liner or casing.
As the well productivity index of the water source wells ranges from 8 to 80 BPD/psi and the reservoir pressure is steady at 4,500 psi, electrical submersible pumps are installed in the 9 5/8 production casing at shallow depths. This configuration reduces operational risks and provides the required discharge pressures to reach the injection points. Over the course of the project the perforated interval for water production was continuously optimized, as pressure and water viscosity are mostly constant, and the absolute permeability is quite homogeneous.
These water source solutions proved to be successful for the first phase of the waterflooding project and were extrapolated to other areas of the asset resulting in 16 wells being converted to water source wells, and 3 wells being recompleted as dump flooding wells.
This document can be used as a guide and set of best practices for recompleting wells to produce high quality water from existing wells by integrating reservoir conditions, mechanical configurations and water demand requirements. The analysis of NPT and UPT will also provide additional clues for converting oil producers to water source wells.
Journey to the Center of Vaca Muerta: Unconventional Reservoir Evaluation Yields Optimum Results
Authors: Abitbol Francisco , Casala Santiago , Arillo Facundo , Sifontes Thais 
Published: July 2020

Abstract
The Vaca Muerta (VM) formation, one of the largest unconventional reservoirs worldwide located in the Neuquén basin, has ceased to be a promise and is becoming a venturous reality. During recent years, the investments in its development have increased significantly. By the year 2040, it is believed that the VM formation may generate 560,000 bbl of liquid and 6,000 million cubic feet of gas per day.
One of the primary challenges of many operators has been to select the most productive landing zones; consequently, the performance of an accurate and complete petrophysical evaluation of the reservoir has become vitally important to increase production and to optimize well completion costs. The evaluation of shale formations using electrical logs is a major challenge for most petrophysicists because many of the measurements from the logging tool are affected by the organic matter concentrated in this type of rock.
This paper highlights the way in which these challenges were addressed. It describes the logging operation, as well as the integral petrophysical interpretation performed for a pilot well located in the oil window of the VM formation.
The key element for the success of this work was the implementation of the integrated workflow to evaluate the potential of the shale oil well. The integrated workflow enabled the identification of hydrocarbon-bearing formations, quantification of reservoir properties and hydrocarbons in place, determination of lithology variations within the objective section, and establishment of reliable correlations between electrical logs and the organic richness of the VM formation. In addition, the assessment of geomechanical properties has become vitally important to optimize well placement and to select the best hydraulic fracturing design.
The integrated analysis of the pilot well presented in this paper has proven to be a successful case in which an effective characterization of the VM formation, following the proposed formation evaluation workflow, and the integration of wireline data with the various data acquisition program components, enabled the delivery of recommendations about the prospective interval in which to land the programmed lateral well.
Comparative Study of the Clinical Competence of Emergency Nurses Using Self-Assessments and Head Nurse Evaluations
Authors: ghahfarokhi motahareh musavi , Mehrafruz Elina , Radmehr Arman , kiarsi maryam , Shamloo Marziyeh Beigom Bigdeli 
Published: July 2020

Abstract
The authors have withdrawn this preprint due to author disagreement.
High-power radiofrequency ablation guided by ablation index for pulmonary vein isolation
Authors: zhu xuefeng , wang chunxiao , li jianping , li wenjing , chu hongxia , zhou huihui 
Published: July 2020

Abstract
Background: Proposed to facilitate pulmonary vein isolation (PVI), high-power ablation may cause extracardiac damage. This study evaluated the safety and efficacy of ablation index (AI) guided high-power ablation first in an animal model and subsequently in a clinical study.Methods:Outcomes of radiofrequency (RF) applications were compared in a swine ventricular endocardial model (n=10 each for 50W, 40W and 30W; AI=500), and in 100 consecutive patients with paroxysmal AF undergoing PVI (40W [last n=50] vs. 30 W [first n=50]; target AI=400/500 on posterior/anterior wall, respectively). Acute PV reconnection was assessed post adenosine administration 20 minutes after ablation.Results: In swine ventricular endocardial RF applications, use of 50W and 40W vs. 30W was associated with greater tissue lesion depth (5.06±0.16 and 4.38±0.13mm vs. 3.95±0.16mm; P<0.001) and smaller lesion maximum diameter (7.81±0.15 and 8.42±0.18mm vs. 9.08±0.15mm; P<0.001). Tissue necrosis caused by 50W vs. 40W and 30W was the deepest and largest (3.15±0.18mm vs. 2.71±0.17 and 2.42±0.13mm; and 5.58±0.18mm vs. 5.18±0.16 and 3.94±0.17mm; respectively; P<0.001). In PVI, use of 40W vs. 30W was associated with shorter procedure time (56.54±1.81min vs. 76.55±2.34min; p<0.001) and ablation time (35.85±14.87min vs. 51.01±17.99min; p<0.001); lower RF energy per point (909.02±354.57J vs. 1045±376.60J; p<0.001); higher first-pass PVI (87% vs. 72%; P<0.01); lower acute PV reconnection (22% vs. 41%; P<0.01); no complications in either group; and similar sinus rhythm maintenance at 12 months (92% vs. 84%; P=0.22).Conclusions: AI-guided high-power (40W) vs. conventional (30W) PVI was related to a reduced time for procedure and was considered safe, with diminished acute PV reconnection.
General Practitioners' Propensity to Cooperate With Other Health Professionals in the Management of Patients With Multimorbidity and Polypharmacy: A Cross-sectional Study.
Authors: Carrier Helene , Zaytseva Anna , Bocquier Aurélie , Villani Patrick , Fortin Martin , Verger Pierre 
Published: July 2020

Abstract
Background. Cooperation between general practitioners (GPs) and other health professionals appears to help reduce the risk of adverse events linked to polypharmacy for patients with multimorbidity. We investigated the existence of different GP profiles according to their opinions and behaviors about such cooperation and studied the association between these profiles and the GPs’ characteristics and deprescribing behaviors.Methods. Between May and July 2016, we performed a cross-sectional survey in a panel of French GPsabout their management of patients with multimorbidity and polypharmacy, focusing specifically on their opinions of healthcare professionals’ roles and interprofessional cooperation. We used an agglomerative hierarchical cluster analysis to identify GP profiles and then multivariable logistic regression models to study their associations with these doctors' characteristics and deprescribing behaviors.Results. We identified four profiles of GPs according to their cooperation propensities: GPs from the “intensive” profile (14%) were favorable to cooperating with various health professionals, including delegating some prescribing tasks to pharmacists; GPs from the "moderate" profile (47%) had favorable opinions about health professionals’ roles, except for this specific task delegation; GPs from the "selective" profile (27%) tended to work only with physicians; GPs from the "low cooperation" profile (12%) didn’t appeared interested in cooperation. These profiles were associated with different professional characteristics.Conclusions. Current health policies encourage interprofessional cooperation for the management of patients with multimorbidity. Our study provides information for understanding disparities among GPs regarding working with other professionals who deal with their patients and suggests possible ways to improve cooperation.
Antimicrobial use and resistance in Escherichia coli from healthy food-producing animals in Guadeloupe
Authors: Gruel Gaëlle , Sellin Arantxa , Riveiro Hélène , Pot Matthieu , Breurec Sébastien , Guyomard-Rabenirina Stéphanie , Talarmin Antoine , FERDINAND Severine 
Published: July 2020

Abstract
Background
Selection pressure exerted by overuse of antibiotics in both human and veterinary medicine is responsible for increasing resistance to antibiotics. The objectives of this study were (i) to better understand antimicrobial use in pigs, beef cattle, and poultry on farms of Guadeloupe, French West Indies, and (ii) to acquire data on antimicrobial resistance in Escherichia coli in these food-producing animals. A cross-sectional survey was conducted in 45 farms on Guadeloupe. Practical use of antimicrobials was documented in declarative interviews between March and July 2018. Fecal samples were collected from 216 pigs, beef cattle, and broiler chickens between January 2018 and May 2019. The samples were cultured for bacterial isolation and identification, antimicrobial testing, and screening for blaCTX−M, blaTEM, and tetA resistance genes by PCR on extracted genomic DNA.
Results
The study shows rational use of antimicrobials consisting of occasional use for curative treatment by veterinary prescription. Tetracycline was the most commonly used antimicrobial, but this was not correlated to E. coli resistance. Extended spectrum β-lactamase (ESBL) E. coli isolates were detected in 7.3% of pigs, 14.7% of beef cattle and 35.3% of broilers. blaCTX−M−1 was the predominant gene found in ESBL E. coli isolates (68.8%), followed by blaCTX−M−15 (31.3%).
Conclusion
Despite rational use of antimicrobials, the rate of ESBL E. coli in food-producing animals in Guadeloupe, although moderate, is a concern. Further studies are in progress to better define the genetic background of the ESBL E. coli isolates.