bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Silica Nanoparticles on Thermal Stability in Bentonite Free Water-Based Drilling Fluids to Improve its Rheological and Filtration Properties After Aging Process
Authors: Vargas Johanna , Roldán Leidy Johanna , Lopera Sergio Hernando , Cardenas José Carlo , Zabala Richard Disney , Franco Camilo Andrés , Cortés Farid Bernardo 
Published: October 2019

AbstractIn the Oil & Gas industry, preserve filtration properties of the drilling fluids based on the rheological behavior under prolonged exposure time, and temperature (aging process) are the most important challenges due to the implications that lead to the formation damage. The polymers as xanthan gum (XG) suffer degradation due to the drilling processes losing their viscosifying capacity, solid suspension, and subsequent the filtration control since the effective build-up of the mudcake is not possible. In this way, this study aims to evaluate the effect of SiO2 nanoparticles on thermal stability under thermal rolling process in the filtration properties through of the rheological behavior in bentonite-free water-based mud (BFWBM). Two kinds of SiO2 nanoparticles were evaluated: (1) synthesized through the sol-gel method and (2) fumed silica nanoparticles. SiO2 nanoparticles were characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and zeta potential (ZP). The SiO2 -XG interactions were evaluated through polymer adsorption onto nanoparticles using a batch-mode, rheological studies, and evaluation of thermal stability. Additionally, the effect of SiO2 nanoparticles on basic (pH, density, solid content, rheological, and filtration) properties in BFWBM were studied according to American Petroleum Institute (API) standard after aging through hot roller oven at 77°C for 16 hours. Results of adsorption experiments showed that adsorption isotherms of XG polymer onto silica followed a Type I behavior and these were modeled using solid-liquid equilibrium (SLE) model, showing an uptake adsorbed higher for the SiC nanoparticle than other materials. The rheological conduct of XG polymer - SiO2 nanoparticles system showed a pseudoplastic behavior with a high performance of SiC nanoparticles with an increase of 15% of the viscosity and inhibition of the degradation of the 32.2% compared with the polymer sample without nanoparticles. Also, the experimental results showed that the addition of SiO2 nanoparticles did not alter the basic properties such as pH, density, and solid content. Meanwhile, SiC increased the plastic viscosity (PV), yield point (YP), yield stress (YS), and gel strength of the drilling fluid and reduced the filtration volume and the mudcake thickness of the drilling fluid after the thermal rolling process. Also, these nanoparticles showed the highest increase of the VP, YP, and YS by 12, 19, and 100%, respectively. Additionally, SiC nanoparticles reduced the spurt loss and total filtration volume by 67 and 49%, respectively. Nanoparticles strengthened the hydrogen bonds with polymer preventing the hydrolysis.
Subsea Arrangements Optimization for Gas Export Systems
Authors: Patusco Carlos Alexandre Pereira , Simões Eugenio Fredericci 
Published: October 2019

Abstract
When defining the subsea arrangement for a gas export system, a few options are available to connect a trunk gas pipeline to other pipelines or to FPUs, especially when there is uncertainty about future projects which may need to be connected to the export system. The objective of this paper is to present an assessment of different options based on a case study. A matrix will be generated pointing the pros and cons of different technical solutions regarding aspects such as: economicity for long and short distances, total length of pipelines, number of subsea structures, technology maturity, risks related to QHSE issues, risks to assets during installation, interruption of gas export during installation, construction duration and availability to deepwater. Considerations about the applicability and relative importance of each of the above mentioned parameters will also be included. Examples of subsea arrangements and strategies of acquisition for gas export systems projects include: using ILTs/ILYs for each connection; using ILTs/ILYs and PLEMs "offline", i.e., PLEMs with several hubs connected to in-line structures along the trunk pipeline; using PLEMs in-line, i.e., PLEMs connected directly to the trunk line, by means of rigid or flexible jumpers and PLETs; using diver assisted or diverless cut after hot tapping; using diver assisted or diverless cut in conjunction with smart plugs. Finally, nonconventional alternatives to export the gas like LNG, CNG, GTW or GTL will also be assessed. The results will present guidelines on how to select the most appropriate subsea arrangement for gas export systems, depending on the specificities of each project, such as: the extension of the field, the distance to shore, the maturity level of the present and future (interconnected) projects, the water depth, the distance between FPUs and others.
Tuning a Fully Convolutional Network for Velocity Model Estimation
Authors: Campos Luan Rios , Nogueira Peterson , Nascimento Erick 
Published: October 2019

Abstract
Different parameters of a fully convolutional network (FCN) are experimented to evaluate which combination predicts sound velocity models from a single configuration of seismic modeling. The evaluation is made considering some fixed parameters of the deep learning model, such as number of epochs, batch size and loss function, but with variations of the optimizer and activation function. The considered optimizers were RMSprop, Adam and Adamax, whilst the activations functions were the Rectified Linear Unit (ReLU), Leaky ReLU, Exponential Linear Unit (ELU) and Parametric ReLU (PReLU). Five metrics were used to evaluate the model during the testing stage: R2, Pearson's r, factor of two, mean absolute error and mean squared error. To the extent of these experiments, it was found that the optimizers have much more influence than the activation functions when determining the resolution of the output model. The best combination was the one using the PReLU activation function with the Adamax optimizer.
Prediction of Wettability Alteration Using the Artificial Neural Networks in the Salinity Control of Water Injection in Carbonate Reservoirs
Authors: Reginato Leonardo Fonseca , Carneiro Cleyton Carvalho , Gioria Rafael Santos , Pinto Marcio Sampaio 
Published: October 2019

Abstract
Artificial Neural Networks (ANN) applications have grown exponentially in all areas of science and technology. The advantages are its versatility, speed and ability to aggregate information, perform predictions of a given set of data. These attributes attract the petroleum industry, which often depends on laboratory analysis or numerical simulation to estimate various reservoir behaviors. This research, aims to predict the relative permeability curves with wettability alteration effect, given a concentration of the ionic composition in water injection. For this, machine learning methods were applied. An analytical algorithm was developed that incorporated the effect of wettability alteration, generating the database for the training process. Two different networks were applied: (i) Self-Organizing Maps - SOM and (ii) Neural Net Fitting – NNF. The forecast data of the networks are compared with calculated for analytical results. This ANN performs a good forecast of data tested (NNF with R-squared results around 90%). The analyses confirm effects on relative permeability of oil and water with salt control, indicating wettability alteration (WA). These tests were able to confirm that the applied methodology is capable to predict, using ANN, results of several laboratory tests.
Lessons Learned from Cuttings Treatment at Offshore Wells in the Campos Basin
Authors: Vadinal Rodolfo Balthazar , Reis Leomir Samuel Tormen , Del Claro Daniel Ribeiro , Ceolin Saulo Pereira , Bernardes Maria Carolina do Couto Pessanha 
Published: October 2019

Abstract
The main wastes associated with well drilling activity are drilling fluids and cuttings. With regard to drilling fluids, the oil industry has invested in more environmentally friendly formulations to reduce environmental impact. For offshore operations, cuttings are generally disposal at sea after meeting environmental criteria of government agencies. This paper presents the lessons learned in the operation of the cuttings collector system and the collection of cuttings associated with water based mud in cutting boxes in Campos Basin wells. The main advances to reduce the non-productive time of the cuttings collector system were the use of hybrid boats and the increase of the screw conveyor reliability. To collect cuttings associated with water-based mud, the drilling fluid + cuttings mixture needs to be treated to prevent H2S generation.
The Science of Capping a Subsea Well Blowout
Authors: Guinn Mitch , Cargol Mike 
Published: October 2019

Abstract
As part of any Source Control Emergency Response Plan (SCERP), capping a subsea well blowout is a significant contingency operation that requires attention to many details to ensure that an operator is prepared to manage the risks involved and to achieve the desired outcome of stopping the flow of an uncontrolled well.
The objective of this paper is to identify and describe the technical considerations (the science behind the procedures) that a prudent operator must address to be able to efficiently and effectively store, maintain, mobilize, install and operate a subsea capping stack in a subsea well blowout event.
The paper will offer a brief description of the critical design and functionality requirements that were considered in the development of the original capping stacks. It will contain some updated guidance regarding storage, maintenance and transportation of a capping stack to the incident site. This paper will also present the latest review of available installation methods and offer a brief narrative regarding operating procedures. The paper will also briefly relay portions of the newly-released guidelines introduced in IOGP Report 594, dated January 2019, regarding the need for and definition of an effective SCERP.
It has been almost 10 years since the last catastrophic offshore well control incident and the industry has responded by building equipment and developing procedures to enable an effective response to a similar incident. However, operating in an offshore environment requires a perpetual risk assessment and constant review and evaluation of contingency plans for all procedures, especially for those relating to protecting the environment. This paper will present an operator with proven guidance statements to enable the operator to properly prepare for a subsea well control incident.
This paper will present updated guidance regarding selected technical issues of capping stack design and pertinent updated guidance regarding capping stack storage, maintenance, mobilization, and installation. The paper will also reinforce the newly released SCERP guidance regarding capping stacks in IOGP Report 594, dated January 2019.
A New Robust Drilling Rate Model
Authors: Al-Rubaii Mohammed Murif , Gajbhiye Rahul N. , Al-Yami Abdullah Saleh , Alouhali Raed A. 
Published: October 2019

AbstractDrilling rate remains a major challenge when it comes to planning and drilling workover and development wells. The main mission of a drilling engineer is to design a well optimizing time, cost, economics and safety. Analysis of previously drilled wells operations' records is required to perform optimization techniques to reduce drilling cost for new wells to be drilled. Among the many potential optimizations, Rate of Penetration (ROP) has the most obvious impact on cost effectiveness of a well's drilling, but to ensure optimized rate of penetration, it must be engineered.There are several correlations, methods, designs, models, tools, charts, fields' results, and experimental studies to enhance the well drilling performance. Many of these are effective, but some others are incomplete and not suited for drilling operations as they are based on unproven theory and lack proper experimental data. Proper models must include knowledge of all factors that affect rate of penetration in order to provide a meaningful tool for optimizing the well design. The objective of this work is to develop a new method for optimized drilling rate that will model rate of penetration more accurately and therefore facilitate improving drilling efficiency and cost.The drilling parameters and mud rheological properties in certain hole sections were collected and analyzed first to determine the effect of mud properties and drilling parameters on ROP performance. The parameters and properties that are selected are from the same hole size, formation type and mud type. The relationship between mud rheological properties and ROP was then evaluated to determine how strong it is. This step helps to determine the significance of mud rheological properties on estimating ROP and that will lead to optimization of the drilling operation and reduction in the drilling time. This is the first model combining the drilling fluid properties, drilling parameters, cuttings volume and dogleg severity with rate of penetration optimization simultaneously.The developed model has been compared with using field data during drilling challenging hole sections in several different fields. It has shown high correlation coefficient regression value matching with actual ROP Values with high percentage of accuracy, which is about 90 %. The new model showed the importance of combining mud properties, cuttings volume percent, drilling parameters and dogleg severity since that will make it applicable in any type of wellbore or hole section such as (vertical, deviated and horizontal). The developed model can assist drilling engineers in selecting improved drilling parameters, mud properties, optimized value of cuttings volume or cuttings concentrations in annulus and dogleg severity value by optimizing the drilling rate using the developed model effectively. It can be used in real time operating center to participate for drilling Automation projects.
Remediation of Hydrate Plug in Gas Export Line – A West Africa Deep Water Case
Authors: Papot Fabien , Alexandre Celma , Abdulssalam Mohammed , Chita Ambrosio , Pina Alberto , Chipoque Antonio , Glenat Philippe 
Published: October 2019

Abstract
This paper describes a recent hydrate plug issue experienced in a 12inch gas export line of one of TOTAL E&P operated FPSOs in the deep water of West Africa. In summer 2018, due to long-term maintenance work on the dehydration unit of the FPSO's gas compression, the off- spec produced gas was injected into a remote subsea gas well injector to avoid gas flaring, in line with TOTAL's flaring policy. Methanol was continuously injected for hydrate inhibition. Unfortunately, at the end of the operation, a hydrate plug occurred in the 12-inch gas export line. Through a multi–disciplinary crisis management team, all necessary efforts and procedures were implemented to remove the plug from the line in less than 1 week. The main steps included topsides depressurisation, a subsea intervention, additional hydrate inhibitor injection (Methanol and especially MEG) and liquid flushing operations.
Duramycin radiosensitization of MCA-RH 7777 hepatoma cells through the elevation of reactive oxygen species
Authors: Yang Bowen , Huang Xiaoke , Li Weiguo , Mouli Samdeep , Lewandowski Robert J. , Larson Andrew Christian 
Published: October 2019

Objective:
The objective of this study is to explore the radiosensitization effects of duramycin against the liver cancer hepatoma cells and relationship to reactive oxygen species (ROS) generation.

Materials and Methods:
MCA-RH 7777 cells were treated with various combinations of duramycin concentrations and radiation doses. After the treatment, cell viabilities were determined by a cell proliferation assay; intracellular ROS levels were detected with the flow cytometric method.

Results:
MCA-RH 7777 cell viability was found significantly reduced after combining duramycin and radiation exposure (comparing to that of either treatment alone). Increased intracellular ROS levels were observed in cells treated with combinations of duramycin and radiation.

Conclusion:
Duramycin increased the intracellular ROS generation and also increased the radiosensitivity of MCA-RH 7777 cells.
Observational study of cone beam computed tomography based interfractional urinary bladder filling variation during image guided radiation therapy in pelvic malignancies
Authors: Shah Manjari , Agarwal Sandeep , Agarwal Rashi , Subramanian Bala , Gupta Sweety , De Sudarsan , Mishra Shiv 
Published: October 2019

Background:
Organ motion is an important factor that limits the precision of radiation treatment. Bladder filling variation has significant impact on the position of target volumes in pelvic malignancies.

Aims and Objective:
This study was an effort to maintain a consistent urinary bladder volume after following a bladder protocol, which was then analyzed by in-room cone-beam computed tomography (CBCT) imaging.

Material and Methods:
A total number of 26 patients/300 scans, i.e. 26 planning scan and 274 CBCT were analyzed. The bladder volumes and bladder wall dimension were analyzed comprehensively, thus adding considerable understanding to the bladder wall motions.

Result:
The mean bladder volume for all 26 patients was 183.07 cc with standard deviation of 90.43 cc. The mean +/- standard deviation of transverse, anteroposterior and longitudinal diameter was 8.35+/- 1.03, 6.69+/-1.05 and 5.59+/-1.79 cm.

Conclusion:
This study showed considerable reduction of margin could be done on the lateral side, as there is less displacement on transverse diameter and more liberal margins should be considered in anteroposterior dimension and longitudinal dimensions. This study has reached the conclusion that bladder-filling protocol is necessary to maintain the consistent bladder volume, but it is too preliminary to state that it will translate into reduction of margin.
Association of interleukin-4 gene polymorphism and rheumatoid arthritis in Egyptian patients
Authors: El Nakeeb Seham M , Ahmed Reem M , Elsied Alzahraa A , Ali Elsied Mohsen M 
Published: October 2019

Introduction
Rheumatoid arthritis (RA) is a progressive disease characterized by chronic joint inflammation and subsequent structural damage. Interleukin (IL)-4-590 promoter polymorphism (rs2243250), a C-to-T base substitution, has been suggested to be associated with RA and has become of great interest to be investigated.

Aim
The aim of this study was to find the relationship between IL-4-590 promoter polymorphism and RA in Egyptians, and also to study the relationship of this gene with clinical and laboratory features of the disease.

Patients and methods
This study was carried on 180 subjects divided into two groups. The first group included 120 patients with RA and the second group were 60 apparently healthy individuals as controls. Genomic DNA was extracted from blood leukocytes of both groups and genotyped by PCR for amplification of IL-4 gene followed by restriction fragment length polymorphism.

Results
IL-4-590 (TT) genotype was significantly more frequent in patients with RA than controls (10 vs. 1.70%, P=0.027, odd ratio (OR)=7.543 and Confidence interval (CI)=0.947–60.049). IL-4-590 (CT) genotype showed no significant difference between patients with RA and controls (31.70 vs. 25%, P=0.195 OR=1.592 and CI=0.786–3.228), whereas IL-4-590 (CC) genotype was significantly less frequent in patients with RA than controls (58.30 vs. 73.30%, P=0.048). Regarding the distribution of different alleles, the frequency of T allele was significantly more in patients with RA than controls (P<0.01). In patients with RA, there were significant differences in some clinical and laboratory parameters of RA disease between different IL-4-590 genotypes (e.g. number of tender and swollen joints, duration of morning stiffness, disease activity score 28, serum rheumatoid factor, serum C-reactive protein, and serum anticyclic citrullinated peptide levels), all were higher in TT genotype, which means patients with RA with TT genotype may have more aggressive course of the disease.

Conclusion
The T allele and the TT genotype at position −590 of IL-4 gene may be related to development of RA in Egyptians and may be associated with the disease activity.
Revisional and conversional operations after bariatric surgery
Authors: Attia Radwa , Sonna Kamal A , Elazim Hoda A 
Published: October 2019

Introduction
Bariatric/metabolic surgery is currently the only effective long-term treatment for morbid obesity and obesity-related diseases such as diabetes, heart disease, hypertension, obstructive sleep apnea, and dyslipidemia. With the increasing number of bariatric procedures being performed annually, it is expected that the incidence of revisions will increase. The overall incidence of surgical revision after a primary bariatric operation is 5–50%. Redo (revisional) surgery can be quite complex and technically challenging and may offer the patient a wide variety of solutions for treatment of weight reduction and complications after primary operations.

Aim
This study aimed to evaluate the initial experience of redo operations after bariatric surgery.

Patients and methods
A total of 20 patients were included in this study who underwent redo operations after bariatric surgery. Their BMI ranged from 25 to 50 kg/m2. They were managed from June 2016 to June 2018 at Al Zahraa University Hospital. The indications, surgical outcomes, and efficacy of the redo surgeries were analyzed.

Result
A total of 20 patients underwent redo operations. The primary bariatric procedures included vertical band gastroplasty in seven patients, Scopinaro operation in six patients, laparoscopic adjustable gastric banding in four patients, and sleeve gastrectomy in three patients. The indications for redo surgery included poor weight loss, weight regain, and malnutrition in cases of Scopinaro operation. The weight loss results varied depending on the indication for redo surgery. Postoperative complications revealed one case (5%) developed leak and required reoperation. However, no bleeding cases, no died cases, or other complications were observed during postoperative follow-up period.

Conclusion
Redo operation after bariatric surgery can be successfully performed via open or laparoscopic approach with acceptable risk. Deliberate selection for the proper revisional or conversion procedure can efficiently manage undesirable results from the primary surgery.