bluuebunny/crossref_metadata_2025_split huggingface dataset:
Making Sense of Why Sometimes Logs Do Not See Cement in the Annulus
Authors: Kalyanraman Ram Sunder , Van Kuijk Robert , Hori Hiroshi 
Published: April 2017

Abstract
Ultrasonic and sonic logs are commonly used to evaluate the quality of cement placement in the annulus of a pipe and its potential to perform as a barrier. In some cases, we observe that the log response is in conflict with the expectations on the outcome of the cementing job that was executed without any major issues. The log sometimes does not see the cement! This apparent disagreement if not resolved could potentially lead to costly and unsuccessful attempts to remediate the cement sheath. We highlight reasons why sometimes logs may not see the cement and implement new workflows that not only recognize these factors but also account for it in the cement sheath evaluation.
The ability to recognize the existence of a wet or dry micro-annulus is critical for cement sheath evaluation and is discussed through two new interpretation workflows using ultrasonic and sonic logs. Firstly, we introduce a new ultrasonic (TIGHT model) interpretation workflow that improves discrimination of light-weight solids from displaced muds and enables identification of dry micro-annulus situations. Secondly, we introduce a new integrated workflow that combines sonic amplitude / attenuation with ultrasonic measurements in the acoustic impedance (AI) space (Sonic vs ultrasonic acoustic impedance). Through this approach, we demonstrate how we can identify cement that is well bonded and discriminate from those with a dry or a wet micro-annulus.
The workflows were applied to data acquired in wells where we compared the results of conventional interpretation approaches as well as those discussed in the two workflows. The gap caused by the detachment of cement from casing (de-bonded cement), either wet or dry micro-annulus, can affect the log responses differently and sometimes significantly. The effect of micro-annulus on logs can be recognized which then facilitates correct assessment of the cement sheath behavior. We note that the log response in the presence of a dry micro-annulus may be different to that for a wet micro-annulus. In the case of a dry micro-annulus, even with relatively smaller gaps between cement and casing, conventional approaches to interpretation of the sonic and ultrasonic logs can completely miss "seeing" the cement.
We observe that the integration of ultrasonic and sonic measurements through these workflows has the potential to improve the quality and reliability of cement evaluation when cements de-bond from casing. The ability to do so with existing ultrasonic and sonic technology not only helps improve confidence on cement sheath evaluation but also has the potential to reduce unwanted and costly remediation decisions.
Organic and Inorganic Formation Damage Removal Using Customized Formulations
Authors: Quintero Lirio , Newberry Michael , Morales Rosanel , Davis Chelsea 
Published: April 2017

Abstract
Paraffin and asphaltenes deposits, scale deposits and emulsions formed by fluids incompatibility in oil-producing wells, and other formation damage mechanisms are a major cause of loss of well productivity.
Organic and inorganic deposits can occur on the surfaces of well tubing and within the pores of the near-wellbore formation, reducing of flow efficiency and possibly blocking the flow paths completely. The damaging process may occur naturally during the production phase of the well or it can be triggered during wellbore intervention treatments or even during the wellbore construction stage.
In general, formation damage is driven by more than one mechanism. A thorough assessment and diagnosis of the fundamental cause(s) of the formation damage is important to properly select the best remediation treatment and procedure. Even if there is no standard, best practices and methodologies to diagnose the cause(s) of the formation damage and evaluate potential chemical treatments have been developed.
A discussion of the improved methods of problem identification, programs to remediate these problems, and stimulation software will be described in this paper. A synopsis of the potential causes that generate organic and inorganic deposits in the wellbore, diagnosis of formation damage, chemical treatment selection and applications are also discussed.
Laboratory test evaluations and smart selection of chemical treatment, according to the type of formation damage, are presented, along with number of example case histories.
Diagnosis of organic and inorganic formation damage, problem identification using production history data, reservoir and fluid properties, well configuration, and history of well intervention and/or stimulation that allowed tailoring customized formulation proved that this approach resulted in better wellbore cleanup and production increase.
Assessment of Rate Transient Analysis Techniques for Multiphase Flow in Unconventional Reservoirs: Application to Eagle Ford Formation
Authors: Uzun Ilkay , Eker Erdinc , Cho Younki , Kazemi Hossein , Rutledge J. M. 
Published: April 2017

Abstract
In reservoir evaluation of unconventional reservoirs, engineers use rate transient analysis (RTA) to assess the performance of hydraulically fractured horizontal wells. This technique consists of plotting rate- normalized pressure drop at the well sandface versus square root of time (i.e., linear flow) to calculate the reservoir effective permeability. In this paper, we report on the use of an in-house multiphase numerical simulator applied to production data from several Eagle Ford wells to assess both single- and multi-phase production performance. Furthermore, a combination of numerical simulation and analytical solution techniques was used to validate the information obtained from the RTA in the Eagle Ford wells. This procedure further improved our insight into the flow behavior of unconventional reservoirs. The multi-phase effective permeability calculated from the RTA was within a few percent of the input data to the numerical model. Furthermore, the multi-phase RTA results produce more accurate than the conventional single-phase RTA approach; and the multi-phase analysis results were more in line with the well performance observations than with when using the single-phase analysis approach. Furthermore, the multiphase results were more consistent with the success or failure of the hydraulic fracturing process.
An Empirical Model to Estimate a Critical Stimulation Design Parameter Using Drilling Data
Authors: Atashnezhad Amin , Cedola Alexandra E. , Hareland Geir 
Published: April 2017

Abstract
Hydraulic fracturing is the stimulation process during which fractures are created by pumping mostly water and sand into the formations. Hydraulic fracturing is done on almost 90% of gas wells in the United States. Selectively determining the fracturing intervals along the borehole is one of the most critical factors for optimizing stimulation and maximizing the net present value (NPV) of the well. In this study, an empirical model was developed to predict the formation porosity using surface drilling data and gamma ray (GR) at the bit without needing log data.
In this study, data from three wells were used to develop an empirical model for porosity prediction through the use of drilling data. To find the best model, a differential evolution algorithm (DE) was applied to the space of solutions. The DE algorithm is a metaheuristic method that works by having a population of solutions, and it iteratively try to improve the quality of answers by using a simple mathematical equation. The developed model uses the unconfined compressive strength (UCS) obtained from an inverted rate of penetration (ROP) model and gamma ray (GR) at the bit to estimate the formation porosity.
Data from three offset wells in Alberta, Canada were evaluated to find a porosity estimation model. The DE algorithm was used to search the infinite space of solutions to find the best model. The models reliability and accuracy were studied by conducting a sensitivity analysis then comparing the results to offset well data. There is good agreement between the models estimated porosity and porosity from the well log data. This paper presents results from individual well sections that compare the neutron porosity from logs in the field to the calculated porosity obtained from the newly developed correlation. The results show accurate quantitative matching as well as trends. The model presented can be applied to horizontal wells where the porosity can be mapped in addition to the UCS value from the drilling data at no additional cost. Based on this formation mapping log, optimum fracturing interval locations can be selected by taking the UCS and porosity of a formation into account. The suggested approach can also be used to determine the porosity in real-time.
The novelty of this model is in the ability to estimate porosity using typically collected drilling data potentially in real time. By applying this model, there is no need for well services such as well logging to find hydraulic fracturing points, which significantly reduces the cost and time associated with the well completion operation.
Use of Decline Curve Analysis for Application of Production Enhancement Treatments in Heavy Oil Reservoirs
Authors: Castro Leo 
Published: April 2017

Abstract
In an environment of soft to declining oil prices, the key to survival for many operators is maintaining production on current producing wells. Stimulating current producing wells is one way of maintaining that production, although the type of stimulation treatment may not always be straightforward. This paper presents strategies for the identification of stimulation candidate wells, and chemical treatment types that will present the best opportunities to increase production based on the specific type of damage mechanism encountered.
The use of decline curve analysis is an important tool in selecting wells for production enhancement. In a day where precious few dollars are available for production enhancement and a long term study for candidate identification is not feasible, it is of particular importance to have the tools readily available to identify and select only those wells that will not only minimize the risk of the expenditure, but also yield justifiable economic returns.
Extensive field experience has identified production profiles that are consistent with different types of damage mechanisms found in the heavy oil environment. Learning to recognize the profiles and the damage that triggered those profiles, will help the production engineer or coordinator decide on the best treatment technique.
This paper discusses the different types of damage profiles observed on production plots, and details the damage mechanisms that caused that damage profile and the treatment products and techniques necessary to restore a well's production to its full potential.
Investigating Impact of Various Properties on Relative Permeability and Non-Wetting Phase Fractional Flow in Brine/Oil System in Water-Wet Reservoir Rock by Numerical Simulation
Authors: Jahan Farjana , Hossain Md Mofazzal , Ahmed Shakil , Iglauer Stefan 
Published: April 2017

Abstract
In this paper, pore-scale numerical modelling predictions are performed to investigate variations in relative permeability behaviour and oil fractional flow under a range of different parameters (contact angle, capillary number and flow direction) through Brine/Oil system in Ottowa F42 Sand Pack. AVIZO (high-performance 3D image processing software) is used to separate the Micro-computed tomography (micro-CT) images of the pore spaces of rocks from grains of Ottowa F42 Sand Pack. ANSYS-CFX (high- performance CFD based simulator) is used to generate volume mesh and carry-out numerical simulation. The simulation results were analysed and compared with other experimental and numerical works. At low capillary number, the relative permeability curves were not smooth. Almost similar trends for relative permeability were observed for the imbibition process by alternate injection of oil and brine. Increase in contact angle showed less effect on fluid relative permeability and oil fractional flow. Also, alternate injection of fluids in imbibition showed a little response on fluid relative permeability and oil fractional flow. The outcomes of this investigation will be extended to intermediate-wet and oil-wet media and also for carbonate formations.
The Patented HyperScratcher Workover Tool – Increasing Production on Existing Wells
Authors: Tuttle John D. 
Published: April 2017

Abstract
The patented HyperScratcher workover tool has recently been reintroduced for use on well workovers in the San Joaquin Valley, Santa Maria Valley and LA Basin. Originally designed, developed and applied successfully in California during the industry downturn of the mid-1980s, the use of this unique tool to clean perforated and slotted liners often resulted in significant production increases. This was a critical goal for Operators during periods of depressed oil prices, when drilling was curtailed and production from existing wells was a primary goal.
This paper will introduce the working components of the HyperScratcher ‘Production Enhancement’ tool, explain how the tool is applied in the field, specific operating considerations, and identify methods to select potential well candidates. Differing well types will be discussed (producers, injectors, water source wells), along with a brief review of past projects and the potential for improvements in well performance. In addition, case histories and results from recent California and other domestic experiences will be shared to validate the claims of the technology.
With key considerations patented in 2013, the HyperScratcher workover tool has been reintroduced to the West Coast workover market during the past year, and when applied on underperforming or damaged wells with perforated or slotted liners, the technology has consistently provided enhanced production or injection capabilities. These results have been obtained during regularly planned workovers of existing wells.
Abdominal aortic aneurysm rupture following cardiopulmonary exercise testing
Authors: Robertson Vaux , Rayt Harjeet , Kirkbride David , Davies Robert 
Published: April 2017

SummaryA 77‐year‐old male presented with an abdominal aortic aneurysm (AAA). He underwent preoperative cardiopulmonary exercise testing (CPET) to help assess his suitability and fitness for complex major vascular surgery. His aneurysm subsequently ruptured in the post‐test period and he underwent emergency open repair.CPET is a useful tool in the repertoire of anaesthetic pre‐assessment and helps inform decision‐making in high‐risk surgical patients. However any single test has its limitations and it should not be used in isolation as a reason to deny a patient surgery.Patients with a diagnosed AAA should not forgo CPET for fear of rupture but should be closely monitored for signs of rapid uncontrolled hypertension ‐ an indication to terminate the test early.
Error features of the hourly GSMaP multi-satellite precipitation estimates over nine major basins of China
Authors: Tan Xianhui , Yong Bin , Ren Liliang 
Published: April 2017

AbstractAs one of the current mainstream satellite precipitation estimates, the Global Satellite Mapping of Precipitation (GSMaP) system of Japan has been developed to produce high-precision and high-resolution global rainfall products by integrating almost all of the available precipitation-related satellite sensors. To quantify the error features of GSMaP estimates and understand their hydrological potentials at short temporal scale, three widely used GSMaP products (GSMaP_NRT, GSMaP_MVK, and GSMaP_Gauge) were comprehensively investigated at 1 hourly and 0.1° × 0.1° resolutions over nine major basins of China. Assessment results show that GSMaP_NRT apparently underestimates the rainfall amounts, while GSMaP_MVK with both forward and backward propagation processes algorithm can effectively capture the most rainfall events and has the lower error and bias. GSMaP_Gauge displays the best error stability and error structure over most basins of China and also exhibits stronger rain-rate dependencies. However, its unexpected positive biases in southeastern basins, which mainly come from the overestimation at lower rain rates, still need to improve further in future developments. We expected the results documented here can both provide the retrieval developers with some valuable references and offer hydrologic users of GSMaP data a better understanding of their error features and potential utilizations for various hydrological applications.
Quantifying multi-source uncertainties in multi-model predictions using the Bayesian model averaging scheme
Authors: Jiang Shanhu , Ren Liliang , Xu Chong-Yu , Liu Shuya , Yuan Fei , Yang Xiaoli 
Published: April 2017

Abstract
This study focuses on a quantitative multi-source uncertainty analysis of multi-model predictions. Three widely used hydrological models, i.e., Xinanjiang (XAJ), hybrid rainfall–runoff (HYB), and HYMOD (HYM), were calibrated by two parameter optimization algorithms, namely, shuffled complex evolution (SCE-UA) method and shuffled complex evolution metropolis (SCEM-UA) method on the Mishui basin, south China. The input uncertainty was quantified by utilizing a normally distributed error multiplier. The ensemble simulation sets calculated from the three models were combined using the Bayesian model averaging (BMA) method. Results indicate the following. (1) Both SCE-UA and SCEM-UA resulted in good and comparable streamflow simulations. Specifically, the SCEM-UA implied parameter uncertainty and provided the posterior distribution of the parameters. (2) In terms of the precipitation input uncertainty, precision of streamflow simulations did not improve remarkably. (3) The BMA combination not only improved the precision of streamflow prediction, but also quantified the uncertainty bounds of the simulation. (4) The prediction interval calculated using the SCEM-UA-based BMA combination approach appears superior to that calculated using the SCE-UA-based BMA combination for both high flows and low flows. Results suggest that the comprehensive uncertainty analysis by using the SCEM-UA algorithm and BMA method is superior for streamflow predictions and flood forecasting.
Comparison of Meniscal Cell-Mediated and Chondrocyte-Mediated Calcification
Authors: Kiraly Alex J. , Roberts Andrea , Cox Michael , Mauerhan David , Hanley Edward , Sun Yubo 
Published: April 2017

Background:
Chondrocytes have been traditionally thought to be responsible for calcium crystal deposits within osteoarthritic knees. Increasing recent experimental evidence suggests that menisci may also play a role. However, the calcifying potential of chondrocytes and meniscal cells derived from same OA patients, and the genes associated with meniscal calcification have never been fully examined.

Objective:
Examine and compare the calcifying potential of articular chondrocytes and meniscal cells derived from same OA patients and identify the calcium crystal type(s) and selected gene expression in OA menisci.

Methods:
Chondrocytes and meniscal cells were isolated from articular cartilage and menisci of OA patients undergoing total knee arthroplasty. Chondrocyte- and meniscal cell-mediated calcification was examined using both monolayer and micromass culture-based assays. Crustal types were examined with histological staining. Levels of Type X Collagen, MMP-13, and ANKH in OA menisci were examined using immunohistochemistry.

Results:
Primary human OA meniscal cells produced calcified deposits at a similar rate compared to OA chondrocytes in-vitro. Histological examinations indicate that both BCP crystals and CPPD crystals are present in the meniscal tissue. Type X collagen, MMP-13, and ANKH were found in human OA menisci and their levels increased with OA severity. In addition, type X collagen was co-localized with calcium crystals.

Conclusion:
These findings suggest that OA meniscal cells have a similar calcifying potential as OA chondrocytes, supporting a pathogenic role of OA menisci in OA.
Synthesis of TiO<sub>2</sub>/Carbon Nanoparticle (C-dot) Composites as Active Catalysts for Photodegradation of Persistent Organic Pollutant
Authors: Syafei Dedri , Sugiarti Sri , Darmawan Noviyan , Khotib Mohammad 
Published: April 2017

TiO2/C-dot composites were synthesised by sol-gel method and investigated as catalysts for photocatalytic degradation of persistent organic pollutants (perchloroethylene, PCE). The composites photoluminescence properties was shown by visual analysis and the synthesis product was characterized by XRD, FTIR, fluorescence spectrophotometer, and UV-Vis spectrophotometer. Degradation of PCE 0.1% (v/v) in the aqueous phase was investigated under sunlight irradiation for 2 h. Photodegrade efficiency of PCE was determined by GC. Composites of TiO2/C-dot 2.5% (w/w) was succesfully to degrade PCE under sunlight irradiation and its photodegrade efficiency was up to 89.45%.
FORMULATION AND IN-VITRO EVALUATION OF TRANSDERMAL MATRIX PATCHES OF DOXOPHYLLINE.
Authors: Jalhan Sunny , Kaur Khushpal , Kaur Preetinder , K Jain Upendra 
Published: April 2017

ABSTRACT Objective: The objective of the present study was to fabricate matrix type transdermal patch with varied proportion of hydrophilic (HPMC E-50) and (PVP) combination incorporating the drug Doxophylline and to execute the physicochemical and in vitro assessment. The motive was to provide the delivery of Doxophylline at a controlled rate across the intact skin to attain a therapeutically effective drug level for a longer time span from transdermal matrix patch.Method: Prefomulation studies and evaluation was done by using different parameter such as Partition coefficient, Physicochemical Compatibility of Drug and Polymer, Physical appearance, Thickness Measurement, Folding Endurance, Weight variation, Percentage moisture lost, Percentage moisture uptake, Drug content Determination.Result: The results shows that patches of Doxophylline obtained by the solvent evaporation method had acceptable physicochemical characteristics and satisfactory percentage drug release. Conclusion: The main conclusion of my work was formulating the Doxophylline transdermal system was to prolong the drug release time, reduce the frequency of administration and to improve patient compliance. Six formulations were prepared using two polymers in different ratios along with plasticizers and penetration enhancer.