bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of Coiled Tubing Electric Line Plug and Perf Technology for Multistage Hydraulic Fracturing in Pakistan
Authors: Khan Rao Shafin , Khalid Aizaz , Ahmed Tofeeq , Ali Usman 
Published: February 2016

Abstract
In certain onshore Pakistan wells, coiled tubing intervention has been used in plug-and-perf operations. Although the plug-and-perf technique is well described in the literature, the existing studies mainly cover fracturing and reservoir productivity aspects. This paper highlights coiled tubing operational techniques that are integral and vital to the success of coiled tubing plug-and-perf multistage fracturing.
The application of coiled tubing plug-and-perf techniques to horizontal, high-temperature wells onshore Pakistan involved specific designs and new processes for the preparation, execution, and evaluation of the coiled tubing interventions. Planning and design considerations included the selection of the bottomhole assembly (BHA) in general and, in particular, the choice of logging head and upgrading the logging head operating envelope. During execution, efficiency was improved by reducing the number of coiled tubing runs with the use of addressable switches.
The plug-and-perf sequence with coiled tubing was repeated successfully in multiple wells. The combination of the addressable switches used as part of the BHA to enable setting the bridge plug and perforating multiple sets of perforations separately in a single run was shown to be very successful. The use of the plug-and-perf with coiled tubing technique improved overall project economics by reducing operating time to half for each zone. These successes validate the advantage of deploying coiled tubing for multistage fracturing operations. Multiple operators have realized the value of this technique compared to other techniques commonly used in such operations.
Design and Analysis of Laboratory Experiment on Surfactant-Flooding with Software Protocol
Authors: Hassan Mohsin , Channa Sadam Hussain , Qazi Shoukat Elahi , Ali Shahzad , Kumar Sandeep 
Published: February 2016

Abstract
Relative permeability and interfacial tension are key parameters to characterize chemical enhanced oil recovery. Chemical flooding, a modern technique of enhanced oil recovery is based on the principle of reduction in interfacial tension of oil/water system. The selection of suitable surfactant is important and it should be compatible in a single phase solution at reservoir conditions and can be capable of reducing the interfacial tension to about 10–3 dynes/cm. In this study, Alcohol Alkoxy sulfate sodium salt (AAS) has been used as a surfactant. AAS was found compatible for conducting core flood experiment and it also reduced the oil/water interfacial tension to a very low value by forming type III micro emulsion. A Berea sandstone core plug of 100md was used in the core flooding experiment. The experimental results showed significant decrease in water/oil interfacial tension of 29 dynes/cm to 4.15*10–4 dynes/cm. SendraTM estimation was used for the history matching between experimental data with simulated one. Recovery with water flooding was 59.28%, whereas with surfactants it was increased to 85.95%. Relative Permeability of oil was 0.92 with water flooding, whereas relative permeability of oil with surfactant flooding was 0.98. The comparative analysis showed that two phase region (oil-water) becomes wider when surfactant was used and also relative permeability of oil was increased with decrease in interfacial tension. This study shows that surfactants can be applied in most oil fields of Pakistan especially in Central Potwar region where oil API is in the range of 10–22◦, so they promise a bright future for Petroleum Industry in Pakistan.
First Application of New Conveyance Technique to Acquire Electric Log Data in Complex Hole Conditions in Margala North and Tal Blocks of Northern Potwar Deform Zone and Kohat Basin, Pakistan
Authors: Farooq Umar , Ahmed Jawad , Ali Saqib , Tashfeen Muhammad , Shah Khurram Abbas , Siddiqi Farrukh , Ali Chand 
Published: February 2016

ABSTRACT
This paper presents the first real field application of Electric logging in Pakistan with a new conveyance Technique in order to acquire logging data where conventional Wireline logging data acquisition is not possible due to complex bore hole condition (depth, deviation and hole size etc.).
The new logging technique was successfully conducted on a wild cat exploratory and a development well in Margala North & Tal Blocks respectively. Open-hole logs data was acquired from potential reservoir zones that under normal wireline logging conditions would not have been possible due to high risk of sticking or losing the well due to presence of radioactive sources in the tool string.
In this new technique, logging tools are conveyed to TD inside the drill pipe by wireline or by pumping them with a specialized piston. Once tools reach the TD, they are pumped out of the drill pipe and latched at the bottom, and then pipes are pulled up while data is recorded by the tools hooked with drill pipes. In some of the runs, the logs were acquired while pipes were constantly rotated and mud was circulated through.
The logs acquired through this technique consisted of Laterolog Resistivity, Neutron Porosity, Bulk Density & PE, Sonic Porosity Cross Dipole Sonic and Formation Imaging.
The successful application of this technique in Pakistan has opened new ways to acquire logs data in challenging bore-hole conditions with logging tools and radioactive sources being at low risk of losing down hole.
Stress Testing in Shale with Advanced Wireline Formation Tester: First Case Study in Pakistan
Authors: Khan M. Wahaj , Samir Magdy , Mughal Haroon , Khalid Arsalan , Dar Usman , Zubair Talha , Javed Qasim 
Published: February 2016

ABSTRACT
Shale gas is a new horizon in Pakistan to meet growing energy demands. Comprehensive data gathering is mandatory for proper evaluation of a shale gas play and to determine feasibility of a prospect. Shale reservoirs require hydraulic fracturing to produce commercially. In Pakistan, stresses are normally high due to plate tectonics. In some cases, the lack of sufficient understanding of stress conditions has led to failures of full hydraulic fracturing operations.
Stress testing is a technique used to evaluate formation breakdown pressures and minimum in-situ stresses. Stress profiles can be estimated using openhole log data, however direct in-situ measurement is needed for calibration. Wireline formation testers have been used in the field to measure formation pressures, estimate mobility and obtain good quality downhole samples. One of the advanced applications of the wireline formation testers is to measure insitu stresses in a wellbore to calibrate the mechanical earth model (MEM) and to design a feasible hydraulic fracturing job.
Traditional wireline insitu-stress technique has been around for some time now, however the technique suffered from a limited pressure ratings, which was not enough to breakdown the formation. An advanced wireline formation tester module capable of achieving a break down through sleeve fracturing at a very high pressure was used for stress measurement for first time not only in Pakistan but worldwide. The technique involves setting a single packer module across the target shale zone and inflating the packer until the formation breaks down. Once formation break down is achieved, either a straddle packer is set across the target formation and injection is performed for fracture reopening, or another cycle is done with the single packer element to record sleeve reopening pressure.
Detailed planning was done by the reservoir and geology departments. Four tests at four different locations were done in the target well where formation break down pressure, closure and fracture re opening pressures were estimated. This information is used for updating a 1D geomechanical earth model for the further use in planning full scale hydraulic fracturing treatment.
Demands of Multi-Lateral Wells Functions
Authors: MacDonald R. R. , Erickson D. M. 
Published: February 2016

Abstract
Demands of Multi-Lateral Well Junctions are shifting from successful shallow wells to deeper and more functional window applications. Reliable window exit, reduced trips and improved debris management while drilling have provided the confidence to take this step. Completion and Production opportunities are the focus areas. Reliable and low cost re-entry capability both through tubing and through casing is demanded. Fluid isolation and shut-off during drilling, production, injection, stimulation and production logging operations are being developed. Innovative multiple lateral completions equipment is required to provide a cost effective solution. These tools and techniques are presented.
Predicting Cuttings Transport and Suspension Using a Viscoelastic Drilling Fluid in Extended Reach and Horizontal Wells
Authors: Marquis de Sa C. , Rosolen M. , Brandao E. 
Published: February 2016

Abstract
This work presents the results obtained in a project developed in PETROBRAS' Research Center – CENPES – aiming at the introduction of concepts of viscoelasticity in drilling, completion and stimulation fluids characterization. One major issue is the study of the cuttings transport and suspension during high component. This component proved to be important especially when such fluids are at rest or in the transient period which happens in the beginning of fluid movement. Such relationship is the base of a methodology for predicting cuttings transport in complex geometry wells anticipating well designers in possible hole cleaning problems based on the usual design data.
Applying Multilateral Well Technology to the Deep Foothills Area of Alberta
Authors: Sanders R. , Shoup M. , Themig D. 
Published: February 2016

Abstract
The foothills area of Alberta, Canada is a challenging exploration area for reservoir definition as well as drilling and completions. The complex geologic structures as well as the logistical difficulties in the area make it a costly area to drill and exploit. During the past three years, several multilateral wells have been successfully drilled and completed in this area. Some of these incorporated advanced drilling and completions system which allowed greater flexibility in both the drilling and testing/production phases of the wells. This paper presents case history descriptions of the application of advanced multilateral technology regarding drilling and completion systems for these wells and the capabilities which were utilized to successfully drill, test, and produce the wells.
Production Control of Horizontal Wells in a Carbonate Reef Structure
Authors: Ellsworth Bill , Muir Marty , Gray John , Themig Dan 
Published: February 2016

Abstract
Open hole completions have been the accepted practice for horizontal wells in the Rainbow Lake area of Northern Alberta. As these fields mature, and the oil bank in these structures thin, the use of effective production control technology has become particularly important. The design of the well trajectory, the ability to intervene to control production, and the incorporation of horizontals in a strategic producing plan for the area has pushed the edge of technology. Many aspects of the planned exploitation of these reef pools have changed based upon successful applications of evolving horizontal well technologies. Production control issues are paramount to these changes. This paper presents several well case histories that illustrate the application of advancements in establishing isolation in the open hole horizontal completions to accomplish various objectives in the successful application of horizontal wells in the Rainbow Lake field.
Effect of Sirolimus on Disease Progression in Patients with Autosomal Dominant Polycystic Kidney Disease and CKD Stages 3b-4
Authors: Ruggenenti Piero , Gentile Giorgio , Perico Norberto , Perna Annalisa , Barcella Luca , Trillini Matias , Cortinovis Monica , Ferrer Siles Claudia Patricia , Reyes Loaeza Jorge Arturo , Aparicio Maria Carolina , Fasolini Giorgio , Gaspari Flavio , Martinetti Davide , Carrara Fabiola , Rubis Nadia , Prandini Silvia , Caroli Anna , Sharma Kanishka , Antiga Luca , Remuzzi Andrea , Remuzzi Giuseppe ,   on behalf of the SIRENA 2 Study Group
Published: February 2016

Background and objectives
The effect of mammalian target of rapamycin (mTOR) inhibitors has never been tested in patients with autosomal dominant polycystic kidney disease (ADPKD) and severe renal insufficiency.

Design, setting, participants, & measurements
In this academic, prospective, randomized, open label, blinded end point, parallel group trial (ClinicalTrials.gov no. NCT01223755), 41 adults with ADPKD, CKD stage 3b or 4, and proteinuria ≤0.5 g/24 h were randomized between September of 2010 and March of 2012 to sirolimus (3 mg/d; serum target levels of 5–10 ng/ml) added on to conventional therapy (n=21) or conventional treatment alone (n=20). Primary outcome was GFR (iohexol plasma clearance) change at 1 and 3 years versus baseline.

Results
At the 1-year preplanned interim analysis, GFR fell from 26.7±5.8 to 21.3±6.3 ml/min per 1.73 m2 (P<0.001) and from 29.6±5.6 to 24.9±6.2 ml/min per 1.73 m2 (P<0.001) in the sirolimus and conventional treatment groups, respectively. Albuminuria (73.8±81.8 versus 154.9±152.9 μg/min; P=0.02) and proteinuria (0.3±0.2 versus 06±0.4 g/24 h; P<0.01) increased with sirolimus. Seven patients on sirolimus versus one control had de novo proteinuria (P=0.04), ten versus three patients doubled proteinuria (P=0.02), 18 versus 11 patients had peripheral edema (P=0.04), and 14 versus six patients had upper respiratory tract infections (P=0.03). Three patients on sirolimus had angioedema, 14 patients had aphthous stomatitis, and seven patients had acne (P<0.01 for both versus controls). Two patients progressed to ESRD, and two patients withdrew because of worsening of proteinuria. These events were not observed in controls. Thus, the independent data and safety monitoring board recommend early trial termination for safety reasons. At 1 year, total kidney volume (assessed by contrast–enhanced computed tomography imaging) increased by 9.0% from 2857.7±1447.3 to 3094.6±1519.5 ml on sirolimus and 4.3% from 3123.4±1695.3 to 3222.6±1651.4 ml on conventional therapy (P=0.12). On follow-up, 37% and 7% of serum sirolimus levels fell below or exceeded the therapeutic range, respectively.

Conclusions
Finding that sirolimus was unsafe and ineffective in patients with ADPKD and renal insufficiency suggests that mTOR inhibitor therapy may be contraindicated in this context.
Assessment of nutritional composition and heavy metal content in some edible mushroom varieties collected from different areas of Bangladesh
Authors: Mohiuddin KM , Alam Md Mehediul , Arefin Md Taufique , Ahmed Istiaq 
Published: February 2016

Four edible mushroom species (Pleurotus ostreatus, Agaricus bisporus, Volvariella volvacea, Ganoderma lucidum) from different locations of Bangladesh, were analysed for their protein and metal content profile (K, Na, Fe, Cu, Zn, Mn, Cr, Pb, As and Cd). Trace metals were determined by atomic absorption spectrophotometer, Na and K by flame emission spectrophotometer and protein by micro Kjeldhal method. All element concentrations were determined on a dry weight basis. The protein content of mushrooms varied from 13.8%34.3% and the metal content of samples ranged from 0.542.25% for K and 12.681.6, 69.5626.2, 39.2163.4, 30.175.5, 52.9104.5, 0.200.30, 0.130.59 ?g g-1 for Na, Fe, Cu, Zn, Mn, Cd, Pb, respectively. Arsenic and cadmium concentrations were below the detection limit of the method used. The detection limits of the method for As and Cd are 0.01 ?g g-1 for each element. In general, K and Fe content were higher than other metals in all mushroom species. The levels of Cu and Zn in some mushroom samples were found to be higher than legal limits.Asian J. Med. Biol. Res. December 2015, 1(3): 495-501
ENSEMBLE EMPIRICAL MODE DECOMPOSITION OF THE MAGNETIC FIELD OF THE SUN AS A STAR
Authors: Xiang N. B. , Qu Z. N. 
Published: February 2016

ABSTRACT
The ensemble empirical mode decomposition (EEMD) analysis is utilized to extract the intrinsic mode functions (IMFs) of the solar mean magnetic field (SMMF) observed at the Wilcox Solar Observatory of Stanford University from 1975 to 2014, and then we analyze the periods of these IMFs as well as the relation of IMFs (SMMF) with some solar activity indices. The two special rotation cycles of 26.6 and 28.5 days should be derived from different magnetic flux elements in the SMMF. The rotation cycle of the weak magnetic flux element in the SMMF is 26.6 days, while the rotation cycle of the strong magnetic flux element in the SMMF is 28.5 days. The two rotation periods of the structure of the interplanetary magnetic field near the ecliptic plane are essentially related to weak and strong magnetic flux elements in the SMMF, respectively. The rotation cycle of weak magnetic flux in the SMMF did not vary over the last 40 years because the weak magnetic flux element derived from the weak magnetic activity on the full disk is not influenced by latitudinal migration. Neither the internal rotation of the Sun nor the solar magnetic activity on the disk (including the solar polar fields) causes the annual variation of SMMF. The variation of SMMF at timescales of a solar cycle is more related to weak magnetic activity on the full solar disk.
TIME-SERIES SPECTROSCOPY OF THE PULSATING ECLIPSING BINARY XX CEPHEI
Authors: Koo Jae-Rim , Lee Jae Woo , Hong Kyeongsoo , Kim Seung-Lee , Lee Chung-Uk 
Published: February 2016

ABSTRACT
Oscillating Algol-type eclipsing binaries (oEA) are very interesting objects that have three observational features of eclipse, pulsation, and mass transfer. Direct measurement of their masses and radii from the double-lined radial velocity data and photometric light curves would be the most essential for understanding their evolutionary process and for performing the asteroseismological study. We present the physical properties of the oEA star XX Cep from high-resolution time-series spectroscopic data. The effective temperature of the primary star was determined to be 7946 ± 240 K by comparing the observed spectra and the Kurucz models. We detected the absorption lines of the secondary star, which had never been detected in previous studies, and obtained the radial velocities for both components. With the published BVRI light curves, we determined the absolute parameters for the binary via Wilson–Devinney modeling. The masses and radii are

,

,

, and

, respectively. The primary star is about

more massive and

larger than the zero-age main sequence stars with the same effective temperature. It is probably because XX Cep has experienced a very different evolutionary process due to mass transfer, contrasting with the normal main sequence stars. The primary star is located inside the theoretical instability strip of δ Sct-type stars on the HR diagram. We demonstrated that XX Cep is an oEA star, consisting of a δ Sct-type pulsating primary component and an evolved secondary companion.
OPTICAL THERMONUCLEAR TRANSIENTS FROM TIDAL COMPRESSION OF WHITE DWARFS AS TRACERS OF THE LOW END OF THE MASSIVE BLACK HOLE MASS FUNCTION
Authors: MacLeod Morgan , Guillochon James , Ramirez-Ruiz Enrico , Kasen Daniel , Rosswog Stephan 
Published: February 2016

ABSTRACT
In this paper, we model the observable signatures of tidal disruptions of white dwarf (WD) stars using massive black holes (MBHs) of moderate mass, ≈103–105 M
⊙. When the WD passes deep enough within the MBH’s tidal field, these signatures include thermonuclear transients from burning during maximum compression. We combine a hydrodynamic simulation that includes nuclear burning of the disruption of a 0.6 M
⊙ C/O WD with a Monte Carlo radiative transfer calculation to synthesize the properties of a representative transient. The transient’s emission emerges in the optical, with light curves and spectra reminiscent of Type I supernovae. The properties are strongly viewing angle dependent, and key spectral signatures are ≈10,000 km s−1 doppler shifts, due to the orbital motion of the unbound ejecta. Disruptions of He WDs likely produce large quantities of intermediate-mass elements, offering a possible production mechanism for Ca-rich transients. Accompanying multi-wavelength transients are fueled by accretion and arise from the nascent accretion disk and relativistic jet. If MBHs of moderate mass exist with number densities similar to those of supermassive BHs, both high-energy wide-field monitors and upcoming optical surveys should detect tens to hundreds of WD tidal disruptions per year. The current best strategy for their detection may therefore be deep optical follow-up of high-energy transients of unusually long duration. The detection rate or the nondetection of these transients by current and upcoming surveys can thus be used to place meaningful constraints on the extrapolation of the MBH mass function to moderate masses.
THE IMPORTANCE OF WIDE-FIELD FOREGROUND REMOVAL FOR 21 cm COSMOLOGY: A DEMONSTRATION WITH EARLY MWA EPOCH OF REIONIZATION OBSERVATIONS
Authors: Pober J. C. , Hazelton B. J. , Beardsley A. P. , Barry N. A. , Martinot Z. E. , Sullivan I. S. , Morales M. F. , Bell M. E. , Bernardi G. , Bhat N. D. R. , Bowman J. D. , Briggs F. , Cappallo R. J. , Carroll P. , Corey B. E. , de Oliveira-Costa A. , Deshpande A. A. , Dillon Joshua. S. , Emrich D. , Ewall-Wice A. M. , Feng L. , Goeke R. , Greenhill L. J. , Hewitt J. N. , Hindson L. , Hurley-Walker N. , Jacobs D. C. , Johnston-Hollitt M. , Kaplan D. L. , Kasper J. C. , Kim Han-Seek , Kittiwisit P. , Kratzenberg E. , Kudryavtseva N. , Lenc E. , Line J. , Loeb A. , Lonsdale C. J. , Lynch M. J. , McKinley B. , McWhirter S. R. , Mitchell D. A. , Morgan E. , Neben A. R. , Oberoi D. , Offringa A. R. , Ord S. M. , Paul Sourabh , Pindor B. , Prabu T. , Procopio P. , Riding J. , Rogers A. E. E. , Roshi A. , Sethi Shiv K. , Shankar N. Udaya , Srivani K. S. , Subrahmanyan R. , Tegmark M. , Thyagarajan Nithyanandan , Tingay S. J. , Trott C. M. , Waterson M. , Wayth R. B. , Webster R. L. , Whitney A. R. , Williams A. , Williams C. L. , Wyithe J. S. B. 
Published: February 2016

ABSTRACT
In this paper we present observations, simulations, and analysis demonstrating the direct connection between the location of foreground emission on the sky and its location in cosmological power spectra from interferometric redshifted 21 cm experiments. We begin with a heuristic formalism for understanding the mapping of sky coordinates into the cylindrically averaged power spectra measurements used by 21 cm experiments, with a focus on the effects of the instrument beam response and the associated sidelobes. We then demonstrate this mapping by analyzing power spectra with both simulated and observed data from the Murchison Widefield Array. We find that removing a foreground model that includes sources in both the main field of view and the first sidelobes reduces the contamination in high k
∥ modes by several per cent relative to a model that only includes sources in the main field of view, with the completeness of the foreground model setting the principal limitation on the amount of power removed. While small, a percent-level amount of foreground power is in itself more than enough to prevent recovery of any Epoch of Reionization signal from these modes. This result demonstrates that foreground subtraction for redshifted 21 cm experiments is truly a wide-field problem, and algorithms and simulations must extend beyond the instrument’s main field of view to potentially recover the full 21 cm power spectrum.