bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drilling Through Depletion in the Bakken; Using Drill Bit Geomechanics to Inform Fracture Stimulation
Authors: Weddle P.. , McChesney J.. , Grande R.. , Marshall E.. , Scott E. L. 
Published: October 2018

Abstract
Seven years ago, some operators in the United States began geo-engineering completions to more efficiently stimulate unconventional horizontal wells. Typically, engineers and geoscientists rely on expensive open-hole logs or the over-simplified use of gamma ray to infer mechanical rock properties along the lateral. Engineers then select treatment stage intervals and place perforation clusters in similarly-stressed, "like rock" to minimize the geomechanical variability. Instead of traditional open-hole logging, this paper discusses geo-engineering applications of drill bit geomechanics.
Drill bit geomechanics is an innovative method for formation evaluation and reservoir characterization. It uses direct, continuous, high-resolution measurements of drilling vibrations recorded downhole. Using earthquake seismology models, one can infer rock properties from the measured drilling vibrations. These rock properties include Poisson's Ratio, Young's Modulus of Elasticity, and the presence of fractures perpendicular to the horizontal well. In this study, the Operator collected drill bit geomechanics data while drilling a new well ~8-34 ft below three existing horizontal wellbores, with over seven years of continuous production. The study well was a 9,500-ft lateral in the Bakken Formation in North Dakota. Using drill-bit-geomechanics-derived rock properties, the operator could confidently geo-engineer a completion, accounting for reservoir depletion from the older wells.
The drill bit geomechanics data showed dramatic changes in mechanical properties and fracturing where the study well intersected the older wells’ stimulated reservoir volumes (SRVs). The operator had a general idea of the wells’ SRVs from microseismic data acquired during two wells’ stimulations. Using the drill bit geomechanics data from the study well, the operator could more effectively constrain the drainage ellipses from the sparse microseismic data. The operator geo-engineered a 27-stage completion by combining "like rock" of the same reservoir pressure. Measured Instantaneous Shut-In Pressures (ISIPs) during the completion showed significantly lower ISIPs for the partially-depleted stages closest to the older wells. Thus, combining similarly-pressured stages was critical to the completion's success. Well performance has proven to be excellent for the area, even when compared to wells without depletion from older producing wellbores.
As shown in this case study, drill bit geomechanics is an economic, useful tool to identify depletion and accurately measure rock properties and fractures at a very high resolution.
3-D Interactions of Hydraulic Fractures with Natural Fractures
Authors: Shrivastava Kaustubh , Agrawal Shivam , Kumar Ashish , Sharma Mukul M. 
Published: October 2018

AbstractDuring hydraulic fracturing, the interaction of hydraulic fractures with natural fractures can result in the formation of complex fracture networks. In the past these interactions have been captured in hydraulic fracturing models using crossing criteria developed based on two-dimensional geometries. In this work, we investigate the interaction of hydraulic fractures and natural fractures in three-dimensions and demonstrate that there can be significant differences in the observed interactions.A hydraulic fracturing simulator is presented that solves the coupled fluid flow and geomechanics problem for three-dimensional fractures. The simulator captures the physics of fracture growth and the intersection of hydraulic fracture with pre-existing discrete fracture network. The model employs a robust algorithm to account for the stress relaxation due to the slippage of natural fractures. The displacement of failed natural fracture elements is calculated rigorously. The model allows the partial failure of three-dimensional natural fractures and accurately calculates the stresses acting on the plane of the natural fracture.It is shown that a natural fracture inclined at an angle to an approaching hydraulic fracture experiences compression in one region (due to the stress shadow of the growing hydraulic fracture) and tension in other regions (in front of the approaching hydraulic fracture tip). The generated stresses can fail the natural fracture partially. The failure of the natural fracture relaxes the stresses around it, which can modify the direction of propagation of the approaching hydraulic fracture. In addition, if the elliptical front of the hydraulic fracture crosses an intact planar natural fracture, the three-dimensional geometry results in a line of intersection (between natural fracture and hydraulic fracture). This can lead to failure of the natural fracture even after the elliptical front has partially crossed the natural fracture. Such an interaction can allow the hydraulic fracture to both cross the natural fracture and activate (or dilate) it. These effects cannot be captured by two-dimensional simulations. This work improves our understanding of the interaction between hydraulic fractures and natural fractures. The novel results provide new insights into the mechanisms responsible for the complexity that is often observed in hydraulic fractures.
Twelve Years and Twelve Thousand Multi-Stage Horizontal Wells in the Bakken - How is Industry Continuing to Increase the Cumulative Production Per Well?
Authors: Pearson C. Mark , Griffin Larry G. , Strickland Stacy L. , Weddle Paul M. 
Published: October 2018

Abstract
Multi-stage horizontal well designs have been used since 2007 in the Bakken oil-field of North Dakota. Since then over 12,000 wells have been completed in either the Middle Bakken or Three Forks zones. Early-time production rates as measured by 180-day state-reported cumulative production have increased 4-fold over this period as industry has pursued a program of innovation and continuous improvement in completions technology with production per well increasing in ten of the twelve years.
Through a "Big-Data" analytical study comparing geological data, completions parameters, and state-reported production results the authors have evaluated the fundamental changes that have guided industry to produce these results over the past twelve years. While geological changes in different areas drove both the drilling "mania" during times of $100 oil and consequent contraction of the industry when wellhead prices dropped below $40 per BO; it is the advances in completion design and hydraulic fracturing that have driven macro performance over the twelve years - and resulted in this significant increase in production per well. These completion advances have allowed the region to compete on a global scale with production that while dipping to ~1.0 Million bopd in 2016 has now rebounded to over 1.2 Million bopd.
Large datasets of geological, completions and production data take years to assemble and analyze. Through the authors use of multivariate analysis techniques this paper presents the deterministic factors affecting well performance in the Bakken and provides guidance and best practices towards applying these techniques in emerging international plays.
An Integrated Analytics Platform for Completion Optimization and Reservoir Characterization
Authors: Yang Junjie , Stolyarov Sergey , Cazeneuve Eduardo , Simmons Jason , Kotov Sergey , Gadzhimizaev David 
Published: October 2018

AbstractAs laterals become longer with more stages, large datasets make evaluation of the information complicated and time consuming. Variations in the obtained data adds more uncertainty to the main industry challenges and questions, such as optimal well spacing, optimal completion (e.g., type of completion, stage and cluster spacing), optimal stimulation treatment (e.g., proppant type, mass and concentration, fluid type, volume and composition).This paper describes a novel automated framework for completion optimization and post-fracture analysis. For pre-fracture analysis, this framework utilizes an integrated dataset from drilling and wireline logs, and automatically places clusters based on heterogeneity along the lateral. This information is then coupled with post-fracture data to examine fracture treating information (breakdown pressure, instantaneous shut in pressure, etc.) and correlate it to rock properties from each fracture stage. The newly identified correlation is looped back into the framework as a guideline for future frac design.The strong correlation between subsurface rock properties and hydraulic fracture treatment parameters suggests that the previous captured heterogeneity reveals the fracture design efficiency, and the multivariable evaluation process can be accelerated by the machine learning platform. A statistical model was built on geomechanical and petrophysical properties used to design fracture treatments. Meanwhile, the platform automatically evaluates fracture treating signatures (surface treating pressure, pumping rate, ISIP, etc.) and links them with subsurface information for each stage. When the model is trained with a sufficient amount of data, it can be used as a real-time advisor that suggests a fracture treatment schedule (pump rate, sand concentration, fluid volume). The fracture geometry as well as the treatment efficiency can be optimized with the enhanced design. The model can eliminate or reduce the need for expensive subsurface characterization logging tools and provide quick recommendations for changes to the treatment.This paper introduces an integrated solution to optimize fracture treatment design assisted by data analytics that can be further improved to solve other multivariable problems in the oil and gas industry.
A Quick Look Approach for Determining Instantaneous Shut-in Pressure ISIP and Friction Losses from Hydraulic Fracture Treatment Falloff Data
Authors: Menouar Nadia , Liu Guoqing , Ehlig-Economides Christine 
Published: October 2018

Abstract
The instantaneous shut-in pressure (ISIP) picked from the pressure falloff following each hydraulic fracturing treatment stage has been used to evaluate stress shadowing effects and required for modeling injection treatment behavior. However, the traditional methods for estimating ISIP as the pressure extrapolated back to the pumping time from a straight line through an arbitrary series of points on a plot of Cartesian falloff pressure versus time or the log of time have no theoretical justification. Further, the ISIP picked by either of these approaches is highly dependent on the selected points. In this paper, we show a more rigorous approach to quantify the ISIP and that also enables estimation of parameters governing wellbore, perforations and near-wellbore tortuosity friction losses.
The wellbore storage (WBS) effect complicates straightforward picking of the ISIP from the pressure curve at shut-in. The existing diagnostic fracture injection test (DFIT) analysis model coupling WBS with friction dissipation that enables estimation of friction losses and the ISIP for the DFIT analysis also enables estimation of these same parameters from falloff data following the hydraulic fracturing treatment.
The pressure difference and its derivative in the log-log diagnostic plot generated from the falloff at the end of the fracture pumping treatment is an effective diagnostic plot to identify portions of the data dominated by WBS and friction losses. Coupled WBS and friction loss dominate the immediate pressure falloff after the end of pumping, and frequently the treatment data include sufficient time to quantify friction losses. The wellbore and perforation friction loss and the total friction loss are picked using the log-log diagnostic plot. Changes in the correctly quantified ISIP estimated for successive treatment stages along the horizontal well may be related to a stress shadowing effect. Field examples demonstrate how the ISIP profile along a well compares between this approach and common field practices.
The paper provides a quick approach to evaluate friction losses and the ISIP from hydraulic fracturing treatment falloff data. The approach provides much more accurate and less uncertain ISIP estimates than current field practices.
Design, Synthesis and Biological Potential of 5-(2-Amino-6-(3/4-bromophenyl)pyrimidin-4-yl)benzene-1,3-diol Scaffolds as Promising Antimicrobial and Anticancer Agents
Authors: Kumar Sanjiv , Narasimhan Balasubramanian , Lim Siong Meng , Ramasamy Kalavathy , Mani Vasudevan , Shah Syed Adnan Ali 
Published: October 2018

Background:
A series of 5-(2-amino-6-(3/4-bromophenyl)pyrimidin-4-yl)benzene-1,3-diol
scaffolds was synthesized by Claisen-Schmidt condensation and characterized by NMR, IR, Mass and
elemental analyses.

Methods:
The synthesized pyrimidine scaffolds were screened for their antimicrobial activity by tube
dilution method as well for antiproliferative activity (human colorectal (HCT116) cancer cell line) by
SRB assay.

Results:
The antimicrobial screening results demonstrated that compounds, k6, k12, k14 and k20 were
found to be the most potent ones against selected microbial species. The anticancer screening results indicated
that compounds, k8 and k14 displayed potent anticancer activity against cancer cell line (HCT116).

Conclusion:
Further, the molecular docking study carried to find out the interaction between active
pyrimidine compounds with CDK-8 protein indicated that compound k14 showed best dock score with
better potency within the ATP binding pocket and may be used as a lead for rational drug designing of
the anticancer molecule.
2-Mercaptobenzimidazole Schiff Bases: Design, Synthesis, Antimicrobial Studies and Anticancer Activity on HCT-116 Cell Line
Authors: Tahlan Sumit , Narasimhan Balasubramanian , Lim Siong Meng , Ramasamy Kalavathy , Mani Vasudevan , Shah Syed A.A. 
Published: October 2018

Background:
Increased rate of mortality due to the development of resistance to currently
available antimicrobial and anticancer agents initiated the need to develop new chemical entities for
the treatment of microbial infections and cancer.

Objective:
The present study was aimed to synthesize and evaluate antimicrobial and anticancer activities
of Schiff bases of 2-mercaptobenzimidazole.

Methods:
The Schiff bases of 2-mercaptobenzimidazole were synthesized from 4-(2-(1H-benzo[d]-
imidazol-2-ylthio)acetamido)benzohydrazide. The synthesized compounds were evaluated for antimicrobial
and anticancer activities by tube dilution method and Sulforhodamine-B (SRB) assay, respectively.

Results:
Compounds 8 (MICpa, an = 2.41, 1.20 µM/ml), 10 (MICse, sa = 2.50 µM/ml), 20 (MICec = 2.34
µM/ml) and 25 (MICca = 1.46 µM/ml) showed significant antimicrobial activity against tested bacterial
and fungal strains and compounds 20 (IC50 = 8 µg/ml) and 23 (IC50 = 7 µg/ml) exhibited significant
anticancer activity.

Conclusion:
In general, the synthesized derivatives exhibited moderate antimicrobial and anticancer
activities. Compounds 8 and 25 having high antifungal potential among the synthesized compounds
may be taken as lead molecules for the development of novel antifungal agents.
Metabolic Effects of Metformin in Humans
Authors: Adeva-Andany María M. , Rañal-Muíño Eva , Fernández-Fernández Carlos , Pazos-García Cristina , Vila-Altesor Matilde 
Published: October 2018

Background:
Both insulin deficiency and insulin resistance due to glucagon secretion cause
fasting and postprandial hyperglycemia in patients with diabetes.

Introduction:
Metformin enhances insulin sensitivity, being used to prevent and treat diabetes, although
its mechanism of action remains elusive.

Results:
Patients with diabetes fail to store glucose as hepatic glycogen via the direct pathway (glycogen
synthesis from dietary glucose during the post-prandial period) and via the indirect pathway (glycogen
synthesis from “de novo” synthesized glucose) owing to insulin deficiency and glucagoninduced
insulin resistance. Depletion of the hepatic glycogen deposit activates gluconeogenesis to replenish
the storage via the indirect pathway. Unlike healthy subjects, patients with diabetes experience
glycogen cycling due to enhanced gluconeogenesis and failure to store glucose as glycogen. These defects
raise hepatic glucose output causing both fasting and post-prandial hyperglycemia. Metformin reduces
post-prandial plasma glucose, suggesting that the drug facilitates glucose storage as hepatic glycogen
after meals. Replenishment of glycogen store attenuates the accelerated rate of gluconeogenesis
and reduces both glycogen cycling and hepatic glucose output. Metformin also reduces fasting hyperglycemia
due to declining hepatic glucose production. In addition, metformin reduces plasma insulin
concentration in subjects with impaired glucose tolerance and diabetes and decreases the amount of insulin
required for metabolic control in patients with diabetes, reflecting improvement of insulin activity.
Accordingly, metformin preserves β-cell function in patients with type 2 diabetes.

Conclusion:
Several mechanisms have been proposed to explain the metabolic effects of metformin,
but evidence is not conclusive and the molecular basis of metformin action remains unknown.
Regulation for Prescribing and Dispensing System of Cannabis: the Italian Case
Authors: Minghetti Paola , Marini Valentina , Zaccara Viviana , Casiraghi Antonella 
Published: October 2018

Background:
The medicinal properties of cannabis are now recognized. Indeed, in many
countries, lawmakers have introduced specific laws and programmes to allow patients to use cannabis
preparations in various forms; nevertheless, controversial situations can still be found. In Europe, medicinal-
grade cannabis is mainly available as standardized dried flower tops of the cannabis plant used
in magistral formulas. These are pharmaceutical preparations compounded in a pharmacy – following
Good Compounding Practices - in accordance with a physician’s prescription for an individual patient.
Aim of this work is to discuss the available Cannabis based preparations and regulation for prescription
and distribution, with reference to Italy.

Methods:
We undertook a structured search of Italian laws, ministerial decree and circulars related to
therapeutic use of Cannabis, interpreted in light of Italian Society of Compounding Pharmacists’ (SIFAP)
position.

Results:
Seven documents were analysed. Cannabis can be orally administered to patients - as a dried
drug dosed in filter or capsules for infusion or as an extract in olive oil prepared in a pharmacy - or inhaled
with a specific vaporizer. Considering the costs and limited availability of Dutch medicinal-grade
cannabis, the Italian Government, with the latest Decree of November 9th, 2015, has authorized the
production of cannabis in the Military Pharmaceutical Chemical Institute on Florence, describing also
the therapeutic use of cannabis and the requirements to be adhered to by physicians and pharmacists.

Conclusion:
A well-established national regulation guarantees the proper therapeutic use of Cannabis.
Description of preparation method in monograph Pharmacopoeia will be the way to assure quality and
therefore the efficacy of these products.
Simultaneous Bioanalysis of Prodrug Oseltamivir and its Metabolite Oseltamivir Carboxylic Acid in Human Plasma by LC/MS/MS Method and its Application to Disposition Kinetics
Authors: Sireesha Dodda , Ajitha Makula , Narayana Kandhagatta Raj 
Published: October 2018

Introduction:
A selective, sensitive, precise and rapid analytical method using liquid chromatography-
tandem mass spectrometry (LC/MS/MS) for simultaneous determination of oseltamivir and
oseltamivir carboxylic acid in plasma has been developed and validated, using oseltamivir-D5 and oseltamivir
acid-D3 as internal standards.

Methods:
The analytes were extracted from 300μL of human plasma using solid phase extraction technique.
A mixture of methanol and 0.1% formic acid (60:40, v/v) was used as mobile phase at a flow rate
of 0.7mL/min, to separate the analytes on Zorbax SB-C18 (50x4.6mm, 3.5μm) analytical column.

Results:
The calibration curves obtained were linear over the concentration ranges of 0.5-200ng/mL and
2.0-800ng/mL for oseltamivir and oseltamivir carboxylic acid respectively. A run time of 2.5min makes
it possible to analyze more than 350 plasma samples in a day, thereby increasing the productivity.

Conclusion:
The present method was applied successfully to a clinical pharmacokinetic study in South
Indian male subjects with 75mg oseltamivir phosphate capsule under fasting conditions and the results
were authenticated by incurred sample reanalysis.
COMPARISON OF THREE OPTIONS FOR TREATMENT OF CALCANEAL FRACTURE
Authors: Kalensky V. O. , Ivanov P. A. , Sharifullin F. A. - K. , Zabavskaya O. A. 
Published: October 2018

Until now the problem of selecting a conservative or operative treatment option for calcaneal fractures and moreover the choice of the most optimal surgical procedure for such lesions have not been solved. Thus, comparative studies in this area is one of the most important tasks of the modern traumatology. Purpose of the study — to compare treatment outcomes, pattern and complications rate following the use of three treatment options for calcaneal fractures. Material and Methods. The authors analyzed treatment outcomes of 95 patients from 2013 till 2016. Mean age of patients was 39.04±12.51 years. Patients were divided into three groups: group 1 consisted of 41 patients with 54 fractures who underwent functional conservative treatment; group 2 consisted of 18 patients with 22 fractures treated by open reduction and plate fixation; group 3 consisted of 36 patients with 40 fractures treated by minimally invasive reduction and intramedullary fixation. Groups did not differ in respect of risk factors rate and rate of surgical risks under ABCDEF scale. Outcomes were evaluated basing on roentgenological criteria of reduction, complications rate and the functional scales FFI (Foot Function Index) and LEFS (Lower Extremity Functional Score). Results. Mean follow up was 20.8±9.0 months. Catamnesis was controlled in 68 out of 95 patients (71.6%). Variances were observed for all criteria of reduction quality between group 1 (no reduction) and groups 2 and 3. Groups 2 and 3 demonstrated similar criteria in respect of reduction quality of posterior articular surface, restoration of height and axis of calcaneus (р0.05). FFI and LEFS scores in group 1 were inferior to results in groups 2 and 3 (р0.05) at 6 and 12 months follow up. At 24 months follow up the variances persisted for mean values but were not statistically significant (р0.05). No differences between groups 2 and 3 were observed during all follow up terms (р0.05). Sum rate of complications in wound healing in group 2 was significantly higher than in groups 1 and 3 (р = 0.033). Conclusion. Any of the described options of surgical treatment resulted in an earlier functional restoration after calcaneal fractures as compared to conservative treatment. Reduction quality and late functional outcomes did not vary between the study groups, however, the rate of complications for wound healing in the group with open internal fixation was higher.