bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incident Free Rig Transition Planning and Project Management
Authors: Andersen Henrik 
Published: August 2014

Abstract
During 2013 Chevron Thailand has gone through a large scale rig transition, bringing five new build rigs (three jackups and two tender assisted rigs) into our operation and releasing four aging rigs. Significant challenges were to maintain world class safety performance through the transition while also maintaining drilling efficiency. During 2014 one more new build rig has been delivered.
This paper describes how the rig transition was managed to ensure the delivery of drill-ready rigs and incident free startup of drilling operations. Main focus is placed on the tools, processes and procedures developed and applied for the first 90 days of operation. Key elements being:
– Combined contractor and operator lead pre-startup safety engagements – Crew transition, management of short service employees and on the job crew training – Methodology and tools applied for repeated assessment of crew safety culture, well control competency, fluency in safety management system, stop work authority, operator's tenets of operation and continual improvement process – How these results were applied to track progress and determine rig readiness for operations, offline activity and simultaneous operations
The paper also presents the new build project management and integrated rig acceptance testing as well as the main elements of the rig demobilization plan.
The intent of this paper is to share best practices and lessons applicable for operators and contractors starting operations on a new build drilling rig.
Mud Cap Drilling (MCD) with Continuous Annular Injection - Offshore Malaysia
Authors: Hamizan Azyyati A. , Hasbullah Utvanuddin P. , Upadhyay Abhishek , Buch M. , Eren S. , Zahari M. Zulkhairi , Roslan M. Rizwan , Hajiyeva M. , Rashid E. Rashidi , Ishak S. Nadiah , Johari M. Raimi , Satar Afzan A. , Razali Ezuan H. , Huong C. S. , Payne J. , Voshall A. , Mathews T. , Houng N. H. 
Published: August 2014

Abstract
Losses are common in carbonate reservoir drilling due to highly fractured nature of limestone and the existence of karst. Complete and unsustainable fluid losses encountered in the offset well threatened the loss of the primary barrier – hydrostatic column – that could result in a catastrophic well control incident / loss gain scenario. Total losses in the offset well were approximately 25,000 bbls. Losses were stopped only with cement plugs. A total of 17 days were spent to mitigate the losses. The well was plugged and abandoned.
To drill and develop this marginal carbonate field with efficient and low cost wells, the team decided to use Mud Cap Drilling (MCD) with Continuous Annular Injection. The sub-normal nature of the reservoir allowed the use of this technique as opposed to a more conventional Pressurized Mud Cap Drilling (PMCD) method utilizing Light Annular Mud (LAM). Continuously injecting seawater down the annulus to prevent gas migration while simultaneously injecting seawater down the string to transport cuttings up to the loss zone and cool the bit, eliminated the mud cost and fluid logistics that normally dominate the PMCD process.
During the development program, two horizontal wells penetrated the carbonate at the same TVD and only one of the wells experienced complete and unsustainable losses. Carbonate structures are anisotropic. Several wells can be drilled that do not experience losses yet the next well in the same field could require MCD. For this reason it is necessary to prepare for MCD as a contingency when drilling carbonates. No kicks or well control issues were experienced during this development program. Well barrier policies were accomplished by maintaining the annulus with overbalanced fluid (seawater) at all times using this method. Well was drilled to TD and completed successfully, and all the primary well objectives were achieved. Drilling time was reduced significantly by over 50%, and fluid cost for this operation was reduced to almost zero. This innovative technique was applied for the first time in PCSB Malaysia drilling operations.
Innovative Cement Spacer Improves Well Cementing Integrity - 60 Case Histories Reviewed
Authors: Budiawan Aditya , Farahani Hamidreza S. , Anugrah Andri , Brandl Andreas 
Published: August 2014

Abstract
This paper reviews the challenges faced during well cementing in the fields of East-North Kalimantan, Indonesia and describes utilizing an innovative cement spacer to successfully solve these issues. Unconsolidated formations and depleted reservoirs are main causes for lost circulation during drilling and cementing operations often resulting in poor cement bond logs and failed Top of Cement (TOC) requirements. The common practice to address these well integrity problems is to apply lost circulation material and low density cementing systems designed at 10.5 to 11.0 ppg. This strategy did not always accomplish the desired results and remedial cement squeeze jobs were needed for many primary cement jobs.
To overcome these challenges, an innovative cement spacer system was engineered and successfully applied. The new environmentally friendly spacer system contains a biopolymer to mitigate loss circulation issues during cementing. It strengthens the wellbore wall by forming an effective seal along the formation, minimizing losses during cementing and preventing cement fall back after placement. The initial field application was immediately successful in obtaining full circulation returns during the cement job, a constant challenge on prior jobs. An added advantage was the cement slurry density could be increased from 10.5 up to 13.5 ppg without encountering any losses; despite exceeding the maximum theoretically allowable equivalent circulating density (ECD). As a consequence the increased slurry density improved early cement strength development which reduced wait-on-cement times and required using less concentration of expensive light weight cement materials. This, in turn, simplified operations and logistics and reduced costs.
Case histories are presented covering more than sixty successful cement jobs using the new spacer system. Specific cases are discussed where: 1. successful results were achieved despite partial to total drilling related losses during the drilling phase, 2. cement bond logs have improved and 3. Remedial jobs have been eliminated. Conservative cost savings utilizing the new spacer design is more than $2.5 million USD. The product can be applied on high-temperature, high-permeability formations, those with low fracture gradients and fragile, unconsolidated, and fractured formations.
Using Seismic While Drilling to Reduce Depth Uncertainty on an Exploration Well Offshore Thailand
Authors: Ahmed Aqil , Quoch Luc Nguyen , Vendrell Jaume 
Published: August 2014

Abstract
Knowing targets depths accurately for Carbonate Exploration wells is critical for a successful well construction process due to the kick / loss scenario if the carbonate is accidentally penetrated.
This paper demonstrates the use of innovative Logging-while-drilling seismic technology used offshore Thailand for the first time which furnishes seismic checkshot information whilst drilling to refine depth prediction ahead of the bit for accurate geostopping.
Field data will be shown to demonstrate this methodology.
Carbonate targets require casing to be set immediately above. Depth uncertainty from the surface seismic is usually in the range of over 50m up to 200m depending on the quality of the surface seismic acquired and the ensuing processing. Lack of offset well velocity information amplifies this uncertainty. By acquiring velocity information while drilling, the depth uncertainty is progressively reduced as drilling proceeds. This is achieved using the seismic while drilling technology, thus avoiding the need for a dedicated intermediate checkshot survey on wireline and saving rig time and cost. The technique consists of a downhole seismic receiver collar forming part of the bottom hole assembly and a surface acoustic source in the form of an airgun cluster. Seismic levels were acquired when drilling entered slips – a natural break in the drilling process and providing an acoustically quiet time. Each seismic level provided a real time seismic waveform which was processed for a Time-Depth pair to update the velocity model and hence refine the target depth prediction.
53 consecutive real time seismic levels were acquired refining the carbonate depth prediction shallower by 30m. The acquisition was transparent to rig operations. The initial error range for the depth was +/− 70m. Casing point was set successfully without penetrating the carbonate. Exploration wells lend themselves well to the use of this service for reducing depth uncertainty.
Perforating Gunshock Loads: Simulation and Optimization in 2014
Authors: Baumann Carlos , Brinsden Mark 
Published: August 2014

Abstract
The ability to predict and reduce large perforating gunshock loads and the associated risk of damage and nonproductive time is very important because of the high cost of most wells, especially deepwater high-pressure wells.
The aim of this paper is to present the most current (as of 2014) capabilities in simulation software to predict perforating gunshock loads produced by hollow carrier guns. This is a joint effort between operators and service companies to promote the discussion on dynamic gunshock modelling. The end goal of this paper is to communicate to a broader audience of oil and gas companies the most current knowledge on predicting perforating wellbore dynamics and the associated gunshock loads and to look ahead for future developments in dynamic gunshock modelling.
Both low- and high-pressure wells are susceptible to gunshock damage when they are perforated with inappropriate gun systems and/or under adverse conditions. As of 2014, there are several software tools available to predict gunshock loads. These software tools help engineers identify perforating jobs with significant risk of gunshock damaged, such as bent tubing and unset or otherwise damaged packers, gun damage, wireline weak-point pull-offs, etc. When the predicted risk of gunshock damage is large, engineers can make changes to the perforating equipment or job execution parameters to reduce gunshock loads and the associated risk of equipment damage and nonproductive time. With the available gunshock software, engineers can also evaluate the sensitivity of gunshock loads to changes in the perforating equipment, such as: gun type, charge type, shot density, tubing size and length, rathole length, and placement/setting of packers and shock absorbers.
In this paper, we describe the main sources of gunshock loads. We present examples showing typical loads on tubing and packers, and we elaborate on the load levels that can lead to equipment damage. Simulation examples included in this paper also illustrate how to reduce gunshock loads by modifying the equipment used. We illustrate how small changes that cost very little to implement can lead to a large reduction in both gunshock loads and the associated job failure risk.
Integrated Workflow of Geological Modelling, Hydraulic Fracturing and Reservoir Simulation for the Evaluation and Forecast of Unconventional Tight Oil Reservoirs
Authors: Cui Esther , Liu Jianchun , Wei Gang 
Published: August 2014

Abstract
Tight hydrocarbon reservoirs are a major unconventional reserve. To profitably develop such reserves, horizontal wells and multistage hydraulic fracturing techniques are applied to maximize the reservoir drainage areas and increase reservoir conductivity to the wellbores by creating flow channels in the tight reservoirs.
Without in-depth studies that include reservoir characterization, field modeling, well test and production data analysis by a multidisciplinary team, reservoir properties cannot be reproduced and well performance cannot be represented to accurately forecast production. Overestimating or underestimating production rates creates tremendous loss for oil companies or operators. Integrated workflow combines multiple disciplines and professionals for specific projects.
The target reservoir is in the central Jungger basin, northern China, which is a green field for tight oil reservoirs with an anticline structure, fault system and unconformity and stratigraphic traps. The paper presents the thorough reservoir characterization, systematic process and reference for a tight oil development plan. The high heterogeneity, low porosity, low permeability and production uncertainty in unconventional reservoirs sped up progress and investment in integrated workflow for reservoir development through risk quantification.
This paper presents a systematic study of unconventional resource characteristics, and describes an integrated workflow for reservoir characterization and development of tight oil reservoirs in northwest China which combines geology, seismic, geostatistics, well logging and core data. The process and methodology comprises a geological study, a field geological model with reservoir characterization, petrophysical modeling, numerical well testing, hydraulic fracture modeling based on a geomechanical study and a field reservoir simulation study. Reservoir grid is refined to capture the effect of hydraulic fracture on well performance, calibrate model using well testing and history matching for examining model accuracy, and then finally production of post-fracturing is estimated.
This paper also includes the details of sensitivity analysis proposed to address the critical uncertainties and strategy to enhance well deliverability such as well placement, half-fracture lengths, hydraulic fracturing stages and fracture conductivity.
The workflow enables the feasibility of coupling multiple disciplines including geology, geophysics, geostatistics, petrophysics and reservoir engineering into an integrated platform for information sharing, project management and strategy using static and dynamic data while simultaneously checking and updating reservoir data.
Development of Mature Fields Using Reservoir Opportunity Index: A Case Study from a Saudi Field
Authors: Varela-Pineda Alfonso , Hutheli Ahmed H. , Mutairi Saad M. 
Published: August 2014

Abstract
This paper presents a rigorous methodology to identify the remaining reservoir opportunities in order to enhance sweep efficiency and increase hydrocarbon production rate in a mature field under water flooding operations. Development of mature fields implies proper reservoir management practices to determine the amount and location of the remaining oil. It also entails optimal placement of new wells and re-entries to enhance the ultimate recovery.
As of today, common approaches to place new wells are usually based on oil column maps derived from saturation and production logs as well as the performance of the neighboring wells in the area of interest. The current work improves on the common practices by combining both static and dynamic variables extracted from the geological and simulation models to estimate the Reservoir Opportunity Index (ROI), which can effectively detect un-swept oil zones not seen by simple methods. The ROI along with other available information in the geological and simulation models such as, production history and well logs are then integrated in one platform to facilitate informed decisions for successful mature field development.
The initial formulation of ROI, previously presented by many authors in the industry, is improved to suit reservoir geology and conditions at different time steps, incorporating changes in oil saturation and reservoir pressure effects. The computed ROI is then normalized to allow accurate representation and comparison among various layers and areas.
The ultimate benefits of the proposed approach are realized when mapping the ROI for different reservoir layers and advising on the location of new wells and re-entries. Moreover, the applicability and the advantages of this work can be expanded to other areas such as: reservoir description, reservoir characterization, reserves estimation and depletion analysis.
Decolorization of Reactive Black‐5 byShewanellasp. in the Presence of Metal Ions and Salts
Authors: Imran Muhammad , Arshad Muhammad , Khalid Azeem , Hussain Sabir , Mumtaz Muhammad Waseem , Crowley David E. 
Published: August 2014

ABSTRACT: In this study, effect of various metal ions and salts on biodecolorization of Reactive black‐5, azoreductase activity, and growth of Shewanella sp. strain IFN4 was evaluated. Among the tested metals, Cr+2, Pb2+, Ni2+, Fe2+, and Mn+2 did not inhibit the biodecolorization of reactive black‐5, azoreductase activity and bacterial growth. Three metals (Cu2+, Zn+2, and Co2+) delayed the decolorization process without completely inhibiting the reaction and also suppressed the bacterial growth. However, no dye decolorization was observed in the presence of Cd+2 (10 mg L−1). Furthermore, bacterium decolorized the dye at high concentration (15 mg L−1) of mixed metal ions. Strain IFN4 was also able to decolorize the dye at 50 g NaCl L−1 and 60 g Na2SO4 L−1. NaCl was found to be more inhibitory to bacterial growth than Na2SO4 and the reverse was observed for azoreductase activity. These findings suggest that strain IFN4 could be used in designing a bioreactor for the treatment of textile effluent.
Effects of apomixis and polyploidy on diversification and geographic distribution inAmelanchier(Rosaceae)
Authors: Burgess Michael B. , Cushman Kevin R. , Doucette Eric T. , Talent Nadia , Frye Christopher T. , Campbell Christopher S. 
Published: August 2014

•Premise of the study: Amelanchierpolyploid apomicts differ from sexual diploids in their more complex diversification, greater species problems, and geographic distribution. To understand these differences, we investigated the occurrence of polyploidy and frequency of apomixis. This research helps clarify species delimitation in an evolutionarily complex genus.•Methods:We used flow cytometry to estimate genome size of 1355 plants. We estimated the frequency of apomixis from flow‐cytometrically determined ploidy levels of embryo and endosperm and from a progeny study using RAPD markers. We explored relationships of triploids to other ploidy levels and of ploidy levels to latitude plus elevation.•Key results:Diploids (32% of sample) and tetraploids (62%) were widespread. Triploids (6%) mostly occurred in small numbers with diploids from two or more species or with diploids and tetraploids. Seeds from diploids were 2% apomictic, the first report of apomixis inAmelanchierdiploids. Seeds from triploids were 75% apomictic. We documented potential triploid bridge and triploid block from unbalanced endosperm and low pollen viability. Seeds from tetraploids were 97% apomictic, and tetraploids often formed microspecies. We did not find strong evidence for geographical parthenogenesis in North AmericanAmelanchier. Most currently recognized species contained multiple ploidy levels that were morphologically semicryptic.•Conclusions:Documentation of numerous transitions from diploidy to polyploidy helps clarify diversification, geographic distribution, and the species problem inAmelanchier. Despite the infrequent occurrence of triploids, their retention of 25% sexuality and capacity for triploid bridge may be important steps between sexual diploids and predominantly apomictic tetraploids.
Epiretinal Membrane Peeling After Uncomplicated Primary Retinal Detachment Repair
Authors: Banker Tanuj P. , Godfrey Kyle W. , Reilly Gayatri S. , Weichel Eric D. 
Published: August 2014

BACKGROUND AND OBJECTIVE:
To identify rates and potential risk factors for epiretinal membrane (ERM) and for membrane peel (MP) after 23- or 25-gauge repair and to compare outcomes for eyes with ERM that underwent MP versus observation.

PATIENTS AND METHODS:
Review of 587 eyes with ERM after retinal detachment repair. Patients who developed ERM either underwent pars plana vitrectomy (PPV) and MP or were observed.

RESULTS:

Preoperatively, the PPV and MP group had a mean best corrected visual acuity (BCVA) of 20/100, compared to 20/40 for the observation group (
P
< .001). The PPV and MP group had a higher mean central subfield mean thickness (CSMT) (414 µm vs 281 µm). In the PPV and MP group, mean BCVA was 20/100 preoperatively and 20/50 postoperatively (
P
< .01). Mean CSMT was 397.5 µm preoperatively and 282.6 µm postoperatively (
P
< .01).

CONCLUSION:
ERM is common after 23- or 25-gauge PPV. PPV and MP can improve BCVA and decrease CSMT.

[
Ophthalmic Surg Lasers Imaging Retina
. 2014;45:415–420.]
Governança Corporativa e Crises: mecanismos importantes durante ciclos econômicos distintos
Authors: Peixoto Fernanda Maciel , Amaral Hudson Fernandes , Correia Laise Ferraz , Das Neves João Carlos Carvalho 
Published: August 2014

Esta pesquisa investigou se os mecanismos de governança corporativa, segundo a Teoria da Agência, assumem importâncias distintas em diferentes ciclos econômicos. O período foi de 2000 a 2009, segmentado em: crises locais (2000-2002); não crise (2003-2007); e crise global (2008-2009). Os mecanismos de governança analisados foram: estrutura de propriedade, conselhos de administração, compensação aos gestores, transparência e proteção aos minoritários. A metodologia envolveu: (a) análise de componentes principais, agregando em um indicador um conjunto de variáveis de governança; (b) reorganização dos componentes para verificar a contribuição das dimensões de governança no índice. Constatou-se que estrutura de propriedade foi o mecanismo menos relevante no período. Durante as crises locais, a dimensão de governança mais importante foi compensação aos gestores. Nos períodos de não crise e de crise global, o mecanismo mais relevante foi proteção aos minoritários. Transparência se mostrou gradativamente menos importante e conselho foi menos relevante do que compensação e proteção.
"Mined" for Its Citizens? Poverty, Opportunity Structure, and Appalachian Soldier Deaths in the Iraq War
Authors: Scanlan Stephen J. 
Published: August 2014

Abstract
This paper examines the opportunity structures of the places from which a subset of US soldiers who have fought and died in Iraq have come, using a spatial inequality framework on poverty and connecting it to research on the military and society. Focusing on Appalachia and the villages, cities, and counties that were the homes to 370 of the combat deaths in Iraq, findings reveal that "place matters" for the opportunities available to the citizenry. Soldiers from Appalachia who have fought and died in the war hailed from a context of disadvantage on multiple fronts. Their hometowns are characterized by less educational attainment, lower household and per capita incomes, greater hunger, and higher poverty rates, relative to the United States as a whole. In such a context, military service may be an important labor market providing otherwise unavailable employment, benefits, and educational opportunities that could potentially empower an escape from a place of disadvantage--particularly when coupled with conservative politics and contributions in wars past. However, more critical perspectives may view enlistment as something those with few options have no other choice but to do--a key debate in the era of the all-volunteer force and new patterns of military recruitment.