bluuebunny/crossref_metadata_2025_split huggingface dataset:
Later is Better: Optimal Timing for Walked Activity Surveys for a European Bat Guild
Authors: Goodenough Anne E. , Deans Liam , Whiteley Laura , Pickering Simon 
Published: October 2015

Bat activity surveys (walked surveys combining transect and point counts) are extremely important for collecting data throughout Europe in conservation and planning contexts. To ensure optimal data, it is vital to ensure synchronicity between survey time and peak bat activity. However, although protocols for two‐hour dusk activity surveys are well accepted, recommended start time in relation to sunset is a ‘best guess’ rather than based on empirical evidence. Accepted practice differs widely with recommended start times varying from 30 min pre‐sunset (finishing 90 min post‐sunset) to 30 min post‐sunset (finishing 2.5 h after sunset). We provide the first empirical test of optimal start times for dusk activity surveys by comparing bat activity at the same sites on the same nights. Four sites were surveyed, viz. two high‐quality woodland sites and two low‐quality agricultural sites. At each site, surveyors walked the same route and stopped at the same pre‐defined listening points for three repeat surveys per night: 1) starting 30 min pre‐sunset; 2) starting at sunset; and 3) starting 30 min post‐sunset. In total, 240 hours' of data were collected. Four species, all widespread and common throughout Europe, were recorded: common pipistrelle Pipistrellus pipistrellus, soprano pipistrelle P. pygmaeus, Natterer's Myotis natterai and noctule Nyctalus noctule. Recorded bat activity was highest on sunset and post‐sunset surveys both generally (overall bat activity) and for all specific species encountered. Findings were generally consistent for both low‐ and high‐quality habitats. The same species were generally represented in both point and transect data but point data yielded higher estimates of overall activity in low‐quality habitat and higher bat species richness in both high‐ and low‐quality habitat relative to transect data. We recommend that: 1) two‐hour dusk bat activity surveys start at/after sunset not before sunset and 2) both transect and point data are collected and analysed.
Unique Hybrid Drill Bit with Novel PDC Cutters Improves Performance in Ultra-Deepwater Brazil Pre-Salt Application
Authors: Oliveira G. D. , Freesz M. P. , Izbinski K. T. , Valbuena F. , Carvalho D. J. , Alonso A. 
Published: October 2015

The Brazil ultra-deepwater, pre-salt application has been a very challenging drilling environment since exploration activity began in 2005. The initial pre-salt section contains limestone with random silicified nodules. Over the last few years, operators have collected large amounts of data for service companies to analyze to improve drilling performance through bit design. Using this information, a hybrid bit design with the most advanced cutter and bit technology was developed successfully increasing the distance drilled by 138% and the rate of penetration (ROP) by 171%.
Prior to advanced hybrid bit technology, a variety of other drill bit technologies such as polycrystalline diamond compact (PDC) bits and impregnated designs were used in the pre-salt. Historically, impregnated bits had longer runs, but with high mechanical specific energy (MSE) and low ROP, drilling with these bits was not economical. Contrarily, PDC bits can deliver higher ROP but cannot drill as far as impregnated bits. Three hybrid designs, the last one using dual-chamfer technology, were brought into this application to reduce cost-per-meter through better drilling efficiency and ROP. Each successive design managed to exceed customer expectations.
Extensive laboratory tests were conducted on the hybrid designs to address the demanding needs of pre-salt applications. These unique bits showed promising results on atmospheric surface rig tests and in pressurized bottomhole simulator testing. Hybrid bits produced much less torque, with smoother torque fluctuations and faster ROPs than roller-cone and PDC bits through the simulated interbedded formations in laboratory testing. Novel dual-chamfer cutters used in the bit have been lab tested on a vertical turret lathe (VTL), a visual pressurized single-point-cutter (VSPC) test machine and a monotonic loading test. Cutter testing showed positive VTL results and increased resistance to diamond fractures.
Ultra-deepwater drilling is very demanding and expensive, so operators want to achieve total depth in just one run by avoiding trips to change out the bit or bottomhole assembly (BHA). The improved bit and cutter technology resulted in significant cost savings and confidence for the customer. The performance of the hybrid bit with dual-chamfer cutters was significantly better than offsets, saving the operator approximately USD 9769/m.
Evaluation of New Technological Routes to Waste Treatment Generated on Oil Platform: Waste-to-Energy
Authors: Scorzelli I. B. , Costa C. L. P. , Furio P. R. 
Published: October 2015

The aim of this study is to assess the state of the art of the hazardous waste treatment generated in offshore activities and propose innovative technological alternatives based on the principles of sustainable development, as the technology of plasma assisted gasification.
This study examines the waste generation from the FPSO platforms and compares the new technological routes with current market solutions from available data, showing the needs of the industries adopt clean technology where the process does not harm the environment and generates recyclable waste, can avoid the use of landfills, can be deployed anywhere and can even adapt to mobile units treating small quantities (minimum 1 ton / day).
Brazil has an environmental waste policy (Law No. 12,305 / 10) requesting that companies have programs to reduce generation avoiding the use of landfills and waste stations. In the case of FPSO platforms, the generation of hazardous waste is more than 54.3% of the total generated, where the main residues are drilling fluids from the ultra deepwater wells.
The current of Brazilian Solid Waste Policy defines the methodology of less impact on the environment disposal of waste. The first alternative is the post-consumer reverse logistic, where the waste generated has to be returned to their respective manufacturers of the products. And the last alternative to be used is de landfill, when the waste has not technological treatment available.
The results show that the waste generated in the platform are mostly intended for co-processing or landfill but the cost to transportation and treatment is high due the distance from the terminal ports. A new technological route, as plasma gasification, stands out by accepting a mixed of different types of waste (hazardous, medical, domestic, others) and produces vitrified slag as a byproduct that is inert and safe to use as aggregate or for use in other applications, as concrete products. The emissions from this sort of plant will be similar to a natural gas fired power plant and power can be produced, when the clean syngas is burned in a gas turbine or reciprocating engine, benn better than incenaration, that in Brazil does not have any kind of energy recover and can generates dioxins; furans and toxic ash if not well managed. The gasification plasma solution can be on of the emerging technologies to reduce environmental impacts, producing energy in a sustainable way from hazardous waste bringing economic and environmental benefits to the sector.
GTL FPSO & Modular GTL as Potential Solutions for Developing Offshore Oil & Gas Fields
Authors: Kwon H. , Choi D. , Moon Y. , Ahn S. , Jang N. , Lim H. , Kim W. , Denholm D. , Park T. 
Published: October 2015

Growing global energy demands have led us to development of new oil & gas fields. In the meantime interest in eco-friendly solutions has been increasing in the area of stranded & associated gas fields. According to the BP report 2015, global natural gas reserves are approximately 6,607 tcf. Nearly half of that is assumed to be stranded & associated gas that is uneconomical for market delivery due to its remoteness from potential markets and lack of economic transportation, infrastructure and GTL conversion technology. Therefore, Daewoo Shipbuilding & Marine Engineering (DSME) has researched Gas-to-Liquids (GTL) Floating Production Storage and Offloading (FPSO) & Modular GTL as potential solutions for developing offshore oil & gas fields. Because products of the GTL process can be easily combined with crude oil in the Hull tanks and used in the existing energy infrastructure.
From a shipbuider's perspective, key design considerations in assessing onshore GTL technology for GTL FPSO & Modular GTL application were studied and analyzed as follows: Robustness to marine motion, Limited space, Weight and height, Self-sufficiency, Safety, Constructability and Certification Requirement. Moreover, commercial & demonstrated GTL technologies involved in Gas Treatment, Pre-Reformer, Reformer, Fischer-Tropsch Reactor, Upgrading and others were compared and reviewed to determine which technology is the best option for GTL FPSO & Modular GTL. Additionally, we have studied which GTL application method would be more competitive depending on the gas production size in offshore fields. Moreover, preliminary market analysis was performed to better define the scope of GTL products to be produced. Economic analysis was also performed to identify the major cost factors and understand their sensitivity on the project.
DSME has recently completed the feasibility study to acquire the preliminary design & engineering of GTL FPSO & Modular GTL for stranded gas & associated gas fields in offshore locations. The results of this feasibility study suggest that design concepts of GTL applications are technically practicable. The clean fuel and the chemical feedstock from the GTL process will be profitable in the markets and the design concept will be economically competitive within the range of the current project cost factors.
DSME hopes to set up a cooperative network with competitive companies for the next stage of GTL FPSO & Modular GTL. The cooperation network will implement at GTL FPSO & Modular GTL Pre-FEED and the economic study and will result in the commercial realization of this innovative approach for monetizing stranded & associated gas fields offshore.
Pre-Salt Limestone Plays in Campos and Santos Basins, Brazil: Additional Potential Identified
Authors: Kattah Senira 
Published: October 2015

AbstractThis study summarizes the pre-salt hydrocarbon play elements in Brazilian offshore and identifies additional exploration potential within the BMS-50/52 and BS-1_South 3D seismic surveys areas within the Santos Basin and of the BC-200 merged and reprocessed PSDM survey located within the deep to ultra-deep waters of the Campos Basin. Several large opportunities have been identified based on seismofacies recognition and preliminary seismic interpretations of 3D Multi-Client PSDM surveys.The BMS-50/52 and BS-1_South 3D surveys are within the pre-salt play polygon of the Santos Basin. The pre-salt exploration trends identified in the these surveys are: a) Rift/Pre-rift play in the central-west, with hydrocarbon accumulations in siliciclastic reservoirs of the Paleozoic (pre-rift) to the Lower Cretaceous rift succession in fault traps; b) Sag/Rift Limestone Edge Play (Sagitário trend), comprising structural or paleo-topographic traps beneath the base salt in microbial platform limestone, with occasional isolated microbial buildups; c) The Carcará North/Itaipava Sag-Rift Limestone Play which is a light-oil trend that includes the Carcará discovery in BMS-8, with hundreds of square kilometers of closures at the base salt and relief reaching 350 to 400 meters. In this trend, reservoir facies are expected to have excellent reservoir properties and are interpreted as very large microbial buildups, oriented along fault zones which are located at the edges of the previous rift horsts.3D seismic interpretation of the pre-salt section in the BC-200, deep to ultra-deepwater area in the Campos Basin has allowed the delineation of several pre-salt plays: i) Structural Play in coquinas (Late Rift to Sag); ii) Stratigraphic/Combination Play in coquinas (Late Rift to Sag); iii) Microbial Build-up Play on rift shoulders (Sag microbialites) and; iv) Microbial Build-up Play on volcanic complexes, potentially large limestone units beneath the salt nucleated on top of large volcanic complexes in distal settings.
A Probabilistic Risk Analysis of Extreme Events Based on Discrete Event Simulation for FPSO Operations
Authors: Chandrasekaran S. , Carrico T. 
Published: October 2015

Abstract
In this paper, a Discrete Event Simulation (DES) model for FPSO operations over its field lifetime is presented as a design tool for probability based risk assessment on occurrence of extreme events such as green water, wave slamming etc. The model simulates the cascading effect of realistic combinations of FPSO loading conditions and its dependence on shuttle tanker operations.
An FPSO engineering project normally includes a model test campaign to identify probability of occurrence and consequences of extreme events, such as green water or wave slam for a limited number of governing sea state with the FPSO in a vulnerable laden condition. At this stage, the risk assessment is limited to the fact that the FPSO experiences a governing sea state at a specified laden condition. The DES model presented in this paper addresses ways to remove the overtly conservatism in this risk assessment.
The DES model aims to characterise the FPSO loading patterns between successive offloading cycles. The model includes delays in offloading cycle due to shuttle tanker arrival and readiness at FPSO, scheduled maintenance on the FPSO process systems, etc. The results from DES iterations help to quantify the occurrence probability for any specified loading pattern in the FPSO over its lifetime. Together with the metocean scatter diagram which defines number of occurrences for each sea state, a conditional probability of FPSO experiencing a loading condition at governing sea state is calculated. This conditional probability can be applied to unbiased risk assessment of extreme events occurring in a governing seastate when the FPSO is at a specified loading condition.
Prospective Drift and Rift Plays in Ceará Basin, Brazilian Equatorial Margin - The Awakening of a Giant?
Authors: Belopolsky A. , Garwood T. , Beckmann G. , Fish P. , Cheshire O. , Crabtree N. , Sanders M. , Gomez R. F. Ballesteros , Pfeffer A. Dominguez , Hourcade A. Garcia , Badajoz D. Martin 
Published: October 2015

Abstract
Exploration in the Ceará basin, on the south-western part of the Equatorial Margin of Brazil, commenced in the early 1970s. Several moderate size fields such as Xaréu, Curimã, Atum, and Espada fields, with URR volume of around 200 MM BOE, were discovered on the shelf and are producing to this day. Exploration in the deep water part of the basin has been sparse (only 5 wells in water depth greater than 1000 m to date) with some success but, most importantly, de-risked the working petroleum system. With significant part of the deep water acreage licensed to operators in the 11th bid round in 2013, the basin is now embarking on a new exciting phase of exploration.
Ceará basin sedimentary fill is divided into three mega-sequences: syn-rift, transitional and drift. The basin is blessed with world-class source rocks of Aptian to Turonian age developed within all three main megasequences.
The Transitional megasequence contains both the source rocks and the reservoirs. This play was tested by the Pecem discovery in 2012 by Petrobras on the flank of a large structural high. Reservoir quality and connectivity remain the main uncertainty for this play. Other plays include a structural play with reservoirs in the syn-rift sandstones (Mundaú formation), and the Upper Cretaceous turbidite slope channel/canyons. In addition, in the outboard blocks onlap wedge plays in the Transitional early lower part of the drift megasequence have been identified. These plays could be analogous to the successfully tested plays on the conjugate margin in West Africa.
Premier Oil plc (Premier) and partner CEPSA have won two exploration licenses (Blocks CE-M-717 and CE-M-665) in the 11th bid round and are now the dominant acreage holders in Ceará basin. The Premier JV has reprocessed two existing 3D surveys resulting in an improved definition of both the syn-rift and drift section and imaging of new prospects and leads. A multi-client 3D survey using broadband technology is planned for 2015 which is expected to result in a superior seismic image in time for impacting the exploration drilling programme in 2017.
Technology Qualification of Tendon Connectors for Deep and Ultra Deep Water Application
Authors: D'Angelo L. , Viteri M. , Bradberry R. , Grimont R. 
Published: October 2015

Abstract
When new technology is deployed, it is critical to have the confidence that it will perform safely and as reliably as designed. For many years, DNV GL has helped companies that develop new technologies to implement a systematic, risk based Technology Qualification process (DNV RP-A203, 2013) [1]. The objective of this process is to ensure that all identified risks are properly addressed and the system performs the duties for which it was designed to. The field example described in this paper is based on Moho Nord's TLP located offshore Africa at 1,050 meters of water depth.
Hutshinson, contracted by Hyundai Heavy Industries (HHI) and Total in 2013, supplied the complete scope of connectors for the project. The overall qualification process covered a solution to install a tension leg platform in deep water, which required the utilization of a tendon connector system. It consisted of a Tendon Top Connector (TTC), Tendon Bottom Connector (TBC) and Intermediate Tendon Coupling (ITC). The focus of this paper will be the TBC which connected the TLP tendons to the sea floor. Although Hutchinson has supplied this type of connection for many years, this was the first time it was used for TLP application.
This paper provides an overview of Hutchinson's TBC, and the main steps covered by DNV GL's Technology Qualification process, as well as the results obtained. The understanding of the novel elements of this technology was obtained through a system to component assessment.
The execution of the TBC Technology Qualification Plan carried out activities addressing the failure modes defined for the novel components. All qualification activities were documented, and the data generated collected to ensure its traceability and to determine the performance margin for each failure mode. The performance assessment was carried out to ultimately compare the available qualification evidence against the boundary conditions established in the technology qualification basis, confirming that the technology had met or exceeded all of the requirements. Once the TQ process was completed, the equipment was considered as fully qualified within the intended application.
Monitoring and Optimizing a Brown Offshore Oilfield with an Integrated Asset Modeling Study
Authors: Garcia Ruiz F. , Ponce G. , Silva M. C. C. , Sauve R. , Rojas Mora J. A. 
Published: October 2015

Producing oilfields are an excellent target for production re-development plan and optimization projects. All the wells were drilled and producing/injecting, fluid samples and ratios are known, artificial lift methods are usually in place, networks were installed, facilities were dimensioned and historical data is available.
This detailed information can be used to feed and calibrate advanced reservoir and network models which can be coupled in an integrate asset modeling platform. Coupling reservoir simulation models with surface networks permits each discipline, reservoir and production, to focus on detailed representation of field information gathered and allows the constrains of each part of the system to be imposed simultaneously.
Therefore, integrated asset modeling generates representative field production forecast and the opportunity to quantify many improvement scenarios options. These options are not limited but include modify gas-lift allocations, surface back-pressures and increase facilities capabilities.
This paper describes the methodology applied to the development of an integrated asset modeling study for a brown offshore oilfield in Brazil and the technical challenges faced. The project conducted included six reservoir models coupled to oil production, water injection and gas-lift distribution networks in order to evaluate the current production and future optimization scenarios.
The results obtained with this project demonstrated the impact of current water treatment facility in the field oil recovery and the potential gains associated with gas-lift optimization.
An Integrated Power Solution for Enabling Large-Scale Subsea Processing: A Base Case for Subsea Standalone Variable Speed Drive in Brazil
Authors: Parente H. E. 
Published: October 2015

There is a growing demand within the oil and gas industry for an integrated subsea power system in order to achieve the highest availability of power supply and power distribution subsea. For that reason, since 2010, a subsea power grid system has been under development by Siemens. The purpose of this system is to provide power to subsea consumers like pumps and compressors in deep and ultra-deep waters for long step-outs.
The subsea power supply and distribution system, including all its components, is designed and qualified to work at a water depth of 3000 meters, and up to more than 200 kilometres step-out distance. It will offer an integrated, reliable and cost-efficient subsea power solution for multiple consumers at seabed.
The development and qualification program is currently in its last stages. Testing of the individual components (subsea transformer, switchgear, variable-speed drive and communication/control system) will be followed by a complete system test. Overall, development and qualification program is expected to be completed in 2016, at which time the system will be ready for a full-scale subsea pilot project.
The power system must have standardized, flexible and configurable interfaces to have an optimal fit with the processing system. The integrity of the power system is governed by a dedicated power control and monitoring system which enables transparent and standardized communication with all the power modules. The Subsea Power Grid solution offers an infrastructure with standardized interfaces both on the topside / onshore power generation and to the subsea consumers – both for the power line and for the power control and communication line. This ensures flexible arrangements with the subsea field’s overall processing system without challenging the integrity of the power distribution.
One typical application for Subsea Power Grid solution would be a subsea standalone variable speed drive. The aim of this paper is to perform an overall analysis on how a subsea standalone variable speed drive can be integrated in a typical subsea pumping system without sacrificing the integrity of subsea variable speed drive sub-assemblies designed as part of subsea power grid solution.