bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Evaluation of Ocean Bottom Hybrid Joint Box System for Real-Time Communication and Monitoring in Deep Seabed
Authors: Kimura T. , Araki E. , Yokobiki T. , Kawaguchi K. , Fujiwara N. , Hishiki K. , Yonezaki Y. 
Published: October 2017

Abstract
We have been developing ocean bottom hybrid joint box system for real-time communication and monitoring in deep seabed. The joint box can provide high voltage power and large data transmission used in seabed as a part of seafloor cable network system. We installed first generation joint boxes in the Nankai Trough area, Japan as a part of DONET (Dense Oceanfloor Network System for Earthquake and Tsunamis)project. 12 joint boxes have been deployed in seabed with depth of up to 4000 m from 2010 to 2016. Backbone submarine cables, which provide main power and communication lines from land station to seabed joint boxes, have been deployed before the installation of the joint boxes. Each port of joint box can supply 45 Watts/port and transmit 50 Mbps data for geophysical instruments including broadband seismometer, pressure gauge (tsunami meter), thermometer, etc. 53 seafloor observation systems were connected to the joint boxes for real-time monitoring in the wide area, approximately 200 × 250 km. Observed long-term data confirmed that the joint box has high stability and reliability. There are almost no missing data except for during maintenance. We also applied a data processing method, seismic interferometry method, to long-term seismic data observed by broad-band seismometer. This method can estimate time variation of velocity structure below each seismometer by calculating auto- and cross-correlation. Obtained results confirmed that small change of seismic velocity, which would be generated by earthquake events, is detectable. Since 2014, we have developed modified joint box, which can provide high power and large data transmission, 250 Watts/port and Giga bps rate, respectively. The new joint box can transmit high density information, for example, real-time video image, and operate large seismic observation system with several hundred channels.
Assessment of Cold Water Injection Geomechanical Effects on Brazilian Pre-Salt Reservoirs and on Its Saline Caprocks
Authors: Amaral Ricardo Fernandes do , Seabra Gabriel Serrao , Laquini Joao Paulo 
Published: October 2017

AbstractCold water injection creates a cooled rock region around the well that can reduce the horizontal stresses acting on the reservoir and, also, the injection pressure to initiate and propagate a fracture. However, the impact of thermal stresses in saline caprocks, where creeping occurs, is not well understood yet. This study aims at modeling the cooled region created by cold water injection and evaluate the thermally induced stresses in both reservoir and saline caprock.In order to assess the evolution of the pressure and temperature in the reservoir and in the caprock during 16 years of cold water injection, reservoir simulations considering thermal effects were carried out. Various simulations were performed using different water injection rates and different thermal diffusivities for the reservoir and for the caprock. The model used in these thermal simulations comprehended not only the pre-salt carbonate reservoir, but also the salt rocks. Stress and strain were evaluated using a 3D finite element in a one-way coupling scheme, including the reservoir, overburden (salt and post-salt), sideburden and underburden.In the worst simulated case, after 16 years of cold water injection, the height of the cooled region in the salt was about 200 m above the top of the reservoir. As expected, horizontal stresses in the reservoir significantly decreased with cooling. On the other hand, horizontal stresses in the saline caprock did not change significantly, even though the thermal expansion coefficient of salt rocks is five times greater than that of carbonates. This result suggests that creeping in the salt relieves thermal stress induced by cooling. Thus, saline caprock integrity is not influenced by cold fluid injection in the reservoir, as long as salt creeping can be considered.Although cold fluid injection may cool the salt, stress state in the caprock remains unaltered. Thermal stress is relieved by the salt creeping at the expense of plastic deformations. Thus, the saline caprock integrity is not impacted by cold fluid injection.
Design One-Build Many: The Execution Strategy Leading to the Successful Delivery of FPSOs Cidade de Maricá and Cidade de Saquarema, Twin Production Systems Copied from Previously Delivered FPSO Cidade de Ilhabela
Authors: Pinto Guilherme , Torres Rafael , Ribas Paulo 
Published: October 2017

Abstract
Due to diverse oil field characteristics, Carbon-Copy type of projects are rarely used in developing Floating Production Systems (FPS). Known as "Clones" or "Replicas," such projects are starting to become more common in the industry. This paper will demonstrate key success factors of the Carbon-Copy approach in the design and construction of complex FPSOs such as Cidade de Maricá and Cidade de Saquarema based in the original Cidade de Ilhabela. While the economy of scale present cost reduction opportunities, continuous improvement processes applied to the execution strategy may provide additional gains not only in costs but also schedule and quality.
When conditions allow for Carbon-Copy application, it is critical to minimize changes from the original design. Hence, it is essential to implement a global strategy covering different project aspects (engineering/procurement/construction) and phases (FEED/Execution/Installation). The strategy should identify situational scenarios that may represent project gains if different execution approaches and tools are implemented providing solutions to the previous bottlenecks and constraints associated to productivity.
The continuously increasing technical, commercial and regulatory challenges imposed by a more demanding deep water market require Operators and Contractors tight collaboration to renew and improve their processes and execution methods. The advantages and cost savings in reusing proven solutions and designs from one project to the next are intuitive to conceptualize, understand and visualize, but the implementation can be subject to unexpected complexities.
This paper will present, based on the delivery of FPSOs Cidade de Maricá and Saquarema, both carbon copied from previously delivered FPSO Cidade de Ilhabela, some of the key parameters such as suitable project organization, solid lessons-learned process and sound execution strategy focused on anticipated delivery, which enable the right conditions for successful FPS Carbon-Copy projects execution.
Nonlinear Model Predictive Controller Applied to an Offshore Oil and Gas Production Facility
Authors: Neto S. Simoes , Secchi A. R. 
Published: October 2017

Abstract
In this work a nonlinear model predictive controller (NMPC) applied to an offshore petroleum production facility is presented. The facility was simulated using Hysys dynamic simulation, and the used NMPC controller with phenomenological mathematical model was the BRNMPC. Some comparisons were conducted regarding the use of NMPC, linear MPC and traditional PID controllers. The results showed that for level control of the separator vessels, the MPC and NMPC have similar performance, but for pressure vessel control, the NMPC are superior because the system has more nonlinearities and many information were lost in the linearization process.
Near-Miscible Flooding by Production Gas Re-Injection in QHD 29-2 Offshore Oilfield
Authors: Chen Hao , Zhang Xiansong , Yang Jiankun , Tang He , Mei Yuan , Li Bowen , Shen Xiong 
Published: October 2017

Abstract
QHD 29-2 block is a newly discovered offshore oilfield of China with an average water depth of 27.6m, covering approximately 2300 km2. Waterflood is not suitable due to the characteristics of complex lithology, strong heterogeneity, small pores and throats, and low water injectivity. In addition, a wide range of CO2 content (24-90%) in the production gas that presents a difficulty for the mixed gas handling. Thus, near-miscible flooding of the production gas re-injection is proposed for the development of this reservoir. It is concluded that the loss of displacement efficiency can be compensated by the mobility improvement with the pressure decrease. Thus, oil recovery is comparative with that of miscible flooding. Also, the economic and operational costs declined to some extent because smaller gas volumes and lower compression are needed with the reduction of pressure.
Slim tube test, slim tube simulation, and selected empirical formulas are used together to determine the near-miscible pressure interval under the condition of different CO2 contents (40%, 55%, 70%, 85%, 100%). On this basis, a new empirical formula was established to determine the lower and upper boundaries of near-miscible flooding.
Two new points are determined as minimum near-miscible pressure (MNMP) and minimum miscible pressure (MMP), respectively. A higher MMP can be expected by this process which is consistent with the argument that some successful application of CO2 miscible flooding are actually partial miscible flooding or near-miscible flooding. Results showed that the ratio of MNMP to the newly defined MMP is about 0.8 to 0.86. In addition, for the wells QHD 29-2E-4 and QHD 29-2E-5, the lower limit of the CO2 content in the production gas to achieve near-miscible flooding are 34% and 64%, respectively. Moreover, the relative error of the new empirical correlation is less than 10% for the prediction of the pressure interval of near-miscible flooding in the targeted wells.
To the best of our knowledge, this is the first time to study the potential of implementing near-miscible flooding by the production gas re-injection with varying CO2 content in an offshore reservoir of China. The results in the paper can provide a new screening criteria for both enhancing oil recovery and reducing greenhouse gas emissions for similar offshore reservoirs.
Integrated Production Management Solution for Maximized Flow Assurance and Reservoir Recovery
Authors: Bouamra Reda , Vielliard Christophe , Spilling Knut Erik , Nilsen Finn Patrick 
Published: October 2017

Abstract
Over the last decade, a number of subsea solutions have been deployed to unlock the commerciality of deepwater fields and increase the overall recovery factor of the reservoirs. Numerous types of monitoring and measurement technologies have been developed and installed downhole, subsea, and topside, but usually in a fragmented manner. The traditional field surveillance approach often addresses the reservoir challenges separately from issues that may affect flow in the production network or from processing facilities considerations. The value of information obtained using sensing equipment is then not fully taken advantage of, and critical information is lost due to the lack of integration. The objective of this work is to link all data collected along the fluid journey from the reservoir to the process facilties in order to optimize its production and better manage reservoir recovery.
In this work, a novel integrated production management solution (IPMS) is introduced. Dedicated subsea and subsurface metering devices, advanced flow control equipment, production surveillance systems, and production optimization tools are combined to increase the understanding of the reservoir and subsea production network, maximize the value of the subsea hardware and address operational challenges to enable increased predictive flow assurance capabilities and production optimization. Bridging the gap from abstract measurement values to production management decisions, such as inflow control actuation; allow a better reservoir management implementation along of the field life, leading to an increased recovery.
The functionality of the system is designed to address a number of challenges, including the following:reservoir management—recovery increase by combining continuous downhole sensing, seabed data, and IPMSEquipement centric monitoring and predictive maitenancethermal management—increase in system no-touch time and improved system preservationhydrate management—opex savings in regards to hydrate inhibitor injection and regenerationliquid management—avoiding unexpected shutdowns due to liquid surgespigging optimization—potential for reduced production losses during pigging operation and reduced pigging frequencylow temperature management—material integrity and hydrate preventioncorrosion and scale inhibition optimization—completion, subsea production system (SPS), and pipeline integrityerosion monitoring—SPSs and pipeline integrity.
For the first time, integrated production data are used in online pore-to-process integrated models to guide reservoir decisions, optimize opex, and enhance recovery. Specific examples such as detection of reservoir property changes and their impact on recovery, optimized inorganic scale, and hydrates management based on integrated downhole seabed and process data are discussed in detail.
Measured Data Provides Insight for Floating Systems Life Extension
Authors: McNeill Scot , Maniar Dilip , Renzi David , Del Vecchio Cesar 
Published: October 2017

Abstract
The primary goal of floating systems life extension efforts is to project how the system or components will behave in the future beyond the original design life. This predicted behavior can then be used to determine the practicality of the proposed life extension in terms of safety, environmental and economic risk. Often, these predictions are limited to reviewing inspection data (which has a limited ability to predict future response) or analysis (which is dependent on various assumptions). Measured data from in-situ monitoring systems provides accurate system response information which, in conjunction with mathematical modeling and inspection data, can be used to determine past and future behavior. The full potential of measured data for life extension activities has not been realized thus far.
Some uses of measured data in life extension efforts are illustrated through examples in this paper. The first example highlights ongoing fatigue assessment of a mooring line chain jack system using line tension measurements. The second example describes how uncertainty was greatly reduced in a polyester rope fatigue assessment by utilizing measured mooring line tension data. The third example demonstrates use of measured vortex induced motion response of a floating system to reduce the conservative assumptions provided during the design phase. The results of all of these examples show that measured data can provide insight into floating production system (FPS) response that cannot be attained otherwise, allowing for significantly reduced conservatism in life extension engineering assessments. Without the availability and use of this data it would be difficult to demonstrate the fitness for service of these facilities.
The examples of utilizing measured data to enhance life extension efforts provide concrete demonstrations as to how life extension of FPS components can be justified where uncertainty in analytical prediction is high. In such situations, demonstrating fitness for service beyond the design life would prove exceedingly difficult if measured data was not available. Continued service feasibility is most effectively demonstrated by augmenting inspection and analysis efforts with field monitoring data.
Experiences from Automated Hardware-In-The-Loop Testing of BOP Control Systems
Authors: Kårvand O. , Pivano L. , Stenbro R. , Ramos de Carvalho C. , Boff S. , Staudacher L. 
Published: October 2017

Abstract
A BOP relies on a sophisticated redundant control system to achieve desired reliability and safety. The BOP system software must work seamlessly integrating sensors, valves, and diagnostic feedback while being able to hot swap in a fully redundant environment. It is known that software errors may lead to nonproductive time, delays, compromise safety and potentially lead to an environmental disaster. Software failure risks can be mitigated by performing HIL testing which is a well-established test methodology in other industries such as automotive and aerospace, where high performing and robust control systems are essential, and has through the last decade been established also in the maritime and offshore industries. NOV Rig Systems and DNV GL Marine Cybernetics Advisory have together developed a test setup for HIL testing of BOP control systems by combining simulators from both parties.
Basic functionality of the BOP control system is tested through automatic scripts, allowing extensive testing and regression testing (to verify that software previously developed and tested still performs correctly after it has been changed during updates or retrofits based on customer requests). Often new functions are added or existing ones are modified and this could potentially lead to undesired errors. This paper demonstrates how this technology reduces the risk of adding software errors, by using a systematic and automatic testing approach.
This paper introduces HIL as a methodology for BOP control system software testing and shares the experiences from automated testing by using CyberSea Signature on the BOP Control System delivered by NOV Rig Systems.
Surface Plasmon Sensors for Fluid Analysis in Upstream Oil
Authors: Monteiro Othon R. , Suresh Radhika , Chandran Ashwin 
Published: October 2017

Abstract
Sensors are becoming increasingly ubiquitous in the oil and gas industry to enhance efficiency in exploration and production (E&P), as well as to improve safety and minimize the impact of these operations on the environment. In particular, knowledge of the properties of fluids contained in a hydrocarbon reservoir helps to identify the fluid type, estimate reserves, assess hydrocarbon value and optimize production. Although measurement of fluid properties can be done at the rig surface or downhole, the latter is preferred because subjecting these fluids to changes in pressure and temperature compared to the downhole environment may induce irreversible changes. Moreover, in many instances, it is important to monitor the chemical composition of a fluid in real time. Dissolved H2S in reservoir fluids has a harmful impact on cost and safety operations in drilling and production. We have investigated localized surface plasmon resonance (LSPR) methodologies and fabricated sensors for measuring dissolved sulfides in liquids. The impact of the specificity of sensing materials and the design concepts were investigated. The chemical composition and morphology of the nanoparticles affect the response of the sensor, and can be used to mitigate the strong absorption in heavy crudes. The effect of temperature on the sensor response was evaluated. Sensor response was not affected below 150o F. The effect of organo-sulfur compounds on sensor response was also investigated.
Designing Fluid Properties to Minimize Barite Sag and its Impact on Annular Pressure Build Up Mitigation in Producing Offshore Wells
Authors: Calcada Luis Americo , Scheid Claudia Miriam , da Cruz Meleiro Luiz Augusto , Oechsler Bruno Francisco , Fagundes Flávia Marques , Santos Nara Brandão Costa , de Oliveira Arouca Fábio , Damasceno João Jorge Ribeiro , Souza Elessandre , Waldmann Alex Tadeu , Martins Andre Leibsohn 
Published: October 2017

Abstract
After the cementing of an oil well, part of drilling fluid is confined in the annulus between the cement and an isolation tool (pack off). During the production phase of a well, the confined fluid will be exposed to a temperature gradient due to the circulation of reservoir fluid through the production screen. This increase in the temperature causes a pressure evolution that can damage isolation.
Among several possibilities for APB mitigation, the strategy of communicating the annulus with a formation is often considered. In this case, when pressure reaches formation fracture, fluid would be drained from the annulus and thus, the pressure would be released. However, several authors claim that, after a period, barite sag in the drilling fluid will create an impermeable layer, which will prevent communication of annulus with the formation; and APB mitigation strategy would fail. These wells are placed in operation a few years after completion is concluded.
This article presents an extensive experimental task aiming the understanding of the effect of rheology on barite sag for different fluid concepts. The experiments consisted of long time sedimentation tests (monitored by gamma ray techniques) and a rheological characterization of the fluids. Fluids tested include new and aged Synthetic based systems. The role of particle diameter in the permeability of the sedimented bed was also investigated. The experimental results provide valuable guidelines for designing fluids aiming APB mitigation.
Long Tiebacks for Life Extension of Existing Offshore Facilities - A Novel Solution for Flowline Wet Insulation
Authors: Rebello Armando , Alexander Lane 
Published: October 2017

Abstract
Blockage of flowlines due to hydrate or paraffin plugging is an on-going issue for the offshore industry. The problem seems to be exacerbated with the higher pressures and colder ambient temperatures as developments progress into deeper and deeper waters. There are many blockage prevention equipment and techniques available to the system designers, but in spite of this, blockages are still occurring.
This paper presents a novel approach for remediating hydrate or paraffin blockages of wet insulated flowlines with the application of heat directly to the steel OD of the pipe instead of the OD of the wet insulation, which is less efficient.
The herein proposed solution offers two possible configurations for the same base design, one for near-riser cooldown time extension, and one for "as-needed" intervention when hydrate or paraffin plug(s) have formed.
The proposed method establishes a new paradigm, since it utilizes an unbonded layer of external insulation with a gap between the insulation and the flowline steel OD. The gap will be used to circulate hot media, with heat being transferred through the steel wall, while being insulated from the environment through the insulation.