Shin, Jong Gye (Dep't of Naval Architecture and Ocean Engineering, Seoul National Univeristy / Research Institute of Marine Systems Engineering, Seoul National University) | Kim, Youngmin (Research Institute of Marine Systems Engineering, Seoul National University) | Woo, Jong Hun (Dep't of Naval Architecture and Ocean Engineering, Seoul National Univeristy / Research Institute of Marine Systems Engineering, Seoul National University) | Son, Seunghyeok (Dep't of Naval Architecture and Ocean Engineering, Seoul National Univeristy) | Shen, Huiqiang (Dep't of Naval Architecture and Ocean Engineering, Seoul National Univeristy) | Kim, Byeong-seop (Dep't of Naval Architecture and Ocean Engineering, Seoul National Univeristy) | Ryu, Cheolho (Dep't of Naval Architecture and Ocean Engineering, Inha Technical College) | Jeong, Yong-Kuk (Dep't of Sustainable Production Development, KTH Royal Institute of Technology)
While leading companies in the manufacturing industry are doing their best to implement smart factories along with the wave of the Fourth Industrial Revolution, shipbuilding companies still seem to be a bit distant from the smart factories, due to the characteristics of the industry. In this study, smart shipbuilding platform is defined by studying the necessary elements for realizing smart shipyard in shipbuilding industry, and a forming shop is presented as an example to which the smart shipyard platform is realized and applied. To this end, the purpose of implementing the smart shipyard is discussed first and then the factors necessary to achieve the purpose are identified. These elements are grouped together into one system with the computational shipyard dynamics to define the smart shipyard platform. The platform is then applied to an actual factory of a shipyard to verify its effectiveness.
In this paper a software suit is described which main purpose is to facilitate the engineering, design and analysis process such that consistency of input is assured and the risk of erroneous input is decreased, and such that results and documentation are automatically generated to increase quality of documentation. Current scope is a standard calculation tool covering different aspects of design in compliance with relevant offshore codes and standards. A modularization technique is used to divide the software system into multiple discrete and independent modules based on offshore codes and standards, which are capable of carrying out task(s) independently. These modules work as basic constructs for the entire software, but at same time these modules can be executed separately and independently. This modularization technique also includes other benefits, such as ease of maintenance and updates. The quality of an implementation of offshore codes and standards in software modules and their interaction among them are measured by defining the level of inter-dependability among the subsea engineering and analysis modules, and by defining the degree of intra-dependability within elements of a module. How modules interfere and interact with each other is defined by couplings. The improvements are related to the objectives of a state-of-the-art procedure of performing engineering, design and analysis by use of offshore codes and standards implemented in this software suit to assure a consistent way of working.
A study by the Electrical Power Research Institute and U.S. Department of Energy (DOE) reported an estimated total available wave energy resource of 2,640 terawatt-hours (TWh) per year and total recoverable wave energy resource at 1,170 TWh per year for the territorial waters over the Outer Continental Shelf of the United States in 2011. While Wave Energy Conversion (WEC) systems have been in development since the first patent in 1799, the industry is still in its infancy globally and large commercial deployments have still not taken place. A key challenge for the commercial viability of WEC systems is effective extraction of the kinetic energy in waves by the power takeoff systems. Since the wave form and motion are critical factors influencing the kinetic energy input to WEC power takeoff systems, increasing the wave steepness acting on the WEC body can significantly enhance the velocities of water particles impacting prime movers and increase power takeoff performance. The use of variable-depth platforms to enhance wave steepness and increase power takeoff performance through increased kinetic energy input to prime movers is a novel idea that provides promise for increasing the capacity factor for WEC systems. The application of a variable-depth platform to wave energy conversion is discussed and quantified based on wave tank testing, wave theory, and the kinetic energy equation.
The existing SNAME OpenCalc System is built upon an open source framework that allows for the creation of long-lasting and reusable calculations that can be combined in many ways to create completely new solutions by naval architects, not programmers. Flexible calculation tools are created by splitting traditional monolithic program applications ("apps") into three separately developed and tested objects: 1. Calculation Engine (CE) batch programs 2. Open source and industry standard (XML) data files 3. Open source user interface frameworks (UIF) that work with any CE without programming. More generically these components (objects) could be described as: 1. The software "compute" component 2. Data payload for data-interchange based on industry standard normalized format 3. User interface and composer The SNAME OpenCalc System offers a new programming structure that returns creative control and flexibility to subject matter experts (SMEs) and users. It can create solutions not possible without access to all source code and expensive custom programming.
The effects of hull roughness, including fouling, are known to affect the performance of a vessel, especially as measured in additional fuel consumption and less so, the number of voyages in a lifetime. Today there is significant attention given to hull surface cleaning, coating and propeller polishing to address these issues. Additionally and even less known are the effects on the maneuvering performance of a vessel. For naval vessels they may affect the success of the mission Roughness of the hull can occur due to a number of factors including hull material utilized and quality of construction, mechanical damage in operation, roughness from paints and coatings and their method of application, damage to the coating during maintenance, corrosion and pitting of the hull structure material, as well as biofouling influenced by the type of antifouling paint or coating and method of application. The roughness never ceases to increase during the vessel's life.
Papanikolaou, Apostolos (Hamburgische Schiffbau-Versuchsanstalt GmbH, Germany & National Technical University of Athens, Greece) | Flikkema, Maarten (MARIN, Netherlands) | Harries, Stefan (FRIENDSHIP SYSTEMS AG, Germany) | Marzi, Jochen (Hamburgische Schiffbau-Versuchsanstalt GmbH, Germany) | Le Néna, Romain (Naval Group, France) | Torben, Sverre (Kongsberg Maritime CM AS, Norway) | Yrjänäinen, Antti (ELOMATIC Oy, Finland)
The present paper introduces the HOLISHIP approach to ship design and demonstrates a subset of its functionality by brief presentations of several case studies. HOLISHIP is the joint effort of 40 European maritime RTD stakeholders, funded by the Horizon 2020 EU framework (www.holiship.eu). It sets out to substantially advance ship design and to develop vessel concepts for the 21st century. The project implements an innovative, holistic approach to ship design by the development of integrated design software platforms, while considering all major ship design aspects, namely building cost, energy efficiency, safety, environmental compatibility and life-cycle cost.
The objective of this work is to demonstrate the application of multivariate statistical tools in unconventional reservoir fluid characterization using publicly available PVT data and design a fluid characterization workflow. Several oil and gas properties were predicted for fluids in Eagle Ford groups, namely Eagle ford 1 (ef1), Eagle Ford 2 (ef2), Eagle Ford Shale (efs) and Eagle Ford (ef).
Principal component analyses (PCA) was first used for dimensionality reduction and selection of components that account for large variation of the dataset. Next, multivariate regression analyses were used to predict PVT properties as a function of reservoir fluid composition using gathered reports. Major steps in regression are trends observation, correlation of trend parameters with composition, model reconstruction and calibration.
PCA results show that virtually all original variables are required to account for substantial variation within the PVT datasets. It is also noticed that the first 3 principal components account for 84% of dataset variability. Regression models of different fluid properties including gas-oil ratio (GOR), oil formation volume factor, gas density, gas viscosity, API, saturation pressure developed for Eagle Ford Shale formation fluids demonstrate a superior level of accuracy on average (R sq. = 0.8-0.94) and it was revealed that most properties can be determined directly from mole percentage of hydrocarbon fractions. A strong correlation between initial reservoir pressure and formation true vertical depth (TVD) was identified from the PVT data. Consequently, oil formation volume factor and GOR maps covering areas where analysed data were collected from with R sq. above 0.8 were designed. A user-friendly reservoir fluid characterization workflow was proposed and can be applied to any type of reservoir fluid window- black oil, dry gas or condensate - in a liquid-rich basin. Exceptions were identified and discussed.
Reliable estimation of reservoir fluid properties has a tremendous impact on different facets of unconventional reservoir field development: drilling, completion, reservoir management, and economic analyses. Current understanding of shale PVT is inadequate due to difficulty in obtaining representative fluid samples before (low permeability) and after (large produced water volumes) hydraulic fracturing. Thus, this study builds on recent efforts in understanding shale PVT behavior and potentially eliminating need for rigorous fluid sampling using multivariate statistical methods.
The artificial lift system (AL) is the most efficient production technique in optimizing production from unconventional horizontal oil and gas wells. Nonetheless, due to declining reservoir pressure during the production life of a well, artificial lifting of oil and gas remains a critical issue. Notwithstanding the attempt by several studies in the past few decades to understand and develop cutting-edge technologies to optimize the application of artificial lift in tight formations, there remains differing assessments of the best approach, AL type, optimum time and conditions to install artificial lift during the life of a well. This report presents a comprehensive review of artificial lift systems application with specific focus on tight oil and gas formations across the world. The review focuses on thirty-three (33) successful and unsuccessful fieldtests in unconventional horizontal wells over the past few decades. The purpose is to apprise the industry and academic researchers on the various AL optimization approaches that have been used and suggest AL optimization areas where new technologies can be developed.
Underbalanced drilling via air drilling is deeply rooted in the Northeast United States due to its distinct geology, high rates of penetration (ROP) and drilling efficiency, and low cost of circulating material. The active drilling programs of several independent operators in the Marcellus and Utica Basins are well suited for air drilling down to the final kick off point by virtue of competent, stable formations, low static reservoir pressures, and manageable water ingress to the wells. Air drilling provides near-atmospheric pressure at the borehole bottom, since there is no fluid column with resulting hydrostatic pressure. The result is very high ROP with essentially 100% drilling efficiency, allowing the completion of intervals in one or two bit runs. A service company deployed a cross-functional product development team to optimize oilfield air bits for these applications over the last two years, resulting in decreased drilling costs through increased performance and reliability.
The oilfield air drilling environment places unique challenges on drill bit design due to the increased risk of downhole vibrations, corrosion, abrasive wear, heat generation, and seal infiltration of very fine cuttings. The application requirements have increased due to deeper intervals requiring passage through multiple high unconfined compressive strength formations, extended tangent angles, and rising input energy levels. Accordingly, enhancements to both the cutting structures and sealed bearing systems were vigorously pursued. Several cutting structure design iterations were evaluated in both laboratory and field tests. A new sealed bearing system was developed and implemented for increased life and reliability. Modifications to the bit body for stability were included, and the bit hydraulics were further optimized.
Through an understanding of the objectives and application challenges, unique solutions were developed for Northeast oilfield air drilling applications. The optimization process for the new air bit designs is described, and the resulting positive performance metrics are presented. Improvements were observed in distance drilled, ROP, seal effective rate, and dull condition. Lessons learned were also used to refine the recommended drilling parameters and practices through the challenging formations encountered in these tangent sections, which can span in excess of 7000 feet. These enhancements all contributed to reduced drilling cost and days per well, for increased rig productivity.
The natural gas fields throughout the Marcellus and Utica Basins in the Northeast U.S. continue to deliver rising total gas production for the U.S. and the world through increased capacities in pipelines and LNG trains. Improved drilling performance as documented in this paper are driving continuous improvement in the overall upstream drilling economics of the region.
Eldabbour, Mohamed (Abu Qir Petroleum) | Fadel, Ayman (Abu Qir Petroleum) | Soliman, Ali (Abu Qir Petroleum) | Safwat, Hatem (Abu Qir Petroleum) | Labib, Amr (Abu Qir Petroleum) | Belli, Andrea (Abu Qir Petroleum) | McLaughlin, Ryan (Corex U.K. Ltd) | Patey, Ian T.M. (Corex U.K. Ltd) | Munro, Murdo S. (Corex U.K. Ltd) | Jones, David (Corex U.K. Ltd)
Gravel pack completion operations are a sand production management technique that is considered successful if the well produces no sand and has minimal impact upon the potential productivity and hydrocarbon recovery. However, statistics show that many gravel packed wells suffer reduced productivity as a result of damaging mechanisms induced by gravel pack operations and completion fluids. This provides an opportunity for improved hydrocarbon recovery if the mechanisms are understood.
A study was conducted to simulate the alterations caused by the gravel pack operations including gravel carrier fluid, completion fluid and lost circulation material. Simulations using reservoir core samples were carried out at near-wellbore conditions, in order to examine operational fluid interactions with the reservoir and assess the impact of a stimulation fluid. Cores from a range of rock types were selected, and prepared to initial gas-leg saturation. An operational sequence consisting of completion fluid, gas production, stimulation fluid, completion fluid, and production of gas was carried out, with permeability measurements before and after the sequence.
In all core samples, the introduction of the completion fluid during gravel pack installation resulted in alterations of 30-60% reduction in core permeability. Geological interpretative analysis showed damage mechanisms including clay fines movement and pore blockage, dissolution of native cement, and retention of operational fluid in the pores. It was believed that retention of fluids was having the most significant impact upon permeability. Stimulations were carried out for all samples to quantify the effect of acid on removing the formation damage resulting from the gravel pack operations. The experiments showed 5-10% improvement on average except for one core sample, which showed 40% improvement.
Based upon the previous results, a modified sequence was examined, utilizing an alternative stimulation fluid/acid sequence and adding an extra operational stage. The experiments showed that after treatment an improvement of around 10% was noted, and after an additional stage, a further 8% improvement was seen. The final permeability was over 80-90% of the initial permeability, indicating that there was the potential for good productivity and recovery of hydrocarbons.
The results of the study were applied to seven gravel pack jobs in three wells and the field results showed the reduction in productivity after gravel pack installation was around only 10%, compared to previous wells which showed more than 50% reduction in productivity.