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Results
Ships interact with the environment in several ways. The focus in this paper is on how ships interact with the wind and how this is treated in design. It is generally sufficient in most cases to model wind force as a static load. However, there may be circumstances where a more detailed description of the wind is appropriate. Some examples discussed include stability under transverse winds, aircraft flight deck operations and wind resistance. The paper summarizes key properties of the wind and recent research related to some key windship interactions. This includes discussion of the challenges and possible remedies.
- North America > United States (1.00)
- Europe (1.00)
- North America > Canada > Ontario > Toronto (0.28)
- Overview (1.00)
- Research Report > New Finding (0.93)
- Transportation > Marine (1.00)
- Transportation > Air (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- (4 more...)
- Health, Safety, Environment & Sustainability > Environment (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Floating production systems (1.00)
- Reservoir Description and Dynamics (0.93)
- (2 more...)
Abstract Natural leaks of multiphase hydrocarbons from the seafloor are widespread. Characterizing the temporal and spatial variability of these emissions provides baselines for comparison to the magnitude of anthropogenic leaks. Determining leakage rates will be important to our understanding the sustainable implementation of subsea infrastructure and the relative contribution of natural sources to global budgets. Multibeam echo soundings from cruise AT21-02 were used to define a region with several ~600 to 900 m tall gas plumes in the water column directly above cratered hummocky regions of the sea floor with high backscatter in water depths of ~1500 m over the Barbados Accretionary Complex. The relationship of seafloor morphologic features such as faults, craters, and mud volcanoes with vent-gas plumes in the water column is indicative of substantial emissions from this region. Disappearance of the acoustic plumes at ~600 m is coincident with the top of CH4 gas hydrate stability in the water column. In the plumes, natural gas hydrate shells that form at the gas-water interface and armor the gas from dissolution during ascent likely encapsulate bubbles. Ascent-driven pressure change in the bubbles causes shattering of shells forming gas hydrate shards that rise with the ascending plume and add to its acoustic reflection strength. The multiphase fluid consisting of gas, shelled bubbles, shards, and water changes character at the top of gas hydrate stability where the hydrate dissociates and dissolves. Differentiating sources and further characterizing emissions will provide baselines and also contribute to understanding the relative importance of the different emissions sources.
- Geology > Geological Subdiscipline > Geochemistry (1.00)
- Geology > Structural Geology > Tectonics (0.93)
- Geology > Geological Subdiscipline > Economic Geology > Petroleum Geology (0.48)
- Geology > Sedimentary Geology > Depositional Environment > Marine Environment (0.46)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.93)
- South America > Colombia > Middle Magdalena Basin > La Luna Shale Formation (0.99)
- North America > United States > Texas > Fort Worth Basin > Jefferson Field (0.98)
- Reservoir Description and Dynamics > Reservoir Characterization (1.00)
- Reservoir Description and Dynamics > Non-Traditional Resources > Gas hydrates (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)
- (3 more...)
The Malampaya Depletion Compression Platform (DCP) was conceived by Shell Philippines Exploration B.V. (SPEX) to provide additional gas compression to account for the future expected decline in well pressure from the Malampaya field. The Malampaya project is very important to the ongoing prosperity of the Philippines, with the exported gas feeding three power stations which provide up to 45% of the power needs of Luzon, the largest and most populous island in the Philippines. The DCP consists of a sealed barge structure which is rigidly connected to four cylindrical legs, each of which is supported on individual strut-linked hexagonal pad footings. The DCP arrangement uses cylindrical rather than truss legs and the base comprised a series of linked pad footings rather than a skirted baseplate. The leg configuration was selected in an attempt to simplify the leg fabrication; whilst the use of pad footings was a result of the site geotechnical conditions. One of the key structural innovations on the project was to design a barge to leg connection which could accommodate both the required vertical movement of the circular leg during installation, as well as form a rigid moment connection at the final design level of the barge without excessive offshore works. One of the key geotechnical innovations was to eliminate the need for a dedicated scour protection layer around the footings, yielding savings in procurement and offshore placement. This was achieved by selecting a foundation fill material capable of resisting self-scour in the 100-year return period cyclonic storm. The use of this larger sized material was agreed in advance with potential offshore Contractors to ensure that the required surface tolerances could be readily achieved. Offshore work prior to the arrival of the DCP consisted of seabed excavation to remove the in-situ carbonate sand and reef limestone, and replacement with the engineered rock fill to form a sufficiently level surface for placement of each of the four pad footings. Installation of the DCP at the Malampaya site commenced after a 3 day wet-tow from the fabrication yard in Subic Bay. Base lowering commenced on the morning of 12 February 2015, with touchdown occurring on the seabed some 26 hours later. Barge raising commenced immediately thereafter with the barge clearing the water around midday on 13 February 2015. Barge raising to the final elevation was completed in the early hours of 14 February 2015, less than 2 days after initial touchdown. As well as providing a general overview, this paper will describe some of the geotechnical and structural innnovations which ensured a successful outcome of the project.
- North America > United States > Texas (0.28)
- Asia > Philippines > Quezon (0.25)
- Asia > Philippines > Palawan > West Philippine Sea (0.25)
- (2 more...)
- Asia > Philippines > Palawan > South China Sea > West Philippine Sea > Northwest Palawan Basin > Block SC 38 > Malampaya Field (0.99)
- Asia > Philippines > Palawan > South China Sea > Quezon > Northwest Palawan Basin > Block SC 38 > Malampaya Field (0.99)
- Asia > Philippines > Palawan > Palawan > West Philippine Sea > Northwest Palawan Basin > Block SC 38 > Malampaya Field (0.99)
- (5 more...)
- Facilities Design, Construction and Operation > Facilities and Construction Project Management (0.54)
- Reservoir Description and Dynamics > Reservoir Characterization (0.47)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (0.47)
- Facilities Design, Construction and Operation > Processing Systems and Design (0.34)
Abstract This paper provides the design basis and case study of soil improvement to secure the stability of jack up rig under operation and fabrication condition to effectively mitigate the risk associated with unexpected spudcan penetration. The two penetration curves of spudcan foundation are presented to confirm soil improvement influence using DMM (Deep Mixing Method) with native soil material. The results from 3D large deformation finite element (LDFE) analyses are reported on vertical penetration of skirted spudcan into multilayer clays. The LDFE analyses were carried out using the Coupled Eulerian-Lagrangian (CEL) approach and the modified simple elastic-perfectly plastic Tresca soil model. The seabed sediments were simulated as single layer soft clay with undrained shear strength increasing linearly with depth, two-layer stiff clayey sand overlying soft clay and sandy gravel. The circular block of soil improvement is partially located in the third sandy clay layer under the spudcan penetration path with specific thickness. The result with native soil condition is validated against ISO recommendation and the penetration curve for reinforced section is also overlaid concurrently. The punch-through phenomeneon predicted in the assessement by ISO method is replicated in the numerical analysis. The validation exercise of the original case shows a good agreement and the present numerical approach is capable of predicting the behavior of a spudcan penetration in multi-layered soil. The partially reinforced layer shows the load distribution during spudcan penetration. It provides the reduction of penetration depth under a given preload and seabed conditions efficiently. To ensure the structural stability of jack up rig, the uncertainties of site condition during installation should be removed such as partially trapped soft soil or soft thin layer at the footing location. The presented numerical approach can provide reasonable design basis for soil treatment to mitigate stability risk.
- North America > United States (0.28)
- Asia (0.28)
- Energy > Oil & Gas > Upstream (1.00)
- Food & Agriculture > Agriculture (1.00)
- Well Drilling (1.00)
- Reservoir Description and Dynamics (1.00)
- Data Science & Engineering Analytics > Information Management and Systems (0.88)
- (2 more...)
Gravity Based Structure Foundation Design and Optimization Opportunities
Tistel, Joar (Norwegian University of Science and Technology) | Eiksund, Gudmund R. (Norwegian University of Science and Technology) | Hermstad, Jon (Kvaerner, Concrete Structures) | Bye, Anders (Multiconsult) | Athanasiu, Corneliu (Multiconsult)
Abstract Concrete Gravity Based Structures (GBS) have been used in the oil and gas industry since the early 1970-ties. Several structures have been installed worldwide at various water depths and soil conditions. Concrete Gravity Based Structures have proved to be well suited in harsh offshore environments. The structures have therefore been chosen as the preferred concept for several recent projects in arctic areas. GBS structures are robust and constitute a solid substructure for the topsides. The geotechnical design of the structures is based on proven principles. The concrete GBS are however relatively expensive, and in order to limit the costs it is important to optimize the design. The first sections within this paper presents the state-of-the-art for GBS geotechnical design. Further, the paper assess a selection of design exercises which can be performed to optimize the foundation design. The examples are especially governing for structures on sands.
- Europe > Norway (0.70)
- North America > United States (0.48)
- Asia > Russia > Far Eastern Federal District (0.16)
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean > Atlantic Margin Basin > Grand Banks Basin > Jeanne d'Arc Basin > Hebron Field (0.99)
- Europe > Norway > North Sea > Northern North Sea > East Shetland Basin > PL 50 > Block 34/10 > Gullfaks Sør Field > Statfjord Group (0.99)
- Europe > Norway > North Sea > Northern North Sea > East Shetland Basin > PL 50 > Block 34/10 > Gullfaks Sør Field > Lunde Formation (0.99)
- (15 more...)
- Health, Safety, Environment & Sustainability (0.93)
- Management (0.68)
- Reservoir Description and Dynamics > Reservoir Characterization (0.68)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (0.68)
Design and Operation Considerations for Large Jacket Installations in South China Sea
Yu, Changsheng (Offshore Oil Engineering Company, Limited) | Li, Zhigang (Offshore Oil Engineering Company, Limited) | Fu, Jian (Offshore Oil Engineering Company, Limited) | Yu, Wentai (Offshore Oil Engineering Company, Limited) | Wang, Alan M. (Offshore Oil Engineering Company, Limited) | Li, Jianmin (China Offshore Oil Engineering Corporation)
Large size of foundation piles, as massive as ø108"(2743mm) 158m 754Te skirt piles, are successfully This paper presents an overview of the design and operation installed which may cause challenges in design of pile upending rigging considerations based on our recent experiences of six large jackets system and pile installation method. Large jacket on-bottom stability installed in the northern waters of South China Sea. Latest progress of and its pile driveability shall be carefully evaluated. Large bollard-pull large jacket installation technology is also reviewed here. This paper positioning tugs and HMPE wet tow riggings shall be required to provides installation design guidelines to enable large jackets to be maintain the position and orientation of large launch barges as well as launched and installed as rapidly as possible co-incident with safe launched mega jackets. Large capacity of flooding system, skirt pile practice for future offshore projects.
- Data Science & Engineering Analytics > Information Management and Systems (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (0.93)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (0.46)
Abstract The CX-15 platform was installed off the coast of Peru in Block Z1 in September 2012. By the time of presentation, the initial drilling phase will be underway and data from the whole process will be available for review, discussion and evaluation. The platform is the world's first application of a proprietary design that is a fusion and combination of existing and proven technology from deep water cell spar floating platforms, compliant tower structures and shallow piled foundations. A key driver in the selection of the design was the ability for the hull and topside to be manufactured, delivered and installed without the use of large heavy lift equipment. Following the successful installation and initial drilling phase, the paper describes some of the high level lessons learned from the execution of the BPZ CX-15 project and how future buoyant towers will benefit from this feedback. In particular, the paper describes how the design could be modified to allow for faster construction and installation and for construction in areas of the world with little experience of building large offshore structures. Modifications to the CX-15 design will be presented to facilitate drilling only and drilling plus production and storage options for extended well test (EWT) and exploration, development and production (EDP) applications. Introduction The buoyant tower consists of a number of conjoined tubular structures (4×60 m in length in the case of CX-15), each consisting of smaller length " cans " welded together. In turn, each can is comprised of smaller 2.5 m length sections welded together. Following the successful installation of the CX-15 buoyant tower, feedback from project personnel was sought in order to refine the design and improve the construction and installation methodologies for subsequent buoyant towers. Some of the major points that were either considered worth keeping or new techniques that we will be considered for implementation next time are: Maintain maximum flexibility in can production. The construction strategy that was developed for the CX-15 buoyant tower was to sub-contract the rolling of the cans to local pressure vessel (PV) shops that would then ship the completed tubular can sections to Wison's yard at Nantong, China where they would be assembled into longer tubes and nested together. See Fig. 2—Assembly in Fabrication Yard. The decision to out-source the rolling of the cans was made because there was, at the time, a shortage of rolling capacity and covered fabrication space in Wison's main assembly yard. The detailed methods and jigs for maintaining tolerances, adding the internal stiffeners and welding the rolled sections together after having stacked them vertically were developed in conjunction with the PV fabricators. The investment in making jigs, in particular, proved to be worthwhile and led to greater productivity as can production stepped up. The ability to sub-contract can production is considered to be a major advantage of the design as it allows considerable flexibility both in scheduling within the main yard and permitting multiple parallel, concurrent can fabrication.
- Asia (0.48)
- North America > United States > Texas (0.28)
- Well Drilling > Drilling Equipment (0.89)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Floating production systems (0.88)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Drillstem/well testing (0.68)
ABSTRACT The reliance on production chemicals, such as scale and corrosion inhibitors, to provide protection for subsea systems from flow assurance and integrity management issues has led to more stringent product quality requirements as the applications have become deeper, further away (tiebacks), and more demanding with respect to product performance, stability, deliverability, and compatibility with the materials of construction. The qualification of chemicals for squeeze application in subsea wells differs from that for continuous subsea application. However, in the context of systems assurance, the processes involved in the product selection, testing and application for the two types of application are similar. This paper contrasts the considerations for the two types of applications with respect to; (1) how system conditions are modeled, (2) the differences in the objectives of performance testing, (3) how the method of product placement impacts performance, (4) the differences in the complexities of the applications, and (5) the importance and types of monitoring that can be employed. Particular focus is directed at ensuring that the developed treatment programs meet the specified performance requirements, and are warranted for the system and operating environment
- Europe (1.00)
- North America > United States > Texas (0.28)
- Water & Waste Management > Water Management (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Downhole chemical treatments and fluid compatibility (0.94)
- (4 more...)
ABSTRACT The main purpose of this work is to develop approaches and conduct analyses necessary for the validation of the structural solutions at Sakhalin shelf. The geological engineering conditions at the sites, nature of loads, impacts and their combinations acting on the facilities are analyzed, analyses and estimations of the stability (bearing capacity) of the platform - foundation system necessary for validation of structural solutions from the point of view of Russian and foreign standards and Russian practice of designing hydro-technical facilities are made. INTRODUCTION Five large fields are currently explored at Sakhalin shelf. Works under Sakhalin I and Sakhalin II projects are being made, other projects are started. The works are impeded by the complicated natural conditions in the region, including high seismic activity. There are a lot of issues in designing fixed oil and gas production platforms in offshore areas due to unique nature of the project, complicated climatic conditions in the construction area, partial insufficiency of the current standards, and methodically different approaches and even some discrepancies in numerical provisions of different standards (both Russian and foreign). During the design of support facilities of gravity platforms at Sakhalin shelf, it was necessary to conduct the following scientific and research work:–analysis of geological engineering conditions of the construction sites, schematization of the foundations, content of necessary design parameters and their values; –determination of the design values of seismic, ice and wave loads on the platforms; –assessment of the stability of platforms under static and dynamic loadings. In addition, in order to ensure reliability of the facilities at all stages of their construction, installation and operation, it was necessary to do the following calculations and assessments in the project:–analyses of the bearing capacity of the foundation and the stability of the platform.
- Asia > Russia > Far Eastern Federal District > Sakhalin Oblast (1.00)
- Asia > Russia > Far Eastern Federal District > Sakhalin Island > Sea of Okhotsk (0.48)
- Asia > Russia > Far Eastern Federal District > Sakhalin Island > Sea of Okhotsk > East Sakhalin - Central Sea of Okhotsk Basin > North Sakhalin Basin > Odoptu Field (0.99)
- Asia > Russia > Far Eastern Federal District > Sakhalin Island > Sea of Okhotsk > East Sakhalin - Central Sea of Okhotsk Basin > North Sakhalin Basin > Chayvo Field (0.99)
- Asia > Russia > Far Eastern Federal District > Sakhalin Island > Sea of Okhotsk > East Sakhalin - Central Sea of Okhotsk Basin > North Sakhalin Basin > Arkutun-Dagi Field (0.99)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (0.67)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (0.34)
Abstract The Perdido Regional Host is a Wet Tree Direct Vertical Access (DVA) Spar Facility in the Gulf of Mexico located approximately 200 miles south of Freeport, Texas. Production from subsea wells flows to Caisson Separators at the seafloor. Pumped oil and free flowing gas travel up risers into the center well of the host facility. Shell, Chevron and BP are joint venture partners with Shell as the Operator. The Perdido Topsides was designed to deliver high producing and drilling functionality while capturing the benefits of a single offshore lift module concept. The benefits of a single module are reduced design interfaces, less steel, pipe & cable, and reduced offshore integration cost and duration. Reduced offshore integration reduces safety risk. Final functionality was 100MBOPD, 200mmcfd gas, 80 MBWPD waterflood, Minimum Area Self Erecting (MASE) Drilling Rig and 150 person Quarters. This paper will communicate the efforts required to successfully meet this goal over the duration of development. System Selection In System Selection, subsurface and water depth requirements drove the solution of a Wet Tree DVA Spar with Artificial lift. In the evaluation of Topsides concepts, Spar Deck benchmarking identified two kinds of facilities (see Figures 1 & 2):Single piece modules - medium throughputs, small rigs and medium staff counts Multi modules were required for larger throughputs, rigs and staff counts This step change opportunity initiated an effort to evaluate the feasibility to extend the single piece concept to the functionality required for Perdido. The technical benchmarking compared dry fabricated weight to functionality, which is independent of market, skewed cost indices. We had found previous functionality metrics such as Barrels of Oil Equivalents (BOE) Throughput as misleading, because it did not take into account the impacts of waterflood, subsea artificial lift power, relative compression requirements or export pipeline pump horsepower. After much trial and error, we chose to use " Total Installed Power?? which included all fired drivers for Power Generation, Compression and Waterflood. This metric captured the impacts previously missing above and showed distinction in the break-over from single lift to multi-module (see Figure 3). Early weight studies placed Perdido's functionality requirements clearly into the multi-module category. Technical benchmarking efforts indicated BP's Horn Mountain design as having the best functionality to weight performance of the Spar Topsides to date. With the assistance of our joint venture partners (BP & Chevron) and Alliance Engineering we evaluated the Horn Mountain design and operating performance. We then created a lightweight Perdido concept with Alliance Engineering that would fall below the maximum lift configuration of Heerema's Thialf Vessel. This was followed by performing extensive reviews challenging the scope and the risking of weight growth exposure.
- Production and Well Operations (1.00)
- Management > Strategic Planning and Management > Benchmarking and performance indicators (0.94)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (0.89)
- (2 more...)