The Newsletter for MCS Software Users Winter 2003

Transcription

1 Intercom The Newsletter for MCS Software Users Winter 2003 In this Issue MCS News... 2 Real Life JIP kicks off Software News... 2 Flexcom 7 update; PipeLay; DeepRiser Version 2; Software Users Meetings MCS Launches CoMet JIP... 3 Major development of new time and frequency domain coupled analysis software starts PipeLay Deepwater Pipeline Installation Analysis... 4 Software Manager Michael Lane writes about the latest addition to the MCS Offshore Software Suite DeepRiser Version 2 GlobalSantaFe s Experience... 7 Julian Soles, Naval Architect with GlobalSantaFe, writes about their experience with the latest version of DeepRiser Editorial Welcome to the Winter 2003 issue of Intercom, the newsletter for MCS software users. We are pleased to announce a number of major developments in this issue, probably the most important of which is the launch of the CoMet (Coupled Methodologies) JIP. This JIP will address the increasingly important area of coupled analysis for offshore floating production systems, and builds on the considerable experience MCS has gained in this area with our existing time domain coupled analysis version of Flexcom. You can read more about this important development inside. Another exciting development is the full release of PipeLay, our new engineering tool for deepwater pipeline installation analysis. The release of this new software, which is attracting a great deal of industry interest, is covered in the Software News section on Page 2, and PipeLay is also the subject of an in-depth article starting on Page 4. Also in the Software News section are details of the latest Flexcom developments including a preview of the new Version 7 GUI and an update on the progress of the Phase II development of DeepRiser, our engineering tool for deepwater riser analysis. Heerema Marine Contractor s deepwater installation vessel Balder. HMC, Allseas and MCS have jointly sponsored the development of PipeLay, a new engineering tool for pipeline installation analysis, which is discussed in this issue. Photo courtesy of Heerema Marine Contractors. Finally, this issue also contains an article by one of the DeepRiser Phase II JIP participants, GlobalSantaFe, describing their experience with the program and how it has delivered improved riser analysis productivity. Donogh Lang Software Business Development Manager DonoghLang@mcs.com Deep Offshore Technology Conference November 19 th - 21 st 2003 MCS will be exhibiting at this years DOT conference in Marseille France. As ever we look forward to meeting you there so please drop by our booth, located at stand number

2 News Winter 2003 MCS News Real Life JIP Kicks Off MCS has recently kicked-off its JIP to develop a fatigue analysis methodology for unbonded flexible pipes. The Real Life JIP is supported by five operators (ExxonMobil, BP, Statoil, ChevronTexaco and Petrobras) and all three flexible pipe manufacturers (Flexi France, Wellstream and NKT). Over the course of the next twelve months engineers at MCS Aberdeen and Galway will work to develop a comprehensive methodology that integrates time and frequency domain global analysis with an innovative and computationally efficient local cross-section analysis. Drawing on industry experience, the integrated methodology will be validated with the latest available flexible pipe test and in-situ field data. The Real Life methodology will be delivered to participants, and subsequently the industry, in the form of a comprehensive set of design guidelines that are set to be adopted as the industry standard for flexible pipe fatigue analysis. For information on the Real Life JIP, please contact Michael O Sullivan (MichaelOSullivan@mcs.com). Software News Flexcom 7 Update In the last edition of Intercom, we mentioned that we were in the detailed planning phase for the next minor and major releases of Flexcom. We ve now decided to combine these two developments and bring the release of the next major version of the program (Flexcom 7) forward to next January. GUI enhancements that we have planned for the next couple of releases of Flexcom. PipeLay Also in the last issue of Intercom, we referred briefly to the first full release of our new deepwater pipeline installation analysis software, PipeLay. Since then, we have released Version 1.3 of the software, which represents the last full release of the software from Phase I of the project. PipeLay, for those unfamiliar with it, has been developed by MCS in collaboration with Allseas and Heerema Marine Contractors to provide a state-of-theart solution to the problems associated with deepwater pipeline installation analysis. For a detailed description of the capabilities of the software take a look at the indepth article starting on Page 4 of this issue of Intercom. Further details of the capabilities of PipeLay are also available on our website PipeLay is now available for evaluation, rental or purchase. If you are interested in taking a look at the software, then please contact DonoghLang@mcs.com. DeepRiser Version 2 The first full release from the Phase II development of our engineering tool for the design and analysis of deepwater top-tensioned and catenary risers, DeepRiser, was issued to the project participants in July. Version 2.1 features some significant advances, including enhanced drilling riser modelling and analysis capabilities (conductor-casing/soil structure interaction, BOP/LMRP, telescopic joint and driftoff/weak point analyses) and improved top-tensioned production and catenary riser modelling features. This issue of Intercom features an article by one of the Phase II project participants, GlobalSantaFe, on their experiences with using the new version of DeepRiser. The final release from this development (Version 2.2), which is due for release in the first quarter of 2004, will incorporate further advances. These include a drilling riser deployment analysis capability and additional spar riser modelling facilities (improved riser guide contact modelling, air-can modelling and stem joints) and a pipe-in-pipe modelling capability. Flexcom 7 will incorporate a whole range of new analytical and modelling features and will also feature a significantly improved GUI with a greater Windows look and feel. The program release will be the subject of an in-depth article in the next issue of Intercom, but for now we ve included a preview of the new GUI above. This, by the way, is the first in a series of major Software Users Meetings We ve already hosted two very successful Software Users Meetings this year one in Houston and one in Aberdeen. We re planning to host another two by year end in Paris and Oslo. For further details, check out our website 2

3 CoMet Coupled Analysis JIP Winter 2003 MCS Launches CoMet JIP MCS are pleased to announce the kick-off of a major new JIP, CoMet (Coupled Methodologies). This JIP, which is being co-sponsored by ChevronTexaco, ConocoPhillips and ExxonMobil, will address the increasingly important area of coupled analysis for offshore floating production systems. Background MCS has already gained considerable expertise in this area and has developed a customised coupled analysis version of our time domain FE software, Flexcom (Version 5.5). This software, which has been verified and validated against third party software and model tests, has already been used extensively for generation of fatigue RAOs for a West of Africa CALM offloading buoy. With the existing software, MCS is in a position to offer a comprehensive coupled analysis capability including design and verification of coupled system components (risers, mooring lines, offloading lines, transfer lines etc.). This capability is offered at each of our Galway, Aberdeen and Houston offices and utilises MCS extensive experience in the area of coupled analysis. The CoMet JIP will build on MCS existing coupled analysis capability and will address a number of technology gaps and issues that have been identified in this area. The objectives of the JIP are to deliver an integrated time and frequency domain coupled analysis tool and accompanying Design Guidelines, which will cover the application of coupled analysis techniques to the design of deepwater production and offloading systems. Coupled Analysis Software The CoMet software will be based on the existing coupled analysis version of Flexcom, which already incorporates advanced features for performing coupled analyses in the time domain. These features include: Mechanical coupling between floating structures achieved by incorporating floating bodies as part of an FE model. Floating body first-order loads computed from force RAOs and second-order wave drift loads computed from QTFs. Frequency-dependent added mass and inertia terms included in the time domain solution scheme using the Cummins impulse response technique and the convolution integral allowing time domain irregular sea coupled analyses to be performed. CoMet will integrate this version of Flexcom with the latest version of MCS industry leading frequency domain FE program, Freecom, to deliver an integrated time and frequency domain coupled analysis tool incorporating a comprehensive range of features, including: Interface to WAMIT for input of floating body force RAOs, QTFs, added mass coefficients and damping coefficients. Hydrodynamic coupling between closely-located floating structures via input of co-influence matrices. Postprocessing facilities to perform automatic generation of response RAOs for both time and frequency domain analyses. Development of the new CoMet software has already commenced and is scheduled for completion by mid The software will be released on a phased basis, with the first version featuring the frequency domain coupled analysis tool followed by the integrated time and frequency domain version. Design Guidelines The CoMet JIP will also deliver a detailed and comprehensive set of Design Guidelines for performing coupled analyses. This document, which will be general in nature, will describe recommended practices for the application of time and frequency domain coupled analysis of deepwater production, export and offloading systems. The areas to be addressed by the Design Guidelines include the impact of coupled analysis on overall system and individual component design, contrasting and comparing the coupled v decoupled approach, and testing and validation. For more details on the CoMet JIP and MCS general coupled analysis capability, please MichaelOSullivan@mcs.com. ExxonMobil Corp. 3

4 PipeLay Deepwater Pipeline Installation Analysis Winter 2003 PipeLay Deepwater Pipeline Installation Analysis The most recent addition to the MCS Offshore Software Suite is PipeLay, a powerful engineering tool for deepwater pipeline installation analysis. In this article Software Manager Michael Lane describes some of the program features and capabilities. Introduction PipeLay is an engineering tool for deepwater pipeline installation analysis that was developed by MCS in collaboration with Allseas and Heerema Marine Contractors. It combines powerful analytical capabilities with an intuitive Graphical User Interface that allows rapid data specification in familiar engineering rather than finite element terms. An example GUI screen is shown below. PipeLay provides the capability to analyse each of the following seven installation scenarios: Normal Lay Abandonment & Recovery Sledge Installation Start-up via Stab & Hinge Start-up via Sheave As-Laid Span SCR Transfer The software automates many of the tasks associated with building complex finite element models, running multiple load cases, and presenting results in reportready format. Components and Projects Files PipeLay models are composed of building blocks known as components. Components are used to store all project data, including pipeline data, vessel data, environmental data, analysis data and so on. PipeLay has over 30 components that provide a comprehensive and flexible range of modelling and analysis options. Components are designed to be as modular as possible, and higher level components generally reference lower level ones. Some example components are shown in the next two sections. In the PipeLay screen above, data for a Support component is displayed on the right of the screen. You store the PipeLay components you define in a project file. A project file is intended to store all the information relevant to a single project. You can define as many different components as you want, representing different pipelines, different environmental and loading conditions, different vessel motions and so on, and store them all in one project file. In the example GUI screen above, all of the components stored in the current project are represented graphically in the Project Sidebar to the left of the screen. When you want to run an analysis, it s simply a matter of selecting the components that you want to include in the analysis. In addition to this, you can readily copy and paste components (or whole groups of components) from one project file to another, so you don t have to keep inputting the same data again and again. Building a PipeLay Model The power and flexibility of this concept is best illustrated by an example. Obviously one of the most basic tasks in a pipelay analysis is to define the pipeline, for which task PipeLay provides a total of 14 components. The lowest level of these is the Material component. PipeLay materials can be linear or nonlinear; this is the data input screen (with some userspecified values) for a linear material, clearly steel. This screen illustrates one important program feature. All PipeLay inputs are in familiar meaningful units. You nominate the units system to be used (imperial or metric), and after that all data entry dialogs display the units required for each input. So you can always be sure that you have used the correct units in your data. The next level of component for defining a pipeline is the Pipeline Sub-Component. These are used to define different elements of a pipeline. The simplest is the Pipe Section sub-component, which is used to define a continuous section of pipe. There are however 11 other pipeline sub-components, including hexjoints, triplates, quadplates, flex joints, pullheads and a sub-component to model a sledge (or sled) assembly. 4

5 PipeLay Deepwater Pipeline Installation Analysis Winter 2003 The data input screen for a Pipe Section is shown below. shows the input screen for one of these, the Normal Lay analysis. You ll note the slot in the middle of the dialog for defining the pipeline material. Clicking on this brings up a list of all of the Material components you ve already defined (in this case there s only one). This illustrates the notion of a hierarchy of components, with higher level components having access to alreadydefined lower level components. This point is further illustrated when you come to use the highest level component for defining a pipeline, which is the Pipeline component itself. Here is an example: Here the full pipeline is defined from sub-components already defined, a list of which is provided when you click on Add Component. In this example three previously defined Pipe Sections are combined: note that all you input are the sections and their respective lengths (Columns 1 and 2 in the picture above); PipeLay automatically calculates the data displayed in the other columns from properties you specified at the various levels below this. PipeLay provides similar hierarchies of components for defining: Environment (seabed, waves and current) Vessels and vessel motion Stinger and support (roller box) data All of these are finally brought together in the highest level component of all, the Analysis component. PipeLay Analyses PipeLay has Analysis components for the seven scenarios listed in the Introduction. The picture below As you can see, here you draw together all of the elements required to simulate the laying of a pipeline on the seabed. So from components you have previously defined you select a pipeline, a vessel (including stinger details), and appropriate environmental conditions. There is also a section to specify Installation Criteria, where the following dropdown box is available to define the criterion you want to use: A Data box to the left of this allows you to specify values appropriate to the criterion you nominate. How PipeLay satisfies this criterion is described shortly. One category of input that is conspicuous by its absence from all of the PipeLay screens shown so far is traditional FE inputs such as nodes and elements. The reason for that is that they are not there! PipeLay is intended as an engineering design tool rather than an FE analysis package, so tasks such as finite element meshing, defining nodal coordinates and element connectivity, grouping elements into sets and assigning 5

6 PipeLay Deepwater Pipeline Installation Analysis Winter 2003 properties to these sets, are undertaken automatically by the program, without user intervention, when you run an analysis. This allows you to concentrate on the core engineering aspects of the pipelay analysis. This philosophy of automation extends to running the analysis as well. Doing a dynamic analysis with, say, Flexcom-3D, usually involves first running a series of preliminary static analyses to provide a stable starting configuration. In PipeLay all of this is automated. Likewise automated is the process of iterating on the pipelay configuration to satisfy installation criteria. For example, in a Normal Lay analysis you specify only the location of the lay vessel in the global coordinate axes, and the total pipeline length. Based on these, PipeLay makes an initial estimate of the global coordinates of the seabed connection, and then progressively refines this estimate until your installation criteria are satisfied. Analysis Results When any PipeLay analysis finishes, the program automatically postprocesses the results to provide a standard range of outputs appropriate to the scenario under examination. A range of output files is generated providing increasing levels of detail on the solution, all of which are immediately accessible via the Results tab on the Analysis component (see for example the Normal Lay component shown previously). Among these is an Analysis Report file, which combines a Data Echo section summarising the analysis details; a succinct Solution Summary table; and a range of response plots, of which the following is an example (this is from a static Normal Lay analysis). Von Mises Stress (MPa) Fig. 7: Von Mises Stress Curvilinear Distance along the set _Pipeline (m) Several of the analysis components perform repeated analyses where the paid-out length of pipeline or cable varies between first and last stages. This is the case, for example, for abandonment and recovery analyses. For these, PipeLay automatically performs summary postprocessing, which presents results as a function of paid-out length. For the Sledge Installation analysis, summary postprocessing presents values as a function of sledge location, as shown in the plot below. Lay Back (m) Lay Back Sledge Position (m) In addition to the above, PipeLay also generates a 3D display of the static configuration or dynamic response, as shown in the view of a typical SCR transfer analysis below. When the standard automated postprocessing doesn t give you exactly the information you need, a Custom Postprocessing component is available to retrieve what you want from the analysis results. Future Plans PipeLay is a powerful and flexible tool, but we are already consulting with the industry to prepare the scope of work for the next phase of the development, to greatly extend the range of program options. Some of the topics that have been suggested are: Reeled installation Dynamic pay-in/out capability Real-time on-board analysis capability Fatigue postprocessing Code checking (including buckling & ovality) User-defined installation scenarios (for example, tow out) Additional design criteria If you are interested in finding out more about or evaluating PipeLay Version 1 or in becoming part of the Version 2 development, simply contact DonoghLang@mcs.com. 6

7 DeepRiser Version 2 GlobalSantaFe s Experience Winter 2003 DeepRiser Version 2 GlobalSantaFe s Experience The second phase of the development of DeepRiser, the engineering tool for deepwater riser design and analysis, has been underway for approximately twelve months. This major development, which is being sponsored by MCS, ChevronTexaco, ConocoPhillips, GlobalSantaFe and Technip, involves some very significant enhancements to the modelling and analytical capabilities of the software. The first software release from this phase of the development, Version 2.1, was released to participants in July. In this article, Julian Soles, Naval Architect with GlobalSantaFe describes some of the features in Version 2 that are of particular relevance to deepwater drilling riser analysis. GlobalSantaFe (GSF) entered into the JIP for the second phase of development of DeepRiser almost 18 months ago and during this time we have successfully been using the first version of DeepRiser. Since DeepRiser incorporates the full suite of MCS software it provides the ability to model the riser in one program and run both time domain and frequency domain analysis using the same model. DeepRiser also enables modal and frequency domain fatigue analysis to be performed using the same riser model. By having a simple GUI and entering riser components in typical dimensions it makes the riser model relatively easy to create and also minimizes the chance of user input error. Once the riser components and vessel characteristics have been defined for the first time they can be used to specify any riser make-up in any water depth, thus making subsequent analysis for different locations even more efficient. Defining the drilling riser stack-up in DeepRiser Version 2 GlobalSantaFe deepwater drillship Jack Ryan During the development of DeepRiser Version 2 many enhancements have been made enabling a more efficient and comprehensive riser analysis to be performed for each well site. One of the most common uses we have for DeepRiser is time-domain drift-off analysis that allows us to determine alert offsets for well sites drilled by our dynamically positioned drilling rigs. DeepRiser Version 2 allows for a fully-coupled timedomain analysis, thus accounting for the riser inertial effects, riser/vessel interaction, riser/conductor/soil interaction and vessel rotation. This analysis capability allows a more accurate and less conservative (compared to static analysis) riser analysis. MCS s Flexcom program has typically been used in the past to perform this type of drift-off analysis and in DeepRiser the analysis engine used for Flexcom is the same, the only difference being the user inputs and GUI. Another feature in DeepRiser Version 2 is the ability to model different soil types with shear strength profiles or enter specific soil P-y curves if available. Currently in DeepRiser Version 1 it is relatively time consuming to model the soil each time since non-linear spring elements must be defined individually. Mudline LMRP BOP Conductor/ Casing Screen-shot showing conductor/casing and BOP/ LMRP stack during drift-off analysis performed with DeepRiser Version 2. Note bending in the conductor casing, which is being restrained by non-linear soil P-y curves. 7

8 DeepRiser Version 2 GlobalSantaFe s Experience Winter 2003 GSF has found that conductor strength often governs the drift-off analysis results in water depths less than 4,000 ft. In deeper water this is not such a concern since it can take up to 30 seconds or more for the bottom of the riser to react to the vessel drift-off at the surface and typically the slip joint stroke will govern. For this reason, a coupled riser/conductor/soil analysis capability is necessary for accurate conductor bending stress results. Since the conductor is below the BOP stack, excessive deformation or failure has severe consequences such as loss of the well or loss of well control. DeepRiser is a tool that helps minimize the risk of all parties involved in a well drilling operation. This is accomplished whilst performing complicated and comprehensive riser analysis in a timely and cost efficient manner. Distance along the Casing (ft) Bending 20 sec Bending 40 sec Bending 60 sec Bending 80 sec Bending 100 sec Bending Moment in Casing (kips.ft) Bending moment distribution in conductor/casing at various times during a drift-off analysis. We welcome any suggestions, comments or ideas that you may have for future editions of Intercom. Should you have anything to contribute please let us know. Please DonoghLang@mcs.com or JamesLittleton@mcs.com Alternatively you can phone us at: Galway Aberdeen Houston Galway Technology Park, Exploration House, Park Ten Place, Parkmore, Galway, Bridge of Don, Aberdeen Suite 202, Houston, Ireland AB23 88GX, Scotland Texas 77084, USA T +353 (0) T +44 (0) T F +353 (0) F +44 (0) F E Galway@mcs.com E Aberdeen@mcs.com E Houston@mcs.com 8