Product information
System requirements
OFFPIPE v2.06 runs on Windows 95/2000/XP based systems. It takes advantage of current technological advances in hardware to provide fast, accurate computations.
Minimum requirements to run v2.06:
- x86 IBM-compatible w/ floating point
- CD / DVD drive
- Windows-based system (All versions incl. 95, 98, NT, 2000, XP)
Demo download
Pipelay analysis
Models pipe laying, davit lift, pipelay initiation and abandonment/recovery operations. It can model both conventional laybarge and stinger based pipe laying methods and "J-lay" configurations.
Models the pipeline in both two and three dimensions (taking advantage of the reduced size of two dimensional problems for faster execution). Three dimensional static analyses may include current profiles, bottom slopes, soil friction and nonzero laybarge headings and offsets from the pipeline right-of-way.
Using its optional dynamic analysis capability, the user can specify the laybarge RAOS and select either a regular wave or wave spectrum. OFFPIPE will then calculate the dynamic response (including the pipe stresses) for the pipeline and stinger.
Provides a menu driven interactive, user interface in which data is entered by filling in the blanks on a series of color screens. These screens are supported by a context sensitive, on-line help system.
Provides an interactive output facility for graphically displaying its calculation results and previewing its printed output and plots on the screen of the IBM-PC. It generates hardware compatible plot files for Hewlett-Packard plotters and laser printers.
Based on a nonlinear, finite element method developed especially for the modeling of offshore pipelines. This method is accurate and converges quickly for all pipe sizes and water depths.
The finite element method considers both geometric (large displacement) and material (nonlinear stress-strain curve) non-linearities.
Provides accurate finite element models for the pipeline, stinger, lay down cable, davits, pipe supports, tensioners, and the seabed.
Provides a detailed model of the laybarge and a simplified structural model of the stinger which includes the effects of the ballast schedule and hinges between stinger sections.
Includes detailed pipe support models, which can include angled horizontal and vertical rollers, overhead restraints and finite length roller beds. Multiple options are provided for defining the elevations of laybarge and stinger pipe supports.
explicit models are provided for dead man, hanging and bowline pipelay initiation techniques.
The seabed is modeled as a continuous elastic-plastic foundation (not a series of point supports). The lateral soil resistance is bilinear, elastic for small horizontal displacements and frictional for large displacements.
Other features include modeling of: pipe bundles, buoys (external flotation), pipe coatings and insulation, pipe fluid contents, nodal fixities, point loads, true catenary davits.
Pipe span analysis
Nonlinear (both geometric and material) modeling of two and three dimensional pipe spans on the ocean floor. Pipe strings may include multiple spans and be many miles or kilometers in length.
Seafloor is modeled as a continuous elastic-plastic foundation using an irregular, two or three dimensional seabed surface profile with any desired roughness. Soil friction coefficients can be specified for lateral and longitudinal pipe displacements.
Seabed profile data may be entered by the user as a series of X-Y-Z coordinates, or taken by computer from digitized survey data.
Environmentalloadings can include steady currents, regular waves and wave spectra, and vortex shedding.
Other loadings can include residual tension, internal fluid contents, internal/external pressure, and thermal expansion due to fluid temperature.
Loadings can be applied and analyses can be performed sequentially. The history of pipe displacements (soil friction) and deformations (plasticity) can be tracked to permit the results of the installation and hydrostatic test to be used as initial conditions in subsequent analyses of service loadings such as cyclic thermal expansion.
In static analyses, OFFPIPE calculates the pipe stresses and deformed geometry at every point along the pipeline and identifies all points at which pipe spans exist. For each pipe span, OFFPIPE also calculates the elevation of the pipeline above the seabed.
In dynamic analyses, OFFPIPE calculates the natural frequencies of pipe spans, and determines the pipe stresses and displacements resulting from wave loadings and vortex shedding. Results can be analyze statistically to estimate pipeline fatigue life.