SAFI Quality Software Inc. is a software research anddevelopment company, headquartered in Canada andfounded in 1986 by CEO Dr. Rachik Elmaraghy, Eng., Ph.D.The R&D team comprises senior structural engineers andcomputer science specialists.

The company’s R&D efforts are directed primarily towardsthe total integration of its innovative state-of-the-artstructural engineering technology. The structural applica-tions offered cover most of the structural fields in civilengineering and are adapted to various international standards and unit systems. The technology addressesstructural analysis, verification, evaluation, rehabilitation,design, detailing as well as drafting, fabrication and estimation.

The company’s main objective is to ensure that the endusers are productive by providing them with reliable, up todate and simple to use technologies.

The PSE Petroleum Structural Engineering software is theengineering tool for the offshore and onshore industries. Itis also the engineering engine of the VPS Virtual PetroleumStructures new technology for offshore and onshore structures. Through its multiple views, the VPS allows tocarry engineering work, connection and weld design as wellas extraction of detail drawings and fabrication data froma unique database. With the VPS new technology, there isno need to use transfer protocols, nor to repeat model gen-eration in the various phases of a project.

Engineering services and training are offered throughStructureTech Network Inc., SAFI’s sister company.

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Technology for theOffshore-Onshore industry:

Companyhistory

PSE PETROLEUM STRUCTURAL ENGINEERING SOFTWARE:

OFFSHORE & ONSHORE

The PSE Petroleum Structural Engineering software is usedfor the design and rehabilitation of drilling structures forthe offshore and onshore industries, including drillingmasts, derricks and substructures. The software accountsfor wind loads, vessel dynamic motions, wave and currentloads.

Wind loads, based on the velocity component approach,and vessel dynamic motions are defined according to API4F Specification for Drilling and Well Servicing Structures(4th edition).

The inertial forces due to the vessel dynamic motion aswell as radial, tangential and translational forces due tothe acceleration of masses attached to the drilling structures have a significant influence on design and reliability.

Wave loads and current generated forces applied to submerged structural members in platforms and floatinghulls are analyzed through linear and nonlinear kinematicsin accordance with the API RP 2A specifications.

Other loads such as seismic, snow and ice loads for farnorthern extreme weather are also considered for thedesign of masts, derricks, platforms and substructures.

Overview

Offshore and Onshore Customers: A number of prestigious companies are using the SAFI “PSE Petroleum Structural Engineering” Softwarefor their production project work and have built innovative offshore and onshore derricks, masts and sub structures. Among these organiza-tions are Mastco Derrick Services Ltd., Empire International Service Rigs Inc., Lakota Drilling a Savanna Energy Services Company, PrecisionDrilling Corporation, Oil Country Engineering Services Ltd. and other major international companies.

The API 4F specifications for wind loadsbased on the velocity component approachis integrated into the PSE PetroleumStructural Engineering software. Accor-dingly, drilling structures are classifiedbased on their Structural Safety Level (SSL)and their offshore or onshore location.

The API 4F specifications are applicable tothe following wind environments:

• Operational wind• Erection wind• Transportation wind• Unexpected wind• Expected wind

The PSE software allows different configu-rations of the drilling structure modelsaccording to a given wind environment.The program requires the input of the rateddesign wind velocity, Vdes, and accountsfor the design reference wind velocity andwind velocity multiplier. The program com-putes the local wind velocity, Vz, by scalingthe rated design wind velocity by theappropriate elevation factor, ß, in order toobtain the velocity for estimating the windforces:

The design reference wind velocity valuerepresents a 3-second gust wind measuredin knots at an elevation of 10 m (33 ft) inopen water, with an associated return period of 100 years.

A wind profile in a selected direction provides the wind intensity that generatesthe wind loads to structural members andsurface areas. As many as required winddirections can be defined through differentbasic loads.

Member selection procedures allow theapplication of the wind profile to the entirestructure or to specific zones and excludingmembers behind or in front of wind walls.It is possible to apply the API 4F wind loadsdirectly to elements such as equipment,wind walls and other objects attached tothe drilling structures.

The shape factor is automated in the PSEsoftware for various section shapes. Theprogram accounts for the gust factor andthe reduction factor for shielding by members and appurtenances.

Wind Load:

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PSE RIG model - API 4F specifications, 3rd edition PSE RIG model - Limit states design

at multiple angles

PSE RIG model - Deflections atmultiple angles

In various production wells, the offshore drilling structuresare located on top decks of vessels, semisubmersible orfloating hulls. Vessel motion includes roll, pitch and yawrotations and heave, sway and surge translations.

The PSE software computes the inertial forces due to thevessel dynamic motion as well as radial, tangential andtranslational forces due to the acceleration of massesattached to the drilling structures. These forces have a sig-nificant influence on the structural design and reliability ofoffshore structures.

High pressure mud piping, electrical cable trays, junctionboxes, racking boards, tong counterweights, turningsheaves, deadline anchors, crown accessories, casingstabbing baskets and other outfitting items add weight tothe derrick. Weight data is converted to masses applied atthe correct locations on the derrick.

The PSE software accepts three types of user input in orderto estimate the inertial forces induced by the vesseldynamic motions:

• Linear displacements, angular rotations and time periods

• Linear and angular velocities and accelerations• Linear accelerations at two points in the vessel which are converted to linear and angular accelerations by the program

Offshore Vessel Dynamic motions:

PSE RIG model Wave and current load

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PSE RIG model -Vessel dynamicmotion- Roll & Heave

Empire InternationalService RigsSlant Rig

Empire InternationalService RigsVertical Rig

MASTCO Derrickservices Ltd.Vertical Rig

Oil Country EngineeringServices Ltd.Vertical Rig

SAFI, simply reliable since 1986

SAFI Quality Software Inc. • 3393, Chemin Sainte-Foy, Sainte-Foy, Quebec, Canada G1X 1S7Phone: (418) 654-9454 • Canada and USA : 1-800-810-9454 • Fax: (418) 653-9475

Web: www.safi.com • e-mail: info@safi.com

The PSE software computes wave and current forces applied onthe structural members. The wave kinematics can be estab-lished using either Airy’s linear theory or Fenton’s nonlinear the-ory.

The linear kinematic theory is valid where the wave height issmall compared to the water depth. On the other hand, the non-linear kinematic theory, proposed by J.D. Fenton, solves themotion equations by representing the velocity potential andsurface elevation with a Fourier series. The later method mini-mizes the error of each parameter governing the wave motionequations and is valid over the entire spectrum.

The PSE software accounts for the following wave profiles andkinematic parameters:

• Wave period• Incidence angle• Elevation of the sea bed• Elevation of the still water line (SWL)• Kinematic reduction factor• Crest position criterion

Preview of the wave surface profiles, velocities and accelera-tions at any point is readily available.

With the PSE software, the current profile is described withrespect to the sea bed. The current speed is defined by a set ofelevation-velocity-angle triplets and the reduction of the cur-rent speed in the vicinity of the structure or the blockage fac-tor is accounted for.

In order to combine the current with the wave profile, the cur-rent needs to be stretched, or compressed, to the local wavesurface. Two stretching methods are available:

• The linear stretching method, also known as the Wheeler stretching

• The non linear method, or hyperbolic stretching

According to commentary C.3.2.1 of the design code API RP-2A-2003, the Doppler effect is accounted for by calculating anapparent period defined as the wave period as seen by anobserver moving with the current.

Marine growth increases the cross section diameter and surface roughness of the members, and it is defined by a set ofelevation-thickness pairs.

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Wave and Current Loads:

The input for the member wave loads consists of the followingsix parameters:

• Current profile• Wave profile• Marine growth profile• Drag coefficient• Inertia coefficient• Shielding factor

The member forces, calculated using Morison equation, varyaccording to the position of the waves with respect to the structure. In order to obtain the maximum forces in the mem-bers, the critical position of the wave crest is determined by theprogram.

SAFI’s PSE Petroleum Structural Engineering software has been used by several notableinternational companies in production work for building innovative offshore andonshore derricks, masts and substructures. The following is a partial customer list:

• ABS American Bureau of Shipping • Aker Solutions• Do All Industries Ltd• Empire International Service Rigs Inc.• Genesis• Helmerich & Payne, Inc.• HongHua America, LLC• Husky Energy Inc.• HYDUKE Energy Services Inc.• Lakota Drilling, a Savanna Energy Services Company

PSE USER Comments:

• Loadmaster Corporation• Mastco Derrick Services Ltd.• NOV NATIONAL OILWELLVARCO Corporation• Oil Country Engineering Services Ltd.• Parker drilling • Precision Drilling Corporation• Savanna Energy Services Corporation• Tianjin Dongfang Xianke Petroleum Machinery Co., Ltd

• Trinidad Drilling• Waston Hopper