case study: structural design and finite element analysis lifting...

Case Study | Enginuity Inc.

Case Study:

Structural Design and Finite Element Analysis Lifting and Code Compliance for the O�shore Oil and Gas Industry

Enginuity Inc.219 Herring Cove Rd,Halifax, NS, B3P 1L3

For more information visit:www.enginuityinc.ca

Clients Needs

• Regulatory approval from class agencies and the Newfoundland and Labrador O�shore Petroleum Board • Structural Analysis and design optimization • Lifting Design and Plans

Services Received

Structural Analysis • Stress analysis • Finite Element Analysis • Load and resistance factor design and analysis • Design recommendations necessary to meet code requirements

Lifting Design and Plans • Code adherence • Multiple payload configurations with single frame • Design for obstructions on lifting paths • Two tiered lifts and multi-legged bridle lifts due to complicated shape and weight distribution

www.enginuityinc.ca +1902 431 7931 © Copyright 2014: Enginuity Inc.

About the ClientAlscott Air Systems specialize in the design, supply, installation and commissioning of Heating, Ventilation & Air Conditioning systems (HVAC) for ships and offshore Oil & Gas facilities. In mid 2013 Alscott was contracted to supply a modular HVAC system for use on the high profile Hebron offshore project, off the coast of Newfoundland.

NeedsIn order for Alscott to enhance their competitive edge and complete their contract in the Hebron project, they needed to review existing designs against requirements prescribed by the Newfoundland and Labrador Offshore Petroleum Board (NLOPB).

Alscott contracted Enginuity to perform structural analyses on existing and new, custom HVAC module designs. In addition, Alscott tasked Enginuity to design engineered lifting sets and lifting plans for the HVAC modules. Alscott wanted to ensure that the handling, transit and installation of the HVAC unit would go as smoothly as possible. For the lifting designs, there needed to be multiple payload configurations done with a single frame. The lifting designs also had to accommodate obstructions in the lifting path.

ResultsEnginuity identified the relevant codes required for operation. Working closely with Alscott’s internal engineering and experienced fabrication teams, Enginuity analyzed and optimized existing designs and developed new custom structural designs to meet the requirements. Similarly, custom lifting beams and lifting sets were developed to handle the fully assembled skids.

Following the build at Alscott, assemblies were subject to functional loading and test-lifting, allowing Alscott to obtain regulatory approvals, allowing offshore installation of the units to proceed.

“Working with Enginuity was a highly positive experience. Alscott needed assistance in making sure these units complied with the especially rigorous demands of the installation, Enginuity’s mix of mechanical engineering and analysis along with their pragmatic approach to problem solving make them an invaluable part of our team.”

Keith Carlaw, Vice President of Alscott Air Systems


Overview of ServicesFinite Element Analysis of Alscott’s HVAC Module

Newfoundland and Labrador Offshore Petroleum Board (NLOPB)

The offshore Oil & Gas industry in Newfoundland is subject to strict, sector specific, regulatory requirements, all geared to ensuring a safe and reliable working environment.

The sector is overseen by the Newfoundland and Labrador O�shore Petroleum Board (NLOPB) and all systems destined for the sector are governed by applicable NLOPB and Classification Society rules and codes.

Relevant Codes: HVAC modules

• CAN/CSA S16-09 and Specifications for upstream skid mounted assemblies – general requirements • CAHE-WP-MSPDS-20-000-120105 RevD1 Skid mounted assemblies on upstream Oil & Gas facilities • CAHE-WP-HSzz-10-430-0010 Rev D0 Equipment for HVAC air handling units


Overview of Services

Compound lifting beams design Lifting plans

Finite Element Analysis of structural HVAC modules Design recommendations Base skid design optimization and recommendations

Lifting lug design Lifting lug analysis

Finite Element Analysis of Alscott’s HVAC modulesEnginuity performed many finite element analyses, on the HVAC modules. These analyses considered Load and Resistance Factor Design (LRFD) indicated by the relevant building codes, o�shore regulations and class standards.

Enginuity determined the suitability of structural members to resist loads during lifting, transportation and operation; and also various environmental loads, such as wind, ice and seismic loading. Maximum factored member loads (axial force, shear loads and bending moments) were determined and compared with factored resistances both individually and through combined loading. This data was used to optimize designs to make best use of space and materials available.

Finite Element Analysis of an HVAC structure and lifting skid

Lifting Beams Design & Lift PlanLifting beams were designed to meet the requirements of the o�shore lifting and installation of the units. Compound and single lifting beams were included to accommodate di�cult lift conditions and obstructions in the lifting paths.

The design requirement included specification of readily available and custom lifting slings, shackles and associated components. Enginuity delivered detail rigging and lifting plans with associated beam fabrication and test data combined in a single full-service package.


Relevant Codes: Lifting beams

• DnV 2.7-1 Certification Offshore Containers • LR Code for lifting appliances in a marine environment - 2009 • SOR/95-104 Newfoundland Offshore Petroleum Installation Regulations • CAHE-WP-MSPDS-20-000-1201505 _D1 Specification for upstream skid mounted assemblies- general requirements


Lifting Beams Design & Lift Plan

Finite Element Analysis of an HVAC lifting beam design

Lifting an HVAC module

Equipment

obstructing

lift path


Relevant Codes: Lifting Lug

• SOR/95-104 Newfoundland offshore petroleum installation regulations• CAHE-WP-MSPDS-20-000-1201505 _D1 Specification for upstream skid mounted assemblies- general requirements• CAN/CSA S16-09 Limit states design of steel structures


Lifting Lug Design and Analysis

Lifting lug design

Lifting Lug DesignAn typical Alscott Lifting Lug was analyzed based on a ‘Standard use’ scenario, using a finite element brick model and on-lead and off-lead loadings. Skid loading interactions, required mounting hardware and test scenarios were also identified.

Custom lifting lugs and custom loading scenarios were accommodated in several skid designs, along with related supporting analyses and calculation documents.

Lifting lug �nite element analysis

Lifting lug

Rendering of the Hebron Project

case study: structural design and finite element analysis lifting...

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