Getting things right the first time is key in today’s hectic business environment. Designing and building offshore drilling or production units is no exception. The earlier errors are identified, the lower is the cost of fixing them. This is precisely the thinking behind DNV’s pre-contract services. We offer valuable insights into key challenges and significantly reduce the downside risk in projects.

Purpose

Highlighting potential areas of concerns at an early stage in the project.

Benefits

Early detection of critical aspects or errors is key to getting the project completed on time and within budget. The earlier errors are identified, the lower the cost of change.

DNV will help you get things right the first time, through a portfolio of pre-contract services tailor-made for the different early phases and decision gates of offshore drilling or production units.

Our approach

Design brief review
The design brief is vital to the development of new projects. Based on extensive experience from other projects, DNV can help ensure that the project is developed correctly and consistently, and that it complies with all relevant rules and standards. In our pre-contract service, the design brief will be reviewed for consistency and compliance with applicable class notations and relevant project-specific requirements.

Based on the general arrangement drawings and simplified structural strength calculations, we evaluate the design with respect to overall structural strength. An approval in principle is normally carried out at an early stage in the project development. The quality of the review depends on the amount of design documentation available from the designer. Actual scantlings should, to a great degree, be used as basis for the evaluation. Typical studies will vary for different objects.

Concept evaluation
The main scantling drawings are reviewed with respect to nominal plate thickness, stiffener and girder dimensions, and the grade of material. Local scantlings of buckling stiffeners, brackets, lugs and welds are normally not considered. Verification is based on the design documentation submitted to DNV as part of the design documentation package. Independent analyses are not part of the concept evaluation. The level of analysis is normally similar to the design analysis carried out for a main scantling approval.

Main scantling approval
The main scantling drawings are approved with respect to nominal plate thickness, stiffener and girder dimensions, and grade of material in a main scantling approval. Local scantlings of buckling stiffeners, brackets, lugs and welds are normally not considered. Independent analyses of global and local strength are carried out to verify the design calculations submitted to DNV as part of the design documentation package. These analyses are normally made with a level of detailing sufficient for full classification at a later stage. However, local FE models of hot-spots may have to be added in the detail design. Drawings approved with respect to main scantlings are normally considered sufficient for ordering material, provided comments given to the main scantling approval are sufficiently accounted for in the design.