Page 42 - 6634

LECTURE 4. FIXED OFFSHORE PLATFORM DESIGNING

PROGRAM QUESTIONS:

Field Development and Concept Selection Activities. Basic Design Phase. Detailed Design

Phase. Fixed Offshore Installation
4.1 Field Development and Concept Selection Activities.

* Offshore platform design is preceded by a sequence of activities that

result in the selection of a field development system that best fits the

field characteristics and economics. Before feasible alternatives for

producing oil and gas from an offshore field are identified and the most

desirable production scheme is selected, exploratory work defining the

reservoir characteristics have to be completed. First, a decision has to

be made whether an offshore location has the potential for hydrocarbon

reserves. Geologists and geophysicists do this assessment through a

study of geological formations.

* Next, a decision has to be made whether the field will be economically

viable and if further exploratory activities are warranted. This decision

involves preparing cost, schedule and financial return estimates for selected

exploration and production schemes, comparing several of these alternatives

and identifying the most beneficial. For this phase, due to the absence of

detailed information with respect to the reservoir characteristics, future

market conditions and field development alternatives, we rely on judgements

made by experts based on their past experience and cost and schedule

estimates based on data available to the owner.

* If the preliminary economic studies are positive, the seismic data generation

and evaluation done by geophysicists follow these. This results in reasonable

information with respect to the reservoir characteristics such as its depth,

42