Page 18 - Hydrocarbon Exploration and Production Second Edition

The Field Life Cycle 5

and shareholders confidence that all aspects of the project have been identified,
considered and discussed between the relevant parties. In particular, it should include

objectives of the development
petroleum engineering data
operating and maintenance principles
description of engineering facilities
cost and manpower estimates
project planning
summary of project economics
budget proposal.

Once the FDP is approved, there follows a sequence of activities prior to the
first production from the field

FDP
Detailed design of the facilities
Procurement of the materials of construction
Fabrication of the facilities
Installation of the facilities
Commissioning of all plant and equipment.

1.5. Production Phase

The production phase commences with the first commercial quantities of
hydrocarbons (first oil) flowing through the wellhead. This marks the turning point
from a cash flow point of view, since from now on cash is generated and can be used
to pay back the prior investments, or may be made available for new projects.
Minimising the time between the start of an exploration campaign and ‘first oil’ is
one of the most important goals in any new venture.
Development planning and production are usually based on the expected
production profile which depends strongly on the mechanism providing the driving
force in the reservoir. The production profile will determine the facilities required
and the number and phasing of wells to be drilled. The production profile shown in
Figure 1.1 is characterised by three phases

1. Build-up period During this period newly drilled producers are progressively
brought on stream.
2. Plateau period Initially new wells may still be brought on stream but the older
wells start to decline. Production facilities are running at full
capacity, and a constant production rate is maintained. This period
is typically 2–5 years for an oil field, but longer for a gas field.
3. Decline period During this final (and usually longest) period, all producers will
exhibit declining production.