Field development planning

Based on the results of the feasibility study, and assuming that at least one option is economically viable, a field development plan can now be formulated and subsequently executed. The plan is a key document used for achieving proper communication, discussion and agreement on the activities required for the development of a new field, or extension to an existing development. 

The field development plan s prime purpose is to serve as a conceptual project specification for subsurface and surface facilities, and the operational and maintenance philosophy required to support a proposal for the required investments. It should give management and shareholders confidence that all aspects of the project have been... 

Once the field development plan (FDP) is approved, there follows a seguence of activities prior to the first production from the field ... 

To a large extent the reservoir geology controls the producibility of a formation, i.e. to what degree transmissibility to fluid flow and pressure communication exists. Knowledge of the reservoir geological processes has to be based on extrapolation of the very limited data available to the geologist, yet the geological model s the base on which the field development plan will be built. 

The non-hydrocarbon components of crude oil may be small in volume percent, typically less than 1 %, but their influence on the product quality and the processing requirements can be considerable. It is therefore important to identify the presence of these components as early as possible, and certainly before the field development planning stage, to enable the appropriate choice of processing facilities and materials of construction to be made. 

Figure 5.21 helps to explain how the phase diagrams of the main types of reservoir fluid are used to predict fluid behaviour during production and how this influences field development planning. It should be noted that there are no values on the axes, since in fact the scales will vary for each fluid type. Figure 5.21 shows the relative positions of the phase envelopes for each fluid type. 

Introduction and Commercial Application The reservoir and well behaviour under dynamic conditions are key parameters in determining what fraction of the hydrocarbons initially in place will be produced to surface over the lifetime of the field, at what rates they will be produced, and which unwanted fluids such as water are also produced. This behaviour will therefore dictate the revenue stream which the development will generate through sales of the hydrocarbons. The reservoir and well performance are linked to the surface development plan, and cannot be considered in isolation different subsurface development plans will demand different surface facilities. The prediction of reservoir and well behaviour are therefore crucial components of field development planning, as well as playing a major role in reservoir management during production. 

The amount of detail input, and the type of simulation model depend upon the issues to be investigated, and the amount of data available. At the exploration and appraisal stage it would be unusual to create a simulation model, since the lack of data make simpler methods cheaper and as reliable. Simulation models are typically constructed at the field development planning stage of a field life, and are continually updated and increased in detail as more information becomes available. 

At the field development planning stage, reservoir simulation may be used to look at questions such as ... 

The production profile for oil or gas is the only source ofrevenueior most projects, and making a production forecast is of key importance for the economic analysis of a proposal (e.g. field development plan, incremental project). Typical shapes of production profile for the main drive mechanisms were discussed in Section 8.2, but this section will provide some guidelines on how to derive the rate of build-up, the magnitude and duration of the plateau, the rate of decline, and the abandonment rate. 

At the stage of field development planning, reservoir simulation would normally be used to generate production profiles and well requirements for a number of subsurface development options, for each of which different surface development options would be evaluated and costs estimated. 

When an oil or gas field has just been discovered, the quality of the information available about the well stream may be sparse, and the amount of detail put into the process design should reflect this. However, early models of the process along with broad cost estimates are needed to progress, and both design detail and cost ranges narrow as projects develop through the feasibility study and field development planning phases (see Section 12.0 for a description of project phases). 

The operations group will develop general operating and maintenance objectives for the facilities which will address product quality, costs, safety and environmental issues. At a more detailed level, the mode of operations and maintenance tor a particular project will be specified in the field development plan. Both specifications will be discussed in this section, which will focus on the input of the production operations and maintenance departments to a field development plan. The management of the field during the producing period is discussed in Section 14.0. 

When preparing a Field Development Plan (FDP), the production operations department will become involved in setting out the way in which the field will be operated, with specific reference to areas such as those shown in the following table ... 

Utilities systems support production operations, and should also be addressed when putting together a field development plan. Some examples of these are ... 

If the original field development plan was not based on a 3-D seismic survey (which would be a commonly used tool for new fields nowadays), then it would now be normal practice to shoot a 3-D survey for development purposes. The survey would help to provide definition of the reservoir structure and continuity (faulting and the extension of reservoir sands), which is used to better locate the development wells. In some cases time-lapse 3-D seismic 4D surveys carried out a number of years apart, see Section 2) is used to track the displacement of fluids in the reservoir. 

The initial field development plan called for reservoir natural depletion with provisions for future installation of water injection and gas lift facilities to enhance recovery. Fig. 2 shows a block flow diagram depicting the deck-mounted faciliues/utilities that have been designed and engineered lor the lazerka FPSU. 

The field development plans are based on the supply of 6 Mt/annum of LNG of Jopan whilst ot the some time providing the mojor source of industrial ond domestic gas to Western Australia over a 20-yeor period. 

Spears, R.W., Saha, S., 2005. Improved fluid typing with NMR better field development planning in deepwater Nigeria. In SPWLA 46th Annual Logging Symposium, June 26-29. Paper LEE. 

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