PETROBRAS has installed 12 Floating Production Systems in Campos Basin and presently there are gas compressors installed in seven of these systems.
Gas operations are discussed, emphasizing the found difficulties and the solutions adopted in the gas compression operations originated from the floating drill rigs.
The control and supervisory systems of the centrifugal and reciprocating compressors are explained.
The various kind of shutdowns in the criteria determining such action are also described, as is the introduction of modifications or procedures to minimize dowtime. In reference to the gas transport system adopted, the modifications introduced as a result of experience are explained.
Safety factors are also focalized.
In the present paper, we wish to demonstrate the experience acquired in the operation of production and utilization of natural gas using floating production systems during the last ten years in the Campos Basin, as well as the advances made in gas production methods.
Oil is the basic aim OF PETROBRAS prospecting efforts, and the discoveries of gas reserves derive mainly from those activities.
The evolution of natural gas production in the Campos Basin has grown steadily since the oil discoveries, and it can be maintained at this level for at least the next ten years, according to current forecasts.
The first production of gas Campos Basin was in the Enchova production system in 1977.
The gas was flared and the oil was transferred to a tanker moored in a four-point system using a float hose arrangement. However, with the construction of two 12" gas pipelines from the Central Platform of Garoupa and Enchova to the coast (383 Km) was initiated the utilization of associated gas.
These are installations which permit the entrance in operation of wells or areas, in a short space of time, attain certain objectives which do not justify (Techinically or economically) the use of fixed or permanent installations.
The basic characteristics of the floating production systems employed by PETROBRAS which gave the most positive results are, without doubt, flexibility and operational mobility.
The systems are conceived simply permiting the total or partial integration of one or more system expansion or reduction of size without great risk and, most important, the reduction of operational costs.
The main reason for the success of the PETROBRAS floating production systems is the simplicity of the concept.
The principal objectives of the floating production systems are:
- –
Anticipated production of oil and gas;
- –
Acquisition of a good knowledge of the field and reservoir characteristics before design permanent facilities;
- –
Data collection for definition of processing installations;
- –
Drainage of part fields not reached by wells from a fixed platform;
- –
Provide the earliest possible return of exploration investments;
- –
Increase oil and gas production by developing marginal fields, otherwise uneconomical with a conventional fixed platform type developed, particularly in deep waters.
