Use Of A Spar Buoy Designed For Interim Production Processing
Authors: Lowd Judson D. , Hill E.C. , Matzer Rudolph F. 
Published: October 2008

Initial cash flow pattern from certain marine fields can be improved if interim production facilities, storage and a sales outlet can be devised within a minimum time after completion of the first few wells in the field development phase. Such interim production also provides the possibility of obtaining maximum reservoir performance data at an earlier date than would otherwise be possible while the development drilling program is continuing. Thus, the basis for design and installation of permanent facilities can be strengthened and expedited. Such interim production will not increase overall profit nor return on total investment. But neither does it deduct from profit and thus the better cash flow and availability of more timely design data may be essentially "cost free."

This paper discussed the design and model basin test results with respect to a floating and portable production processing facility which will make such opportunities possible. The semi-submersed production unit is a spar buoy combining the stability, portability and minimum size of a vertical cylindrical vessel with the utility of a complete production processing unit mounted therein. The unit design provides for transport to location on the deck of presently available vessels and for launching procedures on the final location position without derrick barge assistance.

THE OPPORTUNITY

Reliable information concerning well and reservoir performance is, of course, needed in the development of any new oil field. Unfortunately the time relationship of the "need" and the "availability" is frequently poor. This is especially true in marine-oriented fields at overseas locations. The "need" is NOW, before final decisions on size, type, and location of production and sales facility are made. Yet the availability of data may be skimpy and scattered until long after final irrevocable decisions have been made.

However, there exists a well known period in which timely data might be generated. This is near the end of the exploratory phase and well into the period of development phase but long before the beginnings of the actual producing stage.

Specifically, the last of the exploratory and delineation wells might be put on production, along with the initial development wells, months before or possibly years before the total well pattern and the associated producing facilities are available. Were these early life wells produced as soon as available, there would then be months of highly reliable well performance data available for use in final production planning and design. Furthermore, a significant contribution to cash flow ight be made in the front-end period otherwise devoid of revenue.

Figure 1 shows a typical situation where eight wells, each drilled in the exploratory or "early development" phase, might be produced for data gathering and revenue generation more than a year before the formalized production phase facilities were available.

Well recognized as are these facts, the opportunity to exploit such interim-producing is usually thwarted by the immediately poor economics and operational.