Gerenciamento de reservas petrolíferas: uma análise dos fatores que influenciam o indicador R/P

Abstract

The management of oil reserves use indicators, such as ratio R / P, which indicates how many years the reservoir can produce if no reserve is discovered with constant production. This ratio being low means that the reserves will be consumed in a short time and being high, will be consumed over many years. Usually the latter case occurs in newly discovered fields or when strategically this field is not producing. As Hayhow and Lemee (2000), before 1985 the natural gas industry in Canada has been asked to maintain high levels of reserves for export maintaining the R / P ratio of 20 years. Following deregulation in 1985, the gas production doubled without many discoveries, being R / P relationship around 10 years in 1999 and remained at this level over many years. This maintenance of the relationship R / P is an indication that there are strong economic relations that maximize the net present value, encouraging the industry to develop reserves to maintain this relationship. A question that should always be asked is whether this indication can be proved. Is there a R / P optimized that maximize the net present value (NPV)? What are the factors that influence and how to modify them? In this context, this paper will examine the factors that influence the Reserve to production optimized ratio (R / P), where the Net Present Value (NPV) is maximum, having always as a starting point the collection of petroleum pricing information, variable costs, discount rates, investment per well and flow rate per well and some assumptions, such as exponential decline, fixed costs that were not analyzed and drilling new wells does not include new oil, to thereby perform the analyzes and identify factors that influence this relationship and thus determine the value of R / P optimized. As a result, it was demonstrated that the R / P optimized varies with the oil price and productivity barrels per day from the well, not being influenced by discount rate, ie, the R / P optimized changes when productivity q, costs / price change. Once found the value of R / P optimized and having in hands the current R / P, it is possible to focus the actions in order to achieve the R / P that will bring the greatest NPV.