Crude Oil Reserves

Crude oil is considered as the backbone of the global economy as major revenue is earned by most of the crude oil producing countries through crude oil exports. Crude oil plays a major role in meeting the demands of the transportation and other industrial sectors. With the increasing demand for crude oil, the need for exploring more oil deposits has popped up. Crude oil reserves may be defined as the amount of oil that is expected to be extracted in future with the application of techniques under present economic conditions such as market prices and costs of operation.

Although numerous world crude oil statistics are available, it is pretty hard to provide an accurate prediction with regards to the quantity of crude oil available in the unexplored and unknown areas. Future implementation of geo technologies will help us in exploring the crude oil deposits to some extent. Indirect techniques are implemented for estimating the oil deposits and recoverability factor of the crude oil reserves. Initial estimates of the new oil fields are usually low. As the oil fields develop in time, there is a significant growth in the estimated ultimate recovery.

'Oil in place' is referred to both producible and non-producible oil accounting for the total estimate of oil deposits in a reservoir. Due to limitations in crude oil extraction technologies only a portion of the crude oil is extracted and this producible oil is termed as crude oil reserves. This proportion of producible oil reserves to oil in place is called as recovery factor. As years pass by, due to change in technology and economic conditions the recovery factor may vary among the oil fields. If more investment is made in enhancing the amount of crude oil that can be extracted from a particular field using techniques like water flooding and gas injection, the recovery factor may also rise.

Crude oil reserves meet the criteria if they are commercially recoverable through latest technology, discovered in oil wells and if they remain in the ground. Crude oil reserves may be classified into two major categories, which are proved and unproved reserves. Unproved reserves can be further classified into sub categories such as probable and possible oil reserves. Proven reserves are those which are recoverable under prevailing political and economic conditions using current technology. These reserves have a ninety percent certainty for being qualified as producible reserves. Industry experts have termed this as P90 or it is otherwise known as 1P.

Proved Developed (PD) and Proved Undeveloped (PUD) reserves are sub divisions of proved reserves. With a requirement of minimum extra investment PD reserves are producible using existing oil wells. In case of Proved Undeveloped or PUD reserves huge investment is required for drilling new oil wells so that crude oil can be brought to the surface of the earth. Probable reserves, a sub division of unproved reserves has just fifty percent certainty of being produced and this is usually referred to as P50 or 2P. When compared to this, possible reserves claim just ten percent certainty of being recovered from the ground. The industrial specialists usually refer to this as P10 or 3P. Various factors such as reserve infill, geology and commercial rates have an influence on the crude oil reserves.