What is the difference between proven and probable reserves?

Proven reserves sit at the top of the scale, at a 90-percent or above likelihood of commercial extraction. Probable reserves are those with the likelihood of recovery for between possible and proved reserves, or over 50-percent but under 90-percent.

How are gas reserves estimated?

The most accurate method of estimating gas reserves in tight gas reservoirs is to use a reservoir model, such as a semianalytical model or a numerical-reservoir model, to history match production data from the well.

What are probable reserves?

Probable Reserves — Probable reserves are those additional reserves which analysis of geoscience and engineering data indicate are less likely to be recovered than proved reserves but more certain to be recovered than possible reserves.

What is 1P 2P 3P reserves?

“1P reserves” = proven reserves (both proved developed reserves + proved undeveloped reserves). “2P reserves” = 1P (proven reserves) + probable reserves, hence “proved AND probable.” “3P reserves” = the sum of 2P (proven reserves + probable reserves) + possible reserves, all 3Ps “proven AND probable AND possible.”

What is a proved reserve How does it differ from a proved undeveloped reserve?

Proved reserves consist of natural gas that scientists know to exist and can be economically recovered with the current technology. This natural gas is like the visible, known ice in the iceberg metaphor. Unproved reserves are like the vast amount of ice that may or may not lie under the proved reserves.

What are the methods using to determine oil reserve?

As production and pressure data from a field become available, decline analysis and material balance calculations, become the predominant methods of calculating reserves. These methods greatly reduce the uncertainty in reserves estimates; however, during early depletion, caution should be exercised in using them.

Why do Reserves have to be estimated?

Dependent on quality of reservoir description. Reserves estimates often high because this method does not consider problems of reservoir heterogeneity. Highly dependent on quality of reservoir description and amount of production data available.

What does 2C gas reserves mean?

contingent resources
2C reserves Defined by the internationally-recognised Petroleum Resources Management System as the best estimate of contingent resources. those quantities of petroleum which are estimated, on a given date, to be potentially recoverable from undiscovered accumulations.

What are gas reserves?

Natural gas reserves refer to large deposits of natural gas which, based on geological surveys and engineering studies, are thought to exist to a very high degree of certainty. Natural gas reserves are spread worldwide, however, some countries have more natural gas than others.

What is meant by proved developed reserves?

Proved Developed Reserves are those Proved Reserves that can be expected to be recovered through existing wells and facilities and by existing operating methods.

What are probable reserves in oil and gas?

Companies that report probable reserves use 2P valuation that includes possible and probable reserves. Probable reserves make up a portion of the oil present in an area surveyed by an oil and gas exploration firm.

How do you calculate recoverable oil reserves?

The basic equation used to calculate recoverable oil reserves is. where RF = recovery factor, which equals RF P + RF S. The primary recovery factor, RF P, is estimated from the type of drive mechanism (Table 2).

What is the proved area of a reservoir?

The area of the reservoir considered as proved includes (1) the area delineated by drilling and defined by fluid contacts, if any, and (2) the undrilled portions of the reservoir that can reasonably be judged as commercially productive on the basis of available geological and engineering data.

What are proved proved reserves?

Proved Reserves Proved reserves are those quantities of petroleum which, by analysis of geological and engineering data, can be estimated with reasonable certainty to be commercially recoverable, from a given date forward, from known reservoirs and under current economic conditions, operating methods, and government regulations.