## Abstract

An accurate estimation of oil and gas reserves is a key to the success of every field development, and this continues throughout the life of the field. There are several methods available for hydrocarbon reserves estimation and these are analogy, volumetric, decline analysis, material balance and reservoir simulation. The accuracy of any of these techniques depend solely on the type, quantity and quality of the geologic, geophysical, engineering, and economic data available plus the assumptions adopted for technical and commercial analysis. Also, the success of the reserve evaluation rely on the integrity, skill and judgment of the experienced professional evaluators. Thus, this chapter is basically dedicated for volumetric method of hydrocarbon reserve estimation which requires a limited amount of data. This chapter gives an understanding of the input parameters required and the factors affecting the volumetric reserves estimation. The step by step approach on how to calculate hydrocarbon reserves, bulk volume from Isopach map, condensate reserve calculations, an understanding of the deterministic and probabilities methods of reserves estimation are presented here with example cases.

## Keyword

Volumetric method Reserves Condensate reserve Contouring Probabilistic Deterministic Isopach map Hydrocarbon reserves Field development Bulk volume STOIIP## References

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