Abstract: According to the new criterion for Classification of Oil and Gas Resources/Reserves (GB/T19492-2004) issued in 2004, this paper reviews the studied methods at home and abroad for the purpose of establishment of new series of recoverable reserves such as technically recoverable reserves, economic recoverable reserves, sub-economic recoverable reserves and remaining economic recoverable reserves of oil-gas fields. Combined with the oilfield geology and development feature, this paper further researches and proposes the estimation methods for economic recoverable reserves such as economic limit, well pattern density, marginal cost and analogy ones, based on domestic current financial and taxation system and cash flow method followed by making category and analysis according to the basic principles and applied conditions of each method. Finally, this paper develops a model for estimation of the reserves value, which allows the estimations of the economic recoverable reserves and the remaining economic recoverable reserves to be more scientific by elaborating given parameters hypotheses and by converting the estimation of physical quantity into that of combination of both physical quantity and value quantity, thus brings the work in line with the international practice for reserves estimation.

Key words: oilfield, economy, recoverable reserves, value, estimation