Changes

|+ {{table number|1}}Summary of methods used to derive hydrocarbon reserves

|+ {{table number|1}}Summary of methods used to derive hydrocarbon reserves

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! Method

! Method || Application || Accuracy

! Application

! Accuracy

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| Volumetric

| Volumetric || OOIP, OGIP, recoverable reserves. Use early in life of field. || Dependent on quality of reservoir description. Reserves estimates often high because this method does not consider problems of reservoir heterogeneity.

| OOIP, OGIP, recoverable reserves. Use early in life of field.

| Dependent on quality of reservoir description. Reserves estimates often high because this method does not consider problems of reservoir heterogeneity.

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| Material balance

| Material balance || OOIP, OGIP (assumes adequate production history available), recoverable reserves (assumes OOIP and OGIP known). Use in a mature field with abundant geological, petrophysical, and engineering data. || Highly dependent on quality of reservoir description and amount of production data available. Reserve estimates variable.

| OOIP, OGIP (assumes adequate production history available), recoverable reserves (assumes OOIP and OGIP known). Use in a mature field with abundant geological, petrophysical, and engineering data.

| Highly dependent on quality of reservoir description and amount of production data available. Reserve estimates variable.

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| Production history

| Production history || Recoverable reserves. Use after a moderate amount of production data is available. || Dependent on amount of production history available. Reserve estimates tend to be realistic.

| Recoverable reserves. Use after a moderate amount of production data is available.

| Dependent on amount of production history available. Reserve estimates tend to be realistic.

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| Analogy

| Analogy || OOIP, OGIP, recoverable reserves. Use early in exploration and initial field development. || Highly dependent on similarity of reservoir characteristics. Reserve estimates are often very general.

| OOIP, OGIP, recoverable reserves. Use early in exploration and initial field development.

| Highly dependent on similarity of reservoir characteristics. Reserve estimates are often very general.

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