Improving evaluation of predicted hydrocarbon reserve zones

Predicted hydrocarbon reserves were studied, and four evaluation methods for improving reserve estimates were proposed, including possibility evaluation, upgrading rate evaluation, economic evaluation and comprehensive evaluation. A difficulty index was used to evaluate the possibility of reserve upgrading. Reserve upgrading probability calculation and test were used to evaluate the upgrading rate. A discounted cash flow method was applied in the economic evaluation. The difficulty index, probability calculation and economic methods were jointly used in the comprehensive evaluation. The predicted hydrocarbon reserve blocks were classified into four types according to the comprehensive evaluation, including the blocks with large or medium potential for upgrading, the blocks with medium or small potential for upgrading, the blocks remaining for evaluation, and the blocks not to upgrade at present.