Undeveloped Reserves Potential Research On Z Reservoir Of Block N Of Tamtsag Oilfield In Mongolia

Z reservoir of Block N of Tamtsag oilfield in Mongolia is characterized by complicated faults,small and scattered fault blocks,difficult to identify of oil and water formations,which had not recount undeveloped reserves and producing reserves when it was put into exploitation.In the current situation of lower oil prices,economic evaluation research need to strengthen in Z reservoir of block N to classify and optimize undeveloped reserves.In this paper,the oil-water layer interpretation distinction charts based on different lithology and blocks were drawn in order to accurately identify oil layers and transitional oil-water layers.After studied on the law of the oil-water distribution,we point out that the oil layer is generally above the water layer,each block formed independent oil-water system and oil-water contact was different from other blocks.The reservoir types in the study area are mainly structural-lithologic reservoirs.With the application of the Volume Method,undeveloped reserves and producing reserves of 13 blocks are calculated.Weighting method was used for classification and evaluation of reservoir.The economic evaluation of undeveloped reserves is carried out by the method of Break-Even analysis which could provide the most optimal undeveloped reserves to tentatively develop,achieved good effect.