<b>Reserve Estimation of Initial Oil and Gas by using Volumetric Method in Mann Oil Field</b> This research paper is focused to estimate the current production rate of the wells and to predict field remaining reserves. The remaining reserve depends on the production points that selected to represent the real well behavior, the way of dealing with the production data, and the human errors that might happen during the life of the field. Reserves estimating methods are usually categorized into three families analogy, volumetric, and performance techniques. Reserve Estimators should utilize the particular methods, and the number of methods, which in their professional judgment are most appropriate given i the geographic location, formation characteristics and nature of the property or group of properties with respect to which reserves are being estimated ii the amount and quality of available data and iii the significance of such property or group of properties in relation to the oil and gas properties with respect to which reserves are being estimated. In this research paper, the calculation of collecting data and sample by volumetric method are suggested to estimate the oil and gas production rate with time by using the geological configuration and the historical production data from CD 3700 3800 sand in Mann Oil Field. production, remaining reserve, volumetric, data collecting, estimation 2291-2295 Issue-5 Volume-3 San Win