Real-time estimation of oil quantity in crude oil tanks

A new computational method is proposed to estimate oil quantity in a crude-oil tank that is in constant use. The method is based on calculation of the water/oil ratio in the tank. A mathematical model is established that describes how the oil quantity changes dynamically in the tank. The proposed method in particular considers the possible environment in an oil production field. Uncertainties in the calculation of water content and the measuring of the pure oil quantity are discussed. The main factors leading to inaccuracy in oil quantity estimation are analysed, and compensation schemes are proposed. Application results in oil fields demonstrate the accuracy and practical applicability of the method for oil station networks. The method can well be adopted in automatic inventory systems in oil production fields.