Study On Computational Method Of The Water Flooded Layer Aqueous Saturation In High Water Cut Stage

The process of waterflooding in oil fields becomes very complicated as a result of the anisotropy and heterogeneity of the reservoir in horizontal and vertical. With the oil layer into high waterflooding stage, its physical property, lithology and oil saturation have emerged a series of change, the well logging response becomes various, it makes log interpretation more difficult. In order to solve this problem, the study of new log interpretation technique is great important in view of our logging technology and feature of land facies reservoir, besides developing well logging methods.In view of this condition, this dissertation focuses on log interpretation methods in high water cut stage, aiming at the remaining oil distribution and reservoir evaluation, based on the effects on water flooded layer caused by sedimentary microfacies, structure and production manner, the characteristic of reservoir litofacies, porosity, permeability, rock wettability and salinity have been analysed, and the physical property variation rules of water flooded layer and well logging responses are concluded. With the mathematical and theoretical analysis of the "U" curve, the new interpretation model of water flooded layer based on the Archie equation is established and discussed on different condition. Use SP log in determination of flooding and how to compute resistivity of formation water in flooded zone are also described. The project is guided by the petrophysical experiment of waterflooding at the reservoir conditions, a set of well logging interpretation models of subdivision reservoir parameters at geologic condition restriction is set up. On the basis of petrophysical phase research, a set of method of conventional well logging interpretation of thin-poor water-out zones has been also set up by using of"Performance resistivity drop method". It creates a suit of log evaluaterating model which is in view of sedimentation feature in different area and different reservoir. It raises the log interpretation accuracy of water flooded zone and have great applied value.