Research On The Method To Identify Thin, Poor And Flooded Oil Layers Using The Computer

At present, production of thin layers in many oilfields of China has been accounted for a certain percentage of the total output , and has become the main increasing area of crude oil production capacity in these oilfields. Since Xingshugang area of Daqing oilfield has entered the late period of high water cut stage , in terms of water flooding development strategies and infilling drilling as well as residual oil characterization , like increased complexity in residual oil and gas distribution, shift of development series from thicker pays to thinner pays of inferior quality(i.e. pay zones less than 1.0m in thickness, outside-delimited reservoir included in this paper) result in less evident water-flooding characteristics on logging curve of conventional well logs. Those become"bottle neck"which constraints efficient development of the oilfield. Therefore, evaluation to thin oil layers is the most important thing to geologists and logging analysis experts at home and abroad ; the key to increase interpretation accordant rate of thin ,poor and flooded oil layers is how to cancel the effect which is generated into reservoir lithology, physical properties and pore structure to the response of electric property, and project well logging's characters of water-flooded information.There are two paths to solve straticulate problem. One is to study new detectors and new measuring methods, the other is to improve existing explanation methods and use existing logging datum sufficiently. Aspect of the first kind is the most effective to evaluate thin reservoir exactly by principle, but a large number of human forces ,finance and time is cost and existing datum is not used sufficiently . Mathematics, well logging and geology are applied by logging principle, firstly to increase longitudinal resolution of a single log curve, and secondly to divide and evaluate reservoir by conventional program and accurate reservoir parameters are obtained.Water-flooded mechanics, well logging's characters and integrated interpretation method of thin ,poor and flooded oil layers of Xingshugang district of Daqing oilfield is studied in this paper. Correction to increase longitudinal resolution is made according to principle of various well loggings. Environmental correction is made in spontaneous potential logging using stratigraphic lamination, inverse method is used to increase resolution in gamma logging ,and resolution matching method is applied to resistivity log, etc. Calculation model of reservoir parameters which are porosity, permeability, saturation degree is established , that is based on inclosed core datum and uses BP neutral network and other effective methods. Logging interpretation of thin, poor and flooded oil layers is formed, interpretation accuracy is greatly increased, and it is also applied to medial and thick oil layers.