Study On Shaly Sand Three-pore Conductivity Model Log Interpretation Method

Now, due to the prospecting degree is becoming deep and the prospecting area get abroad for advantageous geologic setting area, some special sand reservoir, fracture reservoir, tight hydrocarbon reservoir and low resistivity reservoir are known . Moreover in our country daqing oil field, there are many shale sand reservoirs, especially periphery oil field, its sedimentation condition is complex, reservoir landscape orientation continuity is bad, portrait lie remarkable change. Complicated problems such as low resistivity hydrocarbon formation, high resistivity water-bearing formation, oil and water same formation and water –bearing formation pressed etc, are always puzzle workers of oil field. But the present log interpretation methods are difficult to resolve these problems. To these problems, regard daqing yingtai area as study object, this paper develop some applied researches. The point of these researches is regard three-pore conductivity model as interpretation model, form a set of systemic log interpretation method of shale sand. When we interpret shale sand reservoir, three-pore conductivity model are applied. This model divides reservoir pore into free fluid pore,micro-capillary pore and clay-water pore. Wherefore, first, we confirm bourn of three-pore size. At the same time, we analyzed and study press mercury, nuclear magnetic, X diffraction, granularity, cation change etc core analyzing data given by daqing log company, which we can offer credible core analyzing data to compute reservoir parameters. For clay water pore, because there are more osculation connection between it and clay mineral, it bourn need not to be marked off from pore radius. It is difficult problem for the bourn of free fluid pore and micro-capillary pore. Now there is uniform difference standard. From theory and fact compute consider, and combine capillary theory, Finally, the bourn of micro-capillary pore and free-liquid pore were confirmed 0.2 μm. At one time, using this bourn and core press mercury data, free liquid pore were ensured, which provide credible core data to log interpratation. When we carry through log interpretation, reservoir parameters calculated is mainly task. This paper use core data and log data that given by daqing log company, some parameters such as the total porosity and shale content were calculated. The total porosity that is reflect capability of reservoir is importance parameter. First, core data of the total porosity were studied and analyzed, the daqing log company give the total porosity that helium method measure, the total porosity of saturation weigh method measure and the total porosity that nuclear magnetic experiment calculate were . Three total porosity were contrasted and analyzed, from analyzed result, any of the total porosity that helium method measure, the total porosity of saturation weigh method measure provide credible core analyzed data for this study. And then, on the basis of credible core data, log wells dealing are divided into small formation, then we use density log and neutron log data calculate the total porosity, and combine daqing area oil-bearing layers character, matrix parameters is different for different oil-bearing layers, thereby the total porosity of every oil-bearing layers absoluteness error lie 1%~2%, relatively error lie 10%~15%, this error reach need of study. At the same time, we also use artificial neural net to calculate the total porosity, the error of this method calculate the total porosity have relevant advance. The shale content is also importance geologic parameter that we will calculate. Aim at daqing section geologic character, we respectively use gamma ray log, meet of compensation density and compensation neutron, resistivity log and spontaneous potential log to calculate shale content , and analyse this four shale content, precision of shale content that gamma ray log calculate is best. After we have appropriately method, log wells dealt were divided into small formations, then to each oil-bearing reservoirs we use shale content of core to get pure sand value, by these disposal, shale content calculated reached precision needed. At the same time, we also use artificial neural net to calculate shale content, then this calculating shale content method is important supplement. Because there are well relation of clay content, granularity median and shale content, clay content and granularity median are calculated by shale content and reach better effect. Then clay-water porosity of three-pore...