VOLCANIC ROCKS WEATHERING CRUST RESERVOIR RESERVOIR MODEL OF UPPER CARBONIFEROUS IN SANTANGHU BASIN

Weathering crust reservoir of Carboniferous volcanic rock was the oil and gas exploration significant target recently years in the Santanghu basin of Tuha oil field.According to Drilling,Logging and the analysis chemical examination material revelation,volcanic rock crust of Weathering section plane as well as its petrology,the natural characteristic,thought this crust of weathering in vertical may divide it into weathered clay layer(sedimentary cover) and Dense volcanic cover,highly weathered detritus,(the upper belt of Weathering crust),weakly weathered block layer(the bottom belt of Weathering crust) and non -weathering rock(dense volcanic belt).Effective reservoir space growth in highly weathered detritus and weakly weathered block layer.According to the pore of volcanic rock reservoir and the relations of the hydrocarbon source rock of volcanic rock,divided the area weathering crust reservoir into two class:One is on the C2h for internal carbonaceous mudstone,shale as source rocks,volcanic rocks of the upper part of C2k weathering crust to freshwater corrosion slit pore with the hole as a reservoir,the upper for the cover of the clastic rocks;constitute a good reservoir - seal combination;the other is the existence of internal weathering crust composition of C2h,weathering crust in the freshwater dissolution porosity and organic acid - soluble pore as a reservoir,the upper dense volcanic rocks for cover.The model have the vital significance for seeking the volcanic rock crust of Weathering reservoir to the next step in Santanghu basin.