Research On Diagenesis Of Volcanic Reservoirs In Carboniferous Harjiawu Formation In Malang Sag

Based on the data of core, thin section，scanning electron microscopy，well logging, and3D seismic, we understand the following points according to the research on diagenesis of ofCarboniferous volcanic reservoirs in Harjiawu Formation in Malang sag. The lithology ismainly componented by basalt, andesite and volcanic breccia. The lithofacies are based onverflow facies, with explosion and volcane-sedimentary facies; Primary porosity ofCarboniferous Harjiawu Formation is not developed very well because of underwater eruption,however the pore, hole, slit often superimposed on the original storage space After thetransformation of the Post-magmatic diagenesis and woven together form the effective storagespace; With the analysis about volcanic diagenesis, thirteen diagenesis types are beingexistence in the studying area. Each type has different effect to the formation of volcanicreservoir, and there are two respects as constructive action and destructiveness;Thephenomenon such as laumontitization, albitization，arfvedsonization and sideritation that theHydrocarbon alkali fluid is obtained in the Carboniferous Volcanic rocks in HarjiawuFormation, and the extensive development of alkali metasomatism;Devitrification, weathering,tectonic, metasomatism and dissolution impact on volcanic reservoir crucially; are maindiagenesis forming secondary pores; are the key to effective reservoirs in Harjiawu Formation.Four kinds of reservoir formation mechanism and model are summarized.