Reservoir Characterization of Fractured Volcanic Gas Reservoir in Deep Zone

摘要

Quite a few large-scale volcanic gas reservoirs have beenrndiscovered in deep zone in Songliao Basin of North-EastrnChina in recent years. The consequent issue is how to producernthis kind of gas reservoir effectively. Reservoirrncharacterization is essential for the effective production ofrnvolcanic gas reservoir, which provides the geological basis forrngas reservoir development. The geological scenarios ofrnvolcanic gas reservoirs are extremely complex, which isrnfeatured by quick changes of lithofacies and its thickness,rndistributions of fractures and pores/vugs, strong heterogeneity,rnchanges of gas well productivities among different wells, etc.rnThe difficulties of reservoir characterization pose a greatrntechnological challenge on effective production of volcanicrngas reservoir. In this paper a systematic methodology isrnproposed for characterization of fractured volcanic gasrnreservoir based on a large amount of laboratory experiments,rntheoretical studies and field practices. The proposedrnmethodology is a multi-discipline integration, includingrnidentification of lithologies and lithofacies, eruption periodrnanalysis and stratigraphic correlation, identification andrnevaluation of fractures, identification of volcanic body andrnreservoir prediction, well log interpretation for the dualporosityrnvolcanic reservoir, discrimination of gas and waterrnlayer, reservoir appraisal and geological modeling, etc. Thesernstudies provide a strong base for making decisions on thernreasonable well pattern and development plan.