Analysis Of Volcanic Reservoir Characteristics In Anda Subsag

Considering the complexity and variety of volcanic lithology, lithofacies and pore type of volcanic reservoir in vertical and literal distribution, this dissertation, on the basis of former research findings and in light of the structural geology, reservoir sedimentology and igneous petrology, makes full use of seismic, logging and drilling data to classify the volcanic lithology and lithofacies of Yingcheng Formation in detail and identify the features of volcanic reservoir in petrology and pore in Anda Subsag.By the lithology identification and contrast between volcanic interval of Yingcheng Formation drilled by exploration wells and logging data in the study area, the fact that the Subsag mainly consists of intermediate-basic volcanic rocks is confirmed and the lithology logging identification technique of basic-intermediate volcanic rocks is established. The coring data and logging identification technique determine that the main types of reservoir space are air hole, devitrified pores, solutional pores of feldspar, pozzolanic solutional void and microcrack.Based on the research of lithology and lithofacies for volcanic reservoir and their relations with reservoir space, volcanic rocks with good physical properties in the Yingcheng Formation of this area are determined to be rhyolite, pyromeride, altered andesite and basalt. The favorable volcanic reservoir mainly develops near crater facies belts.Aiming at volcanic reservoir in the Yingcheng formation of study area, seismic attribute analysis technology is applied to predict that the favorable volcanic bodies are mainly distributed NS in the Midwest of Anda Subsag.At last, by analyzing the gas source conditions, structural features, development of fracture, distribution of volcanic rocks and favorable facies belts, and migration and accumulation conditions of gas, some favorable plays are divided in Anda Subsag.