Study on volcanic reservoir types in Subei exploration area

Being widely developed in Subei exploration area,volcanic rocks are characterized by fast lateral and vertical change,complicated accumulation rule,which causes great difficulties for oil and gas exploration.By analyzing source rocks,matching characteristics of reservoir and cap rock,combining with seismic data,this paper studied the contact relationship of volcanic and source rocks,and studied the volcanic reservoir accumulation model.There are six types of reservoir accumulation model,including indirect contact of source rocks and volcanic rocks,direct contact of source rocks and volcanic rocks,volcanic rocks enwrapped by the source rocks,source rocks developed on and below the volcanic rocks,volcanic reservoir developed on the top of volcanic conduit and volcanic rocks acted as seal.These reservoir accumulation models were used to predict the volcanic reservoir at the Funing and Sanduo formations in Eogene.Totally,they can be summed up to three types of volcanic reservoir,including the relationship of source and reservoir represents as enwrapping(near source rocks),the relationship of source and reservoir shows as up and down(near source rocks),and faults act as the main hydrocarbon migration path.