Abstract:

Volcanic rock reservoir is a main target layer for deep gas exploration in Songliao basin, controlled chiefly in distribution by deep and major fractures showing widespread in belt along the fracture not only in mountainous areas but also in sedimentary layers in the fault subsidence basins; Space of the reservoir are observed to be primary bubble pores, amygdale interior pores, secondary phenocryst solution pores, matrix dissolution pores, structural solution fissures. Pore structural assemblies are discovered to be pore structures made up of unitary fissures, phenocryst solution pores and fissure assemblies. Three stages can be divided in terms of origin namely; primary bubble pores formed in the period of overflow eruption, secondary pores originated by the process of weathering eluviation in the period of eruption intermittent and diagenesis and structure effects in the burial process. Fissures are key factors for the improvement of property of volcanic rock reservoir, diagenesis either intensified secondary pore fillings or intensified the formation of solution fissures,compaction has no an effect on the reservoir property . Relatively independent distribution of volcanic rocks in hydrocarbon source rocks make it possible for them to have exceptional advantages for the formation of reservoir, tectonic movements and deuteric weathering-erosions are main factors for controlling property of the reservoir,development of fractures controls the distribution of gas reservoir.

Key words: Songliao basin, Mesozoic, volcanic rock reservoir, gas reservoir, characteristic, controlling effect