Development characteristics and main controlling factors of Carboniferous volcanic reservoirs in the Shixi area, Junggar Basin

The Carboniferous volcanic reservoirs in the Shixi area of Junggar Basin are complex and diverse. Identifying characteristics main factors controlling high-quality is key to increasing oil gas reserves production this area. Through core observations, thin section identification, physical property pore structure analyses, combined with data, development modes were analysed. results show that strata mainly contain andesite dacite overflow facies, followed by breccia tuff explosive facies. Volcanic study high-porosity–low-permeability medium-porosity–low-permeability reservoirs. facies has best properties, showing high porosity medium permeability. reservoir space composed cavities, corrosion pores fractures, among which most important spaces rocks. Lithology lithofacies, weathering corrosion, fractures rocks had experienced denudation for a long time developed large number secondary due soluble minerals or ash. Fractures further improved causing eventually develop into crust properties far away from through primary cavities structural these inner reservoir.