玛湖-达巴松地区石炭系火成岩储集层分布及其控制因素

准噶尔盆地石炭系火成岩油气勘探已由盆缘转向盆内生烃凹陷及其周缘,为更准确地确定盆地腹部油气藏的分布,利用磁异常、地震和测井等资料,开展了准噶尔盆地腹部玛湖—达巴松地区石炭系火成岩的分布规律、储集层发育特征及其控制因素研究。研究认为,玛湖—达巴松地区石炭系以中基性火成岩和火山沉积岩为主,火成岩主要呈北北东—南南西向条带状展布。火成岩储集空间以次生孔隙为主,为低孔、低—特低渗储集层;有效储集层的形成受火成岩岩性和岩相、风化时间、后期成岩作用的控制,近火山口部位的爆发相和火山机构侧翼的溢流相为火成岩风化壳储集层相对发育的部位。

Carboniferous Igneous Reservoir Distribution and Its Controlling Factors in Mahu-Dabasong Area,Junggar Basin

In recent years,oil and gas exploration of Carboniferous igneous reservoirs in Junggar basin has gradually shifted from basin margin to basin center.In order to more accurately determine the oil and gas reservoir distribution in the hinterland of the basin,a study on Carboniferous igneous reservoir distribution,reservoir development characteristics and its controlling factors is carried out in Mahu-Dabasong area based on aeromagnetic,seismic and logging data.The study results show that the Carboniferous strata are dominated by intermediatebasic igneous rock and volcanic sedimentary rocks and the igneous rock spreads out like a strip with the NNE-SSN direction.The reservoir spaces of the igneous rocks are mainly composed of secondary pores and the reservoir belongs to low porosity,low-extra low permeability reservoirs;The forming of effective reservoir is mainly controlled by igneous rock lithology and lithofacies,weathering time and diagenesis at the late stage;the igneous reservoirs of weathering crust are mainly developed in the explosive facies near craters and the effusive facies on the flanks of volcanoes.