松辽盆地南部火山岩储层主控因素

Main controlling factors of volcanic reservoirs in the southern Songliao Basin

松辽盆地南部火山岩储层是由孔、缝、洞构成的多孔介质储层,其储集空间类型多样、结构复杂,储层物性在空间上变化大,非均质性强,相变快。在勘探过程中需要解决的首要问题就是弄清楚火山岩储层形成的主要控制因素。通过地质、测井和地震资料,结合现有勘探成果,分析发现松南地区火山岩储层发育的三级控制规律:①火山机构类型控制储层发育程度,流纹质火山机构储层物性最好;②火山机构-相带控制储层展布,火山口-近火山口相带物性最好;③成岩作用和构造裂缝控制储层有效性,隐爆角砾岩化作用、风化淋滤作用以及裂缝使储层物性变好。清楚认识火山岩储层发育的控制因素,对储层预测及今后气田的有效开发具有重要意义。

Volcanic reservoirs in the southern Songliao Basin are characterized by various types of accumulation space and complex structures,they are porous reservoirs composed of different media,including different pores,fractures and holes,and their physical properties vary greatly in space,with strong heterogeneity and changeful facies.The most important issue that needs to be solved in exploration is to make main controlling factors for the formation of volcanic reservoirs clear.Combined geological,logging and seismic data with current exploration results,we proposed a three-grade rule that controls the development of volcanic reservoirs in the southern Songliao Basin.①Types of the volcanic edifice control the development degree of reservoirs and a reservoir with the rhyolitic volcanic edifice has the best physical property.②A volcanic edifice-facies belt controls the distribution of reservoirs and a crater-near crater facies（CNCF） belt shows the best physical property.③Diagenesis and tectoclase jointly control the effectiveness of reservoirs,and the cryptoexplosion brecciation and weathering-leaching coupled with fractures bring about a better physical property.The different volcanic edifice has different pore spaces and physical properties of reservoirs.It is significance in predicting reservoirs and effectively exploiting gas accumulations to clearly recognize controlling factors for the development of volcanic reservoirs.