歧口凹陷新生界火山岩储层特征及储层发育的控制因素

Characteristics and Controlling Factors of Volcanic Reservoirs in Cenozoic Group, Qikou Depression

综合利用岩芯观察、岩石薄片、铸体薄片和测井解释成果等资料,对歧口凹陷新生界火山岩储层特征和储层发育的控制因素进行了研究。结果表明,歧口凹陷新生界火山岩中玄武质火山熔岩占绝对优势,其次是浅成侵入辉绿岩,火山碎屑沉积岩和沉积火山碎屑岩也占一定比例。火山岩岩相以火山溢流相为主,其次为浅成侵入相,火山沉积相和火山爆发相所占比例较少。火山岩储集空间类型可分为孔隙–气孔型和裂缝型两大类,玄武岩的储集空间以气孔(残余气孔)和基质溶孔为主,辉绿岩以粒间溶孔、粒内溶孔和蚀变矿物溶孔为主,凝灰质砂岩以粒内溶孔、粒间溶孔和溶蚀缝为主,凝灰岩以砾内溶孔和粒间溶孔为主。歧口凹陷新生界火山岩储层发育过程中,溶蚀作用是决定性因素,岩性和岩相是储层发育的基础,构造裂缝是储层发育必不可少的条件,风化淋滤作用是储层发育的重要条件。

The characteristics and controlling factors ofvolcanic reservoirs in Cenozoic Group, Qikou Depression were researched using a large amount of data from core observation, ordinary slices, cast slices and well logging interpretation results. The results indicate that basaltic volcanic lava takes the highest proportion in volcanic rocks Cenozoic Group, Qikou Depression. Hypabyssal intrusive diabase takes the second highest. Pyroclastic sedimentary and sedimentary pyroclastic rocks also take certain proportion. Volcanic reservoir space can be classified into two main types： pore and fractures. Reservoir space in basalt is mainly stomata, residual stomata and matrix solution pores. Reservoir space in diabase is mainly intergranular dissolution pores, intragranular dissolution and alteration minerals dissolution pores. Reservoir space in tuffaceous sandstone is mainly intergranular dissolution pores, intragranular dissolution pores and dissolved fracture. Reservoir space in tuff is mainly dissolution pores within the gravel and intergranular dissolution pore. In the growing process of volcanic reservoirs in Cenozoic Group, Qikou Depression, dissolution plays the determining function, volcanic lithology and facies are the base of the growing process, tectonic fracture and weathering erosions also play the important part.