三塘湖盆地火成岩储集空间类型及特征

Reservoir space feature and evolution of the volcanic rocks in the Santanghu basin

三塘湖盆地的上、下二叠统和石炭系发育 3套典型的火成岩 ,主要岩类有玄武岩、安山岩和辉绿岩等 ;储集空间包括原生孔隙和裂缝以及次生溶孔和裂缝 ,进一步可分为原生气孔、残余气孔、原生粒间孔隙、冷凝收缩缝、收缩节理、颗粒爆炸纹缝、斑晶溶蚀孔、铸模孔、粒间溶孔、基质溶蚀孔、蚀变物溶蚀孔、裂缝充填再溶蚀孔、杏仁体溶孔、构造裂缝、风化裂缝、溶缝等。火成岩在成岩和后生变化过程中 ,发生了交代蚀变作用、充填作用和溶解作用等成岩事件 ,原生孔隙经历了复杂的充填和溶蚀过程才形成现今的面貌。火成岩的岩相、成岩作用和构造运动控制了火山岩的储集性能。图 1参

Three typical igneous rock series are located in Upper and Lower Permian as well as Carboniferous in Santanghu basin. The main kinds of the rock are basalt, andesite and diabase etc. Reservoir space consists of primary space (involving fracture) and secondary space (involving dissolved pore and fracture). They are subdivided into primary gas bubbles, residual gas bubbles, primary interparticle pore, cooling crack, shrinkage joint, grain explosion crack, phenocryst solution pore, moldic pore, interparticle solution pore, groundmass solution pore, alteration mineral solution pore, filling material solution pore, amygdaloid solution, structural fracture, weathering fracture and solution fissure. Diagenetic events have happened which included replacement, alteration, filling and dissolution. Primary space shows present features after it passes through a complex process of filling and solution. Igneous rock lithofacies, diagenesis and regional tectonic movement mainly control reservoir features.