Abstract: At present, fault-controlled plays have become one of the most active hydrocarbon exploration fields. This study targets at three types of rocks, i.e., carbonate rock, clastic rock and igneous rock, and aims to guide the oil and gas exploration and development in fault-controlled fields. Based on the case study of typical reservoirs reformed by faults and fractures in four basins of the central-western China, an analysis was performed on the macro- and micro-scale characteristics of faults, fractures, pores, micro-fractures and micropores. The results show as follows. (1) Based on the three reservoir reformation mechanisms, including fault and fracture-induced fragmentation, superimposed dissolution, and superimposed metasomatism, the reservoirs can be classified into four types: fault-controlled fragmented reservoirs, fault-facies controlled reservoirs, fault-solution controlled reservoirs, and fault-facies-solution controlled reservoirs. (2) Carbonate rocks exhibit strong physical rigidity, making them prone to forming large-scale fault-controlled fragmented reservoirs; their high chemical reactivity promote dissolution and metasomatism along fractures, thus forming fault-solution-controlled reservoirs. (3) Although clastic rocks are incapable of forming large-scale fracture-induced voids due to their relatively weak rigidity, they can transform tight sandstones into large-scale effective reservoirs, which is attributed to the well-developed fracture systems combined with limited dissolution effects. (4) Fractures in igneous rocks can interconnect isolated amygdules, thus greatly improving reservoir permeability. (5) Faults and fractures not only exert direct control over the development of multi-scale pores, but also have variable coupling relationships with the pre-existing matrix pores, which finally determines the characteristics and quality of the transformed reservoirs.

Key words: fault, fracture, fault-controlled reservoir, carbonate rock, clastic rock, igneous rock

摘要： 断控领域已成为最活跃的油气勘探领域之一。为指导断控领域油气勘探开发,针对碳酸盐岩、碎屑岩和火成岩3种岩石类型,以中国中西部四大盆地受断裂及裂缝改造明显的典型储层为例,分析了断裂、裂缝、孔洞、微裂缝和微孔隙的宏观与微观特征。研究结果表明:①根据断裂及裂缝对储层的破碎作用、叠加溶蚀作用和叠加交代作用3种成储改造作用,可以划分为4种储层类型,即以断裂为核心的断控破碎型储层、断-相双控型储层、断-溶双控型储层和断-相-溶三控型储层。②碳酸盐岩的物理刚性强,易形成大型断控破碎型储层;碳酸盐岩的化学性质活跃,易发生沿裂缝的溶蚀和交代作用,形成断-溶双控型储层。③碎屑岩的物理刚性较弱,虽难以形成大型断裂"空腔",但常发育裂缝系统和有限的溶蚀作用,可将致密砂岩改造成为有效的规模储层。④火成岩中的裂缝可连通孤立杏仁孔从而极大地提升储层的渗透能力。⑤断裂及裂缝不仅直接控制了多尺度孔隙的发育,而且与先存基质孔隙之间存在丰富多样的耦合关系,控制着改造后的储层特征和品质。

关键词: 断裂, 裂缝, 断控储层, 碳酸盐岩, 碎屑岩, 火成岩