摘要
克拉美丽气田滴西地区石炭系火山岩储层由于受到多期成岩作用的影响,孔隙演化特征复杂。在岩心观察描述的基础上,结合铸体薄片、扫描电镜、阴极发光、电子探针、X射线衍射以及包裹体等分析,对火山岩成岩作用及孔隙演化过程进行了研究。结果表明,研究区火山岩成岩作用阶段可划分为冷凝成岩作用、岩浆期后热液作用、风化淋滤作用以及埋藏成岩作用等阶段。冷凝成岩作用阶段是原生孔隙和裂缝的主要形成期。岩浆期后热液作用阶段的蚀变作用和充填作用使原生孔隙急剧减少,孔隙度值降至最低。风化淋滤作用阶段的风化剥蚀碎裂作用和溶蚀淋滤作用产生大量次生裂缝和次生溶孔,对岩石的储集性具有较强的改造作用。埋藏成岩作用阶段是各种原生孔隙的主要破坏期和次生孔隙的主要形成期:机械压实作用影响了部分岩石原生孔隙的保存;充填作用导致原有孔隙和裂缝全部或部分消失,对火山岩原有的储集性具有较大的破坏作用;溶蚀作用及构造碎裂作用可形成各种次生孔隙和裂缝,对火山岩储层的最终形成具有重要作用。
Characteristics of pores evolution of Carboniferous volcanic reservoirs in Dixi area, Kelameili Gas Field, are difficult to predict as the result of obviously complex diagenesis. On the basis of core observation and description, combined with the analysis of cast thin section, scanning electron microscopy, cathodoluminescence, electron microprobe, X-ray diffraction and inclusion, the diagenesis and pore evolution of volcanic reservoirs in the study area were studied. Considering the influence factors and sign of diagenesis, the diagenesis stage would be divided into four periods： condensation stage, post-magmatic hydrothermal stage, weathering and leaching stage and buried stage. Original pores and cracks were mainly formed in condensation stage and decreases drastically under the alteration and infilling of minerals in the post-magmatic hydrothermal stage, when pore porosity down to the lowest value. Weathering fragmentation, dissolution and leaching caused the formation of secondary fractures and dissolved pores, which improves the volcanic reservoir properties. The destruction of the original pores and the formation of secondary dissolved pores are both occurred in burial diagenesis stage. Mechanical compaction affects the preservation of original pores, while infilling of minerals make the disappearance of the original pores in whole or in part, which plays a negative role to volcanic reservoirs. Benefiting from variety of secondary pores and cracks produced from the dissolution and tectonic fragmentation, the volcanic rock develops into high-quality reservoirs.
出处
《岩性油气藏》
CSCD
北大核心
2016年第1期38-48,共11页
Lithologic Reservoirs
基金
国家自然科学基金青年基金项目"火山岩储层中多种自生矿物共生机理及流体示踪意义"(编号:41202109)
四川省教育厅面上项目"克拉美丽气田滴西地区石炭系火山岩储层孔缝成因及分布"(编号:11ZB016)联合资助
