1、第 35 卷 第 2 期2023 年 3 月岩性油气藏LITHOLOGIC RESERVOIRSVol.35 No.2Mar.2023冯明友等：川西南宝兴地区二叠系栖霞组一段白云岩储层充填序列及流体指示收稿日期：2022-03-26；修回日期：2022-05-26；网络发表日期：2022-09-02基金项目：国家科技重大专项“四川盆地二、三叠系构造沉积演化及储层形成机制研究”（编号：2016ZX05007004-001）与中国石油碳酸盐岩重点实验室创新基金项目“热液溶蚀及沉淀作用对深层碳酸盐岩储层复合改造机理”（编号：RIPED-HZDZY-2019-JS-695）联合资助。第一作者：冯明友（
2、1981），男，博士，副教授，主要从事储层地质及非常规油气地质方面的教学与研究工作。地址：（610500）四川省成都市新都区新都大道 8 号。Email：。文章编号：1673-8926（2023）02-0011-10DOI：10.12108/yxyqc.20230202引用：冯明友，高瑞琪，王兴志，等.川西南宝兴地区二叠系栖霞组一段白云岩储层充填序列及流体指示 J.岩性油气藏，2023，35（2）：11-20.Cite：FENG Mingyou，GAO Ruiqi，WANG Xingzhi，et al.Sequence filling succession and fluid indicati
3、on of dolomite reservoirs ofthe first member of Permian Qixia Formation in Baoxing area，southwestern Sichuan Basin J.Lithologic Reservoirs，2023，35（2）：11-20.川西南宝兴地区二叠系栖霞组一段白云岩储层充填序列及流体指示冯明友1，高瑞琪1，2，王兴志1，徐亮3，赵金4，刘小洪1，尚俊鑫1（1.西南石油大学 地球科学与技术学院，成都 610500；2.中国石油西南油气田公司 蜀南气矿勘探开发研究所，四川 泸州 646000；3.中国石油西南油气田公
4、司 勘探开发研究院，成都 610041；4.广元市剑阁县自然资源局，四川 广元 628317）摘要：川西南中二叠统栖霞组白云岩受多期成岩作用改造明显，优质储层成因复杂。结合野外勘察、宏观微观岩石学特征、阴极发光及流体包裹体测温等对研究区白云岩储层充填特征展开分析。研究结果表明：川西南宝兴地区中二叠统栖霞组一段白云岩由半自形中粗晶白云石组成，斑马构造及构造角砾白云岩发育，储集空间类型以残余晶间孔、残余晶间溶孔及溶蚀缝为主，其次为扩溶缝及晶洞，孔隙度多为1%4%。研究区白云岩储层以中粗晶鞍状白云石及亮晶方解石充填为主，其次为少量石英充填，局部见中粗晶白云石呈带状与方解石共同分布于裂缝中，总体上白云
5、岩的分布受断层控制明显，缝洞较发育且表现为粗晶鞍状白云石石英方解石的充填序列。研究区在中晚三叠纪，深盆富镁热卤水沿断裂进入地层并交代原岩形成热液白云岩，热液冷却效应对早期储层进行溶蚀改造，并伴随压力降低导致粗晶鞍状白云石及少量方解石沉淀；侏罗纪末期受燕山运动影响，深盆富硅热液进入储层，部分交代早期鞍状白云石并见少量石英充填孔洞；燕山期晚期，高温-低盐度富二氧化碳流体因构造抬升过饱和析出晚期方解石，大幅度降低了储集空间。多期流体对白云岩复合改造后，区内储层致密化明显，部分孔洞缝连通的晶粒白云岩可形成渗透性储层。关键词：热液白云岩；流体作用；充填序列；成岩作用；栖霞组；二叠系；宝兴地区；川西南中图
6、分类号：TE122.2；P618.13文献标志码：ASequencefillingsuccessionandfluidindicationofdolomitereservoirsofthefirstmem-ber of Permian Qixia Formation in Baoxing area，southwestern Sichuan BasinFENG Mingyou1，GAO Ruiqi1，2，WANG Xingzhi1，XU Liang3，ZHAO Jin4，LIU Xiaohong1，SHANG Junxin1（1.School of Geoscience and Technolo
7、gy，Southwest Petroleum University，Chengdu 610500，China；2.Institute of Explorationand Development，Shunan Gas Field，PetroChina Southwest Oil&Gas Filed Company，Luzhou 646000，Sichuan，China；3.Research Institute of Exploration and Development，PetroChina Southwest Oil&Gas Filed Company，Chengdu610041，China；
8、4.Natural Resources Bureau of Jiange County，Guangyuan 628317，Sichuan，China）Abstract：Dolomites of Qixia Formation of Middle Permian in Baoxing area of southwestern Sichuan Basin display12岩性油气藏第 35 卷第 2 期a complex diagenetic alteration and complex genesis of high-quality reservoirs.The filling charact
9、eristics of dolomitereservoirs in the study area were analyzed based on field investigation，macroscopic and microscopic petrologicalcharacteristics，cathodoluminescence and fluid inclusion measurement.The results show that：（1）The dolomitesof the first member of Qixia Formation of Middle Permian are c
10、omposed of subhedral medium to coarse-graineddolomites，with zebra texture and tectonic breccia developed.The reservoir spaces are mainly residual intercrystalline pores，residual intercrystalline dissolved pores and dissolved fractures，followed by expanding dissolvedfractures and geodes，with porosity
11、 of 1%-4%.（2）The dolomite reservoirs in the study area are mainly filledwith medium to coarse-grained saddle dolomites and bright crystal calcites，followed by a small amount ofquartzs.Locally，medium to coarse-grained dolomites are distributed in the fractures together with calcites in abelt shape.In
12、 general，the distribution of dolomites is obviously controlled by faults，and the fractures and cavesare relatively developed，and the filling sequence is coarse-grained saddle dolomite-quartz-calcite.（3）Duringthe Middle-Late Triassic period，the Mg-rich thermal brine in deep basin entered the formatio
13、n along faults andreplaced original rock to form hydrothermal dolomites.The hydrothermal cooling effect carried out the dissolution transformation of the early reservoirs，and accompanied by the pressure reduction，led to the precipitation ofcoarse-grained saddle dolomite and a small amount of calcite
14、.Under the influence of Yanshan movement at the endof Jurassic，the silicon-rich hydrothermal solution in deep basin entered the reservoir and replaced some saddle dolomites and a small amount of quartzs filled holes.In the late Yanshanian period，the carbon dioxide rich fluids withhigh-temperature an
15、d low salinity were supersaturated due to tectonic uplift and precipitated late calcites，whichgreatly reduced the reservoir space.（4）The reservoirs are intense densification after episodic fluid alteration，andpart of the residual vugs or fracture networks are relative porous for hydrocarbon accumula
16、tion and migration.Key words：hydrothermal dolomite；fluid action；filling action；diagenesis；Qixia Formation；Permian；Baoxing area；southwestern Sichuan Basin0引言深层超深层碳酸盐岩储层受沉积环境影响明显，且在埋藏期遭受多期流体溶蚀，从而导致优质碳酸盐岩储层的影响因素复杂1。众多学者针对碳酸盐岩储层主控因素的讨论重点集中于颗粒滩叠加准同生溶蚀作用2、开放体系的暴露及淡水溶蚀作用3、埋藏4及热液溶蚀作用等方面5-7，并就埋藏条件下能否形成规模性优质储层以及孔洞保存等问题进行了深入分析8-10。围绕碳酸盐岩储层影响因素的探讨，实际是研究不同流体-岩石耦合作用的响应过程。针对多期流体作用下的岩石-流体作用的研究需落实流体来源、温度及成分等11-13，以揭示流体对规模化白云岩的控制及改造效应14-15。流体作用过程及效果是目前白云岩储层研究亟待解决的关键问题，其本质是矿物交代-溶蚀-沉淀的动态平衡过程16-17。以往研究人员对川西地区二叠系栖霞组中
