酒西盆地鸭儿峡志留系白云岩成因模式及勘探启示  

Dolomization Genetic Model and Exploration Significance of Silurian Dolomite Reservoir in Yaerxia of Jiuxi Basin,China

作　　者：张光伟[1] 潘树新[1] 邓毅林[1] 张丽萍[1] 龙礼文[1] 刘震华[1] 冯明[1] 王宏波[1] 马玉虎[1] 

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020

出　　处：《科学技术与工程》2015年第36期21-29,共9页Science Technology and Engineering

基　　金：国家重大科技专项(2011ZX05001);中石油玉门油田项目(2013E-3301)及(2014B-0302)联合资助

摘　　要：以酒西盆地鸭儿峡志留系白云岩为研究对象,分析了其展布规律及作为优质储层的条件。基于对酒西盆地鸭儿峡志留系白云岩碳氧同位素的分析,对酒西盆地鸭儿峡志留系白云岩古盐度和古温度进行研究。分析表明,鸭儿峡志留系白云岩分布受到构造应力、断层发育、裂缝发育带、深部热液等因素影响,符合构造控制白云岩的特点。白云岩化作用、裂缝发育、溶蚀孔洞发育等是鸭儿峡志留系白云岩作为优质储层的先决条件。鸭儿峡白云岩δ^(13)C介于-0.59‰^-0.90‰之间;δ^(18)O值介于-14.2‰^-7.00‰;成岩温度和δ^(18)O平衡温度均较高,平均值分别为69.23℃和69.13℃,显示鸭儿峡白云岩具有热液成因特征;Z值范围在108.30~121.17之间,表明白云岩为海陆交互相,以海相沉积环境为主。δ^(18)O值较低,白云岩形成可能受到后期淡水淋滤的影响。因此,可以推断鸭西白云岩为构造热液控制白云岩成因模式白云岩。鸭南地区地质构造和鸭西地区相似,鸭南地区潜山高部位可能发育构造热液白云岩,是下一步勘探的有利区域。研究结果对于深化鸭儿峡白云岩的成因具有重要作用,对于类似地区白云岩成因研究具有一定的借鉴意义。The dolomite body spreading regularity of Silurian in the Jiuxi Basin was discussed. And the forming condition of high-quality dolomite reservoir was concerned. Base on the carbon and oxygen isotope analysis to carry out reconstruction of ancient salinity and ancient temperature of the dolomite samples selected from in the Yaerxia Jiuxi Basin,China. It found that the tectonic stress,fault development,fracture-developed zones and the hot fluid can be influence the distribution area of dolomite. According the tectonic conditions,is find that the dolomite in this area may be one of the structurally controlled dolomite. The result come from the carbon and oxygen isotope analysis showed that the mean of δ^（13）C range of- 0. 59‰ to- 0. 90‰ and the mean of δ^（18）O range of- 14. 2‰ to- 7. 00‰. Both the average diagenetic temperature and equilibrium temperature were higher than the environment temperature,the value were 69. 23 ℃ and 69. 13 ℃,respectively. The mean of Z range of 108. 30 to 121. 17,most of dolomites were formed in a marine sedimentary surrounding. The mean of δ^（18）O is low,deposits subjected to leaching and dissolution of meteoric fresh water. So,it concluded that the dolomite in this area may be structurally controlled hydrothermal dolomite. As for the geologic structure,it is similar between Yanan area and Yaxi. There may be some structurally controlled hydrothermal dolomite formed in the top of buried hill in Yanan Area. This area may be the future exploration. This study may be useful to understand the dolomization in Yaerxia Area and it also has certain reference value for the study of the same type of dolimite reservoir.

关 键 词：酒西盆地 志留系白云岩 碳氧同位素 构造热液成因模式 

分 类 号：P583[天文地球—岩石学]