塔北地区奥陶系碳酸盐岩缝洞充填方解石的阴极发光特征及对成岩环境的指示意义  

Cathodoluminescence features of the calcite filling in the Ordovician carbonate fractured-vuggy reservoir and its significance to instructions of diagenetic environment in Northern Tarim Basin

作　　者：韦东晓[1,2] 沈安江[1,2] 王莹[1,2] 乔占峰[1,2] 朱永峰[3] 

机构地区：[1]中国石油勘探开发研究院杭州地质研究院,浙江杭州310023 [2]中国石油碳酸盐岩储层重点实验室,浙江杭州310023 [3]中国石油塔里木油田分公司,新疆库尔勒841000

出　　处：《油气地质与采收率》2015年第4期54-58,共5页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"大型油气田及煤层气开发"(2011ZX05004-002)

摘　　要：对碳酸盐矿物和结构组分进行阴极发光分析可以直观、快捷地研究碳酸盐岩储层的成岩环境和成因。基于塔北地区奥陶系碳酸盐岩缝洞充填方解石阴极发光特征分析,结合Mn2+和Fe2+含量及流体包裹体均一温度,深入研究其对成岩环境的指示作用。结果表明:Mn2+和Fe2+含量及发光特征可大致反映成岩环境的氧化还原条件,明亮发光(Mn2+含量高)表明成岩环境为还原条件,也可能是与不发光胶结作用相关的氧化水停滞有关;昏暗—不发光表明成岩环境为氧化条件,是Mn2+趋向于被氧化为高价态而不易置换Ca2+进入晶格所致;不同产状的缝洞充填方解石发光性、Mn2+和Fe2+含量及两者比值各异,指示不同的成岩环境及充填期次,反映研究区缝洞形成及充填的复杂性和多期性。Cathodoluminescence analysis of the carbonate mineral composition and structure is one of the most effective technical methods to research visually and quickly on carbonate reservoir diagenesis environment and its genesis. In this paper,cathodoluminescence features of calcite,filling in Ordovician carbonate fractured-vuggy reservoir,was analyzed further to instruct its diagenetic environment combined with the analysis of Fe-Mn-Sr trace elements and the homogenization temperature of fluid inclusion. Studies have shown that the content of Mn2+and Fe2+and cathodoluminescence characteristics largely reflects the diagenetic environment under oxidation-reduction conditions. Bright glow(high Mn2+)suggests the diagenetic environment was under reducing conditions,or it may be related to the stagnant oxide water connected with nonluminance cementation. Dark or non-luminescence suggests the diagenetic environment was under the conditions of oxidation when Mn2+tended to be oxidized to higher state and difficult to replace Ca2+and get into the lattice. The luminance of calcite filling in different typical fractured-vuggy reservoir,combined with the content and ratio of Mn2+and Fe2+,could be used to indicate different diagenetic environment and filling period which show the complexity and multiple phases of thefractured-vuggy forming and filling in the study area.

关 键 词：阴极发光 缝洞充填方解石 成岩环境 奥陶系 塔北地区 

分 类 号：TE112.2[石油与天然气工程—油气勘探]