白云石-方解石氧同位素温度计在川东北地区飞仙关组白云岩成因研究中的尝试  

Preliminary application of the dolomite-calcite oxygen isotope thermometer in studying the origin of dolomite in Feixianguan Formation,Northeast Sichuan,China

作　　者：胡作维[1] 黄思静[1] 李志明[2] 张雪花[1] 徐二社[2] 刘涛[1] 

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214151

出　　处：《成都理工大学学报（自然科学版）》2012年第1期1-9,共9页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金资助项目(40839908;40672072);教育部博士点基金资助项目(20050616005)

摘　　要：川东北地区三叠系飞仙关组中,作为最重要储集岩的粒屑白云岩和结晶白云岩的形成机制一直都是高度关注的热点问题。在白云岩结构分类、氧同位素分析的基础上,通过白云石-方解石氧同位素温度计获得了川东北地区飞仙关组不同类型白云岩的形成温度,其中大多数计算温度集中分布在40～140℃区间内,结晶白云岩(包括结构类似的过渡岩石类型)和孔洞白云石的计算温度集中分布在相对高温区间,粒屑白云岩和微晶白云岩的计算温度集中分布在相对低温区间,与前人关于流体包裹体、白云岩形成环境等分析结果有较好的一致性。白云石-方解石氧同位素温度计的初步尝试及其获得的计算温度,可望为川东北地区飞仙关组优质白云岩储层的形成机制研究提供有价值的基础资料。The natural gas exploration and production of Triassic Feixianguan Formation in Northeast Sichuan play an important role in the Chinese marine oil ＆ gas industry. The origin of oolitic dolomite and crystalline dolomite, which are the most important reservoirs in Triassic Feixianguan Formation, is one of the hot spot problems, and has been received special attention in recent years. Based on the textural classification and oxygen isotope analyses, the temperatures of different types of dolomite samples from Feixianguan Formation of Northeast Sichuan are calculated by the dolomite-calcite oxygen isotope thermometer. Most of the calculated temperatures range over from 40~C to 140~C. The calculated temperatures of crystalline dolomite （including the transitional rock types with the similar texture） and dolomite cement have a relatively high temperature range and the calculated temperatures of oolitic dolomite and micrite dolomite have a relatively low temperature range. These results are consistent with the fluid-inclusion homogenization temperatures and formation environment of dolomite. The preliminary application and the obtained temperatures of the dolomite-calcite oxygen isotope thermometer will provide some valuable basic data for the studies of high-quality dolomite reservoirs in Triassic Feixianguan Formation of Northeast Sichuan.

关 键 词：氧同位素温度计 白云岩 飞仙关组 三叠系 川东北地区 

分 类 号：P588.245[天文地球—岩石学] P597.2[天文地球—地质学]