渝东北地区五峰组—龙马溪组页岩气地质特征及其勘探方向探讨  

Shale Gas Geological Characteristics of Wufeng and Longmaxi Formations in Northeast Chongqing and Its Exploration Direction

作　　者：熊小辉[1,2] 王剑[1,2] 熊国庆[1,2] 汪正江[1,2] 门玉澎[1,2] 周小琳[1,2,3] 周业鑫[1,2,3] 杨潇[1,2,3] 邓奇[1,2] XIONG Xiaohui;WANG Jian;XIONG Guoqing;WANG Zhengjiang;MEN Yupeng;ZHOU Xiaolin;ZHOU Yexing;YANG Xiao;DENG Qi(Chengdu Center,China Geological Survey,Chengdu,610081,China;Key Laboratory of Sedimentary Basin and Oil and Gas Resources,Ministry of Land and Resources PRC,Chengdu,610081,China;Chengdu University of Technology,College of Earth Sciences,Chengdu 610059,China)

机构地区：[1]中国地质调查局成都地质调查中心,成都610081 [2]国土资源部沉积盆地与油气资源重点实验室,成都610081 [3]成都理工大学地球科学学院,成都610059

出　　处：《地质学报》2018年第9期1948-1958,共11页Acta Geologica Sinica

基　　金：国家自然科学基金青年基金项目(编号41402103);国家自然科学基金重点项目(编号41030315);重庆市政府项目资助成果

摘　　要：渝东北地区五峰组—龙马溪组暗色泥页岩沉积厚度介于30.92~164.47m之间,其中在朝阳镇咸池剖面及田坝一带厚度最大,往研究区东西两侧具有减薄的趋势。全区总有机碳含量平均3.32%,中部(平均3.93%)和西部(平均3.59%)相对东部(平均2.77%)具有更高的有机质丰度。有机质以I型腐泥型为主,西部个别剖面及东部栗子坪一带夹少量Ⅱ_1—Ⅱ_2型干酪根,其成熟度普遍处于高成熟—过成熟阶段,呈现自北向南升高的趋势。石英、脆性矿物含量普遍较高(尤其是中西部区块),黏土矿物较低,更易产生储气裂缝及利于后期压裂。储层特征方面,中部地区泥页岩具有更高的孔隙度和较低的渗透率,同时比表面积也相对更高,以有机质孔隙为主。中部区块田坝—朝阳—文峰一带含气性最好,结合页岩厚度、总有机碳含量分布、储层条件及构造保存条件分析,本区中部区块田坝—朝阳—文峰一带具有更好的页岩气勘探前景,是该区下一步勘探的重点区域。Dark mudstone and shales of Wufeng Formation-Longmaxi Formation in Northeast Chongqing have a thickness ranging from 30.92m to 164.47m,with the thickest layers mainly in the Xianchi section of Chaoyang Town and Tianba section of Tianba Town.Thickness also decreases toward west and the east respectively.The average total organic carbon（TOC）content in the study area is 3.32%,among which the middle area has an average TOC content of 3.93% and the west region has an average TOC content of 3.59%.Compared with 2.77%in the east,the west and east of the study area have much high TOC abundance.The darkwestern and eastern regions.Organic matter in the study area shows generally high or even over maturity,with maturity gradually increasing from north to south.Higher contents of quartz and brittle minerals especially in the middle-western areas and lower clay mineral are better to produce gas-storage cracking and hydrofracturing.In terms of property of reservoirs,the dark mudstone and shales in the middle region are dominated by organic matter porosity with high porosity and lower permeability as well as high surface area.Gas field in the central area from Tianba,Chaoyang to Wenfeng are of better gas-bearing capability.Combined the total thickness of shales,distribution of total organic carbon,and preservation conditions of reservoirs and structures,it can be concluded that the northeastern part of Chongqiang is of favorable prospecting outlook for shale gas and should be the target area for future exploration.

关 键 词：页岩气 五峰组—龙马溪组 勘探方向 渝东北 

分 类 号：P618.13[天文地球—矿床学]