摘要
目前对海陆过渡相页岩的储层及其成藏特征研究较少.湘中地区涟源凹陷下石炭统测水组海陆过渡相页岩是重要的页岩气勘探层位,基于二维地震资料、钻井岩心资料和测录井资料,选取2015H-D6井进行了井区构造与测水组岩性描述,页岩储层地化、物性及含气量等测试分析,以及单井埋藏史和热史模拟.研究表明:涟源凹陷海陆过渡相测水组泥页岩沉积于滨岸泻湖或沼泽环境,有效厚度为71.8m,埋深大于2 500m;泥页岩有机碳含量平均为1.68%,干酪根类型以Ⅱ型为主,具备良好的生气基础和吸附载体;成熟度分布在2.30%～3.32%,平均为2.96%,处于过成熟阶段;储层脆性矿物含量超过60%,粘土矿物含量小于30%,储层整体表现为低孔低渗特性,孔隙以微孔隙为主,具较好的页岩气储层条件.利用测井解释、等温吸附以及现场解析等方法,揭示出测水组泥页岩具有较好的含气量,结合模拟结果提出了构造保存并持续沉降是涟源凹陷海陆过渡相测水组页岩气藏形成的关键因素.
There are few studies on the reservoirs and hydrocarbon accumulation characteristics of the marine-continental transitional shale.Lower Carboniferous Ceshui Formation transitional shale is one of the most important shale gas exploration beds in Lianyuan Sag of Xiangzhong Depression.In this paper,the accumulation characteristics of marine-terrigenous facies shale of the study area are discussed on the basis of 2 Dseismic data,drilling core and logging data.Firstly,the structure of Well 2015H-D6,and the lithology of Ceshui Formation are described.Then,testing and analysis of the geochemical,physical properties and gas content of shale reservoir are carried out.Finally,the burial and thermal history of the single well is simulated.Reuslts illustrate that Ceshui shale in Lianyuan Sag deposited in coastal lagoon or swamp environment with a deposition thickness of 71.8 mand a buried depth of more than 2 500 m.The shale with typeⅡkerogen remains in over-mature stage,with the average organic carbon content of 1.68%,and the maturity ranging from 2.30%~3.32%(average value of 2.96%).The brittle mineral content exceeds 60%,and clay mineral content is less than 30%.The shale is characterized by low porosity and permeability,with microspore dominated reservoir porosity,which shows better shale gas reservoir conditions.It is revealed that the Ceshui shale has agood content of shale gas by well logging interpretation,isothermal adsorption and in-situ gas quantity analysis.Combining with single-well burial,thermal history simulation,and the evolution of shale gas reservoir,it is concluded that the stable tectonic and sustaining subsidence are the key factors of shale gas accumulation formed in Lianyuan Sag.
作者
田巍
彭中勤
白云山
王保忠
王强
苗凤彬
刘飞宇
Tian Wei;Peng Zhongqin;Bai Yunshan;Wang Baozhong;Wang Qiang;Miao Fengbin;Liu Feiyu(Wuhan Center of China Geological Survey,Wuhan 430205,China;School of Earth Sciences,China University of Geosciences,Wuhan 430074,China;No.230 Institute of Nuclear Industry,Changsha 410007,Chin)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2019年第3期939-952,共14页
Earth Science
基金
中国地质调查局项目(No.DD20160179)
关键词
2015H-D6井
测水组
页岩气
成藏特征
涟源凹陷
石油地质
Well 2015H-D6
Ceshui Formation
shale gas
gas accumulation characteristics
Lianyuan Sag
petroleum geology
