摘要
来凤咸丰区块位于湘鄂西褶冲带。页岩气参数井LD2井的钻探揭示了来凤咸丰区块两河口向斜翼部五峰-龙马溪组页岩发育特征和含气性特点,通过有机地球化学、X衍射全岩矿物、扫描电镜以及现场解析等实验方法手段,明确了LD2井五峰-龙马溪组页岩有机碳含量较高(TOC:0.42%~3.20%)、热演化程度适中(Ro:1.47%~2.63%)、矿物成分以碎屑岩脆性矿物为主(石英+长石:37.4%~65.3%)、特低孔特低渗的特征。通过与位于两河口向斜轴部的LD1井对比研究,认为两口井页岩品质大致相当,但LD2井含气量明显偏低,最大含气量仅0.72m^3/t,分析认为LD2井在新滩组钻遇断层,且龙马溪组顶界距离断层的横向距离不足20m,保存条件被破坏是导致LD2井五峰-龙马溪组页岩含气量偏低的主要原因。
The Laifeng - Xianfeng block is one of the 20 areas with shale gas exploration right in the second round of bidding invitation by the Ministry of Land and Resources, which is located in the fold thrust belt of western Hunan and Hubei Provinces. The survey well LD2 reveals the characteristics of Wufeng - Longmaxi Formation shale and its gas - bearing property in Lianghekou syncline＇ s wings. Analysis of organic geochemistry, X - ray diffraction whole rock mineral, SEM and on - site experimental data permit to characterize the Wufeng - Longmaxi shale. It has higher organic carbon content （ TOC ： 0. 42% - 3.20% ）, moderate thermal evolution degree（ Ro ： 1.47% - 2.63% ）, the mineral composition dominated by clastic brittle mineral（ quartz ＋ feldspar：37.4% - 65.3% ）, ultra low porosity and ultra low permeability. Comparing with the well LD1, which is located in Lianghekou syncline axis area, shows that the shale quality of the two wells are roughly the same, but the gas content of well LD2 is obviously low, and its maximum gas content is only 0.72m3/t. The main reason is that a fault in Xintan Formation was encountered by LD2 well drilling, and the horizontal distance between this fault and the top of Longmaxi Formation in LD2 well is less than 20m, leading to destruction of preservation conditions.
出处
《地质与勘探》
CAS
CSCD
北大核心
2018年第1期203-210,共8页
Geology and Exploration
基金
国家重大专项任务(编号:2016ZX05034004-004)
山东省自然科学基金联合专项(编号:ZR2014DL004)联合资助
关键词
来凤咸丰区块
LD2井
五峰-龙马溪组
含气量
LD2 well, Laifeng - Xianfeng block, Wufeng - Longmaxi Formation, gas content
