论文详情
为了发挥非地震勘探技术成本低、效率高的优势,检验电法勘探技术在页岩气勘探中的有效性,分别于2011、2012年对分布于四川盆地南部的志留系龙马溪组-奥陶系五峰组、寒武系牛蹄塘组两套典型富有机质页岩层系进行了时频电磁法(Time-Frequency Electromagnetic Method,TFEM)页岩气勘探试验。岩石样本研究表明,这两套页岩层系具有较为明显的低密度、低磁化率、高极化率、高TOC、相对高电阻率,即“两低、两高、一相对高”的物性特征。2012年进行的面积时频电磁法勘探试验结果与2011年完成的二维时频电磁法勘探试验结果均表明,试验区分布的志留系龙马溪组-奥陶系五峰组层系具有高极化率与相对高电阻率异常分布特征。以时频电磁法勘探获取的高极化率异常为主,通过多参数评价,预测了试验区两套目标层系的TOC高值分布区。
In order to verify the availability of electric exploration technique as well as to exert the advantages of high-efficiency and low-cost of integrated exploration techniques,typical organic-rich shale in Longmaxi Formation of Silurian System,Wufeng Formation of Ordovician System and Niutitang Formation of Cambrian System in Southern Sichuan Basin are selected as the shale gas exploration test area in 2011 and 2012 respectively.We firstly analyze and summarize the petrophysical features of gas shale,then conduct the lithology investigation and TFEM test work.This paper releases a step forward test results in 2012.The physical property data of the test area illustrates that the organic-rich shale in Longmaxi Formation,Wufeng Formation and Niutitang Formation shows low density,low magnetic susceptibility,high polarization ratio,high TOC and relative high resistivity (two-lows,two-highs and one relative high).Both the linear TFEM test in 2011 and the area TFEM test in 2012 show high polarization ratio and relative high resistivity in Longmaxi Formation and Wufeng Formation at the area.Based on the TFEM test data in 2012,the high TOC area is preliminarily evaluated and predicted to the target Longmaxi-Wufeng Formation and Niutitang Formation.
中国地质调查局地质矿产调查评价专项项目(12120114020001)、全国页岩气资源潜力调查评价及有利区优选项目(2009GYXQ15)联合资助。