南昌红盆地区地热构造地球物理勘查

Geothermal tectonic prospecting of the red basin in Nanchang by using geophysics method

为完成对南昌红盆地区地热构造调查任务,分析了南昌红盆地区贮热地质构造特性和热水的形成条件,推测该区域可能存在地热潜力。为探测红盆地区深部控热构造的分布状态,选择探测深度大,抗干扰能力强、横向分辨率高的CSAMT方法进行探测。查明基底埋深约1 500 m,推断上古生界二叠系灰岩地层为热储层,顶板埋深约1 000 m,厚度约500 m。推断出一条断裂破碎带,发现其地球物理电性特征与深部的断裂构造非常明显的对应关系。为地热钻孔位置的选取及其井身结构设计提供了依据。

To complete the geothermal structure survey task of the red basin in Nanchang, this paper analyzes the characteristics of geothermal storage structures and the forming condition of hot water, conjectures the possibility of geothermal potential in this region. For detecting the distribution of deep heat-controlling structures, the CSAMT method was used which has deeper depth of exploration, stronger anti-interference, higher lateral resolution. It has been verified that the depth of the basement is about 1500m, Paleozoic Permian limestone strata is inferred to be the heat reservoir, the depth of cover of geothermal reservoirs is about 1000 m, the thickness of it is about 500m. One fault in red basin has been inferred and defined. Clear corresponding relation is discovered between the geophysical electric character and the deep fracture tectonics. It provides the basis for the selection of borehole location and casing programme design.