兰西地区地热田的形成及地热资源潜力评价

FORMATION OF THE GEOTHERMAL RESERVOIRS AND EVALUATION OF THE GEOTHERMAL RESOURCES IN LANXI AREA

为综合分析兰西地区地热资源开发潜力,通过对地热场地质条件、热源及导热构造、热储和盖层发育特征等进行研究,明确了具有经济价值的地热储层特征,并计算了泉头组三、四段的地热地质资源量、地热水资源量及可开采资源量。结果表明:兰西地区在纵向上发育上部、中部、下部、深部等4套热储组合,分别被嫩一段、嫩二段、青一段、泉一段、泉二段泥岩所分隔,具有地温梯度大、温度高、莫霍面浅等特点;花岗岩分布广泛,具有丰富的深部热源;基底断裂发育,断距较大,是热能和水的良好通道,有利于形成大面积地热田。

In order to systematically analyze the development potentials of the geothermal resources in Lanxi area, with the help of the studies on the geological conditions, main heat sources and conducting structures, characteristics of the thermal reservoirs and caprock development of the geothermal field, the features of the thermal reservoirs with a certain economic value are made clear, and moreover the calculations of the geothermal geological resources, geothermal water resources and recoverable resources amounts for Member 3 and 4 of Quantou Formation are con- ducted. The results show that four sets of the geothermal reservoirs characterized by big geothermal gradient, high temperature, shallow Moho and so on are vertically developed in the upper, middle, lower and deep parts of Lanxi area, and furthermore they are respectively separated by the mudstones of Member 1 and 2 of Nenjiang Formation, Member 1 of Qingshankou Formation, Member 1 and 2 of Quantou Formation; the granite is widely distributed and the deep geothermal sources are well enriched; the basement faults are well developed, the fault throws are rather bigger, and moreover these faults have become the good passways of the heat energy and water. All these advantages are beneficial to the formation of larger geothermal field.