兰考县新近系热储赋存规律及开发适宜性研究

The Occurrence Regularities and Development Suitability of Neogene Thermal Reservoir in Lankao County

兰考县是河南省沿黄地区的重要城市之一,其地热资源丰富,新近系地热流体开采条件优越.以兰考县及其周边一定区域为研究区域,根据研究区域的地热地质调查资料,对其新近系热储赋存规律进行了研究.首先,根据研究区地热构造格局及地温场形成机制对其新近系热储特征及构造影响进行了分析,分析结果显示研究区新近系馆陶组热储层地热流体的赋存与其基底断裂构造的空间展布关系密切,主要受新乡—商丘断裂和聊城—兰考断裂的伴生构造控制.在此基础上,将研究区分为四个地热亚区,不同地热亚区新近系热储层的富水性存在一定差异.然后,根据研究区的地质结构及地热井资料数据得出,地热供暖应优先采用直井+定向井的组合,在断裂构造影响带范围内,新近系馆陶组热储层的开采量可进一步增大且具有良好的回灌效果.最后,对研究区的地热资源量进行了计算,结果显示研究区新近系热储层的地热流体产量大,适宜开发且具有良好的经济性.建议研究区新近系明化镇组热储层优先用于热矿水开发,新近系馆陶组热储层优先用于地热供暖性质的开发.

Lankao County is one of the important cities along the Yellow River in Henan Province.It is rich in geothermal resources and has superior exploitation conditions of Neogene geothermal fluid.Taking Lankao County and its surrounding area as the study area,the occurrence regularities of Neogene thermal reservoir is studied according to the geothermal geological survey data of the study area.Firstly,the Neogene thermal reservoir characteristics and structural influence are analyzed according to the geothermal structural pattern and geothermal field formation mechanism of the study area.The analysis results show that the occurrence of geothermal fluid in Neogene Guantao formation thermal reservoir in the study area is closely related to the spatial distribution of basement fault structure,which is mainly controlled by the associated structures of Xinxiang-Shangqiu fault and Liaocheng-Lankao fault.On this basis,the study area is divided into four geothermal subregions,and there are some differences in the water abundance of thermal reservoirs in different geothermal subregions.Then,according to the geological structure and geothermal well data of the study area,the combination of vertical well and directional well should be preferred for geothermal heating.Within the influence zone of fault structure,the exploitation of Neogene Guantao formation thermal reservoir can be further increased and has good recharge effect.Finally,the geothermal resources in the study area are calculated.The results show that the Neogene geothermal fluid production in the study area is large,and it is suitable for development and has good economy.It is suggested that the Neogene Minghuazhen Formation thermal reservoir in the study area should be preferentially used for thermal mineral water development,and the Neogene Guantao formation thermal reservoir should be preferentially used for geothermal heating development.