济源-开封凹陷东段馆陶组热储水化学特征及成因启示

HYDROCHEMICAL CHARACTERISTICS OF GUANTAO GEOTHERMAL RESERVOIR IN EASTERN JIYUAN-KAIFENG SAG:Implication for Its Formation

对济源-开封凹陷东段馆陶组地热水进行分析研究发现,其水化学性质为中性水、盐水、极硬水,以Cl-Na型水为主,其化学特征、控制因素、特征系数等与上部明化镇组地热水、第四系地下水及地表水差异明显.馆陶组地热水为陆相含盐岩地层沉积型溶滤水,赋存介质为砂岩孔隙,区域发育的断裂、裂隙为其提供导热和运移的通道,在大地热流的传导增温下,不断发生溶滤作用、蒸发浓缩作用等,同时热储层封闭性良好,热水运移较停滞,还原性彻底,浓缩程度高.开封断隆内馆陶组地热水的以上特征与开封-兰考断陷相比程度更高.

The analysis of geothermal water of Guantao Formation in eastern Jiyuan-Kaifeng sag shows that the geothermal water is hydrochemically neutral water,salt water and extra-hard water,mainly Cl-Na type,and its chemical characteristics,controlling factors and characteristic coefficients are significantly different from those in upper Minghuazhen Formation,Quaternary groundwater and surface water.The geothermal water in Guantao Formation is sedimentary type of lixiviation water in continental salt rock strata,occurred in sandstone pores,with regional faults and fissures as channels for heat conduction and migration,and terrestrial heat flow for heat conduction and warming,accompanied by constant lixiviation,evaporation and concentration.On the other hand,due to the well sealed geothermal reservoir,the migration of geothermal water is much stagnant,which contribute to the complete reducibility and higher concentration degree of geothermal water.Compared with Kaifeng-Lankao fault depression,the geothermal water in Guantao Formation of Kaifeng fault uplift shows higher degree of reducibility and concentration.