水-岩平衡在馆陶组热储温度估算中的应用

摘要

地球化学地热温标在地热资源勘查与评价中具有广泛的应用前景，国内外地热工作者推导总结了一系列用于估算热储温度的地热温标，其中二氧化硅地热温标、钾镁地热温标及钾钠地热温标最具代表性。基于地球化学地热温标的水-岩平衡应用原理，认为华北平原区馆陶组热储中见有次生的方解石、白云石矿物，可采用方解石与白云石的饱和指数反推热储温度。并采用PHREEQC软件，通过实例验证方解石与白云石饱和指数地热温标的可靠性。分析认为，热储温度应低于白云石估算温度，而接近并略高于方解石估算温度。%Geochemical geothermometer has extensive application prospect in geothermal resource exploration and evaluation. Geothermal researchers have derived and summarized a series of geothermometers in which silica geothermometer, K-Mg geother-mometer and K-Na geothermometer are most representative used to estimate the thermal reservoir temperature. There are secondary mineral of calcite, dolomite at Guantao thermal reservoir in the North China Plain . Therefore the author thinks the saturation index of calcite and dolomite can be used backstepping the thermal reservoir temperature based on the geochemical geothermometer water-rock balance principle. And by using the PHREEQC software, the author conducted real examples of calcite saturation index geo-thermometer to verify its reliability. It is coming to the dicision that the temperature of geothermal reservoir should be under the dol-omite equilibrium temperature and close to or slightly higher than the calcite equilibrium temperature.