The main drawback in the utilization of geothermal resources arises from the precipitation of secondary minerals within wells, pipelines, steam separators, turbines and other surface equipment in form of scales. Scale...The main drawback in the utilization of geothermal resources arises from the precipitation of secondary minerals within wells, pipelines, steam separators, turbines and other surface equipment in form of scales. Scale formation is an outcome of the alteration of various rocks dissolved in geothermal fluids that find their way into a reservoir. Once geothermal fluids ascend to the surface, hydrostatic pressure decreases toward a phase separation level that permits the dissolved gases such as CO<sub>2</sub>, H<sub>2</sub>S and H<sub>2</sub>, and steam to separate from the liquid phase by “boiling”. Stripping of these volatiles may increase fluid pH, leading to precipitation and deposition of secondary minerals. The study sought to establish the relationship between water-rock interaction and secondary mineral precipitates at the surface and deep fluid at different temperatures during depressurisation boiling and cooling. Samples were collected from selected Olkaria wells;OW-38A, OW-910 and OW-910A. The analysis of the results outlined deep fluid Alkali-Chloride waters and surface steam-heated Alkali-Bicarbonate and acidic Sulphate-Chloride waters. Various models suggested adiabatic boiling, conductive cooling and possible mixing and dilution in the wells. Hydrothermal alteration minerals were found to be in equilibrium with the geothermal fluids at varying temperatures, and the secondary minerals controlled the chemistry of the reservoir. Silica-saturated solutions precipitated silica in OW-910 and OW-910A, which may have resulted from rapid cooling following mixing with cold surface water.展开更多
本文对小化肥厂变换炉通过反应平衡常数与主要气体成分、CO 转化率的关系导出半水煤气中 CO 含量与汽—气比方程式;同时考虑了热水饱和塔所能回收的蒸汽量,进而得到需要添加的蒸汽量计算式,并对此数学模型进行工程实施处理。系统投运后...本文对小化肥厂变换炉通过反应平衡常数与主要气体成分、CO 转化率的关系导出半水煤气中 CO 含量与汽—气比方程式;同时考虑了热水饱和塔所能回收的蒸汽量,进而得到需要添加的蒸汽量计算式,并对此数学模型进行工程实施处理。系统投运后效果令人满意。展开更多
文摘The main drawback in the utilization of geothermal resources arises from the precipitation of secondary minerals within wells, pipelines, steam separators, turbines and other surface equipment in form of scales. Scale formation is an outcome of the alteration of various rocks dissolved in geothermal fluids that find their way into a reservoir. Once geothermal fluids ascend to the surface, hydrostatic pressure decreases toward a phase separation level that permits the dissolved gases such as CO<sub>2</sub>, H<sub>2</sub>S and H<sub>2</sub>, and steam to separate from the liquid phase by “boiling”. Stripping of these volatiles may increase fluid pH, leading to precipitation and deposition of secondary minerals. The study sought to establish the relationship between water-rock interaction and secondary mineral precipitates at the surface and deep fluid at different temperatures during depressurisation boiling and cooling. Samples were collected from selected Olkaria wells;OW-38A, OW-910 and OW-910A. The analysis of the results outlined deep fluid Alkali-Chloride waters and surface steam-heated Alkali-Bicarbonate and acidic Sulphate-Chloride waters. Various models suggested adiabatic boiling, conductive cooling and possible mixing and dilution in the wells. Hydrothermal alteration minerals were found to be in equilibrium with the geothermal fluids at varying temperatures, and the secondary minerals controlled the chemistry of the reservoir. Silica-saturated solutions precipitated silica in OW-910 and OW-910A, which may have resulted from rapid cooling following mixing with cold surface water.
