Developing New Tracer Method for Determining the Steam Wetness in Geothermal Field

Abstract

One important aspect in the process of operating geothermal wells is steam quality. Based on the Steam / Electricity Purchase Agreement, it is stated that the first party (the company), has an obligation to ensure that the steam delivered to the customer meets the conditions agreed upon in the contract. The futility to manage this can result in the failure to achieve the company's annual electricity generation target due to high maintenance costs, high downtime, and loss of revenue. Steam wetness is a part of impurities in the steam beside non-condensable gas (NCG), silica content, and total dissolved solids (TDS). It is stated that steam should contain less than 1% of water from total transferred fluids. The method commonly used to measure steam wetness is throttling calorimeter. Nevertheless, there are several conditions that must be fulfilled so that the measurements taken are accurate, such as the system condition must be adiabatic and the sampling process must use an isokinetic probe. In addition, this method has measurement limitation, depending on the pressure, roughly maximum 7% of wetness. This paper offering a new method in determining steam impurities in term of steam wetness. By using tracer technic and special chemical material, it is possible to measure steam wetness in limitless of range. This material is only soluble in the liquid phase and environmental friendly.