Application of fluorescent melamine resin microspheres for use as a geothermal tracer


Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Petroleum and Natural Gas Engineering, Turkey

Approval Date: 2018

Student: MUSTAFA SALAR

Supervisor: SERHAT AKIN

Abstract:

Tracer testing of flow between injection and production wells is an effective tool to map fluid flow pathways in a geothermal reservoir. Tracer concentration curves can be used to provide insight into projected thermal drawdown in the reservoir or thermal breakthrough of re-injected fluids, estimating inter-well volumes and flow geometries. Although radioactive tracers have been used in the past, many tracer tests now use chemical tracers that are less hazardous to handle. Fluorescent organic compounds such as fluorescein and rhodamine-B, other fluorescent compounds such as naphthalene sulfonates and dissolved inorganic solutes such as potassium iodide (KI) and potassium bromide can be used as geothermal tracers. Nano-micro colloids have been suggested as ‘smart’ geothermal tracers because of controlling parameters such as particle size. Tracer experiments were conducted using micro melamine resin rhodamine B particles with differing sizes ranging from 4 µm to 10 µm and conventional rhodamine B in a 2-D cross sectional model built from marble blocks that represents a low enthalpy liquid dominated geothermal reservoir. It has been observed that first arrival time of micro tracers was 4 times earlier than those observed in conventional rhodamine B tracer. The effect of injection rate, particle size and fracture geometry on recovery of micro particles was also investigated. It was found that the recovery of the micro particles increased with increasing flow rate and the particle size has the inverse relation with particle recovery.