Microstructural Analysis of Calcium Carbonate Scaling in Geothermal Wells of Menderes Massive

Abstract

Calcium carbonate scales are collected from two wells of Kizildere Geothermal Energy Field which is located in the most productive geothermal region of Turkey. Location of the two wells are at the two extremes of the field. Samples are taken from inside the well from the inner walls of the master valve and from the inner walls of the separator. Samples were first cut with a diamond saw to expose the layers of deposits and were analyzed by XRD (X-Ray Diffraction), SEM-EDS(Scanning Electron Microscope, Energy Dispersive Spectrometry). Some layers were observed to be darker than the others. Slices were cut further to analyze dark and light colored layers. Electron microscopy analysis revealed the mineral morphology and the distribution of elemental composition. Most of the samples consisted of aragonite mineral while the master valve of the well R1 contained calcite. Separator of R1 consisted cheifly of aragonite with minor amounts of quartz and some little calcite. There was considerable amount of strontium in almost all samples.