Fourier Transform Infra-Red As A Cost Efficient, Rapid Tool For Hydrothermal Exploration

Abstract

The use of Fourier Transform Infra-Red (FTIR) calibrated with high quality X Ray Diffraction data has become a routine method in the exploration and development of unconventional plays in North America. This application relies on the ability of FTIR to predict mineralogy from rock samples non-destructively, quickly and cost effectively. Additionally, in unconventional plays, where rock mechanics are key, Young’s Modulus and Poisons Ratio can be predicted. It enables data to be gathered on thousands of samples in a fraction of the time and at a fraction of the cost of more traditional tools. The FTIR approach has clear potential for application to hydrothermal exploration. This paper presents initial findings on the use of the FTIR work flow developed for North American unconventional plays to hydrothermal exploration. FTIR and XRD datahave been collectedonover 150 samples from boreholes penetrating Cretaceous Carbonates in the Geneva Basin. The 3 study boreholes range in length from approximately 3000mMD to approximately 250mMD at depths of 50-3000. Within these boreholes the hydrothermally active zones are known and the response of the FTIR in those zones is compared to that of the parent rock. Combining the FTIR with XRD and rock mechanics enables the key features of the hydrothermally altered rock to be elucidated and the controlling factors determined. The work aims to demonstrate to what extent the FTIR approach is applicable to hydrothermal exploration, with the ultimate goal of developing a cost effective tool in this setting and potentially to add information on borehole stability and heat production.

AAPG Datapages/Search and Discovery Article #90346 ©2019 AAPG European Region, 3rd Hydrocarbon Geothermal Cross Over Technology Workshop, Geneva, Switzerland, April 9-10, 2019