Overview of Geothermal Exploration in Saint Lucia, West Indies

Abstract

A recent programme of deep exploratory drilling conducted in the Qualibou Caldera in Soufriere, Saint Lucia has provided new but inconclusive information on the geothermal resource. Well SI-1 located in the Belfond area was drilled to a total depth of 7261 ft. This well encountered low permeability and high temperatures, with a maximum of 241°C at total depth. Following this unsuccessful attempt at penetrating the reservoir, the site of Etangs chosen for the location of well No 2 was abandoned and the second well SL-2 was drilled to a total depth of 4636 ft in the Sulphur Springs area. SL-2 produced superheated steam with a very high gas content from what is assumed to be a vapor dominated zone overlying a brine dominated reservoir. A long term flow test of SL-2 is required, specifically planned to investigate the chemistry of the geothermal fluid and to allow a more definite assessment of the well's permeability and drawdown characteristics.