Laboratory Investigation on the Effects of Different Types of Surfactants on the Wettability Characteristics of Malaysian Coal for CBM Study

Application of surfactant in CBM production has been steadily recognised. Surfactant acts as a wetting agent which helps to lower surface tension of coal bed groundwater, thus decreasing reservoir pressure to allow CBM production. For surfactant consequence enhancement, biosurfactant is introduced to ECBM towards better cost and environmental effect, other than its significant advantages over synthetic surfactants such as lower toxicity, higher biodegradability, better environmental capability, higher foaming and better thermal range. Unlike conventional reservoirs, dewatering process has to be done firsthand in ECBM in order to desorb CBM from coal micropores. Wettability alteration is necessary to increase coal surface hydrophobicity for more efficient dewatering process. However, biosurfactant application in hydrocarbon production is still in laboratory scale for ECBM wettability investigation, thus the information regarding biosurfactant effectiveness in Oil and Gas field is still ambiguous. There are some biosurfactants that have been applied for EOR application. However, researches done for biosurfactant application for ECBM are very few. In this project, the performance of SDS and AOS (synthetic surfactants) in comparison to betaine anhydrous (vegetal biosurfactant) for its potential use in ECBM application for coalbed reservoir is compared. The comparison is based on wettability factor between the surfactants and the coal surface.