Biosurfactant – Higher Standard
The performance of these chemically derived surfactants was sufficient to meet the demands of the oil industry for many years. However, today’s changing operating conditions, including low-porosity, HP/HT reservoirs—combined with the drive for environmentally friendly, sustainable, biodegradable and cost-effective compounds—have created the need for new advances in surfactant technologies, namely biosurfactants. Biosurfactants are surface-active amphiphiles with polar (hydrophilic) and nonpolar (hydrophobic) groups of substances produced by microorganisms using advanced biotechnology. Biosurfactants produced in situ in the reservoir by microbes have been an accepted practice for decades, with microbial EOR (MEOR) first patented in 1946. By 2007 a MEOR review showed a 78% success in EOR across U.S. wells from the production in the reservoir of microbial metabolites, such as nonionic and anionic microbial surfactants, which offer a variety of functions and characteristics unmatched by chemical surfactants. In the MEOR process, microbes and nutrients were injected into oil wells in an attempt to produce biosurfactants in situ. However, the results were inconsistent as the microbial generation of biosurfactants were difficult to control. These challenges triggered a new industry need: a way to produce these metabolites at scale and of consistent quality in a more controlled environment (ex situ) and then apply them where needed in a similar manner to traditional synthetic surfactants.01
The use of biosurfactants as alternatives to petroleum-based surfactants in oilfield applications has grown throughout the past decade. Aside from their green profile, biosurfactants are highly attractive as excellent wetting agents and have remarkably low critical micelle concentrations (minimum effective dosage rates), which reduce surface and interfacial tensions to extremely low levels.
Naturally derived biosurfactant offers significant advantages over synthetic surfactants, such as enhanced performance, environmental compatibility, low toxicity, biodegradability and maintained activity under extreme conditions of temperatures, salinity and pH values. Biosurfactants are also low cost, completely biodegradable and leave no toxic waste from their production processes.02
The advantages of biosurfactants come from their multiple mechanisms of action, including penetrating much deeper into the oil reservoir to reduce viscosity, dispersing blockages, changing interfacial tensions and oil/water contact angles, and mobilizing otherwise immobile oil, ultimately increasing production. These biosurfactants replace and outperform traditional, synthetic counterparts at a fraction of the dosage rates (in some tests as little as 1/50th of the dosages of traditional surfactants) and with no hazardous effects to the environment.03