Enhancement of the amount of oil recovered from existing reservoirs is slowly becoming a standard procedure during the operational life of an oil well. The need for a cost effective and efficient method led to EEOR or Enzyme Enhanced Oil Recovery, a process based on the application of enzymes. It is basically a subset of Microbial EOR in which co-injected micro organisms or nutrients are used for reduction of oil viscosity.
EEOR offers a wide array of applications due to efficient surfactant mechanism and utility in both oil-wet and water-wet systems. Moreover its cost effectiveness has led to applications in marginal oil fields, for example in the Mann Field in Myanmar this led to an increase in production from 10 bopd and 109 bwpd to 17 bopd and approximately 1636 barrels of incremental oil was produced from one of the wells within 9 months of enzymatic treatment.
Use of engineered enzymes not only counter the risk of using nutrients over a long period of time but also enhance the recovery process by accelerating desired biochemical reactions between a substrate, water medium and formation. Enzymes tend to reduce viscosity and inter facial tension to a remarkable extent. Moreover they are not consumed during the reaction and act even in low concentrations. Certain strands of enzymes like Acinetobacter sp.6A2 have the ability to degrade alkanes with a chain length ranging from C10 to C40 and reduce paraffin content.
The present paper effectively summarizes the utility of EEOR through its various advantages. Enzymes are the key to the future which eradicates the long term use of microbes. Moreover its utility in marginal fields and paraffin reduction abilities make it highly suitable for countries like India which greatly suffer from such issues.