Adel Sharif University of Surrey a.sharif@surrey.ac.uk Petroleum Industry uses of Bactria: Microbial Enhanced Oil Recovery (MEOR) Adel Sharif University of Surrey a.sharif@surrey.ac.uk Industrial Uses of Bacteria 19 May 2010, IOM3, London, UK

Petroleum Microbiology MICROBIAL TREATMENT OF PETROLEUM WASTE Treatment of Contaminated Soils and Sludges  Factors affecting bioremediation. Biofiltration of Volatile Organic Compounds Removal of H2S and SOX MICROBIAL PROCESSES FOR RECOVERING AND UPGRADING PETROLEUM Microbial Enhanced Oil Recovery Microbial Deemulsification Microbial Desulfurization      Microbial Denitrogenation Enzymatic Upgrading of Petroleum Fractions and Pure Hydrocarbons BACTERIAL BIOSENSORS

Oil formation

Oil Recovery Methods Primary (natural reservoir energy) (15-20%) - Solution Gas Drive (depletion). - Gas Cap Drive. - Natural water Drive.

Secondary oil Recovery method (30-35%) - Water Injection. - Gas Injection. - WAG method.

Tertiary Oil Recovery method (30-50%) - Thermal Injection (steam). - Chemical Injection (Polymer).

Oil Recovery Techniques During primary stage only 15-20% oil can be recovered naturally. Another 15-25% can be recovered during the secondary stage through water injection. Tertiary stage (of steam injection) is too expensive to be used. Hence, nearly 50% of the oil still needs to be recovered.

Microbial Enhanced Oil Recovery (MEOR) What is the solution? MEOR! MEOR is a process in which micro-organisms are used to produce surfactants, acids, and/or gases using growth substrates from the fossil fuel, to enhance the oil recovery.

Schematic Diagram of MEOR

Microbial Enhanced Oil Recovery (MEOR) MEOR Microorganisms produce Biosurfactants which decrease the oil viscosity to increase oil flow. Acids which increase the rock porosity and hence oil flow. Gases to increase the pressure in the reservoir and improve oil recovery. Exopolymers and biomass to block the thief zones.

MEOR Mechanism

MEOR - Objectives Developing an MEOR technology, to be implemented in the oil fields to recover the oil during the secondary/tertiary stage. Isolating suitable microorganisms from the samples taken from the oil reservoirs. Isolating microorganisms producing biosurfactants and/or organic acids, polymers, gases and using hydrocarbons under low water activity. Isolating microorganisms producing the above chemicals under reservoir conditions from hydrocarbons or cheap feedstocks. To genetically or physiologically manipulate useful microorganisms adapted to be active under the reservoir conditions.

Exploitation of Deep fields High Temperature ( > optimum less bacteria growth) (85C is well known, but 95-100 is possible). High Pressure (careful consideration must be given to the effects of pressure on growth rate and yield as they might result in delays in the bacterial release of oil or possibly even lowered bacterial activity to the point where expected benefits are not obtained at all.) High Salinity (high NaCl concentration will inhibits the growing of bacteria, so better use Halophiles at high NaCl ppm).

Plugging of Formations (due to bacteria metabolism and their products) Down-side of MEOR Plugging of Formations (due to bacteria metabolism and their products) - plug porous rocks causing reduced permeability. Degradation of Oil in Reservoir (CH4 diffusion from oil) Bacterial Corrosion (sulphate-reducing bacteria) Souring (H2S) Insufficient Nutrition for Bacteria.

MEOR- The Hard Part! Process development, scale-up, field implementation….

Sustainable Development and MEOR MEOR reduces or eliminates the need to use harsh chemicals during oil drilling It is an environmentally compatible method of carrying out tertiary oil recovery. MEOR will become increasingly economically feasible as genetic engineering develops more effective microbial bacteria that may subsist on inexpensive and abundant nutrients. Methods for developing and growing MEOR bacteria are improving, thereby lowering production costs and making it a more attractive alternative to traditional chemical methods of tertiary oil recovery.

Conclusions I Key potential advantage of MEOR –ability to use in situ carbon source Key disadvantages of MEOR Likely microbial performance constraints Poor lab, field performance relative to peers (other chemical EOR) Preferred MEOR option Profile modification via biomass Simpler, esp. with indigenous microbes Compared to waterflood -Small incremental cost; Marginal increase in difficulty

Conclusions II While the research on MEOR mechanisms is still not adequate and the success rate is still not high enough to increase heavy oil recovery on a large scale, at today’s oil prices this is a promising technology which offers major R&D and commercial opportunities.