Microbial Enhanced Oil Recovery: An Investigation of Bacteria Ability to Live and Alter Crude Oil Physical Characteristics in High Pressure Condition

Abstract

Indonesia has officially declared its withdrawal from OPEC membership in September 2008 because of failing to meet its oil production quota as what is determined. For that reason, effective and environmentally friendly methods need to be applied in Indonesian reservoirs; one of them is Microbial Enhanced Oil Recovery (MEOR). This method involves the knowledge of biotechnology and petroleum engineering and is aimed to improve oil recovery in old and marginal wells. This paper presents laboratory investigation of bacteria ability to live and alter crude oil physical characteristics in high-pressure condition of 250 psi and 500 psi, provided with a mathematical model for further analysis. The experiment was conducted in a special apparatus called conditioning cells, which is made of stainless steel. Data obtained from the investigation are then used to make a mathematical model and simulation for analysis and prediction. After 3-days of treatment by bacteria in high pressure condition, oil viscosity decreases by 11,27 % in 250 psi and 11,88 % in 500 psi; further investigation after 7-days showed that oil viscosity decreases by 22,48% in 250 psi and 20,70% in 500 psi. The IFT after 3-days of treatment by bacteria in high pressure condition decreases by 18,84% in 250 psi and 6,09 % in 500 psi; further investigation after 7-days showed that IFT decreases by 27,54 % in 250 psi and 9,33 % in 500 psi. The mathematical model shows that the maximum production of bacteria increases with the increase of the initial input of bacteria, and the higher the pressure is, the faster the bacteria growth is. It can be concluded that the bacteria are able to live in high pressure (piezophile bacteria) and give positive impact to the crude oil by decreasing its viscosity and reducing the IFT hence improve oil mobility. It is predicted that by applying this method Indonesia crude oil production can be improved or at least the production decrease can be slowed down. Introduction Having been exploited for more than 100 years, the oil production in Indonesia is now facing a very serious problem due to production declines (Yusuf et al., 1999). Indonesia has become a net oil importer since 2003 and in September 2008 Indonesia officially withdrew its membership from OPEC (Petrominer, 2008).

Investigation of Biosurfactant-Producing Indigenous Microorganisms that Enhance Residue Oil Recovery in an Oil Reservoir After Polymer Flooding

“…The indigenous bacteria used in MEOR application usually are piezophile bacteria, which can survive and grow well in high pressure conditions [19,20].…”

Microbial enhanced oil recovery: interfacial tension and biosurfactant-bacteria growth

“…Growth model of biosurfactant-producing bacteria may couple logistic-growth and modify predator-prey model (see Eq. 1, Halim et al 2009). P is the number of bacteria in base-10 logarithm for each cell/mL, S is biosurfactant concentration (g/L), 1 is bacteria growth rate (h −1 ), 2 is biosurfactant production rate (mg/ cell/h), K 0 is carrying capacity (cell/mL), is toxicity constant (L/g/h), and is predation factor (1/h).…”

“…P is the number of bacteria in base-10 logarithm for each cell/mL, S is biosurfactant concentration (g/L), 1 is bacteria growth rate (h −1 ), 2 is biosurfactant production rate (mg/ cell/h), K 0 is carrying capacity (cell/mL), is toxicity constant (L/g/h), and is predation factor (1/h). Equation 1assumes that there is a significant reduction of bacteria due to environmental adjustment at the initial stage (Halim et al 2009). The initial condition is at the next time step of the data i.e.…”

“…Models isothermal growth kinetics of Listeria monocytogenes in broth and beef frankfurters Halim Halim et al (2009) dP…”

“…This research proposes another model that is modified from the existing model (Eq. 1, Halim et al, 2009), the consistent model, as shown by a set formula in Eq. (8).…”