Microbial Enhanced Oil Recovery: An Investigation of Bacteria Ability ...

3 downloads 0 Views 127KB Size Report
SPE 123506. Microbial Enhanced Oil Recovery: An Investigation of Bacteria Ability to. Live and Alter Crude Oil Physical Characteristics in High Pressure.
SPE 123506 Microbial Enhanced Oil Recovery: An Investigation of Bacteria Ability to Live and Alter Crude Oil Physical Characteristics in High Pressure Condition Amalia Yunita Halim, OGRINDO-ITB; Umar Dani Fauzi, Mathematics-ITB; Septoratno Siregar, SPE, Petroleum Engineering-ITB; Edy Soewono and Agus Yodi Gunawan, Mathematics-ITB; Dea Indriani Astuti, SITH-ITB; and Nuryati Juli, OGRINDO-ITB

Copyright 2009, Society of Petroleum Engineers This paper was prepared for presentation at the 2009 SPE Asia Pacific Oil and Gas Conference and Exhibition held in Jakarta, Indonesia, 4–6 August 2009. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright.

Abstract pressure condition decreases by 18,84% in 250 psi and Indonesia has officially declared its withdrawal

6,09 % in 500 psi; further investigation after 7-days

from OPEC membership in September 2008 because of

showed that IFT decreases by 27,54 % in 250 psi and 9,33

failing to meet its oil production quota as what is

% in 500 psi. The mathematical model shows that the

determined.

and

maximum production of bacteria increases with the

environmentally friendly methods need to be applied in

increase of the initial input of bacteria, and the higher the

Indonesian reservoirs; one of them is Microbial Enhanced

pressure is, the faster the bacteria growth is. It can be

Oil Recovery (MEOR). This method involves the

concluded that the bacteria are able to live in high

knowledge of biotechnology and petroleum engineering

pressure (piezophile bacteria) and give positive impact to

and is aimed to improve oil recovery in old and marginal

the crude oil by decreasing its viscosity and reducing the

wells.

This paper presents laboratory investigation of

IFT hence improve oil mobility. It is predicted that by

bacteria ability to live and alter crude oil physical

applying this method Indonesia crude oil production can

characteristics in high-pressure condition of 250 psi and

be improved or at least the production decrease can be

500 psi, provided with a mathematical model for further

slowed down.

For

that

reason,

effective

analysis. The experiment was conducted in a special apparatus called conditioning cells, which is made of

Introduction

stainless steel. Data obtained from the investigation are then used to make a mathematical model and simulation

Having been exploited for more than 100 years,

for analysis and prediction. After 3-days of treatment by

the oil production in Indonesia is now facing a very

bacteria in high pressure condition, oil viscosity decreases

serious problem due to production declines (Yusuf et al.,

by 11,27 % in 250 psi and 11,88 % in 500 psi; further

1999). Indonesia has become a net oil importer since 2003

investigation after 7-days showed that oil viscosity

and in September 2008 Indonesia officially withdrew its

decreases by 22,48% in 250 psi and 20,70% in 500 psi.

membership from OPEC (Petrominer, 2008).

The IFT after 3-days of treatment by bacteria in high

For that reason, enhanced oil recovery (EOR)

2

SPE 123506

method needs to be applied in Indonesia reservoir to

6.

the capacity to use the foodstuffs anaerobically

increase Indonesian oil production. Microbial Enhanced

(i.e. in the absence of oxygen gas) since

Oil Recovery (MEOR), as a tertiary oil recovery method

molecular oxygen cannot be provided in

is highly relevant to Indonesia because the high diversity

sufficient amounts down-hole to last perhaps for

of its microorganisms (Halim et.al, 2008c).

years on end 7.

a biochemical constitution commensurate with the production in adequate quantities of an

Benefits and Limitations

effective agent to promote mobilization of crude MEOR has several benefits compared to other EOR techniques, especially because this system offers

oil 8.

the absence of any unacceptable properties

multiple and simultaneously occurring mechanisms that

which might lead to plugging of the formation

can help to release the trapped oil in reservoir formation.

with a consequent fall in permeability, or the

The benefits of MEOR process are production of several

production of chemical substances causing

biological products such as biosurfactant, bioacid,

deleterious

biopolymer, biosolvent and gases. In addition this

downstream, etc.

biological

process

also

offer

continue

changes

in

the

oil,

corrosion

and

environmentally friendly process.

Previous Laboratory Experiment

However, there are several limiting factors that are likely to inhibit the successful of MEOR. These are

The bacteria used in this experiment were

some essential characteristics need to be investigated

isolated from brine and oil sample from an oil reservoir in

before

Kalimantan. The bacteria were then identified and tested

microbes

are

applied

in

MEOR.

Those

characteristics are (Moses and Springham, 1982) 1. 2. 3.

4.

their potential to be applied in MEOR (Solihah, 2006).

small in size, to permit most ready penetration

The investigation revealed that the bacteria were small in

through rock strata

size so that they can penetrate into the core pores and they

resistance to high pressure since many reservoirs

were able to live in high temperature environment (Halim

are deep

et al., 2008a). The core flooding experiment showed that

maximum tolerance of the high temperatures

the bacteria could increase oil recovery and also slightly

prevailing in a large number of economically

caused selective plugging in the cores samples (Halim et

important reservoirs

al., 2008b).

ability to withstand brines and sea water, since these are often present in reservoirs or used for

Research focus in this paper

waterflooding 5.

non-fastidious

nutritional

requirements,

the

This paper focuses on the bacteria ability to

simpler the better. The ability to live and thrive

survive in anaerobe and in high-pressure environment.

on the simple mineral salts already present (or

These two conditions are considered as a major concern

cheap and easy to add) in the waterflood, plus

in the successful of MEOR application because they limit

the facility to use part of the crude oil in situ as a

the bacterial growth. Microbial degradation of oil

carbon and energy source, are highly desirable

hydrocarbon in anaerobic condition is by itself an

properties

important problem both for the theoretical and applied research (Rozanova, et al., 2001). Additionally, high-

SPE 123506

3

pressure condition can contribute to the denaturation of

in Kalimantan. The bacterial inoculum concentration used

bacterial protein hence lead to bacterial death. The

was 10% at a density of about 106 -107 cells/mL. The first

bacteria used in MEOR application usually are piezophile

step was the bacteria inoculation into the recovery

bacteria, which can survive and grow well in high-

medium. In this study, we define the oil which was

pressure condition. Piezophile or pressure loving-bacteria

inoculated by bacteria as “the System”. The second step

can live up to 130 Mpa (18854.91 psi) (Rothschil &.

was the System incubation in a rotary shaker incubator of

Mancinelli. 2001).

60ºC for 3 days, with agitation of 120 rpm. The second

This paper presents data of the bacteria ability to live in anaerobe condition and high-pressure condition.

step was repeated 3 times in order to get bacteria in their active condition.

The pressure applied is 250 psi and 500 psi. The data are then used to make a mathematical model and simulation

Investigation of bacterial growth and their abilities to

using MAPLE 9 software.

alter crude oil in high pressure and anaerobic condition (without oxygen).

Material and Methods This experiment was aimed to check the bacteria ability to live in high pressure with limited oxygen amount in the

Materials

environment, as this is always become a limiting factor The bacteria used in this experiment, namely as Bacillus

for the successful of MEOR application. Four Erlenmeyer

polymyxa and Bacillus sp, were isolated from crude oil

flasks containing 250 mL of recovery medium and 20%

and brine samples of an oil reservoir in Kalimantan. Both

of crude oil were provided, they are labeled as A, B, C,

bacteria has been proven to be give positive impact to

and D. The flasks which were labeled as A and B were

crude oil characteristics by decreasing crude oil viscosity,

used for investigation of bacteria ability to live in 250 psi,

density and interfacial tension (IFT) in aerobic condition

A was inoculated by the mixed culture of Bacillus

(Solihah, 2006). There were two medium used in this

polymyxa and Bacillus. sp treatment while B was used as

experiment. The first was recovery medium, containing

a control (without bacteria inoculation). The flasks, which

one litre connate water; amonium nitrate (0.5%); molasses

were labeled as C and D, were used for investigation of

®

(2%) (Solihah, 2006). The second was Difco Nutrient

bacteria ability to live in 500 psi; C was inoculated by the

Agar (NA) as the general medium to grow the bacteria.

mixed culture of Bacillus polymyxa and Bacillus. sp

The crude oil and brine samples were collected from an

treatment while D was used as a control (without bacteria

Oil Reservoir in Kalimantan.

inoculation). The bacterial inoculum ratio was 1:1 and inoculum concentration was 10% (v/v) at about 106 -107

Methods

cells/mL. The age of the bacterium cell was in the half log of its growth phase. The liquid inside A, B, C and D was

Bacterial activation

then aseptically poured into conditioning cells made of stainless steel (figure 1), each cell for each flask. After

In this part of experiment, the bacteria were activated in

that the conditioning cells were then vacuumed and

aerobic condition to ensure that the bacteria were in their

injected by 250 psi of nitrogen for A and B; and 500 psi

active condition and to reduce the lag phase of the

of nitrogen for C and D. The conditioning cells were then

bacteria. The bacteria were activated in the recovery

incubated in an incubator at 60ºC for seven days. On the

medium containing 20% of crude oil from an oil reservoir

third and seventh day of the incubation 2 mL of the

4

SPE 123506

sample was taken from each cells, 1 mL for counting the

the data the simulation of the model is done with MAPLE

bacterial cell number and 1 mL for measuring the medium

9 software to simulate the dynamics of bacteria and

pH. In addition, crude oil physical characteristics changes

biosurfactan. The parameters

(viscosity, density and IFT) were also observed.

μ1 , μ 2 are

estimated from

the early growth (during the first day), assuming that the growth is still nearly exponential. The rest of parameters

Mathematical modeling of bacteria and biosurfactant

are estimated by curve fitting.

and Simulation of the model Oil The mathematical model simulates the experiment which

Physical

Characteristics

Post-Treatment

by

Bacteria

is conducted in laboratory. The model consists a coupling and the growth of

Oil density was measured by Pyrex picnometer. Viscosity

biosurfactant being produced by the bacteria. The growth

was measured by Ostwald Fenske Viscometer type 350 A

of bacteria is modeled by a logistic growth with toxicity

469. Interfacial tension was measured by DuNuoy

factor due to interaction with biosurfactan. This equation

Processor Tensiometer mode 21 O-ring = 6 cm.

between the growth of bacteria

is coupled with a predator-prey type equation for the biosurfactan.

Result and Discussion

The bacteria growth model is modeled by the The investigation has revealed that the bacteria

equation

μ P 2 (t ) dP ( t ) = μ1 P (t ) − 1 − γ P (t ) S (t ) dt K0

are facultative anaerobe as they can live with or without the presence of oxygen. In addition, these bacteria are also piezophiles, as they did not die when the pressure

where P (t ), μ1 , K 0 are the density, growth rate, and

was increased until 250 and 500 psi. Table 1 shows the

carrying capacity of bacteria, respectively, S (t ) is the density of biosurfactan, and γ is toxicity interaction factor due to the increase of biosurfactan.

bacteria log cell number during the 3rd and 7th day of incubation. If we compare it with the previous laboratory research (table 2), it can be seen that the bacteria can live better and also produce more acid if the pressure is

The biosurfactant growth model can is given by the equation

dS (t ) = μ 2 P(t ) − δP(t ) S (t ) dt

and

δ

where μ 2 is the production rate of biosurfactan, is the predation factor.

increased.

This

happen

because

pressure

favors

piezophiles bacterial growth by stabilizing their proteins, increasing their activities (Gilis, 1994) and also increasing the proportion of unsaturated fatty acids in their membranes (Bartlett & Bidle, 1999). It can be concluded that the bacteria used in this experiment are piezophiles bacteria because if the bacteria are not barotolerance or sensitive to pressure changes, they will fail to grow at pressure greater than atmospheric pressure. Pressure

It is assumed, as shown from the data, that at the initial

limits the growth of non-barotolerance because when

stage (at the time t1 = 12 hours) there is a significant

pressure increases the molecules in lipid membranes pack

reduction of bacteria due to environmental adjustment.

tighter, resulting in decreased membrane fluidity. (Pledger

The initial condition for bacteria is taken at t1 the from

et.al, 1994). Additionally, high pressure can alter gene expression (Nakasone et al., 1998) and also damage DNA

SPE 123506

5

and particularly proteins (Abe & Horikoshi, 1999).

between oil and brine water. It is also supported by

Investigation by Barlett and Ellen Chi revealed that the

previous lab research which showed that these two

gene, which is associated with pressure adaptation, is the

bacteria produce biosurfactant (Halim et al., 2008b).

outer membrane gene called ompH and regulatory locus

It is shown from the simulation that the maximum

called ompJ (Gillis, 1994).

production of bacteria increases if we increase the initial

Besides the bacterial growth, the bacterial ability

input of bacteria. As illustrated in Figure 3, if the initial

to alter the crude oil physical characteristic (density,

condition is increased by 24.19 %, the maximum density

viscosity, IFT) is also observed. Viscosity is a parameter

of bacteria increases by 24 %.

used to determine how easily fluids flow; the lower the

Besides the crude oil, the bacteria also change the

viscosity the easier fluids flow. The bacteria used in

medium water characteristics (density and viscosity). This

MEOR should have the ability to reduce oil viscosity.

can be seen in the figure 7 and 8 that water density and

Figure 4 shows the bacteria ability to alter the viscosity. It

viscosity decreased. It means that some materials inside

can be inferred from the figure that after 3 days of

the water were used by bacteria, the water density

incubation, the bacteria decrease oil viscosity by 11,27%

decrease was better in higher pressure. This result was

in 250 psi and 11,8% in 500 psi. Further investigation

supported by the log cell number result (table 2). This

showed that the bacteria decrease oil viscosity by 22,48%

happened because more bacteria live in 500psi so more

in 250 psi and 20,70% in 500 psi after 7 days of

materials were used by bacteria.

incubation. This means that the bacteria not only able to live in high pressure environment but also give positive

Conclussions

impact to the crude oil by decreasing its viscosity. This is supported by previous laboratory research which revealed



The bacteria used in this experiment, namely as

that the bacteria could degrade the crude oil (Solihah,

Bacillus polymixa and Bacillus sp are piezophiles

2006) and also produced gases (Halim et al., 2008b).

bacteria because they can grow in high pressure

Bacteria activities in degrading crude oil also give

environment.

contribution to the changes of oil density. In general, oil



Based on the mathematical model it can be assumed

density can be describe as oil weight per unit volume or

that the bacteria growth better as we increased the

oil weight compared with water weight in standard

initial condition of bacteria.

condition (60ºF, 14 psi). Oil density is affected by its physical characteristics (Halim et al., 2008a). The density

Acknowledgement

changes are depicted in figure 5. The figure shows that the oil was slightly degraded by bacteria so that the oil

The authors want to say thank you to OGRINDO (Oil and

fraction did not change totally and still classified in the

Gas Recovery for Indonesia) for the financial funding

intermediate fraction (between 20-30 ºAPI gravity).

during the research and to Total E&P Indonesie for the

rd

th

Figure 6 shows the IFT decrease after 3 and 7 day of

brine and crude oil samples

rd

incubation. After 3 day of incubation IFT decrease by 18,84% in 250 psi and 6,09 % in 500 psi. Further

Nomenclature

investigation showed that the bacteria decrease oil viscosity by 27,54 % in 250 psi and 9,33 % in 500 psi after 7 days of incubation. This result showed that the bacteria produce biosurfactant which can reduce the IFT

P(t) S(t) µ1 K0

= the number of bacteria in time t = the number of biosurfactant in time t = growth rate of bacteria = initial carrying capacity

6

SPE 123506

Pressure = Pressure (Psi) t = time β, γ, α, δ, ε = constant. µ2 = growth rate of biosurfactant µ21 = growth rate of biosurfactant 1

Petrominer. No 10 vol xxxv (October 15, 2008) 38-39. Pledger, R. J., Crump, B. C., Baross, J. A.: “A barophilic

response

by

two

hyperthermophilic,

hydrothermal vent Archaea: an upward shift in the optimal temperature and acceleration of growth rate at

References

supra-optimal temperatures by elevated pressure”, FEMS Abe, F., Kato, C., Horikoshi, K.: “Pressureregulated

metabolism

in

review articles : Life in extreme environments”, Natural

Bartlett, D. H. and K. A. Bidle (ed. Seckbach, J.): Microorganisms

Rothschil, L.J. and R.L.: “Mancinelli. Insight

Trends

microorganisms”,

Microbiol. 7 (1999) 447–453. Enigmatic

Microbiol. Ecol. 14 (1994) 233–242.

and

Life

in

Extreme

Vol 409 22 February 2001, Macmillan Magazines Ltd, California, USA (2001). Rozanova, E. P., I. A. Borzenkov, A. L. Tarasov,

Environments, Kluwer, Dordrecht (1999) 503–512. Gillis, A.M.: “A pressure-filled life”, Bioscience,

L. A. Suntsova, Ch. L. Dong, S. S. Belyaev, and M. V. Ivanov.:

Academic Research Library (Oct 1994) 584. Halim, A.Y., Astuti, D.I., Juli, N., S. Siregar: “The EOR Impact of Bacteria from Handil Field on

”Microbiological

Processes

in

a

High-

Temperature Oil Field”, Mikrobiologiia 70(1) (2001) 118-27.

Crude Oil from X reservoir in Java Island”, 32nd Annual

Saputra, T.D, S. Primeia, A.Y. Halim, I.A.

IPA convention and exhibition proceedings, Jakarta

Purwasena, N. Juli, D.I Astuti, P. Aditiawati.: “Chapter

(2008a).

VII : Microbial Enhanced Oil Recovery (MEOR)

Halim, A. Y., T.D. Saputra, N. Priharto, A.M.B. Laskary., I.G. Pandu, S. Primeia, N. Juli, D.I Astuti, P.

Research in Handil Field”, 4th Annual OGRINDO Report May 2008, Bandung, Institut Teknologi Bandung (2008).

Aditiawati.: “Chapter VIII : Investigation of Indigenous

Solihah, E.: “Isolasi Bakteri Hidrokarbonoklastik

Bacteria Activities from Handil Reservoir: Next Step for

Thermofilik yang Berpotensi untuk MEOR dari Minyak

Field Application”, 5th Biannual OGRINDO Report,

Bumi dan Air Formasi Ladang Y di Kalimantan”, Skripsi

November 2008, Bandung, Institut Teknologi Bandung

SITH ITB, Bandung (2006). V. Moses and D.G. Springham: “Bacteria and

(2008b) Halim, A.Y., Astuti, D.I., Juli, N., Siregar, S., Solihah E.: “Laboratory Study of Bacteria from an Oil

Enhancement

of

Oil

Recovery”,

Applied

Science

Publisher, London (1982).

Reservoir in Kalimantan to be applied as indigenous and

Yusuf, A.S., Kadarwati, Nurkamelia, Sumaryana.:

non-indigenous bacteria in Microbial Enhanced Oil

“Field Test of the Indigenous Microbes for Oil Recovery,

recovery (MEOR)”, Proceedings International Conference

Ledok Field, Central Java”, Society of Petroleum

on Mathematics and Natural Sciences (ICMNS), 2nd

Engineers, SPE 57309 (1999).

Conference, Institut Teknologi Bandung, Indonesia

J.

H.:

”Numerical

Methods

for

Engineering Applications”, John Wiley and Sons (1998).

(2008c). Nakasone, K., Ikegami, A., Kato, C., Usami, R., Horikoshi,

Ferziger

K.:

“Mechanisms

of

gene

expression

controlled by pressure in deep-sea microorganisms”, Extremophiles 2 (1998) 149–154.

SPE 123506

7

Crude Oil Viscosity 1,8 1,6

viscosity (cP)

1,4 1,2 1 0,8 0,6 0,4 0,2 0 250

Control

3 days

500

pressure (psi)

7 days

Viscosity

Decrease percentage (%)

days

250 psi

3 days

Figure 1. The result of simulation bacteria growth model compare with the data in the 7 days.

7 days

500 psi

11,270

11,878

22,476

20,697

Figure 4. Oil viscosity decrease after 3rd and 7th day of incubation.

Crude Oil Density 31

30

o

density ( API )

30,5

29,5 29 28,5 28 250

Control

Figure 2. The result of simulation biosurfactant

3 days

7 days

Density

growth model compare with the data in the 7 days.

500

pressure (psi)

Decrease percentage (%)

days 3 days 7 days

250 psi

500 psi

0,057

0,069

0,125

0,137

Figure 5. oil density decrease after 3rd and 7th day of incubation.

Figure 3. The result of simulation which the initial condition increased compare with the data in the 7 days.

8

SPE 123506

Table 1. bacteria log cell and medium pH changes

Interfacial Tension (IFT) 16

during incubation in 250 psi and 500 psi

IFT (dyne/cm)

14 12 10 8 6 4 2 0 250

Control

3 days

7 days

IFT

500

pressure (psi)

days

250 psi

3 days 7 days

Table 2. bacteria log cell and medium pH changes

500 psi

18,841

6,086

27,536

9,331

Figure 6. Interfacial tension decrease after 3rd and 7th day of incubation.

Water density 0,984

density (gram/ml)

0,983 0,983 0,982 0,982 0,981 0,981 250,000

3 days

7 days

500,000

pressure (psi)

Figure 7. Water density decrease after 3rd and 7th day of incubation.

Water viscosity 0,500 0,450

viscosity (cP)

0,400 0,350 0,300 0,250 0,200 0,150 0,100 0,050 0,000 250,000

Control

3 days

250 psi 500 psi 7,23 7,20 7,51 8,80 6,04 6,20 7 7 5,5 5 5 4,5

Decrease percentage (%)

Control

Treatment Log cell 0 day number 3 days 7 days pH 0 day 3 days 7 days

7 days

500,000

pressure (psi)

Figure 8. Water viscosity decrease after 3rd and 7th day of incubation.

during incubation in 50 psi (Saputra, et. Al., 2008)

Treatment Log cell 0 day number 3 days 7 days pH 0 day 3 days 7 days

50 psi 7,53 6,25 5,75 7 5,5 5