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MICROBIOLOGICAL TECHNOLOGIES
MICROBIOLOGICAL METHOD FOR ARPD REMOVAL FROM THE
PRODUCING WELLS
The intensive paraffin deposition in the field equipment shortens
its overhaul life and requires rather complicated and expensive
operation. The technology is recommended for the producing wells
equipped with the sucker-rod pumps. Removal of paraffin deposits
from the well equipment and bottom-hole zone is based on employment
of the aerobic hydrocarbon-oxidizing bacteria oxidizing and making
paraffin oil hydrocarbons movable. Vital activity of the hydrocarbon-oxidizing
microorganisms results in formation of substances having combined
ARPD decomposing, removing and inhibiting properties. The microbiological
method for paraffin control is new but it has found use both abroad
and in Tatarstan.
The technology has been employed in NGDU "Bavlyneft"
on a large scale. Altogether more than 150 wells were treated in
JSC "Tatneft". Economic return is 1 - 1.5 thousand roubles
per 1 producing well. The scraping interval of producing wells increases
from 1-2 up to 2-12 months.
 
BIOTECHNOLOGICAL METHOD FOR IMPROVED OIL RECOVERY
BY RESERVOIR SYNTHESIS OF OIL-DISPLACING AGENTS
The method is recommended for the highly encroached fields (90-95%)
at the later stage of exploitation. The method comprises an increase
in efficiency of residual oil displacement from the flooded reservoirs
using the oil-displacing agents - the products of vital functions
of microorganisms formed directly in pore space of the oil reservoirs
by stimulation of the microflora populating formation fluids of
the flooded fields. If the reservoir microflora is absent the suitable
microorganisms are injected.
The technology comprises 4 cycles for the injection of salts, biostimulator
and hydrocarbon-oxidizing bacteria (HOB). 1 - 2 cycles involve the
injection of aerated salt solutions and biostimulator stimulating
the bacteria causing the degradation of residual hydrocarbons in
the bottom-hole formation zone and the formation of low-molecular
fatty acids, alcohols, aldehydes and biopolymers from them. 3 -
4 cycles involve the injection of salt solution stimulating other
microflora causing the formation of gaseous oil-displacing agents.
The intermediate products of microorganisms’ vital functions become
the new oil-displacing agents such as CH4, CO2,
H2 and N2 as they travel through the reservoir.
The alternation of the aerated salt solutions’ injection and conventional
waterflooding promotes travel of the oil-displacing agents’ system
through the reservoir towards the producing wells.
The incremental oil production amounts 37% of total production
in the area by using the technology. The technology is cheap, available,
simple and ecologically safe, it is used employing the equipment
availiable in the field.
TECHNOLOGY FOR OIL POLLUTION REMOVAL FROM BASINS
AND SOIL BY COMBINED METHOD USING HYDROCARBON-OXIDIZING BACTERIA
The technology is based on preliminary oil gathering by the mechanical
method and further application of adsorbent with oil as a fuel or
destruction of adsorbent by microorganisms.
The mechanical method being primary is used for treating water
surface, waterside part of basins and soil at high degree of pollution
and fuel oil fouling. The method involves mechanical gathering of
oil products, their decantation from water or soil and preparation
for utilization. Oil skimmers (desilters), soil rippers with floating
barriers, decantation and dewatering units, reagent assembly, mobile
treating facilities are used for this purpose.
The oil products can be gathered both from soil surface and water
surface with adsorbent. The adsorption capacity ranges from 6 to
8 g/g depending on oil viscosity. The oil product gathered with
the adsorbent can easily regenerate or decompose with microorganisms
if required.
We use the adsorbent of combined action containing basically the
hydrocarbon-oxidizing bacteria (HOB) and other bacteria for specific
pollution. They are able to decompose oil and adsorbent to ecologically
neutral compounds or to transform into water-soluble organic compounds
up to their complete oxidation to CO2 and water. The
booms of adsorbents with HOB trapping oil are placed for treating
water surface.
The adsorbent can be removed or left for biodegradation on the
surface depending on the specified conditions after their oil saturation.
The treatment of the oil-polluted areas is started at the end of
April - at the beginning of May (depending on the climatic conditions)
and then the cyclic soil treatment is carried out with 20-30 days’
interval.
The conventional facilities and ecologically safe and readily available
reagents have been used for the treatment of the oil-polluted area.
The technology for soil treatment has been successfully used in
West Siberia and Tatarstan.
COMBINED TECHNOLOGY FOR OIL POLLUTION REMOVAL FROM
BASINS AND SOIL
The technology is used for oil products’ gathering during workover
and for utilization of accidentally spilled liquid oil products:
motor oil of various grades, crude oil, fuel oil, diesel oil etc.
The technology comprises:
- mechanical and adsorptive gathering of oil products from soil
and water surface. The spilled oil products can be gathered from
soil and water surface with adsorbent by powder spraying or with
adsorptive elements in a form of mats and booms;
- complete recultivation of soil by the bioadsorptive method.
The oil product can be regenerated after the mechanical and adsorptive
gathering. Consumer goods can be made of double adsorbent-oil product
mass if required. The adsorbents are ecologically safe, they are
made of readily available raw materials and certified. Their large-
scale production has been arranged.
The mechanical treating method is used for severe oil pollution.
The conventional facilities are used for treatment of the oil-polluted
areas. Soil is recultivated in April - October.
| Characteristics |
| Appearance |
powder or flat elements in a form of ribbons and mats |
| Adsorption capacity, g/g |
not less than 2-8 (viscosity of oil product is not more than
40 mm2/s) |
| Specific mass, g/cm3 |
0,6-0,85 |
| Period of complete soil recultivation |
not more than 10 months (temperature of soil is not more than
10°C) |
Guaranty period:
- mechanical adsorbent
- biological adsorbent |
unlimited when normal storage conditions are obeyed
not more than a year |
The technology for soil and water surface treatment was patented
and has been successfully used in West Siberia, Samara region and
Tatarstan.
COMBINED TECHNOLOGY FOR APPLICATION OF FIBER-DISPERSION
SYSTEM AND MICROORGANISMS FOR IMPROVED OIL RECOVERY
The technology is used for improved oil recovery from the flooded
heterogeneous formations under the conditions of ultimate water
content of produced fluids at the later stage of the oil field development.
When the technology is employed oil recovery increases by an increase
of the sweep efficiency and by higher degree of the oil sweepout
applying the products of microorganisms’ vital functions.
The reagent included into the composition has high selectivity,
substantially increases filtration resistance of the encroached
flushed formation zones, promotes filtration redistribution in the
formation and sweeping of the unswept intervals.
The technology comprises the successive-alternate injection of
the medium-volume slug of the aqueous suspensions of wood flour,
microorganisms, inorganic salt and clay powder through the injection
wells into the reservoir. The oil-driving agents: fatty acids, alcohols,
aldehydes, biopolymers, CH4, CO2, H2
and N2 promoting incremental oil displacement form in
the formation within 15-20 days of the composition injection as
a result of microorganisms’ vital functions.
The technology is ecologically safe, available and simple and it
doesn’t require expensive and unavailable reagents. The standard
field equipment is employed for the formation treatment. 1000-1200
t of incremental oil is produced per 1 producing well by employing
the technology.
Incremental oil production is 30-78% of total production in the
area having 1 injection and 4 producing wells.
LABORATORY SET FOR ANALYSES
The set is used for determination of the level of sulfate reducing
bacteria (SRB) contamination of the oil-field systems and for evaluation
of the performance of the reagents inhibiting microbiological corrosion.
The secondary oil recovery by waterflooding is accompanied by contamination
of the producing formations with microorganisms, particularly such
corrosion-hazardous as sulfate reducing bacteria (SRB).
Development of SRB biocenosis in the producing formation causes
formation of hydrogen sulfide and more severe corrosion processes.
The pipes’ life is 10-12 years but they can fail within 2-3 years
because of microbiological corrosion. Hence, monitoring of SRB contamination
level of the oil-field systems is an important and necessary operation.
To promote monitoring of SRB contamination level of the oil-field
systems NIIneftepromchim arranged the commercial production of the
sets containing everything required for making such control by the
technicians.The set consists of 20 ml bottles with nutrient for
SRB and syringes.
The set can also evaluate the efficiency of the reagents having
bactericide properties.
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