JP2018076714A - Petroleum recovery increasing nutrition - Google Patents

Abstract

The present invention provides a nutrient that can be enhanced and recovered more efficiently by microorganisms in an oil reservoir.
A nutritional agent for enhanced recovery of oil that is injected into an oil reservoir to increase the amount of recovered oil, 0.01% by mass or more of casein peptone, or 0.025% of fermented barley extract. Contains 0.1% by mass or more of fish extract, 0.1% by mass or more of skim milk powder, or 0.1% by mass or more of corn steep liquor.
[Selection figure] None

Description

  The present invention relates to a nutrient for enhanced oil recovery (hereinafter sometimes simply referred to as a nutrient) that is injected into an oil reservoir to increase the amount of oil recovered.

  Oil existing in oil reservoirs such as underground rock formations can generally be extracted by drilling an oil well and pushing the oil up to the borehole of the oil well with the pressure in the oil field. If it decreases, it will be the limit of natural and oil production. In the primary recovery using the waste oil energy in the oil reservoir, it is said that only about 5% to 25% of crude oil existing underground can be recovered on the ground. In order to enhance the oil drainage energy in the oil reservoir, it is possible to artificially restore the pressure in the oil field by a method such as injecting water or gas into the oil reservoir, so that enhanced oil recovery can be achieved. However, even in such secondary recovery, it is said that more than 50% of crude oil is left in the oil reservoir.

  The technology for further recovering crude oil left underground is called EOR (Enhanced Oil Recovery), and heat attack, chemical attack, gas attack, microbial attack, etc. are known depending on the principle applied. . Among them, Microbial Enhanced Oil Recovery (MEOR) is a technology that introduces microorganisms into oil storage together with nutrient solution, and promotes enhanced oil recovery through various functions of microorganisms. Is also attracting attention as a small economical EOR technology (see Patent Document 1). Moreover, it is thought that the same effect is acquired also by introduce | transducing a nutrient solution into an injection well, without inject | pouring microorganisms (refer patent document 2).

The following mechanism is guessed about the effect of enhanced oil recovery by microorganisms (see Non-Patent Document 3).
(1) Carbon dioxide produced by microorganisms, or when the oil layer is carbonate rock, carbon dioxide produced by the reaction of organic acid produced by microorganisms and carbonate rock dissolves in crude oil and swells.
(2) A surfactant, which is a metabolite, reduces the oil-water interfacial tension.
(3) Generated gases such as hydrogen, carbon dioxide, and methane increase the oil reservoir pressure.
(4) The mobility of the water phase that is easier to flow than crude oil is reduced by the water-soluble polymer that is a metabolite.
(5) The wettability of the oil layer rock surface changes due to the attachment of microorganisms to the oil layer rock surface and metabolites.
(6) Microorganisms decompose crude oil components, thereby reducing the viscosity of the crude oil and improving fluidity.
(7) Bubbles are formed by the surface active substance as a metabolite and the produced gas, and the fluidity is equalized.
(8) Microorganisms grow in relatively large pores and cracks and selectively block these places.
(9) Metabolized low-molecular organic acids such as formic acid and acetic acid erode carbonate rock and increase porosity and permeability.

  However, since MEOR has been proposed since 1926, research has progressed and there are many applications in the 1940s and 1950s, but it has not yet been put into practical use (Non-Patent Documents 1 and 2). reference). At the beginning of the development of this technology, the species of the injected microorganism was unknown, the knowledge about the interrelationship between the oil reservoir environmental conditions and the microorganism was not clear, the technical evaluation was not performed, and the microorganisms and nutrients to be injected The causal relationship between the oil recovery effect and the oil recovery recovery effect is not clear, and the certainty of the oil enhancement effect in different oil fields is unknown.

Special table 2010-535271 gazette JP-T-03-505106

Beckman, J.M. W. : Ind. Eng. Chem. , November, 10, 3 (1926). Kazuhiro Fujiwara et al .: Journal of Petroleum Technology Association, Vol. 73, No. 6, 531-540 (2008) Eiji Yonebayashi: Oil Development and Stockpile, '96 / 12 62-79, (1996)

  Therefore, in order to metabolize the carbon source in the oil reservoir in the oil reservoir and increase the amount of oil recovered, the oil is utilized, the viscosity of the oil in the oil reservoir is lowered, and the surface tension is lowered. Therefore, there is a need for microorganisms that can increase the fluidity of oil by further increasing the fluidity of petroleum by generating low-molecular gas such as methane in the oil reservoir, and nutrients for culturing these microorganisms. ing.

  For example, Patent Document 1 proposes an enhanced oil recovery method in which various nutrients such as vitamins, phosphates, and various electron donors are injected into an oil reservoir together with microorganisms. Patent Document 2 proposes an enhanced oil recovery method in which peptone or protein and / or their digest or extract is injected as a nutrient into an oil reservoir.

  However, when the above-mentioned nutrients are used, hydrogen sulfide is generated in the oil reservoir, and even if it is recovered, it is actually soured and unsuitable for use, and the enhanced recovery effect cannot be obtained. There was a case. Infusion of organic nutrients, including peptones and extracts, often promotes the growth of anaerobic microorganisms that have the effect of enhanced oil recovery, while at the same time introducing microorganisms that generate hydrogen sulfide that causes sourization of oil. Proliferation is also promoted, and the fact that it was difficult to develop nutrients and microorganisms that show the effect of enhanced oil recovery without generating hydrogen sulfide is presumed to be the reason for the delay in practical application.

  Hydrogen sulfide is a toxic gas, and is known as a so-called rotten odor of eggs, which is generated when microorganisms propagate under anaerobic conditions in, for example, organic waste. A typical example of such anaerobic microorganisms is a type of microorganism called sulfate-reducing bacteria, which is a group of microorganisms that obtain energy by reducing sulfate to produce hydrogen sulfide. The generation of hydrogen sulfide is recognized even in an anaerobic environment such as an oil reservoir and becomes a cause of sourization of oil. Wells producing oil often attempt to suppress the generation of hydrogen sulfide by preventing the growth of anaerobic microorganisms that cause the generation of hydrogen sulfide. A growth inhibitor for microorganisms that generate hydrogen is used. However, in MEOR technology, the basic principle is to activate microorganisms that inhabit oil reservoirs and oil reservoir water, and an effective method for suppressing only the activities of microorganisms that cause hydrogen sulfide generation is required. .

  Accordingly, it is an object of the present invention to provide a nutrient that can be more efficiently enhanced and recovered in a state where it is difficult for hydrogen sulfide to be generated by microorganisms in an oil reservoir.

In order to achieve the above object, the characteristic constitution of the nutrient for recovery enhancement of the present invention is as follows:
A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
Casein peptone 0.01% by mass or more, or
0.025% by mass or more of fermented barley extract, or
0.1% by weight or more of fish extract, or
0.1% by weight or more of skim milk powder, or
More than 0.1% by mass of corn steep liquor,
It may be contained.

  As a result of intensive studies, the present inventors have found that a nutrient containing 0.01% by mass or more of casein peptone, or 0.025% by mass or more of fermented barley extract, or 0.1% by mass or more of fish meat extract, or A nutrient containing 0.1% by mass or more of skim milk powder or 0.1% by mass or more of corn steep liquor is sufficiently effective to inject oil into the oil reservoir and increase the amount of oil recovered. In addition to clarifying experimentally, the present inventors have newly found that the hydrogen sulfide content of petroleum recovered using these nutrients is sufficiently low. Especially for nutrients containing 1.0% by mass of casein peptone or 0.5% by mass of fermented barley extract, the amount of hydrogen sulfide generated is small (less than 2.5 ppm (volume)), and methane gas or carbon dioxide gas. In addition, the amount of digestion gas such as is large (15 mmol / L or more), and it is considered that the generation of these gases greatly contributes to enhanced oil recovery. In addition, a nutrient containing 0.5% by mass of fish meat extract, 1.0% by mass of skim milk powder, or 1.0% by mass of corn steep liquor produces a large amount of surfactant (0. 008% or more), it is considered that the reduction of the oil-water interfacial tension of petroleum greatly contributes to the enhanced oil recovery.

  Furthermore, it is preferable to contain the said nutrient further 0.1 mass% or more of milk, or 0.1 mass% or more of whey.

  In such a case, it is clear from experimental examples described later that the generation of the surfactant is further promoted by containing 0.1% by mass or more of milk or 0.1% by mass or more of whey.

  In addition, if the content of each component specified in the present invention is equal to or higher than the specified concentration, it is sufficient to activate the activity of microorganisms in the oil reservoir, and even if contained at a higher concentration, the same effect is obtained. The upper limit is not limited. Actually, it can be freely set within the limit of solubility of each component as a whole.

  In particular, a nutrient containing 0.1% by mass or more of milk, 0.1% by mass or more of fish extract and 0.1% by mass or more of glucose, 0.1% by mass or more of whey, and 0% of fish extract A nutrient containing 0.1% by mass or more and 0.1% by mass or more of glucose has a large amount of digestion gas and a large amount of surface active substance, and is considered to contribute further to enhanced oil recovery.

  Further, in particular, a nutrient containing 0.01% by mass or more of casein peptone, 0.1% by mass or more of corn steep liquor, and 0.1% by mass or more of glucose, or 0.1% by mass or more of skim milk powder, And a nutrient containing 0.025% by mass or more of fermented barley extract, 0.01% by mass or more of casein peptone, 0.025% by mass or more of fermented barley extract, and 0.025% by mass or more of glucose The amount of digestive gas such as methane gas and carbon dioxide gas is also large, and the generation of these gases and the generation of surface active substances are considered to contribute greatly to the enhanced oil recovery.

  Therefore, according to the nutrient, the enhanced oil can be recovered more efficiently by the microorganisms inside the oil reservoir.

  Below, the nutrient for oil enhancement collection | recovery concerning embodiment of this invention is demonstrated. Preferred examples are described below, but these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

[Nutrients for enhanced oil recovery]
The nutritional supplement for enhanced oil recovery of the present invention is:
Casein peptone 0.01% by mass or more, or
0.025% by mass or more of fermented barley extract, or
0.1% by weight or more of fish extract, or
0.1% by weight or more of skim milk powder, or
Containing 0.1% by mass or more of corn steep liquor.
More specifically,
As the content of casein peptone, 0.01 mass% or more, 1.0 mass% or less,
As content of fermented barley extract, 0.025 mass% or more, 1.0 mass% or less,
As the content of the fish meat extract, 0.1 mass% or more, 1.0 mass% or less,
As content of skim milk powder, 0.1 mass% or more, 1.0 mass% or less,
The content of corn steep liquor can be set to 0.1% by mass or more and 1.0% by mass or less.
Also preferably,
In addition, the milk contains 0.1% by weight or more of milk or 0.1% by weight or more of whey.

More specifically,
Containing 0.1% by weight or more of milk and 0.1% by weight or more of fish extract and 0.5% by weight or more of glucose, or
Containing 1.0% by weight or more of whey and 0.5% by weight or more of fish extract and 0.5% by weight or more of glucose, or
Casein peptone 1.0% or more and corn steep liquor 0.5% or more and glucose 0.5% or more, or
Containing 1.0% by weight or more of skim milk powder and 0.5% by weight or more of fermented barley extract, or
Casein peptone 0.1% by mass or more, fermented barley extract 0.25% by mass or more, and glucose 0.25% by mass or more,
Used as a thing.
More specifically,
From 0.1% by weight to 1.0% by weight of milk, and
Fish extract 0.1% by mass or more, 1.0% by mass or less, and
Glucose 0.1 mass% or more, 1.0 mass% or less, or
Whey 0.1% by mass or more, 1.0% by mass or less, and
Fish extract 0.1% by mass or more, 1.0% by mass or less, and
Glucose 0.1 mass% or more, 1.0 mass% or less, or
Casein peptone 0.01% by mass or more, 1.0% by mass or less, and
Corn steep liquor 0.1% by mass or more, 1.0% by mass or less, and
Glucose 0.1 mass% or more, 1.0 mass% or less, or
Non-fat dry milk 0.1 mass% or more, 1.0 mass% or less, and
Fermented barley extract 0.025 mass% or more, 1.0 mass% or less, or
Casein peptone 0.01 mass% or more, 1.0 mass% or less, and
Fermented barley extract 0.025 mass% or more, 1.0 mass% or less, and
It can be set as the nutrient for oil recovery collection | recovery containing 0.025 mass% or more of glucose and 1.0 mass% or less.

[Enhanced oil recovery method]
Oil present in oil reservoirs such as underground rock formations is produced from oil fields with injection wells and production wells. Both the injection well and the production well reach the oil reservoir formed on the surface side of the rock formation from the ground surface. Accordingly, the oil reservoir and oil reservoir water obtained from the production well contain resident microorganisms that inhabit the oil reservoir of the oil field. And in embodiment which applied the oil enhancement collection method in such an oil field, the upper nutrient (medium) which shows the high oil increase effect and the low hydrogen sulfide generation | occurrence | production risk is press-fitted into an oil reservoir from an injection well.
As a result of a core sweep test as a confirmation test of the effect of the enhanced oil recovery method, a nutrient containing 0.01% by mass or more of casein peptone or 0.025% by mass or more of fermented barley extract or a fish meat extract A nutrient containing 0.1% by mass or more, or 0.1% by mass or more of skim milk powder, or 0.1% by mass or more of corn steep liquor is injected into the oil reservoir to reduce the amount of oil recovered. It was clarified that the effect of increasing is sufficiently high. The test methods will be described in order below.

[Culture experiment with nutrients using oil layer and oil layer water (vial culture test)]
The crude oil sampled from the well head of the oil field producing crude oil was separated into oil and water, and an oil reservoir and oil reservoir water were obtained. Nutrient components shown in Table 1 were prepared in various combinations and concentrations using oil layer water as a solvent to prepare nutrient solutions. The amount of each component shown in the composition of the nutrient shown in Table 1 is mass% in the oil layer water used as a solvent, and the balance is oil layer water as a solvent. Here, as each nutrient component, a commercially available product that was available at a low cost was selected. 10 ml of oil layer was added to a nutrient solution (20 ml) in a glass vial (Marum No. 7; 50 ml), and sealed with a butyl rubber stopper and an aluminum cap. The vial headspace was purged with argon gas. Each vial was statically cultured anaerobically at 48 ° C. for a certain period. After a certain period of culture, headspace hydrogen, methane, carbon dioxide, and hydrogen sulfide were analyzed by gas chromatography. In addition, the biosurfactant concentration in the culture broth was analyzed by the oil spreading method. In addition, since oil reservoir water is an aqueous solvent collected from an oil reservoir and containing essentially no nutrients, it can be replaced with solvent components that are actually injected into the ground, such as tap water and seawater.

[Various analysis methods]
Various experiments in the following examples were performed as follows.

(Gas component)
The gas concentrations of carbon dioxide, methane, and hydrogen were analyzed using Shimadzu Gas Chromatography (GC2014). Argon gas was used as the carrier, and Shincarbon ST was used as the separation column. The analysis was performed at an oven temperature of 200 ° C.
Hydrogen sulfide in the gas phase in the vial culture test and the core sweep test was analyzed using Shimadzu gas chromatography (GC2014). The separation column was 1,2,3-TCEP (25% 3.2mmID × 5m). The detector was FPD, and the column temperature was 100 ° C.

(Measurement of biosurfactant activity)
In this study, the production of surfactants by microorganisms was evaluated by the oil spreading method. 10 μL of crude oil was added to a Petri dish containing 15 ml of water. 5 μL of the sample was dropped on the generated oil film, and the diameter of the formed water surface circle was measured. The results are shown in an equivalent amount of Triton X100, which is one of the surfactants.

（定量下限値：2.5 vol ppm）

(Lower limit of quantification: 2.5 vol ppm)

(result)
From Table 1, nutrient containing 1.0% by mass of casein peptone, whey or skim milk powder and 0.5% by mass of fermented barley extract, fish extract or corn steep liquor, respectively (Test 5, 7, 8, 12) When injected into an oil reservoir and increasing the amount of oil recovered, the amount of hydrogen sulfide generated is small enough, and in addition, the amount of digestion gas generated and the amount of surface active substances generated are large. It was revealed.

  Casein peptone, fish extract, skim milk powder, corn steep liquor, and fermented barley extract generate little hydrogen sulfide even when used alone, especially fish meat extract, skim milk powder, and corn steep liquor also produce a large amount of surfactant. Therefore, it can be expected that the oil-water interfacial tension of the oil will be reduced to greatly contribute to enhanced oil recovery.

  Although the function of each nutrient component is not clear, casein peptone, whey, and skim milk powder that are made from raw milk have a particularly low hydrogen sulfide generation rate and digestive gas due to the effect of increasing the added amount. It can be seen that the amount of hydrogen sulfide tends to be suppressed as the amount of hydrogen generated increases, which is considered to contribute to the suppression of the generation of hydrogen sulfide. Similarly, fish meat extract, corn sleep liquor and fermented barley extract are also expected to have the effect of suppressing the amount of hydrogen sulfide generated due to the effect of increasing the amount added. Casein peptone, whey and nonfat dry milk are nutrient rich in protein, while fish extract, corn sleep liquor and fermented barley extract are rich in nutrients that activate microbial growth such as vitamins and minerals. Combining these nutrients promotes the growth of microorganisms, promotes the generation of gas and surfactant that are effective in increasing oil, and consequently increases the amount of oil recovered while suppressing the generation of hydrogen sulfide. Can be expected.

  Furthermore, for a nutritional supplement containing 0.5% by mass of fish extract, 1.0% by mass of skim milk powder, or 0.5% by mass of corn steep liquor, 1.0% by mass of milk ( By containing Test 3) or 1.0% by mass of whey (Tests 5 and 7), the generation of the surfactant is further promoted.

  From these tests, 0.01% by mass or more and 1.0% by mass or less of casein peptone, or 0.025% by mass or more and 1.0% by mass or less of fermented barley extract, or 0.1% of fish meat extract. Contains from 0.1% by mass to 1.0% by mass, or from 0.1% by mass to 1.0% by mass or less of skim milk powder, or from 0.1% by mass to 1.0% by mass of corn steep liquor It can be seen that the nutrients to be injected are sufficiently effective to increase the amount of oil recovered when injected into the oil reservoir, and the hydrogen sulfide content of petroleum recovered using these nutrients is sufficiently low. In particular, for nutrients containing 0.01% by mass or more and 1.0% by mass or less of casein peptone, or 0.025% by mass or more and 1.0% by mass or less of fermented barley extract, the amount of hydrogen sulfide generated is small. In addition, the amount of digestion gas such as methane gas and carbon dioxide gas is large, and it was found that the generation of these gases greatly contributes to the enhanced oil recovery. Further, the fish extract is 0.1% by mass or more and 1.0% by mass or less, the skim milk powder is 0.1% by mass or more, 1.0% by mass or less, or the corn steep liquor is 0.1% by mass or more. As for the nutrient containing 1.0% by mass or less, it was found that a large amount of surface-active substance was produced, and that the oil-water interfacial tension of petroleum decreased greatly contributed to enhanced oil recovery.

  Furthermore, it was found that the nutritional supplement is preferably contained in an amount of 0.1% by mass or more and 1.0% by mass or less of milk or whey.

  In particular, a nutrient containing 1.0% by weight of milk, 0.5% by weight of fish extract and 0.5% by weight of glucose (Test 6), 1.0% by weight of whey, and 0% of fish extract The nutrient containing 0.5% by mass and 0.5% by mass of glucose (Test 7) has a large amount of digestion gas and a large amount of surface active substance, and is considered to contribute more to enhanced oil recovery. It is done. Further, in particular, a nutrient containing 1.0% by mass of casein peptone, 0.5% by mass of corn steep liquor, and 0.5% by mass of glucose (Test 8), 1.0% by mass of skim milk powder, And a nutrient containing 0.5% by mass of fermented barley extract (test 12), 0.1% by mass of casein peptone, 0.25% by mass of fermented barley extract, and 0.25% by mass of glucose (test) 13) also contains a large amount of digestion gas such as methane gas and carbon dioxide gas, and the generation of these gases and the generation of surfactants are considered to contribute greatly to enhanced oil recovery.

  Therefore, in particular, milk 0.1% by mass or more, 1.0% by mass or less, and fish extract 0.1% by mass or more, 1.0% by mass or less, and glucose 0.1% by mass or more, 1.0% Nutrients containing less than 10% by weight, whey 0.1% by weight or more, 1.0% by weight or less, and fish meat extract 0.1% by weight or more, 1.0% by weight or less, and glucose 0.1% by weight It was found that a nutrient containing 1% or more and 1.0% by mass or less has a large amount of digestion gas generated and a large amount of surface active substance, which contributes to enhanced oil recovery.

  In particular, casein peptone 0.01% by mass or more, 1.0% by mass or less, corn steep liquor 0.1% by mass or more, 1.0% by mass or less, and glucose 0.1% by mass or more, Nutrients containing 0.0 mass% or less, skim milk powder 0.1 mass% or more, 1.0 mass% or less, and nutrition containing fermented barley extract 0.025 mass% or more, 1.0 mass% or less Agent, casein peptone 0.01% by mass or more, 1.0% by mass or less, and fermented barley extract 0.025% by mass or more, 1.0% by mass or less, and glucose 0.025% by mass or more. Nutrients containing less than 0% by mass also generate a large amount of digestion gas such as methane gas and carbon dioxide, and it was found that the generation of these gases and the generation of surface active substances greatly contribute to enhanced oil recovery. .

  Next, a core sweep test was carried out on representative examples of the above nutrients.

[Core sweep test]
The sandstone core (hereinafter simply referred to as “core”) was sterilized by dry heat at 140 ° C. for 4 hours or longer, and then the unsterilized oil layer water was placed in an acrylic vacuum container so that the core was sufficiently immersed and sealed. The core was impregnated with oil layer water using a vacuum pump. Thereafter, the core was taken out and weighed to determine the amount of water inside the core. The core was introduced into a sterilized core holder and sealed, and then placed in a constant temperature bath at 47 ° C.

  The inside of the core holder was set to 3.0 MPa, and a non-sterile oil layer water heated to 47 ° C. was pressed into the core using a high-pressure constant flow rate pump while loading a peripheral pressure of 7.5 MPa from the nitrogen gas cylinder to the core. . The oil reservoir water was injected with 2.0 pore volume (PV) at a flow rate of 0.1 mL / min. Thereafter, unsterilized crude oil similarly heated to 47 ° C. was press-fitted into the core for a total of 30 PV at a final flow rate of 0.2 mL / min while gradually increasing the flow rate.

  As a primary recovery experiment, a water flooding method was implemented in which oil reservoir water was injected into the core to recover the oil. As in the case of the above-described press-fitting of unsterilized oil reservoir water and unsterilized crude oil, the core of the oil reservoir water (unsterilized) bottle is pressurized with nitrogen gas (<0.1 MPa) using a high-pressure constant flow rate pump. The oil layer water was injected into the inside at a flow rate of 0.1 mL / min to perform primary recovery. The press-in pressure was recorded during the press-in. The effluent was collected in a graduated test tube, and the oil recovery rate was determined by measuring the amount of spilled oil visually using the scale as an index. The oil-layer water injection was stopped when oil spill was no longer confirmed. The amount of oil obtained here (primary recovered oil amount) corresponds to the amount of oil mined from the oil reservoir by the conventional oil mining method.

  Next, a nutrient solution was pressed into the core subjected to the primary recovery experiment (2.0 PV at a flow rate of 0.1 mL / min). Thereafter, the core holder was sealed, and microorganisms were cultured in the core. The microorganisms were cultured for 4 weeks.

  After completion of the culture period, oil layer water was injected into the core at a flow rate of 0.1 mL / min, and an enhanced oil recovery experiment was conducted. The spilled oil and water were collected in a test tube and the gas was separated, and the gas was collected in another test tube by the water displacement method, and the hydrogen sulfide concentration was analyzed. The spilled oil amount (increased recovered oil amount) was measured visually using the scale of the test tube as an index, and the increased oil recovery rate was determined. The oil-layer water injection was stopped when oil spill was no longer confirmed.

  As a result, it was confirmed that any of the nutrients tested showed an oil-increasing effect and that the generation of hydrogen sulfide in the core was small. These nutrients showed an oil increase effect of 10% or more in the core sweep test, and further the generation of hydrogen sulfide was below the detection limit, which proved to be an excellent nutrient for the enhanced oil recovery method. . From the above results, it is expected that when these nutrient supplement candidates are actually injected into the oil reservoir in the field, the same enhanced oil recovery effect can be expected.

（定量下限値：2.5 vol ppm）

(Lower limit of quantification: 2.5 vol ppm)

Claims (7)

A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
Casein peptone 0.01% by mass or more, or
0.025% by mass or more of fermented barley extract, or
0.1% by weight or more of fish extract, or
0.1% by weight or more of skim milk powder, or
More than 0.1% by mass of corn steep liquor,
Contains nutrients for enhanced oil recovery. The nutrient for enhanced oil recovery according to claim 1,
More than 0.1% by weight of milk, or
Whey 0.1% by mass or more,
Contains nutrients for enhanced oil recovery. A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
More than 0.1% by weight of milk, and
More than 0.1% by weight of fish extract, and
Glucose 0.1 mass% or more,
Contains nutrients for enhanced oil recovery. A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
Whey 0.1% by mass or more, and
More than 0.1% by weight of fish extract, and
Glucose 0.1 mass% or more,
Contains nutrients for enhanced oil recovery. A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
Casein peptone 0.01 mass% or more, and
Corn steep liquor 0.1 mass% or more, and
Glucose 0.1 mass% or more,
Contains nutrients for enhanced oil recovery. A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
Skim milk powder 0.1% by weight or more, and
Fermented barley extract 0.025 mass% or more,
Contains nutrients for enhanced oil recovery. A nutritional supplement for enhanced oil recovery that is injected into an oil reservoir to increase the amount of oil recovered,
Casein peptone 0.01 mass% or more, and
Fermented barley extract 0.025 mass% or more, and
Glucose 0.025% by mass or more,
Contains nutrients for enhanced oil recovery.