Biological nano solution and application thereof

Abstract

The invention belongs to the technical field of biology and oil exploitation, and discloses a biological nano solution and application thereof.The biological nano solution is prepared from a rhamnolipid solution, a lipopeptide solution and a sophorolipid solution according to the volume ratio of (1-5): (1-5): (1-5), and the concentration of the rhamnolipid solution is 30-60 g / L, the concentration of the lipopeptide solution is 30-90 g / L, and the concentration of the sophorolipid solution is 30-90 g / L. According to the biological nano solution provided by the invention, the contact angle can be obviously reduced, and the deoiling efficiency within 48 hours can reach about 90%; meanwhile, saturated crude oil in the rock core can be effectively displaced, the rock core displacement efficiency is improved, the crude oil recovery rate is increased, and the method can be applied to improvement of the recovery rate of tertiary oil recovery of a low-permeability oil field and preparation of a biological agent for improving the crude oil recovery rate; in addition, the preparation process of the biological nano solution is simple and easy to operate, and production can be expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of biology and oil extraction, and relates to a biological nano solution and application thereof. Background Art

[0002] Composite bio-nano solution refers to a technology that changes the physical and chemical properties of crude oil and improves crude oil recovery by fermenting and culturing selected microbial strains with high-efficiency degradation functions, taking their metabolites for compounding, and scientifically constructing a specific composite bio-nano solution oil displacement agent with complete functions, clear purpose, and significantly improved comprehensive oil recovery effect based on the physical properties of different oil layers and crude oil components through comprehensive evaluation, thereby changing the physical and chemical properties of crude oil and improving crude oil recovery. Bio-nano solution has less damage to the environment, is non-toxic and harmless, has high safety, will not harm the health of workers, will not damage the formation, has a wide source of raw materials, and is economical and environmentally friendly.

[0003] As the exploitable potential of conventional oil reservoirs around the world is decreasing rapidly, the difficulty of exploring and developing new oil reservoirs is increasing, and people's demand for petroleum products is increasing. However, the bio-nano solution in the existing technology is used for oil field recovery. After the oil field is flooded with water twice, a large amount of residual oil is still retained in the formation, the crude oil recovery rate is low, the oil production is low, and it cannot meet people's demand for petroleum products.

[0004] In view of this, the present invention provides a bionano solution and application thereof to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a bionano solution and its application, which can effectively reduce the contact angle, improve the oil washing efficiency, reduce the water content of saturated crude oil, and increase oil production.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A bionano solution is prepared by mixing a rhamnolipid solution, a lipopeptide solution and a sophorolipid solution in a volume ratio of (1-5):(1-5):(1-5), wherein the concentrations of the rhamnolipid solution, the lipopeptide solution and the sophorolipid solution are 30-60 g / L, 30-90 g / L and 30-90 g / L respectively.

[0008] Furthermore, the bionano solution is prepared by mixing a rhamnolipid solution, a lipopeptide solution and a sophorolipid solution in a volume ratio of 2:1:1.

[0009] Furthermore, the preparation process of the bionano solution is as follows: mixing the prepared rhamnolipid solution, lipopeptide solution, and sophorolipid solution;

[0010] The preparation process of the rhamnolipid solution is as follows: Pseudomonas aeruginosa is inoculated into a first liquid culture medium for cultivation to obtain a culture solution, and then the culture solution is inoculated into a tank containing a first fermentation culture medium for fermentation to obtain a rhamnolipid fermentation solution, and finally the rhamnolipid fermentation solution is filtered through a ceramic membrane, and the filtered clear liquid is collected and then concentrated through a nanofiltration membrane to obtain a rhamnolipid solution;

[0011] The preparation process of the lipopeptide solution is as follows: Bacillus subtilis is inoculated into the second liquid culture medium for cultivation to obtain a culture solution, and then the culture solution is inoculated into a tank containing the second fermentation culture medium for fermentation to obtain a lipopeptide fermentation solution, and finally the lipopeptide fermentation solution is filtered through a ceramic membrane, and the filtered clear liquid is collected and then concentrated through a nanofiltration membrane to obtain a lipopeptide solution;

[0012] The preparation process of the sophorolipid solution is as follows: Candida is inoculated into the third liquid culture medium for cultivation to obtain a culture solution, and then the culture solution is inoculated into a tank containing the third fermentation medium for fermentation to obtain a sophorolipid fermentation solution, and finally the sophorolipid fermentation solution is filtered through a ceramic membrane, the filtered clear liquid is collected and then concentrated through a nanofiltration membrane to obtain a sophorolipid solution.

[0013] Further, the formula of the first liquid culture medium is: 0.5 g of yeast extract, 0.5 g of peptone, 1.5 g of glucose and 0.5 g of NaCl are added to every 100 g of water, and the pH value is 6.8 to 7.0;

[0014] The formula of the first fermentation medium is: 5 g of yeast extract, 5 g of peptone, 15 g of glucose, 15 g of rapeseed oil, 5 g of NaCl and 20 g of agar are added to 1 kg of water, and the pH value is 7.6;

[0015] The formula of the second liquid culture medium is as follows: 1.0 g of yeast extract, 1.5 g of sucrose, 0.8 g of dipotassium hydrogen phosphate, and 0.05 g of potassium dihydrogen phosphate are added to every 100 g of water, and the pH value is 6.8;

[0016] The formula of the second fermentation medium is: 10 g of yeast extract, 15 g of sucrose, 10 g of rapeseed oil, 8 g of dipotassium hydrogen phosphate and 0.5 g of potassium dihydrogen phosphate are added to every 1 kg of water, and the pH value is 7.0.

[0017] Furthermore, the specific preparation process of the rhamnolipid solution is as follows:

[0018] (1) inoculating the Pseudomonas aeruginosa strain into a shake flask containing a first liquid culture medium, and culturing for 20 to 24 hours at a temperature of 35 to 37° C. and a stirring speed of 220 to 240 rpm to obtain a shake flask seed solution;

[0019] (2) inoculating the shake flask seed solution into the shake flask containing the first liquid culture medium, and culturing for 16 to 20 hours under the conditions of a temperature of 35 to 37° C., a stirring speed of 100 to 180 rpm, a ventilation volume of 1.0 to 1.5 vvm, and a tank pressure of 0.03 to 0.05 MPa to obtain a seed solution;

[0020] (3) inoculating the seed liquid into a tank containing the first fermentation medium, and fermenting for 136 to 140 hours at a temperature of 33 to 35° C., a stirring speed of 80 to 120 rpm, a ventilation volume of 0.2 to 0.6 vvm, and a tank pressure of 0.03 to 0.05 MPa to obtain a rhamnolipid fermentation liquid;

[0021] (4) filtering the rhamnolipid fermentation broth through a ceramic membrane and collecting the filtered clear liquid;

[0022] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a rhamnolipid solution.

[0023] Furthermore, the specific preparation process of the lipopeptide solution is as follows:

[0024] (1) inoculating the Bacillus subtilis strain into a shake flask containing a second liquid culture medium, and culturing for 22 to 25 hours at a temperature of 35 to 37° C. and a stirring speed of 200 to 240 rpm to obtain a shake flask seed solution;

[0025] (2) inoculating the shake flask seed solution into a shake flask containing a second liquid culture medium, and culturing for 16 to 20 hours at a temperature of 35 to 37° C., a stirring speed of 180 to 220 rpm, a ventilation volume of 1.0 to 2.0 vvm, and a tank pressure of 0.08 to 0.095 MPa to obtain a seed solution;

[0026] (3) inoculating the seed liquid into a tank containing a second fermentation medium, and fermenting for 60 to 72 hours at a temperature of 35 to 37° C., a stirring speed of 180 to 220 rpm, a ventilation volume of 0.2 to 0.6 vvm, and a tank pressure of 0.08 to 0.095 MPa to obtain a lipopeptide fermentation liquid;

[0027] (4) filtering the lipopeptide fermentation broth through a ceramic membrane and collecting the filtered clear liquid;

[0028] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a lipopeptide solution.

[0029] Further, the formula of the third liquid culture medium is: 1.0 g of yeast extract, 1.0 g of glucose, 0.1 g of dipotassium hydrogen phosphate, 0.1 g of potassium dihydrogen phosphate and 0.02 g of magnesium sulfate are added to every 100 g of water, and the pH value is 4.8;

[0030] The formula of the third fermentation medium is: 10 g of yeast extract, 10 g of glucose, 10 g of rapeseed oil, 1 g of dipotassium hydrogen phosphate, 1 g of potassium dihydrogen phosphate and 0.2 g of magnesium sulfate are added to every 1 kg of water, and the pH value is 3.5.

[0031] Furthermore, the specific preparation process of the sophorolipid solution is as follows:

[0032] (1) inoculating the Candida strain into a shake flask containing the third culture medium, and culturing for 20 to 24 hours at a temperature of 35 to 37° C. and a stirring speed of 180 to 220 rpm to obtain a shake flask seed solution;

[0033] (2) inoculating the shake flask seed solution into a shake flask containing the third culture medium, and culturing for 16 to 20 hours under the conditions of a temperature of 35 to 37° C., a stirring speed of 180 to 220 rpm, a ventilation volume of 2.8 to 3.2 vvm, and a tank pressure of 0.1 to 0.2 MPa to obtain a seed solution;

[0034] (3) inoculating the seed liquid into a tank containing the third fermentation medium, and fermenting for 118 to 124 hours at a temperature of 35 to 37° C., a stirring speed of 200 to 300 rpm, a ventilation volume of 3.0 to 4.0 vvm, and a tank pressure of 0.1 to 0.2 MPa to obtain a sophorolipid fermentation liquid;

[0035] (4) filtering the sophorolipid fermentation broth through a ceramic membrane and collecting the filtered clear liquid;

[0036] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a sophorolipid solution.

[0037] In addition, the present invention also proposes to use the above bionano solution to improve the recovery rate of tertiary oil recovery in low permeability oil fields.

[0038] In addition, the present invention also proposes to use the above bio-nano solution in preparing biological preparations for improving crude oil recovery.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The bio-nano solution provided in the present application can significantly reduce the contact angle, and the oil removal efficiency can reach about 90% in 48 hours; at the same time, the bio-nano solution can effectively displace the saturated crude oil inside the core, increasing the core displacement efficiency by about 10 to 20%, with high oil washing efficiency, reducing the water content of the saturated crude oil, and increasing the crude oil recovery rate. It can be used in tertiary oil recovery in low-permeability oil fields to improve oil recovery and in the preparation of biological preparations for improving crude oil recovery; in addition, the preparation process of the bio-nano solution provided in the present application is simple and easy to operate, and can be expanded for production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0043] Figure 1 A flow chart for the preparation of the bionano solution provided for this application;

[0044] Figure 2 This is a comparison chart of the deoiling experiment of the bio-nano solution dilution with a concentration of 1% provided in this application. DETAILED DESCRIPTION

[0045] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of devices consistent with some aspects of the present invention as detailed in the appended claims.

[0046] See also Figure 1 A bionano solution is prepared by mixing a rhamnolipid solution, a lipopeptide solution and a sophorolipid solution in a volume ratio of (1-5):(1-5):(1-5), wherein the concentrations of the rhamnolipid solution, the lipopeptide solution and the sophorolipid solution are 30-60 g / L, 30-90 g / L and 30-90 g / L, respectively.

[0047] Example 1

[0048] 1. Preparation of Rhamnolipid Solution

[0049] (1) inoculating the Pseudomonas aeruginosa strain into a shake flask containing the first liquid culture medium, and culturing the culture at a temperature of 35° C. and a stirring speed of 220 rpm for 20 h to obtain a shake flask seed solution;

[0050] (2) inoculating the shake flask seed solution into the shake flask containing the first liquid culture medium at an inoculum rate of 5% (V / V), and culturing for 16 h under the conditions of a temperature of 35° C., a stirring speed of 100 rpm, a ventilation volume of 1.0 vvm, and a tank pressure of 0.03 MPa to obtain a seed solution;

[0051] (3) inoculating the seed liquid at an inoculum rate of 5% (V / V) into a tank containing the first fermentation medium, and fermenting for 136 hours under the conditions of a temperature of 33° C., a stirring speed of 80 rpm, a ventilation volume of 0.2 vvm, and a tank pressure of 0.03 MPa to obtain a rhamnolipid fermentation liquid;

[0052] (4) filtering the fermentation broth through a 50 nm pore size ceramic membrane and collecting the filtered clear liquid;

[0053] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a rhamnolipid solution with a concentration of 30 g / L.

[0054] 2. Preparation of Lipopeptide Solution

[0055] (1) inoculating the Bacillus subtilis strain into a shake flask containing the second liquid culture medium, and culturing for 22 hours at a temperature of 35° C. and a stirring speed of 200 rpm to obtain a shake flask seed solution;

[0056] (2) inoculating the shake flask seed solution into a shake flask containing the second liquid culture medium at an inoculum rate of 5% (V / V), and culturing for 16 h under the conditions of a temperature of 35° C., a stirring speed of 180 rpm, a ventilation volume of 1.0 vvm, and a tank pressure of 0.08 MPa to obtain a seed solution;

[0057] (3) inoculating the seed liquid into a tank containing the third fermentation culture at an inoculum amount of 5% (V / V), and fermenting for 60 hours at a temperature of 35° C., a stirring speed of 180 rpm, a ventilation volume of 0.2 vvm, and a tank pressure of 0.08 MPa to obtain a lipopeptide fermentation liquid;

[0058] (4) filtering the lipopeptide fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0059] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a lipopeptide solution with a concentration of 30 g / L.

[0060] 3. Preparation of Sophorolipid Solution

[0061] (1) inoculating the Candida strain into a shake flask containing the third culture medium, and culturing the culture medium at a temperature of 35° C. and a stirring speed of 180 rpm for 20 h to obtain a shake flask seed solution;

[0062] (2) inoculating the shake flask seed solution into a shake flask containing the third culture medium at an inoculum rate of 5% (V / V), and culturing for 16 h under the conditions of a temperature of 35° C., a stirring speed of 180 rpm, a ventilation volume of 2.8 vvm, and a tank pressure of 0.1 MPa to obtain a seed solution;

[0063] (3) inoculating the seed liquid into a tank containing the third fermentation medium at an inoculum amount of 5% (V / V), and fermenting for 118 hours at a temperature of 35° C., a stirring speed of 200 rpm, a ventilation volume of 3.0 vvm, and a tank pressure of 0.1 MPa to obtain a sophorolipid fermentation liquid;

[0064] (4) filtering the sophorolipid fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0065] (5) The filtered clear liquid is concentrated by a nanofiltration membrane to obtain a sophorolipid solution with a concentration of 30 g / L.

[0066] 4. The above rhamnolipid solution, lipopeptide solution and sophorolipid solution are mixed in a volume ratio of 1:1:1 to obtain a bionano solution. During the mixing process, there is no restriction on the order of adding the rhamnolipid solution, lipopeptide solution and sophorolipid solution.

[0067] Example 2

[0068] 1. Preparation of Rhamnolipid Solution

[0069] (1) inoculating the Pseudomonas aeruginosa strain into a shake flask containing the first liquid culture medium, and culturing the culture at a temperature of 35° C. and a stirring speed of 220 rpm for 20 h to obtain a shake flask seed solution;

[0070] (2) inoculating the shake flask seed solution into the shake flask containing the first liquid culture medium at an inoculum rate of 5% (V / V), and culturing for 16 h under the conditions of a temperature of 35° C., a stirring speed of 100 rpm, a ventilation volume of 1.0 vvm, and a tank pressure of 0.03 MPa to obtain a seed solution;

[0071] (3) inoculating the seed liquid at an inoculum rate of 5% (V / V) into a tank containing the first fermentation medium, and fermenting for 136 hours under the conditions of a temperature of 33° C., a stirring speed of 80 rpm, a ventilation volume of 0.2 vvm, and a tank pressure of 0.03 MPa to obtain a rhamnolipid fermentation liquid;

[0072] (4) filtering the fermentation broth through a 50 nm pore size ceramic membrane and collecting the filtered clear liquid;

[0073] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a rhamnolipid solution with a concentration of 45 g / L.

[0074] 2. Preparation of Lipopeptide Solution

[0075] (1) inoculating the Bacillus subtilis strain into a shake flask containing the second liquid culture medium, and culturing for 22 hours at a temperature of 35° C. and a stirring speed of 200 rpm to obtain a shake flask seed solution;

[0076] (2) inoculating the shake flask seed solution into a shake flask containing the second liquid culture medium at an inoculum rate of 5% (V / V), and culturing for 16 h under the conditions of a temperature of 35° C., a stirring speed of 180 rpm, a ventilation volume of 1.0 vvm, and a tank pressure of 0.08 MPa to obtain a seed solution;

[0077] (3) inoculating the seed liquid into a tank containing the third fermentation culture at an inoculum amount of 5% (V / V), and fermenting for 60 hours at a temperature of 35° C., a stirring speed of 180 rpm, a ventilation volume of 0.2 vvm, and a tank pressure of 0.08 MPa to obtain a lipopeptide fermentation liquid;

[0078] (4) filtering the lipopeptide fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0079] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a lipopeptide solution with a concentration of 60 g / L.

[0080] 3. Preparation of Sophorolipid Solution

[0081] (1) inoculating the Candida strain into a shake flask containing the third culture medium, and culturing the culture medium at a temperature of 35° C. and a stirring speed of 180 rpm for 20 h to obtain a shake flask seed solution;

[0082] (2) inoculating the shake flask seed solution into a shake flask containing the third culture medium at an inoculum rate of 5% (V / V), and culturing for 16 h under the conditions of a temperature of 35° C., a stirring speed of 180 rpm, a ventilation volume of 2.8 vvm, and a tank pressure of 0.1 MPa to obtain a seed solution;

[0083] (3) inoculating the seed liquid into a tank containing the third fermentation medium at an inoculum amount of 5% (V / V), and fermenting for 118 hours at a temperature of 35° C., a stirring speed of 200 rpm, a ventilation volume of 3.0 vvm, and a tank pressure of 0.1 MPa to obtain a sophorolipid fermentation liquid;

[0084] (4) filtering the sophorolipid fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0085] (5) The filtered clear liquid is concentrated by a nanofiltration membrane to obtain a sophorolipid solution with a concentration of 60 g / L.

[0086] 4. The above rhamnolipid solution, lipopeptide solution and sophorolipid solution are prepared in a volume ratio of 2:1:1 to obtain a bionano solution. During the mixing process, there is no restriction on the order of adding the rhamnolipid solution, lipopeptide solution and sophorolipid solution.

[0087] Example 3

[0088] 1. Preparation of Rhamnolipid Solution

[0089] (1) inoculating the Pseudomonas aeruginosa strain into a shake flask containing the first liquid culture medium, and culturing the culture medium at a temperature of 36° C. and a stirring speed of 230 rpm for 22 h to obtain a shake flask seed solution;

[0090] (2) inoculating the shake flask seed solution into the shake flask containing the first liquid culture medium at an inoculum rate of 8% (V / V), and culturing for 18 h under the conditions of a temperature of 36° C., a stirring speed of 140 rpm, a ventilation volume of 1.3 vvm, and a tank pressure of 0.04 MPa to obtain a seed solution;

[0091] (3) inoculating the seed liquid at an inoculum rate of 8% (V / V) into a tank containing the first fermentation medium, and fermenting for 138 hours under the conditions of a temperature of 34° C., a stirring speed of 100 rpm, a ventilation volume of 0.4 vvm, and a tank pressure of 0.04 MPa to obtain a rhamnolipid fermentation liquid;

[0092] (4) filtering the rhamnolipid fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0093] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a rhamnolipid solution with a concentration of 60 g / L.

[0094] 2. Preparation of Lipopeptide Solution

[0095] (1) inoculating the Bacillus subtilis strain into a shake flask containing the second liquid culture medium, and culturing for 24 hours at a temperature of 36° C. and a stirring speed of 220 rpm to obtain a shake flask seed solution;

[0096] (2) inoculating the shake flask seed solution into a shake flask containing the second liquid culture medium at an inoculum rate of 8% (V / V), and culturing for 18 h under the conditions of a temperature of 36° C., a stirring speed of 200 rpm, a ventilation volume of 1.5 vvm, and a tank pressure of 0.09 MPa to obtain a seed solution;

[0097] (3) inoculating the seed liquid into a tank containing the third fermentation medium at an inoculum amount of 8% (V / V), and fermenting for 66 hours at a temperature of 36° C., a stirring speed of 200 rpm, a ventilation volume of 0.4 vvm, and a tank pressure of 0.09 MPa to obtain a lipopeptide fermentation liquid;

[0098] (4) filtering the lipopeptide fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0099] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a lipopeptide solution with a concentration of 90 g / L.

[0100] 3. Preparation of Sophorolipid Solution

[0101] (1) inoculating the Candida strain into a shake flask containing the third culture medium, and culturing for 22 hours at a temperature of 36° C. and a stirring speed of 200 rpm to obtain a shake flask seed solution;

[0102] (2) inoculating the shake flask seed solution into a shake flask containing the third culture medium at an inoculum amount of 8% (V / V), and culturing for 18 h under the conditions of a temperature of 36° C., a stirring speed of 200 rpm, a ventilation volume of 3.0 vvm, and a tank pressure of 0.15 MPa to obtain a seed solution;

[0103] (3) inoculating the seed liquid into a tank containing the third fermentation medium at an inoculum amount of 8% (V / V), and fermenting for 121 hours at a temperature of 36° C., a stirring speed of 250 rpm, a ventilation volume of 3.5 vvm, and a tank pressure of 0.15 MPa to obtain a sophorolipid fermentation liquid;

[0104] (4) filtering the sophorolipid fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0105] (5) The filtered clear liquid is concentrated by a nanofiltration membrane to obtain a sophorolipid solution with a concentration of 90 g / L.

[0106] 4. The above rhamnolipid solution, lipopeptide solution and sophorolipid solution are prepared in a volume ratio of 5:3:5 to obtain a bionano solution. During the mixing process, there is no restriction on the order of adding the rhamnolipid solution, lipopeptide solution and sophorolipid solution.

[0107] Example 4

[0108] 1. Preparation of Rhamnolipid Solution

[0109] (1) inoculating the Pseudomonas aeruginosa strain into a shake flask containing the first liquid culture medium, and culturing the culture medium at a temperature of 37° C. and a stirring speed of 240 rpm for 24 hours to obtain a shake flask seed solution;

[0110] (2) inoculating the shake flask seed solution into the shake flask containing the first liquid culture medium at an inoculum rate of 10% (V / V), and culturing for 20 h under the conditions of a temperature of 37° C., a stirring speed of 180 rpm, a ventilation volume of 1.5 vvm, and a tank pressure of 0.05 MPa to obtain a seed solution;

[0111] (3) inoculating the seed liquid into a tank containing the first fermentation medium at an inoculum amount of 10% (V / V), and fermenting for 140 hours under the conditions of a temperature of 35° C., a stirring speed of 120 rpm, a ventilation volume of 0.6 vvm, and a tank pressure of 0.05 MPa to obtain a rhamnolipid fermentation liquid;

[0112] (4) filtering the rhamnolipid fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0113] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a rhamnolipid solution with a concentration of 50 g / L.

[0114] 2. Preparation of Lipopeptide Solution

[0115] (1) inoculating the Bacillus subtilis strain into a shake flask of the second liquid culture medium, and culturing for 25 hours at a temperature of 37° C. and a stirring speed of 240 rpm to obtain a shake flask seed solution;

[0116] (2) inoculating the shake flask seed solution into a shake flask containing the second liquid culture medium at an inoculum rate of 10% (V / V), and culturing for 20 h under the conditions of a temperature of 37° C., a stirring speed of 220 rpm, a ventilation volume of 2.0 vvm, and a tank pressure of 0.095 MPa to obtain a seed solution;

[0117] (3) inoculating the seed liquid into a tank containing the third fermentation medium at an inoculum amount of 10% (V / V), and fermenting for 72 hours under the conditions of a temperature of 37° C., a stirring speed of 220 rpm, a ventilation volume of 0.6 vvm, and a tank pressure of 0.095 MPa to obtain a lipopeptide fermentation liquid;

[0118] (4) filtering the lipopeptide fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0119] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a lipopeptide solution with a concentration of 80 g / L.

[0120] 3. Preparation of Sophorolipid Solution

[0121] (1) inoculating the Candida strain into a shake flask containing the third culture medium, and culturing for 24 hours at a temperature of 37° C. and a stirring speed of 220 rpm to obtain a shake flask seed solution;

[0122] (2) inoculating the shake flask seed solution into a shake flask containing the third culture medium at an inoculum rate of 10% (V / V), and culturing for 20 h at a temperature of 37° C., a stirring speed of 220 rpm, a ventilation volume of 3.2 vvm, and a tank pressure of 0.2 MPa to obtain a seed solution;

[0123] (3) inoculating the seed liquid into a tank containing the third fermentation medium at an inoculum amount of 10% (V / V), and fermenting for 124 hours at a temperature of 37° C., a stirring speed of 300 rpm, a ventilation volume of 4.0 vvm, and a tank pressure of 0.2 MPa to obtain a sophorolipid fermentation liquid;

[0124] (4) filtering the sophorolipid fermentation broth through a ceramic membrane with a pore size of 50 nm, and collecting the filtered clear liquid;

[0125] (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a sophorolipid solution with a concentration of 80 g / L.

[0126] 4. The above rhamnolipid solution, lipopeptide solution and sophorolipid solution are prepared in a volume ratio of 3:5:3 to obtain a bionano solution. During the mixing process, there is no restriction on the order of adding the rhamnolipid solution, lipopeptide solution and sophorolipid solution.

[0127] In the above-mentioned Examples 1-4, the formula of the first liquid culture medium is: 0.5 g of yeast extract, 0.5 g of peptone, 1.5 g of glucose and 0.5 g of NaCl are added to every 100 g of water, and the pH value is 6.8 to 7.0;

[0128] The formula of the first fermentation medium is: 5 g of yeast extract, 5 g of peptone, 15 g of glucose, 15 g of rapeseed oil, 5 g of NaCl and 20 g of agar are added to every 1 kg of water, and the pH value is 7.6.

[0129] The formula of the second liquid culture medium is as follows: 1.0 g of yeast extract, 1.5 g of sucrose, 0.8 g of dipotassium hydrogen phosphate, and 0.05 g of potassium dihydrogen phosphate are added to every 100 g of water, and the pH value is 6.8;

[0130] The formula of the second fermentation medium is: 10 g of yeast extract, 15 g of sucrose, 10 g of rapeseed oil, 8 g of dipotassium hydrogen phosphate and 0.5 g of potassium dihydrogen phosphate are added to every 1 kg of water, and the pH value is 7.0.

[0131] The third liquid culture medium has a formula of: 1.0 g of yeast extract, 1.0 g of glucose, 0.1 g of dipotassium hydrogen phosphate, 0.1 g of potassium dihydrogen phosphate, and 0.02 g of magnesium sulfate per 100 g of water, with a pH value of 4.8;

[0132] The formula of the third fermentation medium is: 10 g of yeast extract, 10 g of glucose, 10 g of rapeseed oil, 1 g of dipotassium hydrogen phosphate, 1 g of potassium dihydrogen phosphate and 0.2 g of magnesium sulfate are added to every 1 kg of water, and the pH value is 3.5.

[0133] Example 5

[0134] The bionano solution provided by the invention can be used for improving the recovery rate of tertiary oil recovery in low permeability oil fields.

[0135] Example 6

[0136] The bionano solution provided by the invention can be used to prepare biological preparations for improving crude oil recovery.

[0137] The performance of the bionano solution provided by the present invention is measured by the following experiment to further demonstrate the beneficial effects of the bionano solution provided by the present invention.

[0138] Water is added to the bionano solution provided by the present invention to dilute it into bionano solution dilutions with concentrations of 0.5%, 1%, and 3%, where the concentration refers to the volume percentage concentration. In the process of adding water to dilute the bionano solution, the bionano solution and water only undergo physical dissolution, and no other chemical reactions occur.

[0139] (1) Determination of contact angle of bionanosolution dilution

[0140] The contact angle, also known as the wetting contact angle, refers to the angle formed between the tangent of the liquid-gas interface and the solid surface and including the liquid at any point around the three-phase contact when the solid, liquid and gas three-phase contact reaches equilibrium. It is a measure of the degree of wettability. If the contact angle is less than 90°, the solid is lyophilic, that is, the liquid can wet the solid. The smaller the angle, the better the wettability; if the contact angle is greater than 90°, the solid is lyophobic, that is, the liquid does not wet the solid, it is easy to move on the surface and cannot enter the pores.

[0141] A drop of water or a drop of 1% or 3% bio-nano solution dilution was dropped on the quartz plate treated with n-pentane. After 10 minutes, the contact angle was measured using an S-2 contact angle meter. The experimental results are shown in Table 1.

[0142] Table 1 Contact angle measurement results of bionano solution dilution (10min)

[0143]

[0144] The results show that the bio-nano solution dilutions with concentrations of 1% and 3% can effectively reduce the contact angle, thereby changing the wettability of the rock and facilitating the stripping of crude oil.

[0145] (2) Determination of deoiling efficiency of bionanosolution dilution

[0146] Take 20g of dried quartz sand with oil, add 100ml of bio-nano solution diluent with concentration of 1% and 3%, respectively, place it in a 37 degree constant temperature box for observation, take out and calculate the amount of oil after 0.5, 1, 3, 6, 12, 24, and 48 hours, respectively. The oil removal efficiency of the bio-nano solution diluent is shown in Table 2, and the oil removal efficiency of the bio-nano solution diluent with concentration of 1% is shown in Figure 2 .

[0147] Table 2 Deoiling efficiency test results of bionano solution dilution

[0148] Time (h) 0.5 1 3 6 12 24 48 1% solution deoiling rate (%) 1.8 10.8 23.5 47.3 65.8 75.4 86.1 3% solution deoiling rate (%) 8.9 23.8 31.5 57.2 72.9 81.2 92.3

[0149] From Table 2 and Figure 2 It can be seen that the deoiling efficiencies of the bio-nano solution dilutions with concentrations of 1% and 3% are 86.1% and 92.3% respectively after 48 hours, and the deoiling efficiency is high and the deoiling effect is good.

[0150] (3) Determination of oil displacement efficiency of bio-nano solution dilution

[0151] Indoor oil displacement experiments were conducted using artificial cemented cores (Shengli crude oil) and Chang 6 cores (Changqing crude oil). The specific experimental steps are as follows:

[0152] ①Measure gas phase permeability;

[0153] ②Evacuate and saturate with water;

[0154] ③Measure water phase permeability;

[0155] ④Saturated crude oil;

[0156] ⑤ Water drive to 99% water content;

[0157] ⑥ Bio-nano solution dilution slug;

[0158] ⑦Subsequent water drive.

[0159] The results of the oil displacement efficiency determination of the bio-nano solution dilution are shown in Table 3. Core displacement efficiency increase rate = core displacement efficiency (injection of bio-nano solution dilution) + core displacement efficiency (subsequent water flooding).

[0160] Table 3 Results of oil displacement efficiency determination of bio-nano solution dilution

[0161]

[0162]

[0163]

[0164] From the results of the oil displacement efficiency determination of the bio-nano solution dilution in Table 3, it can be seen that when the concentration of the bio-nano solution dilution is 0.5% and 1% for the artificial cemented core (Shengli crude oil) with a permeability of 21-27mD, the core displacement efficiency increases by 18.7% and 22.9% respectively, and the injection pressure is significantly reduced. When the permeability of the Chang 6 core (Changqing crude oil) with a permeability of 2.7-2.8mD is displaced, when the concentration of the bio-nano solution dilution is 1% and 3%, the core displacement efficiency increases by 9.6% and 13.9% respectively, but the water injection pressure increases significantly. It can be seen that after injecting the bio-nano solution dilution provided by the present invention, the crude oil that cannot be mobilized by water drive can be displaced, and the overall core displacement efficiency is increased, thereby improving the recovery rate of crude oil, and it is suitable for the exploitation of crude oil in different formations.

[0165] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0166] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A bionano solution, characterized in that: The rhamnolipid solution, the lipopeptide solution and the sophorolipid solution are prepared in a volume ratio of (1-5):(1-5):(1-5), and the concentrations of the rhamnolipid solution, the lipopeptide solution and the sophorolipid solution are 30-60 g / L, 30-90 g / L and 30-90 g / L, respectively.

2. The bionano solution according to claim 1, characterized in that: The bionano solution is prepared by mixing a rhamnolipid solution, a lipopeptide solution and a sophorolipid solution in a volume ratio of 2:1:

1.

3. The bionano solution according to claim 1 or 2, characterized in that: The preparation process of the bionano solution is as follows: mixing the prepared rhamnolipid solution, lipopeptide solution and sophorolipid solution; The preparation process of the rhamnolipid solution is as follows: Pseudomonas aeruginosa is inoculated into a first liquid culture medium for cultivation to obtain a culture solution, and then the culture solution is inoculated into a tank containing a first fermentation culture medium for fermentation to obtain a rhamnolipid fermentation solution, and finally the rhamnolipid fermentation solution is filtered through a ceramic membrane, and the filtered clear liquid is collected and then concentrated through a nanofiltration membrane to obtain a rhamnolipid solution; The preparation process of the lipopeptide solution is as follows: Bacillus subtilis is inoculated into a second liquid culture medium for cultivation to obtain a culture solution, and then the culture solution is inoculated into a tank containing a second fermentation culture medium for fermentation to obtain a lipopeptide fermentation solution, and finally the lipopeptide fermentation solution is filtered through a ceramic membrane, and the filtered clear liquid is collected and then concentrated through a nanofiltration membrane to obtain a lipopeptide solution; The preparation process of the sophorolipid solution is as follows: Candida is inoculated into a third liquid culture medium for cultivation to obtain a culture solution, and then the culture solution is inoculated into a tank containing a third fermentation culture medium for fermentation to obtain a sophorolipid fermentation solution, and finally the sophorolipid fermentation solution is filtered through a ceramic membrane, the filtered clear liquid is collected and then concentrated through a nanofiltration membrane to obtain a sophorolipid solution.

4. The bionano solution according to claim 3, characterized in that: The formula of the first liquid culture medium is: 0.5 g of yeast extract, 0.5 g of peptone, 1.5 g of glucose and 0.5 g of NaCl are added to every 100 g of water, and the pH value is 6.8 to 7.0; The formula of the first fermentation medium is: 5g of yeast extract, 5g of peptone, 15g of glucose, 15g of rapeseed oil, 5g of NaCl and 20g of agar are added to every 1kg of water, and the pH value is 7.6; The formula of the second liquid culture medium is: 1.0 g of yeast extract, 1.5 g of sucrose, 0.8 g of dipotassium hydrogen phosphate and 0.05 g of potassium dihydrogen phosphate are added to every 100 g of water, and the pH value is 6.8; The formula of the second fermentation medium is: 10 g of yeast extract, 15 g of sucrose, 10 g of rapeseed oil, 8 g of dipotassium hydrogen phosphate and 0.5 g of potassium dihydrogen phosphate are added to every 1 kg of water, and the pH value is 7.

0.

5. The bionano solution according to claim 3, characterized in that: The specific preparation process of the rhamnolipid solution is as follows: (1) inoculating the Pseudomonas aeruginosa strain into a shake flask containing a first liquid culture medium, and culturing for 20 to 24 hours at a temperature of 35 to 37° C. and a stirring speed of 220 to 240 rpm to obtain a shake flask seed solution; (2) inoculating the shake flask seed solution into the shake flask containing the first liquid culture medium, and culturing for 16 to 20 hours under the conditions of a temperature of 35 to 37° C., a stirring speed of 100 to 180 rpm, a ventilation volume of 1.0 to 1.5 vvm, and a tank pressure of 0.03 to 0.05 MPa to obtain a seed solution; (3) inoculating the seed liquid into a tank containing the first fermentation medium, and fermenting for 136 to 140 hours at a temperature of 33 to 35° C., a stirring speed of 80 to 120 rpm, a ventilation volume of 0.2 to 0.6 vvm, and a tank pressure of 0.03 to 0.05 MPa to obtain a rhamnolipid fermentation liquid; (4) filtering the rhamnolipid fermentation broth through a ceramic membrane and collecting the filtered clear liquid; (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a rhamnolipid solution.

6. The bionano solution according to claim 3, characterized in that: The specific preparation process of the lipopeptide solution is as follows: (1) inoculating the Bacillus subtilis strain into a shake flask containing a second liquid culture medium, and culturing for 22 to 25 hours at a temperature of 35 to 37° C. and a stirring speed of 200 to 240 rpm to obtain a shake flask seed solution; (2) inoculating the shake flask seed solution into a shake flask containing a second liquid culture medium, and culturing for 16 to 20 hours at a temperature of 35 to 37° C., a stirring speed of 180 to 220 rpm, a ventilation volume of 1.0 to 2.0 vvm, and a tank pressure of 0.08 to 0.095 MPa to obtain a seed solution; (3) inoculating the seed liquid into a tank containing a second fermentation medium, and fermenting for 60 to 72 hours at a temperature of 35 to 37° C., a stirring speed of 180 to 220 rpm, a ventilation volume of 0.2 to 0.6 vvm, and a tank pressure of 0.08 to 0.095 MPa to obtain a lipopeptide fermentation liquid; (4) filtering the lipopeptide fermentation broth through a ceramic membrane and collecting the filtered clear liquid; (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a lipopeptide solution.

7. The bionano solution according to claim 3, characterized in that: The formula of the third liquid culture medium is: 1.0 g of yeast extract, 1.0 g of glucose, 0.1 g of dipotassium hydrogen phosphate, 0.1 g of potassium dihydrogen phosphate and 0.02 g of magnesium sulfate are added to every 100 g of water, and the pH value is 4.8; The formula of the third fermentation medium is: 10 g of yeast extract, 10 g of glucose, 10 g of rapeseed oil, 1 g of dipotassium hydrogen phosphate, 1 g of potassium dihydrogen phosphate and 0.2 g of magnesium sulfate are added to every 1 kg of water, and the pH value is 3.

5.

8. The bionano solution according to claim 3, characterized in that: The specific preparation process of the sophorolipid solution is as follows: (1) inoculating the Candida strain into a shake flask containing the third culture medium, and culturing for 20 to 24 hours at a temperature of 35 to 37° C. and a stirring speed of 180 to 220 rpm to obtain a shake flask seed solution; (2) inoculating the shake flask seed solution into a shake flask containing the third culture medium, and culturing for 16 to 20 hours under the conditions of a temperature of 35 to 37° C., a stirring speed of 180 to 220 rpm, a ventilation volume of 2.8 to 3.2 vvm, and a tank pressure of 0.1 to 0.2 MPa to obtain a seed solution; (3) inoculating the seed liquid into a tank containing the third fermentation medium, and fermenting for 118 to 124 hours at a temperature of 35 to 37° C., a stirring speed of 200 to 300 rpm, a ventilation volume of 3.0 to 4.0 vvm, and a tank pressure of 0.1 to 0.2 MPa to obtain a sophorolipid fermentation liquid; (4) filtering the sophorolipid fermentation broth through a ceramic membrane and collecting the filtered clear liquid; (5) The filtered clear liquid is concentrated through a nanofiltration membrane to obtain a sophorolipid solution.

9. The use of the bionano solution according to any one of claims 1 to 8, characterized in that: The bionano solution is used for improving the recovery rate of tertiary oil recovery in low permeability oil fields.

10. The use of the bionano solution according to any one of claims 1 to 8, characterized in that: The bionano solution is used for preparing biological preparations for improving crude oil recovery.

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