A shear-resistant foam cleanup composition, foam cleanup agent, and use thereof

Abstract

The present application relates to a kind of anti-shearing foam displacement composition, foam agent and its application.The anti-shearing foam displacement composition of the present application is composed of main agent, thickening agent and stabilizer;The main agent is composed of first zwitterionic surfactant and second ionic surfactant;The first zwitterionic surfactant accounts for 70-80% of the mass of main agent;The thickening agent is used in an amount of 0.2-0.4% of the mass of main agent;The stabilizer is used in an amount of 0.06-0.1% of the mass of main agent;The first zwitterionic surfactant is cocamide propyl betaine;The second ionic surfactant is dodecyl dimethyl amine oxide.The foam agent provided by the present application does not contain fluorocarbon surfactant, but still has the performance advantages of strong foaming power, good stability, large liquid carrying capacity under the conditions of high temperature, high salinity, high condensate oil and methanol content, and strong adaptability, especially suitable for high-temperature deep-well foam drainage gas recovery.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of anti-shearing foam drainage composition, foam drainage agent and its application, belong to gas field exploitation technical field. BACKGROUND

[0002] At present, there are dozens of foam drainage agents suitable for different reservoir conditions at home and abroad, and most of them are greatly affected by temperature changes in performance, generally applicable to temperature below 90℃, salinity is 100000ppm, no H2S gas and condensate oil content is not high. With the continuous development of natural gas, high deep gas wells are also paid more and more attention, and the temperature of gas reservoir is higher, which leads to the foaming performance and liquid carrying performance of conventional foam drainage agents are greatly reduced. The foam produced by many foam drainage agents under the condition of temperature greater than 120℃ and salinity greater than 100000ppm will completely disappear within 1-2min, or even no foam is produced, which seriously restricts the application of foam drainage gas recovery in high temperature gas wells.

[0003] The Chinese invention patent document with the application publication number CN105086980A discloses "a foam drainage agent for deep gas well drainage gas recovery and its preparation method", wherein the composition of the foam drainage agent includes, by weight percentage: zwitterionic surfactant A 15-35%, zwitterionic surfactant B 10-30%, anionic surfactant 10-20%, fluorocarbon surfactant 0.1-2%, solid foam stabilizer, and the balance is deionized water. The foam drainage agent has certain foaming, foam stabilizing and liquid carrying performance under high temperature and high salinity conditions, but from the experimental results in the examples, the liquid carrying capacity is generally less than 180mL, and the liquid carrying rate is less than 90%. At the same time, fluorocarbon surfactant is used in the foam drainage agent formula, however, some fluorocarbon surfactants are restricted use chemicals in oil field chemicals, and as can be known from the content description, the foam drainage agent has low toxicity characteristics, and importantly, the price of fluorocarbon surfactant is also relatively high, thus limiting the popularization and application of the technology.

[0004] The foam drainage agent described in the publication "nanoparticle foam drainage agent suitable for deep water producing gas wells" also contains fluorocarbon surfactant, which also has the problems of restricted use and high price limiting popularization. The foam drainage agent described in the publication "a foam drainage agent suitable for high temperature deep gas well drainage" uses SDS, BS and PO complex, and the performance before and after aging at 120℃ is evaluated by conventional Ross foam instrument, but the adaptability under high temperature and high pressure conditions is not given, and the adaptability to high salinity and condensate oil content is not evaluated, and the adaptability is unknown.

[0005] Therefore, it has become a problem to be solved in the field to provide a foam drainage agent for high temperature gas well drainage gas recovery, which is resistant to high temperature and high salinity, has simple composition and is easy to obtain, and also considers production cost, popularization and other problems. SUMMARY

[0006] The first object of the present application is to provide an anti-shearing foam displacement composition to solve the problem that the foam displacement agent usually contains fluorocarbon surfactant, resulting in complex composition, high cost and certain biological toxicity, which is not conducive to large-scale promotion, when facing high temperature, high salinity and high condensate gas wells.

[0007] The second object of the present application is to provide an anti-shearing foam displacement agent to solve the problem that the foam displacement agent without fluorocarbon surfactant has poor adaptability and low drainage efficiency when applied to high-temperature deep condensate gas wells.

[0008] The third object of the present application is to provide the application of the anti-shearing foam displacement composition or the anti-shearing foam displacement agent in the foam drainage gas recovery of natural gas wells to solve the problem that the foam displacement agent usually contains fluorocarbon surfactant, resulting in complex composition, high cost and certain biological toxicity, which is not conducive to large-scale promotion, when the foam displacement agent is applied to high-temperature deep condensate gas wells.

[0009] In order to achieve the above object, the technical scheme of an anti-shearing foam displacement composition in the present application is:

[0010] An anti-shearing foam displacement composition, which is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 70-80% of the mass of the main agent; the thickening agent accounts for 0.2-0.4% of the mass of the main agent; the stabilizer accounts for 0.06-0.1% of the mass of the main agent; the first zwitterionic surfactant is cocamide propyl betaine; and the second ionic surfactant is dodecyl dimethyl amine oxide.

[0011] The above technical scheme has the following advantages: the present application selects cocamide propyl betaine and dodecyl dimethyl amine oxide as the main agent, and matches with the thickening agent and the stabilizer to form the anti-shearing foam displacement composition, which has the advantages of simple composition, easy availability and low cost, and can maintain high foaming and stable foaming capacity and excellent liquid carrying rate without fluorocarbon surfactant when facing high temperature, high salinity and high condensate gas wells. Experiments have proved that the foam displacement agent prepared from the anti-shearing foam displacement composition of the present application has the advantages of strong foaming and liquid carrying capacity, excellent cleanliness, good low-temperature resistance and flowability, meets the requirements of different injection processes, and is especially suitable for foam drainage gas recovery in high-temperature deep gas wells.

[0012] The cocoamide propyl betaine and the dodecyl dimethyl amine oxide have good foaming and stable foaming effects, and contain cationic groups and anionic groups at the same time, and the solubility is less limited by the dielectric medium and the pH value range of the solution, and is less affected by the high mineralization and condensate oil in the formation. The stable foaming agent composed of the solid stable foaming agent and the macromolecular stable foaming agent and the selected main agent play a synergistic effect, so that the molecules in the foam displacement agent are densely arranged, the strength and elasticity of the generated foam are enhanced, the dispersion effect caused by the violent Brownian motion of the molecules at high temperature in the high-temperature deep gas well is reduced, and the stable foaming capacity of the foam displacement agent is further enhanced.

[0013] As a further improvement, the stabilizer is composed of magnesium lithium silicate and sodium gluconate; and the mass ratio of the magnesium lithium silicate and the sodium gluconate is 1:(1-1.1).

[0014] The above technical solution has the beneficial effects that the magnesium lithium silicate forms a certain space barrier network structure, increases the rigidity of the bubbles; the sodium gluconate, the cocoamide propyl betaine and the dodecyl dimethyl amine oxide have strong interactions on the surface of the solution, improve the surface viscosity and the volume repulsion effect between the two surfaces in the foam, and improve the stability of the foam. The two types of stabilizers cooperate with each other to significantly improve the stability of the foam of the foam displacement agent, and further increase the liquid carrying capacity.

[0015] As a further improvement, the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl beta cyclodextrin; and the mass ratio of the polyethylene glycol 2000 and the hydroxypropyl beta cyclodextrin is 1:(1-1.1).

[0016] The above technical solution has the beneficial effects that the polyethylene glycol 2000 has good solubility, is stable to heat, acid and alkali, and has good moisture absorption, lubricity and viscosity, can effectively improve the viscosity and shear resistance of the foam displacement agent, improve the strength of the foam film, and further improve the stability of the foam; the cyclodextrin has a thickening effect and also has strong stability. The two thickening agents cooperate with each other to effectively improve the stability of the foam displacement agent, and greatly reduce the production cost.

[0017] In order to achieve the above purpose, the technical scheme of an anti-shearing foam displacement agent in the present application is:

[0018] An anti-shearing foam displacement agent, comprising an anti-shearing foam displacement composition and water.

[0019] The beneficial effects of the above technical solution are that the amphoteric ion surfactant cocoamide propyl betaine with appropriate hydrophobic chain length, strong hydrophilic group hydration capacity and high temperature resistance and dodecyl dimethyl amine oxide are compounded with stabilizers and thickening agents, the synergistic effect and position adaptability are fully played, and the anti-shear foam displacement agent with good foaming property and foam stability is obtained.

[0020] As a further improvement, the first amphoteric ion surfactant in the anti-shear foam displacement composition accounts for 59-71% of the weight percentage of the anti-shear foam displacement agent.

[0021] As a further improvement, the anti-shear foam displacement agent includes an anti-freezing agent.

[0022] The beneficial effects of the above technical solution are that the anti-freezing agent is added to the foam displacement agent of the application, without affecting the foaming and foam stability of the foam displacement agent, the foam displacement agent also has good anti-freezing property, is still a flowable liquid after being frozen at-18℃ for 24 hours, can be well adapted to smooth injection of the agent in winter in the north, and further expands the geographical range of practical application of the foam displacement agent.

[0023] Preferably, the anti-freezing agent is methanol.

[0024] As a further improvement, the amount of the anti-freezing agent is 0-5% of the mass of the main agent.

[0025] In order to achieve the above-mentioned purposes, the technical solution of the application of the anti-shear foam displacement composition or the anti-shear foam displacement agent in foam drainage gas recovery in natural gas wells is:

[0026] The application of an anti-shear foam displacement composition or an anti-shear foam displacement agent in foam drainage gas recovery in natural gas wells.

[0027] The beneficial effects of the above technical solution are that the anti-shear foam displacement agent of the application can maintain high foaming and foam stability and excellent liquid carrying rate when facing high-temperature, high-salinity and high-condensate gas wells for drainage gas recovery without containing fluorocarbon surfactants. At the same time, all the components are good in human body compatibility, small in biological toxicity, easy in biological degradation, and small in influence on reservoirs and formations.

[0028] Compared with the prior art, the beneficial effects of the application are that:

[0029] The anti-shearing foam displacement agent has the advantages of strong foaming and liquid carrying capacity, excellent cleanliness, good low-temperature resistance and flowability, and meets the requirements of different filling processes, and is especially suitable for high-temperature deep well foam drainage gas recovery. Under the conditions of a temperature of 130 DEG C, a salinity of 200000 ppm, a condensate oil content of 20% (volume concentration of condensate oil in liquid), and a methanol content of 20% (volume concentration of methanol in liquid), the anti-shearing foam displacement agent has high foaming property, foam stability and liquid carrying rate. Under the conditions of a pressure of 3 MPa and 10 MPa and a temperature of 130 DEG C, the liquid carrying rate is more than 95%. The anti-shearing foam displacement agent has strong adaptability, and even without fluorocarbon surfactant, the anti-shearing foam displacement agent still has the performance advantages of strong foaming force, good stability and large liquid carrying capacity in high-temperature, high-salinity, high-condensate-oil and methanol-containing formation water. After the anti-shearing foam displacement agent is added with an antifreeze, the anti-shearing foam displacement agent still has good antifreeze property without affecting the foaming and foam stability of the anti-shearing foam displacement agent, and is still a flowable liquid after being frozen for 24 hours under the condition of-18 DEG C, so that the anti-shearing foam displacement agent can be smoothly filled in northern winter, and the geographical range of practical application of the anti-shearing foam displacement agent is further expanded. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a preparation flow chart of the anti-shearing high-efficiency foam displacement agent in the embodiment 7 of the present application (wherein the amphoteric surfactant C and the amphoteric surfactant O represent the first and second amphoteric surfactants respectively; the stabilizer 1 and the stabilizer 2 represent magnesium lithium silicate and sodium gluconate respectively; and the thickening agent 1 and the thickening agent 2 represent polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin respectively). DETAILED DESCRIPTION

[0031] The present application will be further described in conjunction with specific embodiments. It should be noted that the embodiments described below or technical features thereof can be combined with each other to form new embodiments without conflict. The equipment and raw materials used are commercially available or commonly used in the art. The methods in the following examples are conventional methods in the art unless otherwise specified.

[0032] The first amphoteric surfactant cocoamide propyl betaine and the second amphoteric surfactant dodecyl dimethyl amine oxide used in the following examples are commercial products, wherein the cocoamide propyl betaine is CAB-35 and CAB-45, and the active content is 28%-47%; the dodecyl dimethyl amine oxide is OB-2, and the active content is 30±2%.

[0033] Magnesium lithium silicate, CAS No.: 37220-90-9.

[0034] Firstly, the specific embodiments of the anti-shearing foam displacement composition of the present application are as follows:

[0035] Example 1

[0036] The anti-shearing foam displacement composition of the present embodiment is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 70% of the mass of the main agent; the thickening agent is used in an amount of 0.4% of the mass of the main agent; the stabilizer is used in an amount of 0.1% of the mass of the main agent; the first zwitterionic surfactant is CAB-35; the second ionic surfactant is OB-2; the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin, and the mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:1; the stabilizer is composed of magnesium lithium silicate and sodium gluconate, and the mass ratio of magnesium lithium silicate to sodium gluconate is 1:1.

[0037] Example 2

[0038] The anti-shearing foam displacement composition of the present embodiment is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 80% of the mass of the main agent; the thickening agent is used in an amount of 0.4% of the mass of the main agent; the stabilizer is used in an amount of 0.1% of the mass of the main agent; the first zwitterionic surfactant is CAB-35; the second ionic surfactant is OB-2; the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin, and the mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:1; the stabilizer is composed of magnesium lithium silicate and sodium gluconate, and the mass ratio of magnesium lithium silicate to sodium gluconate is 1:1.

[0039] Example 3

[0040] The anti-shearing foam displacement composition of the present embodiment is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 80% of the mass of the main agent; the thickening agent is used in an amount of 0.2% of the mass of the main agent; the stabilizer is used in an amount of 0.1% of the mass of the main agent; the first zwitterionic surfactant is CAB-35; the second ionic surfactant is OB-2; the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin, and the mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:1; the stabilizer is composed of magnesium lithium silicate and sodium gluconate, and the mass ratio of magnesium lithium silicate to sodium gluconate is 1:1.

[0041] Example 4

[0042] The anti-shearing foam displacement composition of the embodiment is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 80% of the mass of the main agent; the thickening agent is used in an amount of 0.2% of the mass of the main agent; the stabilizer is used in an amount of 0.06% of the mass of the main agent; the first zwitterionic surfactant is CAB-35; the second ionic surfactant is OB-2; the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin, and the mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:1; the stabilizer is composed of magnesium lithium silicate and sodium gluconate, and the mass ratio of magnesium lithium silicate to sodium gluconate is 1:1.

[0043] Example 5

[0044] The anti-shearing foam displacement composition of the embodiment is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 80% of the mass of the main agent; the thickening agent is used in an amount of 0.2% of the mass of the main agent; the stabilizer is used in an amount of 0.06% of the mass of the main agent; the first zwitterionic surfactant is CAB-35; the second ionic surfactant is OB-2; the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin, and the mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:1; the stabilizer is composed of magnesium lithium silicate and sodium gluconate, and the mass ratio of magnesium lithium silicate to sodium gluconate is 1:1.

[0045] Example 6

[0046] The anti-shearing foam displacement composition of the embodiment is composed of a main agent, a thickening agent and a stabilizer; the main agent is composed of a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 80% of the mass of the main agent; the thickening agent is used in an amount of 0.2% of the mass of the main agent; the stabilizer is used in an amount of 0.06% of the mass of the main agent; the first zwitterionic surfactant is CAB-35; the second ionic surfactant is OB-2; the thickening agent is composed of polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin, and the mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:1; the stabilizer is composed of magnesium lithium silicate and sodium gluconate, and the mass ratio of magnesium lithium silicate to sodium gluconate is 1:1.

[0047] Second, the specific implementation of the anti-shearing foam displacement agent of the application is as follows:

[0048] Example 7

[0049] The anti-shearing foam control agent of the present example is composed of the anti-shearing foam control composition of Example 1, water and an anti-freezing agent; the first zwitterionic surfactant in the anti-shearing foam control composition accounts for 59.3% by weight of the anti-shearing foam control agent.

[0050] The specific formulation composition is as follows:

[0051] Cocamidopropyl betaine (CAB-35) 70 g, dodecyl dimethyl amine oxide (OB-2) 30 g, polyethylene glycol 2000 0.2 g, hydroxypropyl β cyclodextrin 0.2 g, magnesium lithium silicate 0.05 g, sodium gluconate 0.05 g, methanol 5 g and water 12.5 g.

[0052] The preparation process is as shown in Figure 1 The specific preparation steps are as follows:

[0053] a. 70 g of CAB-35 and 30 g of OB-2 were directly mixed at 45°C for 1 h with slow stirring to form 100 g of solution A.

[0054] b. 0.2 g of PEG2000 and 0.2 g of carboxypropyl β cyclodextrin solid powder were mixed uniformly and then slowly added to 7.6 g of deionized water at 60°C while continuously stirring, and after addition, the stirring was continued for 5 h until complete dissolution to form 8 g of solution B.

[0055] c. 0.05 g of magnesium lithium silicate and 0.05 g of sodium gluconate solid powder were mixed uniformly and then slowly added to 4.9 g of deionized water at 80°C while continuously stirring, and the stirring was continued for 8 h until complete dissolution to form 5 g of solution C.

[0056] d. The solutions A, B and C obtained in steps a, b and c and 5 g of methanol were directly mixed and stirred at 45°C for 2 h to obtain the foam control agent 1.

[0057] Example 8

[0058] The anti-shearing foam control agent of the present example is composed of the anti-shearing foam control composition of Example 2, water and an anti-freezing agent; the first zwitterionic surfactant in the anti-shearing foam control composition accounts for 67.8% by weight of the anti-shearing foam control agent.

[0059] The specific formulation composition is as follows:

[0060] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, polyethylene glycol 2000 0.2 g, hydroxypropyl β cyclodextrin 0.2 g, magnesium lithium silicate 0.05 g, sodium gluconate 0.05 g, methanol 5 g and water 12.5 g.

[0061] The specific preparation steps are as follows:

[0062] a. 80 g of CAB-35 and 20 g of OB-2 are directly mixed at 45°C for 1 h with slow stirring to form 100 g of solution A.

[0063] b. 0.2 g of PEG2000 and 0.2 g of carboxypropyl β-cyclodextrin solid powder are uniformly mixed and then slowly added to 7.6 g of deionized water at 60°C while continuously stirring, and after addition, the stirring is continued for 5 h until complete dissolution to form 8 g of solution B.

[0064] c. 0.05 g of lithium magnesium silicate and 0.05 g of sodium gluconate solid powder are uniformly mixed and then slowly added to 4.9 g of deionized water at 80°C while continuously stirring, and the stirring is continued for 8 h until complete dissolution to form 5 g of solution C.

[0065] d. The solutions A, B, and C obtained in steps a, b, and c, and 5 g of methanol are directly mixed and stirred at 45°C for 2 h to obtain foam 2.

[0066] Example 9

[0067] The shear-resistant foam agent of the present example is composed of the shear-resistant foam agent composition of Example 3, water, and an antifreeze agent; the first zwitterionic surfactant in the shear-resistant foam agent composition accounts for 67.8% of the weight percentage of the shear-resistant foam agent.

[0068] The specific formula composition is as follows:

[0069] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, polyethylene glycol 2000 0.1 g, hydroxypropyl β-cyclodextrin 0.1 g, lithium magnesium silicate 0.05 g, sodium gluconate 0.05 g, methanol 5 g, and water 12.7 g.

[0070] The specific preparation steps are as follows:

[0071] a. 80 g of CAB-35 and 20 g of OB-2 are directly mixed at 45°C for 1 h with slow stirring to form 100 g of solution A.

[0072] b. 0.1 g of PEG2000 and 0.1 g of β-cyclodextrin solid powder are uniformly mixed and then slowly added to 7.8 g of deionized water at 60°C while continuously stirring, and after addition, the stirring is continued for 4 h until complete dissolution to form 8 g of solution B.

[0073] c. Take 0.05 g of magnesium lithium silicate and 0.05 g of sodium gluconate solid powder, mix them evenly, then slowly add them to 4.9 g of deionized water at 80°C while continuously stirring, continue stirring for 8 h until completely dissolved to form 5 g of solution C.

[0074] d. Mix the solutions A, B, and C obtained in steps a, b, and c, and 5 g of methanol directly at 45°C and stir for 2 h to obtain foam agent 3.

[0075] Example 10

[0076] The shear-resistant foam agent of this example is composed of the shear-resistant foam agent composition of Example 4, water, and an antifreeze agent; the first zwitterionic surfactant in the shear-resistant foam agent composition accounts for 67.8% of the weight percentage of the shear-resistant foam agent.

[0077] The specific formula composition is as follows:

[0078] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, polyethylene glycol 2000 0.1 g, hydroxypropyl β-cyclodextrin 0.1 g, magnesium lithium silicate 0.03 g, sodium gluconate 0.03 g, methanol 5 g, and water 12.74 g.

[0079] The specific preparation steps are as follows:

[0080] a. Take 80 g of CAB-35 and 20 g of OB-2, mix them directly at 45°C and stir slowly for 1 h to form 100 g of solution A.

[0081] b. Take 0.1 g of PEG2000 and 0.1 g of β-cyclodextrin solid powder, mix them evenly, then slowly add them to 7.8 g of deionized water at 60°C while continuously stirring, continue stirring for 4 h after adding to completely dissolve to form 8 g of solution B.

[0082] c. Take 0.03 g of magnesium lithium silicate and 0.03 g of sodium gluconate solid powder, mix them evenly, then slowly add them to 4.94 g of deionized water at 80°C while continuously stirring, continue stirring for 8 h until completely dissolved to form 5 g of solution C.

[0083] d. Mix the solutions A, B, and C obtained in steps a, b, and c, and 5 g of methanol directly at 45°C and stir for 2 h to obtain foam agent 4.

[0084] Example 11

[0085] The anti-shearing foam control agent of this example is composed of the anti-shearing foam control composition of Example 5, water and an anti-freezing agent; the first zwitterionic surfactant in the anti-shearing foam control composition accounts for 67.8% by weight of the anti-shearing foam control agent.

[0086] The specific formulation composition is as follows:

[0087] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, polyethylene glycol 2000 0.2 g, hydroxypropyl β cyclodextrin 0.2 g, magnesium lithium silicate 0.03 g, sodium gluconate 0.03 g, methanol 5 g and water 12.54 g.

[0088] The specific preparation steps are as follows:

[0089] a. Mix 80 g of CAB-35 and 20 g of OB-2 directly at 45°C for 1 h with slow stirring to form 100 g of solution A.

[0090] b. Mix 0.2 g of PEG2000 and 0.2 g of β cyclodextrin solid powder uniformly, then slowly add to 7.6 g of deionized water at 60°C while continuously stirring, continue stirring for 4 h after adding until completely dissolved to form 8 g of solution B.

[0091] c. Mix 0.03 g of magnesium lithium silicate and 0.03 g of sodium gluconate solid powder uniformly, then slowly add to 4.94 g of deionized water at 80°C while continuously stirring, continue stirring for 8 h until completely dissolved to form 5 g of solution C.

[0092] d. Mix the solutions A, B and C obtained in steps a, b and c and 5 g of methanol directly at 45°C to obtain foam control agent 5 after stirring for 2 h.

[0093] Example 12

[0094] The anti-shearing foam control agent of this example is composed of the anti-shearing foam control composition of Example 2 and water; the first zwitterionic surfactant in the anti-shearing foam control composition accounts for 70.8% by weight of the anti-shearing foam control agent.

[0095] The specific formulation composition is as follows:

[0096] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, polyethylene glycol 2000 0.2 g, hydroxypropyl β cyclodextrin 0.2 g, magnesium lithium silicate 0.05 g, sodium gluconate 0.05 g and water 12.5 g.

[0097] The specific preparation steps are as follows:

[0098] a. Take 80g of CAB-35 and 20g of OB-2 directly mixed at 45°C and stirred slowly for 1h to form 100g of solution A.

[0099] b. Take 0.2g of PEG2000 and 0.2g of β-cyclodextrin solid powder mixed uniformly and slowly added to 7.6g of deionized water at 60°C while continuously stirring, and continue stirring for 4h after adding to completely dissolve to form 8g of solution B.

[0100] c. Take 0.05g of lithium magnesium silicate and 0.05g of sodium gluconate solid powder mixed uniformly and slowly added to 4.9g of deionized water at 80°C while continuously stirring, and continue stirring for 8h after adding to completely dissolve to form 5g of solution C.

[0101] d. Mix solution A, solution B, solution C obtained in steps a, b, c and 0g of methanol at 45°C directly to stir for 2h to obtain foam agent 6.

[0102] Example 13

[0103] The shear-resistant foam agent of the present example is composed of the shear-resistant foam agent composition of example 2, water and antifreeze; the first zwitterionic surfactant in the shear-resistant foam agent composition accounts for 67.8% of the weight percentage of the shear-resistant foam agent.

[0104] The specific formula composition is as follows:

[0105] Cocamidopropyl betaine (CAB-45) 80g, dodecyl dimethyl amine oxide (OB-2) 20g, polyethylene glycol 2000 0.2g, hydroxypropyl β-cyclodextrin 0.2g, lithium magnesium silicate 0.05g, sodium gluconate 0.05g, methanol 5g and water 12.5g.

[0106] The specific preparation steps are as follows:

[0107] a. Take 80g of CAB-45 and 20g of OB-2 directly mixed at 45°C and stirred slowly for 1h to form 100g of solution A.

[0108] b. Take 0.2g of PEG2000 and 0.2g of carboxypropyl β-cyclodextrin solid powder mixed uniformly and slowly added to 7.6g of deionized water at 60°C while continuously stirring, and continue stirring for 5h after adding to completely dissolve to form 8g of solution B.

[0109] c. Take 0.05g of lithium magnesium silicate and 0.05g of sodium gluconate solid powder mixed uniformly and slowly added to 4.9g of deionized water at 80°C while continuously stirring, and continue stirring for 8h after adding to completely dissolve to form 5g of solution C.

[0110] d. The solution A, solution B, solution C obtained in steps a, b, c and 5 g of methanol were mixed directly at 45 °C and stirred for 2 h to obtain foam control agent 7.

[0111] Example 8

[0112] Example 8

[0113] The difference between the foam control agent of the present comparative example and the shear resistant foam control agent of Example 8 is that the polyethylene glycol 2000 is replaced by detergent 6501. The specific formulation is as follows:

[0114] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, detergent 6501 0.2 g, hydroxypropyl beta cyclodextrin 0.2 g, magnesium lithium silicate 0.05 g, sodium gluconate 0.05 g, methanol 5 g and water 12.5 g.

[0115] The specific preparation steps are as follows:

[0116] a. 80 g of CAB-35 and 20 g of OB-2 were mixed directly at 45 °C and stirred slowly for 1 h to form 100 g of solution A;

[0117] b. 0.2 g of detergent 6501 and 0.2 g of carboxypropyl beta cyclodextrin were mixed evenly and then slowly added to 7.6 g of deionized water at 60 °C while continuously stirring. After addition, stirring was continued for 5 h until complete dissolution to form 8 g of solution B.

[0118] c. 0.05 g of magnesium lithium silicate and 0.05 g of sodium gluconate were mixed evenly and then slowly added to 4.9 g of deionized water at 80 °C while continuously stirring. Stirring was continued for 8 h until complete dissolution to form 5 g of solution C.

[0119] d. The solution A, solution B, solution C obtained in steps a, b, c and 5 g of methanol were mixed directly at 45 °C and stirred for 2 h to obtain foam control agent 7.

[0120] Example 8

[0121] The difference between the foam control agent of the present comparative example and the shear resistant foam control agent of Example 8 is that the polyethylene glycol 2000 is replaced by detergent 6501. The specific formulation is as follows:

[0122] Cocamidopropyl betaine (CAB-35) 80 g, dodecyl dimethyl amine oxide (OB-2) 20 g, detergent 6501 0.2 g, hydroxypropyl beta cyclodextrin 0.2 g, magnesium lithium silicate 0.05 g, sodium gluconate 0.05 g, methanol 5 g and water 12.5 g.

[0123] The specific preparation steps are as follows:

[0124] a. 80 g of CAB-35 and 20 g of OB-2 were directly mixed at 45°C for 1 h with slow stirring to form 100 g of solution A;

[0125] b. 0.2 g of PEG2000 and 0.2 g of carboxypropyl β-cyclodextrin solid powder were uniformly mixed and then slowly added to 7.6 g of deionized water at 60°C while continuously stirring, and after addition, stirring was continued for 5 h until complete dissolution to form 8 g of solution B.

[0126] c. 0.05 g of silicon dioxide and 0.05 g of sodium gluconate solid powder were uniformly mixed and then slowly added to 4.9 g of deionized water at 80°C while continuously stirring, and stirring was continued for 8 h until complete dissolution to form 5 g of solution C.

[0127] d. The solutions A, B, and C obtained in steps a, b, and c, and 5 g of methanol were directly mixed and stirred at 45°C for 2 h to obtain foam displacement agent 1-2.

[0128] Comparative Example 3

[0129] The foam displacement agent of the present comparative example is different from the shear-resistant foam displacement agent of Example 8 in that the cocamidopropyl betaine is replaced by sodium α-olefin sulfonate, and the polyethylene glycol 2000 is replaced by sodium dodecyl sulfate. The specific formula composition is as follows:

[0130] Sodium α-olefin sulfonate 6 g, dodecyl dimethyl amine oxide (OB-2) 20 g, sodium dodecyl sulfate 0.2 g, hydroxypropyl β-cyclodextrin 0.2 g, silicon dioxide 0.05 g, sodium gluconate 0.05 g, methanol 5 g, and water 26.5 g.

[0131] The specific preparation steps are as follows:

[0132] a. 6 g of sodium α-olefin sulfonate was dissolved in 14 g of water with slow stirring for 1 h to form 20 g of aqueous solution A;

[0133] b. 80 g of CAB-35 and 20 g of solution A were directly mixed at 45°C for 1 h with slow stirring to form 100 g of solution B;

[0134] c. 0.2 g of sodium dodecyl sulfate and 0.2 g of carboxypropyl β-cyclodextrin solid powder were uniformly mixed and then slowly added to 7.6 g of deionized water at 60°C while continuously stirring, and after addition, stirring was continued for 5 h until complete dissolution to form 8 g of solution C.

[0135] d. Take 0.05 g of solid powder of magnesium lithium silicate and 0.05 g of sodium gluconate, mix them evenly, and slowly add them to 4.9 g of deionized water at 80°C while continuously stirring. Continue stirring for 8 h until complete dissolution to form 5 g of solution D.

[0136] e. Mix and stir solution B, solution C, solution D obtained in steps b, c, and d, and 5 g of methanol at 45°C directly for 2 h to obtain foam drainage agent 1-3.

[0137] Four, Application of Anti-shear Foam Drainage Composition or Anti-shear Foam Drainage Agent in Natural Gas Well Foam Drainage Gas Recovery

[0138] Experimental Example 1

[0139] In this experimental example, the foaming performance and foam carrying performance of foam drainage agents 1-7 prepared in Examples 7-13 and foam drainage agents 1-1-1-3 prepared in Comparative Examples 1-3 were evaluated.

[0140] (1) Using a Ross-Miles instrument, the foaming performance and liquid carrying performance experiments were carried out at 80°C using 50,000 mg / L and 200,000 mg / L standard solutions (composed of sodium chloride, calcium chloride, and magnesium chloride, with a mass ratio of NaCl:CaCl2:MgCl2·6H2O of 7:0.6:0.4). The performance test results of foam drainage agents 1-6 and foam drainage agents 1-1-1-3 are shown in Tables 1 and 2. Among them, the foaming power and foam stability were determined according to the Ross-Miles method in GB / T13173-2021 Surface Active Agent Detergent Test Method, and the liquid carrying performance was detected according to the liquid carrying amount determination method in QSH CG0.135-2021 Foam Drainage Agent Technical Requirements.

[0141] Table 1 Foaming performance and liquid carrying performance test results under 80°C, 50,000 mg / L standard solution

[0142] Foaming power (mm) Foam stability (mm) Liquid carrying rate (%) Foam killer 1 178 178 98.5 Foam killer 2 182 182 99.3 Foam killer 3 175 175 97.6 Foam killer 4 173 173 97.3 Foam killer 5 177 177 98.3 Foam killer 6 179 179 98.6 Foam killer 7 185 185 99.8 Foam killer 1-1 167 159 99.3 Foam killer 1-2 169 164 87.5 Foam killer 1-3 161 152 85.3

[0143] Table 2 Foaming performance and liquid carrying performance test results under 80°C, 200,000 mg / L standard solution

[0144]

[0145]

[0146] (2) Using a high temperature and high pressure reactor, foamers were aged at 2 MPa (pressurized to 2 MPa with nitrogen to keep the liquid in a liquid phase state at 130℃, avoiding evaporation of the solution) and 130℃ for 24h, and then using Ross-Miles instrument, foam performance and liquid carrying performance experiments were carried out at 80℃ using 50000mg / L and 200000mg / L standard solution (composed of sodium chloride, calcium chloride and magnesium chloride, wherein the mass ratio of NaCl:CaCl2:MgCl2·6H2O is 7:0.6:0.4). The performance test results of foamer 1-6 and foamer 1-1-1-3 are shown in Table 3 and Table 4. Among them, the foaming power and foam stability were determined by Ross-Miles method in GB / T13173-2021 Surface active agent-detergent test methods, and the liquid carrying performance was detected by the liquid carrying amount determination method in standard QSH CG0.135-2021 Foam agent technical requirements.

[0147] Table 3 Foam performance and liquid carrying performance test results after aging at 80℃, 50000mg / L standard solution

[0148] Foaming power (mm) Foam stability (mm) Liquid carrying rate (%) Foam killer 1 177 177 97.2 Foam killer 2 180 180 98.8 Foam killer 3 173 173 96.8 Foam killer 4 172 172 97.1 Foam killer 5 176 176 98.1 Foam killer 6 178 178 98.6 Foam killer 7 185 185 99.7 Foam killer 1-1 163 150 90.2 Foam killer 1-2 166 150 86.0 Foam killer 1-3 157 150 82.6

[0149] Table 4 Foam performance and liquid carrying performance test results after aging at 80℃, 200000mg / L standard solution

[0150]

[0151]

[0152] (3) Using a high temperature and high pressure foam performance evaluation device, high temperature and high pressure foam performance and liquid carrying performance experiments were carried out at 130℃, 10 MPa (pressurized to 10 MPa with nitrogen) with stirring at a speed of 3200r / min using 50000mg / L and 200000mg / L standard solution (composed of sodium chloride, calcium chloride and magnesium chloride, wherein the mass ratio of NaCl:CaCl2:MgCl2·6H2O is 7:0.6:0.4). Among them, the liquid carrying performance was detected by the liquid carrying amount determination method in standard QSH CG0.135-2021 Foam agent technical requirements. The specific operation of foam performance detection is:

[0153] The 250 mL foam agent solution (foam agent concentration of about 3% (volume ratio): 1000 mL of standard solution was prepared, then 3 mL of foam agent solution was added, and after uniform mixing, it was ready for use; during the experiment, 250 mL of the mixed solution was taken from 1003 mL of the mixed solution to carry out the related foam agent performance evaluation experiment, wherein the standard solution was composed of sodium chloride, calcium chloride and magnesium chloride, and the mass ratio of NaCl: CaCl2: MgCl2.6H2O was 7:0.6:0.4) was transferred to a high-temperature and high-pressure visual reactor with a high-speed stirring device, pressurized to 10 MPa with nitrogen, and heated to 130°C with an oil bath circulation. After the pressure and temperature reached the experimental conditions, the stirring motor was turned on, and the stirring speed was set to 3200 r / min. After stirring for 3 min, the stirring was stopped, and the initial foam height (foaming power) and the foam height after 5 min (foam stability) were read through the visual window.

[0154] The performance experiment results of foam agents 1-6 and foam agents 1-1-1-3 are shown in Tables 5 and 6.

[0155] Table 5 High-temperature and high-pressure foaming performance and liquid carrying performance experiment results 1

[0156]

[0157]

[0158] Table 6 High-temperature and high-pressure foaming performance and liquid carrying performance experiment results 2

[0159] Foaming power (mm) Foam stability (mm) Liquid carrying rate (%) Foam killer 1 190 190 98.5 Foam killer 2 193 193 98.9 Foam killer 3 187 187 98.9 Foam killer 4 186 186 98.1 Foam killer 5 191 191 98.8 Foam killer 6 194 194 99.0 Foam killer 7 198 198 99.6 Foam killer 1-1 171 171 93.0 Foam killer 1-2 170 170 86.8 Foam killer 1-3 Foaming power (mm) Foam stability (mm) Liquid carrying rate (%) 162 162 82.7

[0160] (4) Anti-freezing detection

[0161] Foam agents 1-5, 7 and foam agents 1-1-1-3 were still flowable liquids after being frozen at -18°C for 24 h, and had good anti-freezing properties. Foam agent 6 lost its flowability after being frozen at -18°C for 1 h, indicating that it had no anti-freezing property.

[0162] Experimental Example 2

[0163] The experimental example is the field application effect of the foam displacement agent, the experimental site is a high temperature gas well in Ordos Basin, the bottom hole reservoir temperature of the well is 132℃, the foam displacement agent is added into a high temperature gas well in Ordos Basin by using the wellhead automatic dosing device to carry out the drainage gas recovery. The conventional foam displacement agent (model: SPR-01, manufacturer: Dongying Shipuili Petroleum Engineering Technology Co., Ltd.) is used before the gas well, 37.5 liters of the conventional foam displacement agent solution (75 liters of the agent solution (the foam displacement agent and water are prepared in a solution of 1:4)) is added by the wellhead automatic dosing device at 11:00 and 20:00 for two times per day, the stable production daily gas production is 6506 cubic meters, and the daily liquid production is 1.6 cubic meters. The foam displacement agent solution in the adding device is replaced by the foam displacement agent of the present application example 9, the same system is used, 37.5 liters of the foam displacement agent solution (75 liters of the agent solution (the foam displacement agent and water are prepared in a solution of 1:4)) of the present application is added at 11:00 and 20:00 for two times per day, the stable production daily gas production is 7792 cubic meters, and the daily liquid production is 2.0 cubic meters. Through the production effect comparison, the foam displacement agent has good liquid drainage and production increasing effect.

[0164] The above is only the preferred embodiment of the present application, and is not used to limit the present application, the patent protection scope of the present application is subject to the claims, any equivalent structural changes made by using the content of the specification and drawings of the present application should be included in the protection scope of the present application.

Claims

1. A shear-resistant bubble-draining composition, characterized in that: The anti-shear foaming composition comprises a main agent, a thickener, and a stabilizer; the main agent comprises a first zwitterionic surfactant and a second ionic surfactant; the first zwitterionic surfactant accounts for 70-80% of the main agent by mass; the thickener accounts for 0.2-0.4% of the main agent by mass; the stabilizer accounts for 0.06-0.1% of the main agent by mass; the first zwitterionic surfactant is cocamidopropyl betaine; the second ionic surfactant is dodecyl dimethylamine oxide; the stabilizer comprises lithium magnesium silicate and sodium gluconate; the thickener comprises polyethylene glycol 2000 and hydroxypropyl β-cyclodextrin.

2. The shear-resistant bubble-dissipating composition according to claim 1, characterized in that: The mass ratio of lithium magnesium silicate to sodium gluconate is 1:(1 to 1.1).

3. The anti-shear bubble-dissipation composition according to claim 1, characterized in that: The mass ratio of polyethylene glycol 2000 to hydroxypropyl β-cyclodextrin is 1:(1-1.1).

4. A shear-resistant foaming agent, characterized in that: It includes the anti-shear bubbling composition according to any one of claims 1 to 3 and water.

5. The anti-shear foaming agent according to claim 4, characterized in that: The first zwitterionic surfactant in the anti-shear bubbling composition accounts for 59-71% by weight of the anti-shear bubbling agent.

6. The anti-shear foaming agent according to claim 4 or 5, characterized in that: The anti-shear foaming agent includes an antifreeze agent.

7. The anti-shear foaming agent according to claim 6, characterized in that: The amount of antifreeze used is 0-5% of the mass of the main agent.

8. The application of an anti-shear foaming composition as described in any one of claims 1 to 3 or an anti-shear foaming agent as described in any one of claims 4 to 7 in natural gas well foam drainage gas production.

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