Corrosion inhibition fluidity control agent and preparation method and application thereof

Abstract

The invention provides a corrosion inhibition fluidity control agent as well as a preparation method and application thereof. The general molecular formula of the corrosion inhibition fluidity control agent is shown in the specification, wherein R'is selected from one of alkyl or substituted alkyl with the carbon atom number of C4-C36; r1, R2, R3, R4, R5 and R6 are respectively and independently selected from at least one of H, C1-C5 alkyl carboxylate or substituted alkyl carboxylate, C1-C5 alkyl sulfonate or substituted alkyl sulfonate, C1-C5 alkyl phosphate or substituted alkyl phosphate or C1-C5 alkyl sulfate or substituted alkyl sulfate, and are not H at the same time; m1, m2, m3, m4, m5, m6, n1, n2, n3, n4, n5 and n6 are independently selected from any numerical values of 0-30, and the value of m1 + m2 + m3 + m4 + m5 + m6 and the value of n1 + n2 + n3 + n4 + n5 + n6 are not zero at the same time. The corrosion inhibition fluidity control agent provided by the invention has good gas fluidity controllability and corrosion inhibition in high-temperature and high-salinity oil reservoir gas drive.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide foam flooding technology, and more specifically, to a corrosion inhibitor flow control agent, its preparation method, and its application. Background Technology

[0002] CO2 flooding is one of the most effective methods for enhancing oil recovery in complex reservoirs. However, because the viscosity of injected CO2 is much lower than that of underground crude oil, the mobility ratio becomes too high, easily leading to viscous fingering and gas channeling during the gas flooding process, thus reducing oil production. Given the intelligent control characteristics of foam—"blocking large volumes but not small ones" and "blocking water but not oil"—the technology of using foam to control CO2 mobility has attracted widespread attention. However, CO2 dissolved in water causes severe corrosion to the injection and production tubing. Corrosion inhibitors are usually added to delay corrosion, but these inhibitors have complex compositions and poor compatibility with most mobility control agents, easily leading to flocculation and precipitation, causing both the mobility control agent and the corrosion inhibitor to fail, thus affecting the application prospects of CO2 foam flooding.

[0003] Extensive research has been conducted both domestically and internationally on CO2 foaming agents. For example, patent CN 108570318A discloses a CO2 foaming liquid composition for oilfield use and its preparation method. The foaming liquid composition contains 0.05–1% fatty alcohol polyoxyethylene ether sulfate, 0.01–0.5% α-olefin sulfonate, 0.005–0.3% alkyl glycoside, 0.004–0.1% coconut oil diethanolamide, and 0.001–0.05% hydrophobically modified nano-silica particles. CN101619210A discloses a carbon dioxide foam stabilizer suitable for low-permeability reservoirs, composed of modified guar gum, hydroxyethyl cellulose, and dodecyl alcohol. However, none of these studies considered corrosion issues.

[0004] Therefore, it is necessary to study a CO2 foam flooding method that can control its flow rate while solving the corrosion problem, as well as the problems of gas channeling and severe tubing corrosion in gas-driven systems. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a corrosion-inhibiting flow control agent, its preparation method, and its application.

[0006] The corrosion-inhibiting flow control agent in this invention uses a polyether polyamine compound containing a triazine ring. The triazine ring has a high electron cloud density and contains N and O heteroatoms to increase active sites. Under acidic conditions, it carries a positive charge and adsorbs negatively charged iron, forming a protective film on the metal surface to prevent corrosion. Simultaneously, it contains multiple N atoms, which form Lewis acid-base interactions with CO2, increasing the adsorption amount at the CO2 / water interface and improving foaming performance. It also contains multiple polyether fragments to enhance salt resistance and does not contain functional groups such as amide bonds that are easily decomposed at high temperatures, giving it excellent gas flow control and corrosion inhibition properties in high-temperature, high-salinity oil reservoir gas drive applications.

[0007] The corrosion inhibitor flow rate control agent of the present invention can effectively control the gas flow rate during gas drive and has a good corrosion inhibition effect on the tubing.

[0008] One objective of this invention is to provide a corrosion-inhibiting flow control agent, with the general molecular formula shown in formula (I):

[0009]

[0010] Wherein, R′ is selected from one of the hydrocarbon groups or substituted hydrocarbon groups having the number of carbon atoms from C4 to C36; R1, R2, R3, R4, R5, and R6 are each independently selected from at least one of H, C1 to C5 hydrocarbon carboxylates or substituted hydrocarbon carboxylates, C1 to C5 hydrocarbon sulfonates or substituted hydrocarbon sulfonates, C1 to C5 hydrocarbon phosphates or substituted hydrocarbon phosphates, or C1 to C5 hydrocarbon sulfates or substituted hydrocarbon sulfates, and are not all H at the same time;

[0011] m1, m2, m3, m4, m5, m6, n1, n2, n3, n4, n5, and n6 are each independently selected from any value from 0 to 30, and the value of m1+m2+m3+m4+m5+m6 and the value of n1+n2+n3+n4+n5+n6 are not both zero.

[0012] In practical applications, the slow-release flow control agent of this invention can be supplied in various forms to facilitate transportation, storage, or on-site use. These forms include anhydrous solid form, aqueous solid form, aqueous paste form, or aqueous solution form. The aqueous solution form includes the form of a concentrated solution prepared with water, or the form of a solution prepared directly to the concentration required for on-site drainage. There are no special requirements for the water; it can be deionized water or water containing inorganic minerals. The water containing inorganic minerals can be tap water or gas field formation water.

[0013] In a preferred embodiment of the present invention,

[0014] The Rˊ is selected from a hydrocarbon group or a substituted hydrocarbon group having a carbon number of C12 to C30; and / or,

[0015] R1, R2, R3, R4, R5, and R6 are each independently selected from one of H, CH2COOM, (CH2)3SO3M, and CH2(CHOH)CH2SO3M, and are not all H at the same time; wherein M is hydrogen, an alkali metal, or NH4+. + At least one of them; and / or,

[0016] m1+m2+m3+m4+m5+m6=0~5; n1+n2+n3+n4+n5+n6=0~10; and the sums are not all zero at the same time; preferably, m1+m2+m3=0~3, m4+m5+m6=0~3; n1+n2+n3=0~6, n4+n5+n6=0~6; more preferably, m1+m2+m3=0~2, m4+m5+m6=0~2; n1+n2+n3=2~5, n4+n5+n6=2~5.

[0017] A second objective of this invention is to provide a method for preparing a corrosion-inhibiting flow control agent, comprising the following steps:

[0018] (1) Mix cyanuric chloride, ethylenediamine, and optional catalyst A and react to obtain compound A;

[0019] (2) In the presence of catalyst B, compound A is reacted sequentially with either propylene oxide or ethylene oxide to obtain compound B; wherein at least one of propylene oxide or ethylene oxide is present.

[0020] (3) Compound B, ethylenediamine, and optional catalyst C are mixed and reacted to obtain compound C;

[0021] (4) In the presence of catalyst D, compound C is reacted sequentially with optional propylene oxide and optional ethylene oxide to obtain compound D; wherein, at least one of propylene oxide and ethylene oxide is present.

[0022] (5) Compound D, RˊNH2, and optional catalyst E are mixed and reacted to obtain compound E;

[0023] (6) React compound E, ionizing reagent, and base in a solvent to obtain the corrosion inhibitor flow control agent.

[0024] In a preferred embodiment of the present invention,

[0025] Step (1),

[0026] The molar ratio of cyanuric chloride, ethylenediamine, and catalyst A is 1:(1-2):(0-0.5), preferably 1:(1-1.3):(0.01-0.1), more preferably 1:(1-1.3):(0.05-0.1); and / or,

[0027] The reaction temperature is -20 to 0℃; and / or,

[0028] The reaction time is 3 to 10 hours; and / or,

[0029] The reaction product undergoes post-treatment, which includes solvent removal; and / or,

[0030] The catalyst A is at least one of alkali metal hydroxide, alkali metal alkoxide, and alkali metal carbonate, preferably at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0031] The structural formula of compound A is as follows:

[0032]

[0033] In a preferred embodiment of the present invention,

[0034] Step (2),

[0035] The catalyst B is an alkaline catalyst, preferably at least one of potassium hydroxide, sodium hydroxide, and potassium carbonate; and / or,

[0036] The molar ratio of compound A, propylene oxide, and ethylene oxide is 1:(0-4):(0-7), and the molar ratios of propylene oxide and ethylene oxide cannot both be 0; the preferred molar ratio of compound A, propylene oxide, and ethylene oxide is 1:(0-3):(2-6); and / or,

[0037] The molar ratio of catalyst B to the total molar amount of reactants in step (2) is (0.1–1):1; and / or,

[0038] The reaction temperature with propylene oxide is 80–160 °C; and / or,

[0039] The reaction time with propylene oxide is 3 to 12 hours, preferably 3 to 6 hours; and / or,

[0040] The reaction temperature with ethylene oxide is 80–160 °C; and / or,

[0041] The reaction time with ethylene oxide is 3 to 12 hours, preferably 3 to 6 hours.

[0042] The structural formula of compound B is as follows:

[0043]

[0044] In a preferred embodiment of the present invention,

[0045] Step (3),

[0046] The molar ratio of compound B, ethylenediamine, and catalyst C is 1:(1-2):(0-0.5); preferably 1:(1-1.5):(0.01-0.1), more preferably 1:(1-1.2):(0.05-0.1); and / or,

[0047] The reaction temperature is 40–50°C; and / or,

[0048] The reaction time is 3 to 10 hours; and / or,

[0049] The catalyst C is at least one selected from alkali metal hydroxides, alkali metal alkoxides, and alkali metal carbonates, preferably at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; and / or,

[0050] The reaction is followed by post-treatment, which includes solvent removal.

[0051] The structural formula of compound C is as follows:

[0052]

[0053] In a preferred embodiment of the present invention,

[0054] Step (4),

[0055] The catalyst D is an alkaline catalyst, preferably at least one selected from potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate; and / or,

[0056] The molar ratio of compound C, propylene oxide, and ethylene oxide is 1:(0-4):(0-7), and the molar ratios of propylene oxide and ethylene oxide cannot both be 0; the preferred molar ratio of compound C, propylene oxide, and ethylene oxide is 1:(0-3):(2-6); and / or,

[0057] The molar ratio of catalyst D to the total molar amount of reactants in step (4) is (0.1–1):1; and / or,

[0058] The reaction temperature with propylene oxide is 80–160 °C; and / or,

[0059] The reaction time with propylene oxide is 3 to 12 hours, preferably 3 to 6 hours; and / or,

[0060] The reaction temperature with ethylene oxide is 80–160 °C; and / or,

[0061] The reaction time with ethylene oxide is 3 to 12 hours, preferably 3 to 6 hours.

[0062] The structural formula of compound D is as follows:

[0063]

[0064] In a preferred embodiment of the present invention,

[0065] Step (5),

[0066] The molar ratio of compound D, R′NH2, and catalyst E is 1:(1-2):(0-1); preferably 1:(1-1.5):(0.1-0.5); and / or,

[0067] The reaction temperature is 100–120°C; and / or,

[0068] The reaction time is 3 to 10 hours, and can be any range of two values ​​from 3, 5, 7, 10 hours or more, for example, 7 to 10 hours; and / or,

[0069] The catalyst E is at least one selected from alkali metal hydroxide, alkali metal alkoxide, and alkali metal carbonate, preferably at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; and / or,

[0070] The reaction is followed by post-treatment, which includes solvent removal.

[0071] The structural formula of compound E is as follows:

[0072]

[0073] In a preferred embodiment of the present invention,

[0074] Step (6),

[0075] The ionizing reagent is selected from XR7Y; wherein X is chlorine, bromine, or iodine; R7 is a C1-C4 alkylene group or a substituted alkylene group; Y is SO3N or COON′, and N and N′ are alkali metals; and / or,

[0076] The base is an alkali metal hydroxide or an alkali metal alkoxide; and / or,

[0077] The molar ratio of compound E, ionizing reagent, and base is 1:(1-12):(1-12), preferably 1:(4-8):(4-8); and / or,

[0078] The solvent is at least one of C3-C8 ketones and C6-C9 aromatic hydrocarbons; and / or,

[0079] The amount of solvent used is 1–5 mL solvent / 1 g compound E; and / or,

[0080] The reaction temperature is 50–120°C; and / or,

[0081] The reaction time is 3 to 20 hours, preferably 6 to 16 hours; and / or,

[0082] The reaction is followed by post-treatment, which includes solvent removal.

[0083] The third objective of this invention is to provide a corrosion-inhibiting flow control agent obtained by the above-mentioned preparation method.

[0084] The fourth objective of this invention is to provide an application of a corrosion-inhibiting flow rate control agent in gas drive of oil reservoirs, preferably in the control of gas flow rate in gas drive of high-temperature and high-salinity oil reservoirs.

[0085] In the above technical solution, the application of the corrosion-inhibiting flow control agent is not particularly limited. Those skilled in the art can apply it according to the existing gas drive process, for example, but not limited to CO2 gas drive, with a total salinity of 0 to 200,000 mg / L and a temperature of 80 to 200°C.

[0086] The fifth objective of this invention is to provide a method for controlling gas flow rate in gas drive of high-temperature and high-salinity oil reservoirs, comprising the following steps:

[0087] The gas flow rate is controlled by co-injecting a solution of corrosion-inhibiting flow rate control agent with gas-driven gas; the corrosion-inhibiting flow rate control agent is the aforementioned corrosion-inhibiting flow rate control agent.

[0088] Preferably,

[0089] The gas used for gas-driven propulsion is carbon dioxide; and / or,

[0090] The concentration of the corrosion-inhibiting flow control agent solution is 0.1–5 wt%, more preferably 0.5–2 wt%; and / or,

[0091] The volume ratio of the corrosion-inhibiting flow control agent solution to the gas is 1:(0.5-9), preferably 1:(1-3).

[0092] The method includes injecting the corrosion-inhibiting flow control agent and gas alternately or together into a porous medium to form foam in situ in the porous medium, thereby controlling the gas flow rate.

[0093] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0094] The corrosion-inhibiting flow control agent of this invention uses a polyether polyamine compound containing a triazine ring. The triazine ring has a high electron cloud density and contains N and O heteroatoms to increase active sites. Under acidic conditions, it carries a positive charge and adsorbs negatively charged iron, forming a protective film on the metal surface to prevent corrosion. Simultaneously, it contains multiple N atoms, which form Lewis acid-base interactions with CO2, increasing the adsorption amount at the CO2 / water interface and improving foaming performance. It also contains multiple polyether fragments to enhance salt resistance and does not contain functional groups such as amide bonds that are easily decomposed at high temperatures, giving it excellent gas flow control and corrosion inhibition properties in high-temperature, high-salinity oil reservoir gas drive applications.

[0095] Using the technical solution of this invention, corrosion tests were conducted on the slow-release flow rate control agent according to SY / T 5273-2014 "Performance Inhibitors and Evaluation Methods for Oilfield Produced Water Treatment". The corrosion inhibition rate was ≥80% at 80℃ and ≥70% at 200℃. According to Q / SH 3375 139-2020 "Technical Requirements for Surfactants for Oil Displacement", the resistance factor of the slow-release flow rate control agent was tested. At a concentration of 0.1% to 1 wt%, the resistance factor of the slow-release flow rate control agent reached 625, and it maintained a high value even at 200℃ and lower concentrations, achieving good technical results. Detailed Implementation

[0096] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0097] All raw materials used in the examples are commercially available.

[0098] Test method:

[0099] Corrosion experiment:

[0100] Corrosion tests were conducted on the slow-release flow rate control agent in accordance with SY / T 5273-2014 "Performance Indicators and Evaluation Methods for Corrosion Inhibitors Used in Oilfield Produced Water Treatment". The test water was deionized water, 100,000 mg / L sodium chloride brine, and 200,000 mg / L sodium chloride brine. The temperatures were 80℃ and 200℃, the carbon dioxide partial pressure was 1.0 MPa, and the total test pressure was 10 MPa.

[0101] Resistance factor:

[0102] The permeability of the sand-filled pipe is 2103 mD. First, use brine to drive the flow until the pressure is constant. Then, use brine to prepare a flow control agent solution of the required concentration and co-inject it with CO2 at a gas-liquid ratio of 2:1 until the pressure is constant. Calculate the resistance factor.

[0103] Example 1

[0104] Preparation of sustained-release flow control agent LE01

[0105] (1) Mix 1 mol of cyanuric chloride with 1.2 mol of NH2CH2CH2NH2 and 0.05 mol of sodium carbonate, react at 0℃ for 6 hours, and remove the solvent by vacuum evaporation to obtain compound A;

[0106]

[0107] (2) Add 0.4 mol of compound A and 0.7 mol of potassium hydroxide to a pressure reactor equipped with a stirring device, and react with 0.85 mol of propylene oxide at 140°C for 4 hours and with 1.3 mol of ethylene oxide at 140°C for 4 hours to obtain compound B (m1+m2+m3=2;n1+n2+n3=3).

[0108]

[0109] (3) Mix 0.2 mol of compound B with 0.24 mol of NH2CH2CH2NH2 and 0.02 mol of potassium carbonate, react at 40 °C for 5 hours, and remove the solvent by vacuum evaporation to obtain compound C;

[0110]

[0111] (4) Add 0.1 mol of compound C and 0.2 mol of sodium hydroxide to a pressure reactor equipped with a stirring device, and react with 0.21 mol of propylene oxide at 160°C for 3 hours and with 0.45 mol of ethylene oxide at 160°C for 3 hours to obtain compound D (m4+m5+m6=2;n4+n5+n6=4);

[0112]

[0113] (5) 0.1 mol of compound D was mixed with 0.13 mol of R'NH2 and 0.05 mol of potassium carbonate, and reacted at 100 °C for 8 hours. The solvent was removed by vacuum evaporation to obtain compound E ((R'=C20H41)).

[0114]

[0115] (6) 0.1 mol of compound E was mixed with 0.6 mol of sodium hydroxide, 0.6 mol of sodium chloroacetate, and 500 mL of toluene / benzene (v / v = 1) in a four-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser. The mixture was heated under reflux for 8 hours. The solvent was removed by evaporation, and water was added to obtain a 30% slow-release flow control agent solution. LC-MS analysis showed that, based on the retention time and mass-to-charge ratio, four of the components R1, R2, R3, R4, R5, and R6 of the corrosion-inhibiting flow control agent were CH2COONa, and the remainder were H.

[0116] The structural formula of the obtained sustained-release flow control agent is:

[0117]

[0118] Example 2

[0119] Preparation of sustained-release flow control agent LE02

[0120] (1) 1 mol of cyanuric chloride was mixed with 1.3 mol of NH2CH2CH2NH2 and 0.1 mol of sodium hydroxide and reacted at -20°C for 3 hours. The solvent was removed by vacuum evaporation to obtain compound A, the structural formula of which is shown in Example 1.

[0121] (2) 0.4 mol of compound A and 1 mol of sodium hydroxide were added to a pressure reactor equipped with a stirring device, and reacted with 0.85 mol of ethylene oxide at 80°C for 6 hours to obtain compound B (m1+m2+m3=0; n1+n2+n3=2), the structural formula of which is shown in Example 1.

[0122] (3) Mix 0.2 mol of compound B with 0.2 mol of NH2CH2CH2NH2 and 0.02 mol of sodium carbonate, react at 50 °C for 10 hours, remove the solvent under reduced pressure to obtain compound C, the structural formula of which is shown in Example 1.

[0123] (4) Add 0.1 mol of compound C and 0.5 mol of sodium carbonate to a pressure reactor equipped with a stirring device, and react with 0.21 mol of propylene oxide at 100°C for 6 hours and with 0.55 mol of ethylene oxide at 100°C for 6 hours in sequence to obtain compound D (m4+m5+m6=2; n4+n5+n6=5), the structural formula of which is shown in Example 1.

[0124] (5) 0.1 mol of compound D was mixed with 0.15 mol of R'NH2 and 0.01 mol of potassium carbonate, and reacted at 120 °C for 10 hours. The solvent was removed by vacuum evaporation to obtain compound E((R'=C 12 H 25 The structural formula is shown in Example 1.

[0125] (6) 0.1 mol of compound E was mixed with 0.4 mol of sodium hydroxide, 0.4 mol of sodium chloropropionate, and 500 mL of toluene / benzene (v / v = 1) in a four-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser. The mixture was heated to reflux for 8 hours. The solvent was removed by evaporation, and water was added to obtain a 30% slow-release flow control agent solution. The structural formula of the slow-release flow control agent after 8 hours is shown in Example 1. By LC-MS detection, based on the retention time and mass-to-charge ratio, it can be determined that three of R1, R2, R3, R4, R5, and R6 of the corrosion-inhibiting flow control agent are CH2COONa, and the rest are H.

[0126] Example 3

[0127] Preparation of sustained-release flow control agent LE03

[0128] (1) Mix 1 mol of cyanuric chloride with 1 mol of NH2CH2CH2NH2 and 0.01 mol of sodium hydroxide, react at -10℃ for 10 hours, and remove the solvent under reduced pressure to obtain compound A, the structural formula of which is shown in Example 1.

[0129] (2) Add 0.4 mol of compound A and 2.5 mol of sodium hydroxide to a pressure reactor equipped with a stirring device, and react with 0.45 mol of propylene oxide at 160°C for 3 hours and with 2.1 mol of ethylene oxide at 160°C for 3 hours in sequence to obtain compound B (m1+m2+m3=1; n1+n2+n3=5), the structural formula of which is shown in Example 1.

[0130] (3) Mix 0.2 mol of compound B with 0.22 mol of NH2CH2CH2NH2 and 0.01 mol of sodium carbonate, react at 50 °C for 3 hours, remove the solvent under reduced pressure to obtain compound C, the structural formula of which is shown in Example 1.

[0131] (4) Add 0.1 mol of compound C and 0.35 mol of sodium carbonate to a pressure reactor equipped with a stirring device, and react with 0.25 mol of ethylene oxide at 80°C for 6 hours to obtain compound D (m4+m5+m6=0; n4+n5+n6=2), the structural formula of which is shown in Example 1.

[0132] (5) 0.1 mol of compound D was mixed with 0.1 mol of R'NH2 and 0.05 mol of potassium carbonate, and reacted at 100 °C for 7 hours. The solvent was removed by vacuum evaporation to obtain compound E((R'=C 30 H 61 The structural formula is shown in Example 1.

[0133] (6) 0.1 mol of compound E, 0.7 mol of sodium hydroxide, 0.7 mol of sodium chloroethyl sulfonate, and 500 mL of toluene were placed in a four-necked flask equipped with a mechanical stirrer, thermometer, and reflux condenser, and heated to reflux for 15 hours. The solvent was removed by evaporation, and water was added to obtain a 30% slow-release flow control agent solution. The structural formula of the slow-release flow control agent is the same as in Example 1. By LC-MS detection, based on the retention time and mass-to-charge ratio, it can be determined that five of R1, R2, R3, R4, R5, and R6 of the corrosion-inhibiting flow control agent are CH2COONa, and the rest are H.

[0134] Comparative Example

[0135] Commonly used foaming agent sodium α-olefin sulfonate and corrosion inhibitor XSH-4 were subjected to corrosion and displacement experiments under the same conditions, and the results are shown in Tables 2 and 4.

[0136] Corrosion tests were conducted on the slow-release flow rate control agent in accordance with SY / T 5273-2014 "Performance Indicators and Evaluation Methods for Corrosion Inhibitors Used in Oilfield Produced Water Treatment". The test water was deionized water, 100,000 mg / L sodium chloride brine, and 200,000 mg / L sodium chloride brine. The temperatures were 80℃ and 200℃, respectively. The carbon dioxide partial pressure was 1.0 MPa, and the total test pressure was 10 MPa. The results are shown in Table 1.

[0137] Table 1. Corrosion inhibition rate of the slow-release flow control agents prepared in Examples 1-3

[0138]

[0139] The corrosion inhibition rate is the percentage of weight retained under corrosive conditions, measured according to the test method of SY / T 5273-2014.

[0140] Table 2 Corrosion inhibition rates of comparative examples

[0141]

[0142] As shown in Table 1, the slow-release flow control agents prepared in Examples 1 to 3 have good corrosion inhibition properties, with a corrosion inhibition rate of 80.1-86.3% at 80°C and 72.6-80.0% at 200°C when the mineralization is 200,000 mg / L.

[0143] Table 2 shows that sodium α-olefin sulfonate, at a mineralization of 200,000 mg / L, exhibited a corrosion inhibition rate of 11.6% at 80°C and 8.8% at 200°C, indicating virtually no corrosion inhibition effect. Corrosion inhibitor XSH-4, at a mineralization of 200,000 mg / L, showed a corrosion inhibition rate of 85.1% at 80°C and 54.2% at 200°C. Its corrosion inhibition effect at 80°C was comparable to that of the corrosion-inhibiting flow control agent. However, when the temperature rose to 200°C, due to the presence of amide bonds in XSH-4, it decomposed at high temperature, resulting in a poorer corrosion inhibition effect. Compared with the comparative examples, the slow-release flow control agents prepared in Examples 1-3 showed better corrosion inhibition properties.

[0144] The 30% slow-release flow control agent solutions obtained in Examples 1-3 were further prepared into 0.1wt%, 0.5wt%, and 1wt% aqueous solutions, respectively, and co-injected with carbon dioxide to control gas flow. The permeability of the sand-filled pipe was 2103 mD. First, brine was used to drive the flow control agent solution to a constant pressure. Then, brine was used to prepare the required concentration of flow control agent solution and co-injected with CO2 at a gas-liquid ratio of 2:1 until the pressure remained constant. The resistance factor was calculated, and the specific test data are shown in Table 2.

[0145] Table 3. Resistance factors of the sustained-release flow control agents prepared in Examples 1-3

[0146]

[0147] As shown in Table 3, when the concentration of Examples 1 to 3 is 0.1 to 1 wt%, the mineralization is 0 to 200,000 mg / L, and the temperature is 80 to 200°C, the resistance factor is 102 to 625. Among them, when the concentration of Example 1 is 1 wt%, the resistance factor reaches 625, which shows good gas flow control.

[0148] Table 4 shows the drag factors for comparative examples.

[0149]

[0150] Table 4 shows that corrosion inhibitor XSH-4, at concentrations of 0.1–1 wt%, mineralization of 0–200,000 mg / L, and temperatures of 80–200°C, has a resistance factor of 2–3, exhibiting virtually no foaming properties and failing to form a good plugging effect. Sodium α-olefin sulfonate, at concentrations of 0.1–1 wt%, mineralization of 0–200,000 mg / L, and temperatures of 80–200°C, has a resistance factor of 24–596, demonstrating good plugging ability. At 80–100°C, its resistance factor is comparable to that of the corrosion flow control agent. However, sodium α-olefin sulfonate has poor salt tolerance and easily precipitates and decomposes at 200°C and 200,000 mg / L, resulting in a decrease in the resistance factor. Compared to the comparative examples, the slow-release flow control agents prepared in Examples 1–3 exhibit better gas flow control performance.

[0151] The corrosion-inhibiting flow control agents prepared in Examples 1-3 have good sealing ability and can effectively prevent oil pipe corrosion at 80-200℃. They also have good gas flow control and corrosion inhibition properties in gas drive of high-temperature and high-salinity oil reservoirs.

Claims

1. A corrosion-inhibiting flow control agent, with the general molecular formula shown in formula (I): in, R′ is selected from one of the hydrocarbon groups or substituted hydrocarbon groups with C4 to C36 carbon atoms; R1, R2, R3, R4, R5, and R6 are each independently selected from at least one of H, C1 to C5 hydrocarbon carboxylates or substituted hydrocarbon carboxylates, C1 to C5 hydrocarbon sulfonates or substituted hydrocarbon sulfonates, C1 to C5 hydrocarbon phosphates or substituted hydrocarbon phosphates, or C1 to C5 hydrocarbon sulfates or substituted hydrocarbon sulfates, and are not all H at the same time; m1, m2, m3, m4, m5, m6, n1, n2, n3, n4, n5, and n6 are each independently selected from any value from 0 to 30, and the value of m1+m2+m3+m4+m5+m6 and the value of n1+n2+n3+n4+n5+n6 are not all zero at the same time.

2. The corrosion-inhibiting flow control agent as described in claim 1, characterized in that: The R′ is selected from a hydrocarbon group or a substituted hydrocarbon group having a carbon number of C12 to C30; and / or, R1, R2, R3, R4, R5, and R6 are each independently selected from one of H, CH2COOM, (CH2)3SO3M, and CH2(CHOH)CH2SO3M, and are not all H at the same time; wherein M is hydrogen, an alkali metal, or NH4+. + At least one of them; and / or, m1+m2+m3+m4+m5+m6=0~5; n1+n2+n3+n4+n5+n6=0~10; and the sums are not all zero at the same time; preferably, m1+m2+m3=0~3, m4+m5+m6=0~3; n1+n2+n3=0~6, n4+n5+n6=0~6; more preferably, m1+m2+m3=0~2, m4+m5+m6=0~2; n1+n2+n3=2~5, n4+n5+n6=2~5.

3. A method for preparing a corrosion-inhibiting flow control agent as described in claim 1 or 2, comprising the following steps: (1) Mix cyanuric chloride, ethylenediamine, and optional catalyst A and react to obtain compound A; (2) In the presence of catalyst B, compound A is reacted sequentially with either propylene oxide or ethylene oxide to obtain compound B; wherein at least one of propylene oxide or ethylene oxide is present. (3) Compound B, ethylenediamine, and optional catalyst C are mixed and reacted to obtain compound C; (4) In the presence of catalyst D, compound C is reacted sequentially with optional propylene oxide and optional ethylene oxide to obtain compound D; wherein, at least one of propylene oxide and ethylene oxide is present. (5) Compound D, RˊNH2, and optional catalyst E are mixed and reacted to obtain compound E; (6) React compound E, ionizing reagent, and base in a solvent to obtain the corrosion-inhibiting flow control agent.

4. The method for preparing the corrosion-inhibiting flow control agent as described in claim 3, characterized in that: Step (1), The molar ratio of cyanuric chloride, ethylenediamine, and catalyst A is 1:(1-2):(0-0.5), preferably 1:(1-1.3):(0.01-0.1); and / or, The reaction temperature is -20 to 0℃; and / or, The reaction time is 3 to 10 hours; and / or, The reaction product undergoes post-treatment, which includes solvent removal; and / or, The catalyst A is at least one of alkali metal hydroxide, alkali metal alkoxide, and alkali metal carbonate, preferably at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

5. The method for preparing the corrosion-inhibiting flow control agent as described in claim 3, characterized in that: Step (2), The catalyst B is an alkaline catalyst, preferably at least one of potassium hydroxide, sodium hydroxide, and potassium carbonate; and / or, The molar ratio of compound A, propylene oxide, and ethylene oxide is 1:(0-4):(0-7), and the molar ratios of propylene oxide and ethylene oxide cannot both be 0; the preferred molar ratio of compound A, propylene oxide, and ethylene oxide is 1:(0-3):(2-6); and / or, The molar ratio of catalyst B to the total molar amount of reactants in step (2) is (0.1–1):1; and / or, The reaction temperature with propylene oxide is 80–160 °C; and / or, The reaction time with propylene oxide is 3 to 12 hours, preferably 3 to 6 hours; and / or, The reaction temperature with ethylene oxide is 80–160 °C; and / or, The reaction time with ethylene oxide is 3 to 12 hours, preferably 3 to 6 hours.

6. The method for preparing the corrosion-inhibiting flow control agent as described in claim 3, characterized in that: Step (3), The molar ratio of compound B, ethylenediamine, and catalyst C is 1:(1-2):(0-0.5); preferably 1:(1-1.5):(0.01-0.1), more preferably 1:(1-1.2):(0.05-0.1); and / or, The reaction temperature is 40–50°C; and / or, The reaction time is 3 to 10 hours; and / or, The catalyst C is at least one selected from alkali metal hydroxides, alkali metal alkoxides, and alkali metal carbonates, preferably at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; and / or, The reaction is followed by post-treatment, which includes solvent removal.

7. The method for preparing the corrosion-inhibiting flow control agent as described in claim 3, characterized in that: Step (4), The catalyst D is an alkaline catalyst, preferably at least one selected from potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate; and / or, The molar ratio of compound C, propylene oxide, and ethylene oxide is 1:(0-4):(0-7), and the molar ratios of propylene oxide and ethylene oxide cannot both be 0; the preferred molar ratio of compound C, propylene oxide, and ethylene oxide is 1:(0-3):(2-6); and / or, The molar ratio of catalyst D to the total molar amount of reactants in step (4) is (0.1–1):1; and / or, The reaction temperature with propylene oxide is 80–160 °C; and / or, The reaction time with propylene oxide is 3 to 12 hours, preferably 3 to 6 hours; and / or, The reaction temperature with ethylene oxide is 80–160 °C; and / or, The reaction time with ethylene oxide is 3 to 12 hours, preferably 3 to 6 hours.

8. The method for preparing the corrosion-inhibiting flow control agent as described in claim 3, characterized in that: Step (5), The molar ratio of compound D, RˊNH2, and catalyst E is 1:(1-2):(0-1); preferably 1:(1-1.5):(0.1-0.5); and / or, The reaction temperature is 100–120°C; and / or, The reaction time is 3 to 10 hours; and / or, The catalyst E is at least one selected from alkali metal hydroxide, alkali metal alkoxide, and alkali metal carbonate, preferably at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; and / or, The reaction is followed by post-treatment, which includes solvent removal.

9. The method for preparing the corrosion-inhibiting flow control agent as described in claim 3, characterized in that: Step (6), The ionizing reagent is selected from XR7Y; wherein X is chlorine, bromine, or iodine; R7 is a C1-C4 alkylene group or a substituted alkylene group; Y is SO3N or COONˊ, and N and Nˊ are alkali metals; and / or, The base is an alkali metal hydroxide or an alkali metal alkoxide; and / or, The molar ratio of compound E, ionizing reagent, and base is 1:(1-12):(1-12), preferably 1:(4-8):(4-8); and / or, The solvent is at least one of C3-C8 ketones and C6-C9 aromatic hydrocarbons; and / or, The amount of solvent used is 1–5 mL solvent / 1 g compound E; and / or, The reaction temperature is 50–120°C; and / or, The reaction time is 3 to 20 hours, preferably 6 to 16 hours; and / or, The reaction is followed by post-treatment, which includes solvent removal.

10. A corrosion-inhibiting flow control agent obtained by the preparation method according to any one of claims 3 to 9.

11. The application of a corrosion-inhibiting mobility control agent as described in claim 1, 2 or 10 in gas drive of oil reservoirs, preferably in controlling gas mobility in gas drive of high-temperature and high-salinity oil reservoirs.

12. A method for controlling gas flow rate in gas drive of high-temperature, high-salinity oil reservoirs, comprising the following steps: The gas flow rate is controlled by co-injecting a solution of corrosion-inhibiting flow rate control agent with gas-driven gas; the corrosion-inhibiting flow rate control agent is the corrosion-inhibiting flow rate control agent according to claim 1, 2 or 10; Preferably, The gas used for gas-driven propulsion is carbon dioxide; and / or, The concentration of the corrosion-inhibiting flow control agent solution is 0.1–5 wt%, more preferably 0.5–2 wt%; and / or, The volume ratio of the corrosion-inhibiting flow control agent solution to the gas is 1:(0.5-9), preferably 1:(1-3).

Images