Method for increasing high temperature aging stability of polyacrylamide

Abstract

The present invention relates to a method for increasing high temperature aging stability of polyacrylamide, wherein the problem that stability of polyacrylamide can become poor in a high temperature stratum due to oxidation, thermal destruction and other reasons so as to cause failure during a tertiary oil recovery technology is mainly solved with the present invention. The technical scheme comprises that: a stabilizer is added to a polymer solution so as to substantially increase stability of the solution during a high temperature aging process, wherein the stabilizer comprises, by mass concentration, (a) 50-300 mg / L of thiourea, and (b) 100-1000 mg / L of a small molecule alcohol compound, and the polyacrylamide is partially hydrolyzed polyacrylamide, sulfonated polyacrylamide or hydrophobically associated polyacrylamide. With the technical scheme, the problem in the prior art is well solved, and the method can be used for industrial production of tertiary oil recovery.

Description

technical field

[0001] The invention relates to a method for improving the high-temperature aging stability of polyacrylamide. Background technique

[0002] Polyacrylamide oil displacement agents (such as partially hydrolyzed polyacrylamide, hydrophobically associated polyacrylamide, etc.) are products for large-scale industrialized polymer flooding to enhance oil recovery, but there are stability problems in field applications. At high temperatures, especially in formations above 60°C, the viscosity of the polymer solution will decrease due to oxidation, thermal damage, etc., thus losing its use value.

[0003] In order to inhibit the oxidative degradation of polyacrylamide and achieve the purpose of stabilizing the viscosity of polyacrylamide aqueous solution, a stabilizer can be added to the polymer solution. There are almost no patents on improving polymer stability, and some only relate to how to use crosslinking agents to prepare polymer gels or microspheres; in polym...

Examples

Embodiment 1

[0013] The self-made partially hydrolyzed polyacrylamide 1 (solid content is 90.5% according to the method of GB / T 12005.2-89; the intrinsic viscosity is tested according to the method of GB / T12005.10-92, and [η]=3.73×10 -4 mw 0.66 The calculated molecular weight is 32.5 million; the hydrolysis degree is 20.6% according to the GB / T12005.6-89 method), and the simulated water (the total salinity is 8730mg / L) is used to prepare a 1500mg / L solution, and 50mg / L of sulfur is added Urea, 100mg / L ethylene glycol, connect the clean ampoule bottle to the vacuum system, first evacuate the ampoule bottle at -0.1MPa for 2min, then twist the piston, put 30ml solution into the ampoule bottle, burn it with an alcohol blowtorch seal up. Put the fired-sealed ampoule into a constant temperature oven at 95±1°C for aging. Samples were regularly taken out at 15 days, 30 days, 45 days, and 60 days, and the viscosity value of the solution was measured with a Brookfield viscometer until 90 days, and...

Embodiment 2

[0015] The self-made partly hydrolyzed polyacrylamide 2 (the solid content is 89.8% according to the GB / T 12005.2-89 method; the intrinsic viscosity is tested according to the GB / T12005.10-92 method, and [η]=3.73×10 -4 mw 0.66 The calculated molecular weight is 28.35 million; the hydrolysis degree is 14.8% according to the GB / T12005.6-89 method), and a 1500mg / L solution is prepared with simulated water (the total salinity is 8730mg / L), and 200mg / L of sulfur is added Urea, 200mg / L ethylene glycol, 200mg / L glycerin, connect the clean ampoule bottle to the vacuum system, first evacuate the ampoule bottle at -0.1MPa for 2min, then twist the piston, put 30ml solution into In ampoules, seal with an alcohol blowtorch. Put the fired-sealed ampoule into a constant temperature oven at 95±1°C for aging. Samples were regularly taken out at 15 days, 30 days, 45 days, and 60 days, and the viscosity value of the solution was measured with a Brookfield viscometer until 90 days, and the visc...

Embodiment 3

[0017] The self-made partially hydrolyzed polyacrylamide 3 (solid content is 89.9% according to the method of GB / T 12005.2-89; the intrinsic viscosity is tested according to the method of GB / T12005.10-92, and [η]=3.73×10 -4 mw 0.66 The calculated molecular weight is 26.5 million; according to the method of GB / T12005.6-89, the degree of hydrolysis is 16.5%, and the simulated water (total salinity is 8730mg / L) is used to prepare a 1500mg / L solution, and 300mg / L of sulfur is added Urea, 400mg / L ethylene glycol, 300mg / L isopropanol, 300mg / L isobutanol, connect the clean ampoule to the vacuum system, first evacuate the ampoule at -0.1MPa for 2min, and then Twist the plunger, put 30ml of the solution into the ampoule, and seal it with an alcohol blowtorch. Put the fired-sealed ampoule into a constant temperature oven at 95±1°C for aging. Samples were regularly taken out at 15 days, 30 days, 45 days, and 60 days, and the viscosity value of the solution was measured with a Brookfiel...

technical field

[0001] The invention relates to a method for improving the high-temperature aging stability of polyacrylamide. Background technique

[0002] Polyacrylamide oil displacement agents (such as partially hydrolyzed polyacrylamide, hydrophobically associated polyacrylamide, etc.) are products for large-scale industrialized polymer flooding to enhance oil recovery, but there are stability problems in field applications. At high temperatures, especially in formations above 60°C, the viscosity of the polymer solution will decrease due to oxidation, thermal damage, etc., thus losing its use value.

[0003] In order to inhibit the oxidative degradation of polyacrylamide and achieve the purpose of stabilizing the viscosity of polyacrylamide aqueous solution, a stabilizer can be added to the polymer solution. There are almost no patents on improving polymer stability, and some only relate to how to use crosslinking agents to prepare polymer gels or microspheres; in polym...

Examples

Embodiment 1

[0013] The self-made partially hydrolyzed polyacrylamide 1 (solid content is 90.5% according to the method of GB / T 12005.2-89; the intrinsic viscosity is tested according to the method of GB / T12005.10-92, and [η]=3.73×10 -4 mw 0.66 The calculated molecular weight is 32.5 million; the hydrolysis degree is 20.6% according to the GB / T12005.6-89 method), and the simulated water (the total salinity is 8730mg / L) is used to prepare a 1500mg / L solution, and 50mg / L of sulfur is added Urea, 100mg / L ethylene glycol, connect the clean ampoule bottle to the vacuum system, first evacuate the ampoule bottle at -0.1MPa for 2min, then twist the piston, put 30ml solution into the ampoule bottle, burn it with an alcohol blowtorch seal up. Put the fired-sealed ampoule into a constant temperature oven at 95±1°C for aging. Samples were regularly taken out at 15 days, 30 days, 45 days, and 60 days, and the viscosity value of the solution was measured with a Brookfield viscometer until 90 days, and...

Embodiment 2

[0015] The self-made partly hydrolyzed polyacrylamide 2 (the solid content is 89.8% according to the GB / T 12005.2-89 method; the intrinsic viscosity is tested according to the GB / T12005.10-92 method, and [η]=3.73×10 -4 mw 0.66 The calculated molecular weight is 28.35 million; the hydrolysis degree is 14.8% according to the GB / T12005.6-89 method), and a 1500mg / L solution is prepared with simulated water (the total salinity is 8730mg / L), and 200mg / L of sulfur is added Urea, 200mg / L ethylene glycol, 200mg / L glycerin, connect the clean ampoule bottle to the vacuum system, first evacuate the ampoule bottle at -0.1MPa for 2min, then twist the piston, put 30ml solution into In ampoules, seal with an alcohol blowtorch. Put the fired-sealed ampoule into a constant temperature oven at 95±1°C for aging. Samples were regularly taken out at 15 days, 30 days, 45 days, and 60 days, and the viscosity value of the solution was measured with a Brookfield viscometer until 90 days, and the visc...

Embodiment 3

[0017] The self-made partially hydrolyzed polyacrylamide 3 (solid content is 89.9% according to the method of GB / T 12005.2-89; the intrinsic viscosity is tested according to the method of GB / T12005.10-92, and [η]=3.73×10 -4 mw 0.66 The calculated molecular weight is 26.5 million; according to the method of GB / T12005.6-89, the degree of hydrolysis is 16.5%, and the simulated water (total salinity is 8730mg / L) is used to prepare a 1500mg / L solution, and 300mg / L of sulfur is added Urea, 400mg / L ethylene glycol, 300mg / L isopropanol, 300mg / L isobutanol, connect the clean ampoule to the vacuum system, first evacuate the ampoule at -0.1MPa for 2min, and then Twist the plunger, put 30ml of the solution into the ampoule, and seal it with an alcohol blowtorch. Put the fired-sealed ampoule into a constant temperature oven at 95±1°C for aging. Samples were regularly taken out at 15 days, 30 days, 45 days, and 60 days, and the viscosity value of the solution was measured with a Brookfiel...

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