阅读说明：本技术 高温调堵助排剂及其制备方法与应用 (High-temperature blockage-regulating cleanup additive and preparation method and application thereof ) 是由 陈小凯 田志达 杨婧 张学智 张津睿 苗哲玮 赵甲男 李�瑞 马昌明 刘强 王尧 于 2020-06-10 设计创作，主要内容包括：本发明提供了高温调堵助排剂及其制备方法与应用。该高温调堵助排剂包括丙烯酰胺及其衍生物、酮碳基单体、交联剂、引发剂、缓凝剂、磺酸盐型表面活性剂和水。本发明还提供了上述高温调堵助排剂的制备方法。本发明还进一步提供了上述高温调堵助排剂在200℃以上的稠油油藏调堵封窜技术中的应用。本发明提供的高温调堵助排剂封堵率可达92％以上,耐温达300℃,250℃蒸汽条件下有效期可达1个月以上,封堵强度可达22MPa/m；该高温调堵助排剂具有良好的流动性、耐温性,制备简单、成本低廉,成胶时间可调,封堵能力强,能够进入地层深部,有效解决普通稠油井吸汽剖面不均、井间汽窜的问题。(The invention provides a high-temperature blockage-regulating cleanup additive, and a preparation method and application thereof. The high-temperature blockage-regulating cleanup additive comprises acrylamide and derivatives thereof, a ketonic-carbon-based monomer, a cross-linking agent, an initiator, a retarder, a sulfonate surfactant and water. The invention also provides a preparation method of the high-temperature blockage-regulating cleanup additive. The invention further provides the application of the high-temperature plugging and discharging assistant agent in a plugging and channeling adjusting technology of a heavy oil reservoir at the temperature of more than 200 ℃. The plugging rate of the high-temperature plugging and discharging assistant agent provided by the invention can reach more than 92%, the high-temperature plugging and discharging assistant agent can resist the temperature of 300 ℃, the effective period can reach more than 1 month under the steam condition of 250 ℃, and the plugging strength can reach 22 MPa/m; the high-temperature plugging and discharging assistant has good fluidity and temperature resistance, is simple to prepare, low in cost, adjustable in gelling time and strong in plugging capability, can enter deep parts of stratums, and effectively solves the problems of uneven steam absorption profile and steam channeling among wells of a common heavy oil well.)

1. The high-temperature blockage-regulating cleanup additive comprises the following components in percentage by mass based on 100% of the total mass of the high-temperature blockage-regulating cleanup additive:

0.2-0.5% of acrylamide and derivatives thereof, 0.1-0.4% of ketonic-based monomer, 0.15-0.3% of cross-linking agent, 0.1-0.6% of initiator, 0.4-1% of retarder, 0.2-1% of sulfonate surfactant and the balance of water.

2. The high temperature plugging and cleanup additive of claim 1, wherein said acrylamide and its derivatives comprise acrylamide and/or N, N-methylenebisacrylamide.

3. The high temperature conditioning block and cleanup additive of claim 1, wherein the ketocarbon based monomer comprises one or a combination of two or more of diacetone acrylamide, acrolein, methacrolein, methyl vinyl ketone, acetoxyethyl acrylate, and acetoxyethyl methacrylate.

4. A high temperature plugging and cleanup additive according to any one of claims 1-3, wherein said cross-linking agent comprises one or a combination of two or more of acetohydrazide, adihydrazide, N-diacetylhydrazide, and benzenesulfonylhydrazide;

the initiator comprises one or the combination of more than two of ammonium persulfate, sodium persulfate and potassium persulfate.

5. The high temperature plugging and cleanup additive of claim 1, wherein the retarder comprises one or a combination of two or more of calcium ethylenediaminetetramethylenephosphonate, sodium ethylenediaminetetramethylenephosphonate, and ethylenediaminepentamethylenephosphonic acid.

6. The high temperature plugging and cleanup additive of claim 1, wherein the sulfonate-type surfactant comprises one or a combination of two or more of alkyl benzene sulfonate, alpha-olefin sulfonate, alkyl sulfonate, succinate sulfonate, alkyl naphthalene sulfonate, petroleum sulfonate, lignin sulfonate, and alkyl glycerol ether sulfonate;

preferably, the alkyl group of the alkylbenzene sulfonate and/or the alkyl group of the alkyl sulfonate has a carbon number of 12 to 16.

7. The high-temperature plugging and discharging assistant according to claim 1, wherein the water comprises one or more of tap water, surface water, shallow water and oilfield reinjection wastewater, preferably oilfield reinjection wastewater.

8. The high temperature plugging and cleanup additive of claim 1, wherein the cleanup additive has a pH of 5-7;

preferably, a pH value regulator is adopted to regulate the pH value of the high-temperature plugging and cleanup additive;

more preferably, the pH adjuster comprises sodium hydroxide and/or potassium hydroxide.

9. A process for the preparation of a high temperature plugging and cleanup additive as recited in any one of claims 1-8, comprising:

adding acrylamide and derivatives thereof, a ketonic-based monomer, a cross-linking agent, an initiator, a retarder and a sulfonate surfactant into water, and mixing to obtain the high-temperature blockage-regulating cleanup additive.

10. The use of the high-temperature plugging and cleanup additive as defined in any one of claims 1 to 8 in a plugging and channeling regulating technology for heavy oil reservoirs at a temperature of 200 ℃ or higher;

preferably, the application temperature of the high-temperature plugging and discharging assistant agent is 200-300 ℃.

Technical Field

The invention relates to the technical field of oilfield development, in particular to a high-temperature plugging-regulating cleanup additive and a preparation method and application thereof.

Background

With the increase of the huff and puff times of the thickened oil block of the Liaohe oil field, the formation pressure is low, the vacancy is serious, the steam channeling is prominent, the oil extraction speed is low, the thickened oil block is in a low-efficiency exploitation state and is influenced by various factors such as formation heterogeneity, the steam gravity is overlaped in the exploitation process, the steam absorption profile is uneven, the steam channeling among wells, heavy components of the crude oil in the formation are increased, the crude oil is emulsified in reverse phase, the oil flow channel is blocked, in addition, the formation energy is low, the flowback performance is poor, and the like, so that the thickened oil thermal recovery efficiency is seriously reduced, and the improvement of the recovery ratio is influenced.

At present, the gel water shutoff agent which is most widely applied is mainly a complex cross-linked polymer of Polyacrylamide (PAM) or polysaccharide and high-valence metal ions such as chromium, aluminum and the like, and a chemical cross-linked polymer of the complex cross-linked polymer and formaldehyde, phenol and the like. Because the original water of the continental-phase oil reservoir in China is mainly sodium carbonate, the aluminum cross-linking agent system is easy to decompose to generate aluminum hydroxide precipitate; compared with an aluminum crosslinking system, the organic chromium system has wider applicable conditions and high tolerance mineralization and temperature, however, chromium ions, particularly high-valence chromium ions, have very high lasting danger to the environment and do not meet the actual requirements of large-scale gel water plugging; the chemical cross-linking agents such as formaldehyde, phenol and the like are difficult to calculate accurately, inconvenient to transport, high in toxicity and harmful to the environment. The existing high-temperature profile control agent mainly comprises high-temperature organic gel, thermosetting resin, gel particle plugging agent, foam plugging agent and the like. Wherein the price of the high-temperature organic jelly is higher; the thermosetting resin has no selectivity, the curing speed is very sensitive to the temperature, and the controllability is poor; the gel particle plugging agent cannot be injected into the deep part of the stratum; the plugging strength of the foam water plugging agent is too low, and the stratum adaptability is poor.

Therefore, aiming at the current problems of safety and environmental protection, the high-temperature blockage regulating measures lack a chemical agent with low toxicity and low damage, can effectively block a hypertonic channel or a steam channeling channel, and can be quickly degraded after steam injection is finished, thereby playing a role of high-temperature blockage regulating and discharge aiding agent integrating milk prevention, emulsion breaking, viscosity reduction and flowback on the formation crude oil.

Disclosure of Invention

In order to solve the above problems, the present invention aims to provide a high temperature plugging and cleanup additive, and a preparation method and an application thereof. When the temperature of the stratum reaches more than 200 ℃, the high-temperature plugging and cleanup additive system provided by the invention can be gradually hydrated and release a high-temperature surfactant, so that a 'Jamin effect' is formed in the stratum, and the effects of performing secondary profile control and expanding steam swept volume are achieved.

In order to achieve the above object, the present invention provides a high temperature plugging and cleanup additive, wherein the high temperature plugging and cleanup additive comprises, based on 100% of the total mass of the high temperature plugging and cleanup additive: 0.2-0.5% of acrylamide and derivatives thereof, 0.1-0.4% of ketonic-based monomer, 0.15-0.3% of cross-linking agent, 0.1-0.6% of initiator, 0.4-1% of retarder, 0.2-1% of sulfonate surfactant and the balance of water.

In the high-temperature plugging and discharging assistant, the acrylamide and the derivatives thereof can be used as the molecular structure of a gel-forming framework and polymerized to form a gel-forming system; under the action of steam, the polymer molecular chain of the gel-forming skeleton is broken, so that the organic components of the high-temperature plugging and discharging assistant are degraded and hydrated. Preferably, the acrylamide and its derivatives include acrylamide and/or N, N-methylenebisacrylamide.

In the high-temperature blockage and cleanup additive, the ketocarbonyl monomer (such as diacetone acrylamide) is low in toxicity and harmless to the environment, can introduce ketocarbonyl to a polymer chain formed by acrylamide and derivatives thereof, and is safe and environment-friendly. Preferably, the ketocarbon based monomer comprises one or a combination of two or more of diacetone acrylamide, acrolein, methacrolein, methyl vinyl ketone, acetoxyethyl acrylate, and acetoxyethyl methacrylate.

In the high-temperature plugging and discharging assistant, a polymer which is formed by a cross-linking agent containing a hydrazine group, polyacrylamide and derivatives thereof and has a ketone carbonyl group can be subjected to dehydration reaction under an acidic condition to generate a hydrazone compound, so that the high-temperature plugging and discharging assistant is cross-linked at a room temperature, and the gelling strength and the temperature resistance of the high-temperature plugging and discharging assistant are improved. Preferably, the cross-linking agent comprises one or a combination of more than two of acethydrazide, adihydrazide, N-diacetylhydrazide and benzenesulfonylhydrazide.

In the high-temperature plugging and cleanup additive, the initiator is used for catalyzing the polymerization reaction of the ketocarbon-based monomer and the acrylamide derivative monomer. Preferably, the initiator comprises one or a combination of two or more of ammonium persulfate, sodium persulfate and potassium persulfate.

In the high-temperature blockage and drainage-assisting agent, the sulfonate surfactant is used as a high-temperature surfactant, and the solution of the sulfonate surfactant can effectively strip an oil film on the surface of a rock, change the wettability of a stratum and prevent steam condensate water and thickened oil from forming a water-in-oil emulsion. Meanwhile, the surfactant, the condensed water and the thickened oil can form a good oil-in-water emulsion, so that the viscosity of the thickened oil is greatly reduced, the mobility of formation fluid is improved, and the effects of preventing emulsification, demulsifying, reducing viscosity and assisting drainage are achieved. Preferably, the sulfonate-type surfactant includes one or a combination of two or more of alkylbenzene sulfonate, α -olefin sulfonate, alkyl sulfonate, succinate sulfonate, alkyl naphthalene sulfonate, petroleum sulfonate, lignin sulfonate, and alkyl glyceryl ether sulfonate; more preferably, the alkyl group of the alkylbenzene sulfonate and/or the alkyl group of the alkyl sulfonate has a carbon number of 12 to 16.

In the high-temperature blockage and discharge assistant, the retarder is used for reducing the crosslinking reaction speed of the ketonic-carbon-based monomer and the acrylamide and the derivative thereof. Preferably, the retarder comprises one or a combination of more than two of ethylene diamine tetra methylene phosphonic acid calcium, ethylene diamine tetra methylene phosphonic acid sodium and ethylene diamine pentamethylene phosphonic acid.

According to particular embodiments of the invention, the water may include one or a combination of two or more of tap water, surface water, shallow water, and oilfield reinjection wastewater, preferably oilfield reinjection wastewater. In some embodiments, oilfield reinjection of wastewater above 20 ℃ may be employed.

According to a specific embodiment of the invention, the pH of the high temperature plugging and cleanup additive is generally controlled to be 5 to 7. In some embodiments, the pH of the high temperature plugging drainage aid may be adjusted using a pH adjuster, which preferably includes sodium hydroxide and/or potassium hydroxide.

According to the embodiment of the invention, the high-temperature plugging-adjusting cleanup additive can be applied to various oil wells, particularly thick oil wells.

The invention also provides a preparation method of the high-temperature blockage-regulating cleanup additive, wherein the preparation method comprises the following steps: adding acrylamide and derivatives thereof, a ketonic-based monomer, a cross-linking agent, an initiator, a retarder and a sulfonate surfactant into water, and mixing to obtain the high-temperature blockage-regulating cleanup additive.

According to a specific embodiment of the present invention, the preparation method of the high-temperature plugging and cleanup additive preferably comprises: the high-temperature plugging and discharging assistant is prepared by adding acrylamide and derivatives thereof, a ketonic-based monomer, a retarder and a sulfonate surfactant into water, stirring, adding a cross-linking agent and an initiator, and mixing. The stirring condition can be controlled to be 50-200r/min and the stirring time is controlled to be 20-30 min.

The invention further provides the application of the high-temperature plugging and discharging assistant agent in a plugging and channeling adjusting technology of a heavy oil reservoir at the temperature of more than 200 ℃. In the specific embodiment of the invention, the high-temperature plugging and discharging assistant agent can be suitable for plugging and channeling adjusting technologies of heavy oil reservoirs such as steam flooding, steam stimulation, SAGD and the like. For example, the method is applied to the plugging and channeling regulating technology of heavy oil reservoirs at 200-300 ℃.

The beneficial effects of the invention include:

1. the plugging rate of the high-temperature plugging and discharging assistant provided by the invention can reach more than 92%, the temperature can be up to 300 ℃, the effective period can reach more than 1 month under the condition of steam at 250 ℃, and the plugging strength can reach 22 MPa/m.

2. The high-temperature plugging and discharging assistant has the characteristics of good fluidity, temperature resistance, simple preparation, low cost and the like, has adjustable gelling time and strong plugging capability, is suitable for wide oil reservoir types, is not easy to pollute stratum, can enter deep part of the stratum, and effectively solves the problems of uneven steam absorption profile and steam channeling among wells of the common heavy oil well.

3. In the plugging control construction, along with the prolonging of steam injection time, when the temperature of a stratum reaches more than 200 ℃, the system of the high-temperature plugging control cleanup additive is gradually hydrated to release a high-temperature surfactant, and the surfactant can form a good foam system under the action of steam and steam condensate water, so that a 'Jamin effect' is formed in the stratum to play a role in secondary profile control, the trend of the steam is controlled and changed, and the steam swept volume is enlarged.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1

The embodiment provides a high-temperature blockage-regulating cleanup additive, which is prepared by the following processes:

1. by taking the total mass of the high-temperature plugging and discharging assistant as 100 percent, 0.2 percent of acrylamide, 0.1 percent of diacetone acrylamide, 0.15 percent of acethydrazide, 0.1 percent of ammonium persulfate, 0.4 percent of calcium ethylene diamine tetramethylene phosphonate, 0.2 percent of sodium dodecyl benzene sulfonate and the balance of oil field reinjection sewage are weighed.

2. Adding weighed acrylamide, diacetone acrylamide, acethydrazide, ammonium persulfate, calcium ethylene diamine tetramethylene phosphonate and sodium dodecyl benzene sulfonate into oil field reinjection sewage, adjusting the pH value to 5 by using sodium hydroxide, and stirring and mixing uniformly to obtain the high-temperature plugging and discharging assistant.

Example 2

The embodiment provides a high-temperature blockage-regulating cleanup additive, which is prepared by the following processes:

1. by taking the total mass of the high-temperature plugging and cleanup additive as 100 percent, 0.5 percent of N, N-methylene bisacrylamide, 0.4 percent of diacetone acrylamide, 0.3 percent of adipic dihydrazide, 0.6 percent of sodium persulfate, 1 percent of ethylene diamine tetramethylene phosphonic acid sodium, 1 percent of alpha-olefin sodium sulfonate and the balance of oilfield reinjection sewage are weighed.

2. Adding the weighed N, N-methylene bisacrylamide, diacetone acrylamide, adipic dihydrazide, sodium persulfate, sodium ethylene diamine tetramethylene phosphonate and alpha-olefin sodium sulfonate into the oilfield reinjection sewage, adjusting the pH value to 7 by using sodium hydroxide, and stirring and mixing uniformly to obtain the high-temperature plugging and cleanup additive.

Example 3

The embodiment provides a high-temperature blockage-regulating cleanup additive, which is prepared by the following processes:

1. based on the total mass of the high-temperature plugging and cleanup additive being 100%, 0.3% of N, N-methylene bisacrylamide, 0.2% of methacrolein, 0.2% of N, N-diacetyl hydrazide, 0.4% of potassium persulfate, 0.8% of ethylenediamine pentamethylene phosphonic acid, 0.6% of sodium hexadecyl benzene sulfonate and the balance of oilfield reinjection sewage are weighed.

2. Adding the weighed N, N-methylene bisacrylamide, methacrolein, N-diacetyl hydrazine, potassium persulfate, ethylenediamine pentamethylene phosphonic acid and sodium hexadecylbenzene sulfonate into the oil field reinjection sewage, adjusting the pH value to 6 by using sodium hydroxide, and stirring and mixing uniformly to obtain the high-temperature plugging and cleanup additive.

Example 4

The embodiment provides a high-temperature blockage-regulating cleanup additive, which is prepared by the following processes:

1. by taking the total mass of the high-temperature plugging and cleanup additive as 100 percent, 0.4 percent of acrylamide, 0.35 percent of methyl vinyl ketone, 0.25 percent of benzenesulfonyl hydrazide, 0.5 percent of ammonium persulfate, 0.6 percent of calcium ethylene diamine tetramethylene phosphonate, 0.8 percent of sodium sulfosuccinate and the balance of oilfield reinjection sewage are weighed.

2. Adding the weighed acrylamide, methyl vinyl ketone, benzenesulfonyl hydrazide, ammonium persulfate, calcium ethylene diamine tetramethylene phosphonate and sodium succinate sulfonate into the oilfield reinjection sewage, adjusting the pH value to 6 by using sodium hydroxide, and uniformly stirring and mixing to obtain the high-temperature plugging and discharging assistant.

Example 5

The embodiment provides a high-temperature blockage-regulating cleanup additive, which is prepared by the following processes:

1. based on the total mass of the high-temperature plugging and cleanup additive being 100%, 0.3% of N, N-methylene bisacrylamide, 0.2% of acetoxyethyl acrylate, 0.2% of adipic dihydrazide, 0.25% of ammonium persulfate, 0.5% of calcium ethylene diamine tetramethylene phosphonate, 0.5% of sodium dodecyl sulfate and the balance of oilfield reinjection sewage are weighed.

2. Adding the weighed N, N-methylene bisacrylamide, acetoxyethyl acrylate, adipic dihydrazide, ammonium persulfate, calcium ethylene diamine tetramethylene phosphonate and sodium dodecyl sulfate into the oilfield reinjection sewage, adjusting the pH value to 5 by using sodium hydroxide, and stirring and mixing uniformly to obtain the high-temperature plugging and drainage-assisting agent.

Test example 1

The test example provides a core single tube simulation experiment on the high-temperature plugging and cleanup additive of example 2, and is used for inspecting the permeability change condition of the core before and after being treated by the high-temperature plugging and cleanup additive. The specific process of the simulation experiment is as follows: the method comprises the steps of vacuumizing saturated water of a rock core, measuring the permeability of the rock core before plugging under a certain pump displacement, injecting a certain amount of high-temperature plugging and cleanup additive into the rock core in a forward direction until the rock core is saturated, placing the rock core injected with the high-temperature plugging and cleanup additive into a water bath at 80 ℃, and measuring the permeability of the rock core after plugging in a reverse direction after a period of time.

The relevant experimental parameters and the plugging strength properties of the high temperature plugging and cleanup additive are summarized in table 1.

TABLE 1

The results in table 1 show that the high-temperature plugging and cleanup additive provided by the invention has very strong formation plugging capability, and the effective plugging rate can reach more than 92%.

Test example 2

The test example providesThe single-tube model core experiment of the high-temperature plugging and cleanup additive prepared in example 2 is carried out to investigate the steam scouring resistance. The experimental parameters were: the core length is 5.5cm, and the core permeability is 1418 multiplied by 10^-3μm²Core pore volume 11.5cm³The mass of injected steam is 115g (10PV), the injection temperature is 250 ℃, the injection flow is 2g/min, and the high-temperature plugging and cleanup additive is injected until the core is saturated. Table 2 summarizes the plugging rates for different steam injection times.

TABLE 2

Time of steam injection, min	5	10	20	30	40	50	60
								Plugging rate%	95.4	93.6	91.4	88.7	82.4	78.6	73.5

From the results in table 2, it can be seen that as the steam scouring time is prolonged, the plugging rate of the high-temperature plugging and discharging assistant agent is reduced, which indicates that the gel-forming structure of the high-temperature plugging and discharging assistant agent is damaged, and finally the formed aqueous solution is discharged. When the volume of injected steam is 10PV, the plugging rate of the high-temperature plugging and cleanup additive to the rock core is kept at about 70%, which shows that the high-temperature plugging and cleanup additive has very strong steam scouring resistance, and simultaneously shows that the high-temperature plugging and cleanup additive can be degraded under the action of high temperature, thereby restoring the permeability of the stratum.

Test example 3

In the test example, a core single tube simulation experiment was performed on the high-temperature plugging and cleanup additive of example 3, and the breakthrough pressure of the high-temperature plugging and cleanup additive was measured to evaluate the plugging strength of the high-temperature plugging and cleanup additive on the formation. The plugging strength of the high-temperature plugging and cleanup additive can be evaluated by breakthrough pressure.

The test process of the core single tube simulation experiment is as follows:

(1) saturating the core with water;

(2) injecting 1PV high-temperature plugging and cleanup additive at a flow rate of 10ml/min, and setting conditions of external pressure of 20MPa and constant-temperature water bath at 80 ℃;

(3) placing the rock core injected with the high-temperature plugging and cleanup additive in a closed container, and placing the rock core in a water bath at 80 ℃;

(4) keeping the temperature and the external pressure of the water bath, injecting water at the flow rate of 15ml/min until the first drop of liquid flows down from the outlet end of the core holder and then the liquid continuously flows out, and recording the reading of a pressure gauge at the inlet end at the moment as the breakthrough pressure P of the high-temperature plugging and cleanup additive_t. The permeability of the core No. 2019-14 is 684X 10^-3μm²Pore volume 9.5cm³(ii) a 2019-15 core had a permeability of 735X 10^-3μm²Pore volume 9.7cm³. Table 3 summarizes the results of the blocking strength test of the high temperature blocking and cleanup additive.

TABLE 3

Core numbering	Length (cm)	Injection blocking agent (PV)	Liquid outlet pressure (MPa)	Breakthrough pressure (MPa/m)
					2019-14	5.2	1	1.18	22.7
2019-15	5.5	1	1.21	22.0

As can be seen from Table 3, the plugging strength of the high-temperature plugging and cleanup additive provided in example 3 reaches 22MPa/m, meets the requirements of high-temperature plugging of steam flooding and huff-puff wells, has very high plugging capability, and can effectively avoid steam channeling.

Test example 4

The test example provides a high-temperature aging test of the high-temperature plugging and discharging assistant agent so as to investigate the temperature resistance of the high-temperature plugging and discharging assistant agent. The test procedure was as follows:

the high-temperature plugging and discharging assistant prepared in example 4 was allowed to stand for 24 hours until completely coagulated, and then placed in a thermostat, the temperature of the thermostat was adjusted every 24 hours, the weight loss rate of the high-temperature plugging and discharging assistant under different temperature conditions was tested, and the experimental results are summarized in table 4.

TABLE 4

Temperature of	100	150	200	250	300
						Status of state	Solid body	Solid body	Solid body	Solid body	Solid body
Weight loss ratio (%)	0	0	1.5	9.7	55.2

As can be seen from table 4, the weight loss rate of the high-temperature plugging and cleanup additive provided in example 4 increases with the increase of temperature, and when the temperature exceeds 200 ℃, the structure of the high-temperature plugging and cleanup additive changes, and high-temperature hydration starts to occur. The test result shows that the high-temperature plugging and cleanup additive can resist the high temperature of more than 200 ℃, has good high-temperature resistance, and can adapt to the application conditions of developing oil reservoirs by using steam to huff and puff heavy oil in China.

Test example 5

The test example is a high-temperature long-term stability experiment carried out on the high-temperature blockage-adjusting discharge-assisting agent, and the influence of a high-temperature environment on the long-term stability of the high-temperature blockage-adjusting discharge-assisting agent is examined. The experimental temperature was 250 ℃, the change in the dehydration rate over time of the high temperature plugging and cleanup additive prepared in example 5 was recorded, and the experimental results are summarized in table 5.

TABLE 5

Stabilization time of day	1	3	7	10	15	21	30	45
									A rate of dehydration%	9.7	13.2	18.5	24.6	29.8	34.5	41.2	48.3

As can be seen from Table 5, the high temperature plugging and discharging assistant can maintain strong plugging for more than 1 month for a long time under the condition of 250 ℃.

Test example 6

The test example provides a single-tube model core experiment of the high-temperature plugging and drainage aid, and the experiment takes hydrate removed after the high-temperature stability experiment of test example 5 (namely hydrate stabilized at 250 ℃ for 45 days) as a sample, and inspects the stripping and wetting effects of the hydrated high-temperature plugging and drainage aid on crude oil of stratum rocks. The experimental procedure was as follows:

(1) saturating the crude oil in the rock core, introducing saturated water into the rock core, and displacing until no crude oil flows out;

(2) injecting hydrate of the 2PV high-temperature plugging and drainage assistant;

(3) the volume of displaced crude oil was measured at the outlet end using a graduated cylinder and the test results are summarized in table 6.

The experimental parameters were: the core length is 5.2cm, and the core permeability is 857 multiplied by 10^-3μm²Pore volume 6.5cm³And injecting hydrate mass: 13g (2PV), injection flow rate: 2 g/min.

TABLE 6

Injection volume, PV	0.2	0.5	1	1.5	2
						Volume of crude oil, ml	1.5	2.4	3.7	3.9	4.0

From table 6, it can be seen that the solution of the high-temperature surfactant released by the gradual hydration of the gel system of the high-temperature plugging and cleanup additive can effectively strip the oil film on the surface of the rock, change the wettability of the formation, improve the fluidity of the formation fluid, and perform the functions of viscosity reduction and cleanup.