Temperature-resistant and salt-resistant chemical water shutoff agent for low-permeability oil reservoir and preparation method thereof
By using chemical reactions of aluminum-ferrous salt minerals, silicate polymers and amine compounds with polyester fiber reinforcement in low permeability reservoirs to generate gel water blocking agents, the problem of difficult injection of existing water blocking agents in high-temperature and high-salt environments is solved, and the high sealing rate and erosion resistance are improved, and the water flooding development effect is improved.
Patent Information
- Application Number
- CN202410012843.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-04
- Publication Date
- 2025-07-04
AI Technical Summary
The existing water plugging agent is difficult to inject in a high-temperature and high-salt environment in low-permeability reservoirs, and its stability and erosion resistance cannot meet the application requirements, affecting the water flooding development effect.
Aluminum-ferrous salt minerals, silicate polymers, amine compounds and polyester fiber reinforcement are used to generate gel water blocking agents through chemical reactions, forming chemical water blocking agents with easy injection, high thermal stability and erosion resistance.
In the high temperature and high salt environment of low permeability reservoirs, easy injection and high sealing rate are achieved, excellent erosion resistance, and improved the water flood development effect.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of oilfield development, relates to a temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs, and also relates to a preparation method of the above-mentioned temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs. Background Art
[0002] With the progress of oilfield development, major oilfields have entered the high water cut development stage. In order to further explore subsequent resources and increase the remaining recoverable reserves, unconventional reservoirs such as low-permeability or extra-low-permeability, high-temperature or ultra-high-temperature reservoirs have received increasing attention. In some oilfields with characteristics of high-temperature and high salinity reservoirs, after long-term water flooding, a large number of preferential flow channels will be generated. After the injected water rushes through the preferential flow channels rapidly, the swept volume of water flooding decreases, making it difficult to start the remaining oil in the low-permeability oil layer, which seriously affects the water flooding development effect.
[0003] In order to improve the water injection effect and the ultimate oil recovery rate of the oilfield, technical measures of water shutoff and profile control are usually taken. However, the currently studied temperature- and salt-resistant profile control systems in China are still in the indoor research and field test stage, and the relevant research mainly focuses on plugging the temperature in the near-wellbore area at 90°C - 120°C and the formation water salinity in the range of 10×10 4 mg / L - 20×10 4 mg / L and other ranges of reservoirs. For the high-temperature and high-salt environment of low-permeability reservoirs, the existing water shutoff agents are difficult to inject, and their stability and erosion resistance cannot meet the application requirements. Summary of the Invention
[0004] The purpose of the present invention is to provide a temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs, which has the characteristics of being easy to inject, high stability, and erosion resistance in the high-temperature and high-salt environment of low-permeability reservoirs.
[0005] Another purpose of the present invention is to provide a preparation method of the above-mentioned temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs.
[0006] The first technical solution adopted by the present invention is that a temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs is composed of the following raw material components according to weight parts:
[0007] 5 - 15 parts of aluminum-iron salt minerals, 10 - 25 parts of silicic acid high polymer, 5 - 10 parts of amine compounds, 1 - 5 parts of polyester fiber reinforcing agent, and 40 - 79 parts of water.
[0008] The characteristics of the first technical solution of the present invention also lie in:
[0009] The aluminum-iron salt minerals are any one or more of aluminum chloride, iron chloride, polyferric sulfate, and alum.
[0010] The silicic acid high polymer is any one or more of silicon dioxide powder, water glass, polymeric silicic acid, and silica sol.
[0011] The amine compound is any one or more of urea, thiourea, ammonium chloride, ammonium sulfate, and amino group-containing compounds.
[0012] The polyester fiber reinforcing agent is any one or more of polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate.
[0013] The salinity of water is 20×10 4 mg / L.
[0014] The second technical solution adopted by the present invention is a preparation method of a temperature-resistant and salt-resistant chemical plugging agent for low-permeability reservoirs, which is specifically implemented according to the following steps:
[0015] Step 1: Weigh the following raw materials by weight parts respectively:
[0016] 5-15 parts of aluminum-iron salt minerals, 10-25 parts of silicic acid high polymer, 5-10 parts of amine compounds, 1-5 parts of polyester fiber reinforcing agent, and 40-79 parts of water;
[0017] Step 2: Add water and aluminum-iron salt minerals into the reaction kettle, stir and dissolve, then continue to add the silicic acid high polymer, heat up to the first reaction temperature, keep the temperature constant for reaction, then add the amine compound, stir and dissolve, continue to add the polyester fiber reinforcing agent, heat up to the second reaction temperature, stir and react for a set time, cool down to the set temperature, and discharge to obtain the temperature-resistant and salt-resistant chemical plugging agent for low-permeability reservoirs.
[0018] The characteristics of the second technical solution of the present invention also lie in:
[0019] In Step 2: The first reaction temperature is 100°C - 150°C, the constant-temperature reaction time is 1 - 3 hours, the second reaction temperature is 75°C - 90°C, and the set stirring reaction time is 2 - 4 hours.
[0020] The beneficial effects of the present invention are:
[0021] The temperature-resistant and salt-resistant chemical plugging agent for low-permeability reservoirs of the present invention uses aluminum-iron salt minerals, silicic acid high polymer amine compounds, and polyester fiber reinforcing agents to generate functional structures through chemical reactions, which are dispersed in the prepared water. At a certain temperature and time, the temperature-resistant and salt-resistant chemical plugging agent for low-permeability reservoirs of the present invention is formed, which has the characteristics of easy injection, high thermal stability, and erosion resistance.
[0022] The preparation method of the temperature-resistant and salt-resistant chemical plugging agent for low-permeability reservoirs of the present invention has the advantages of simple raw material composition, convenient batching, convenient process, and low production cost. Specific Embodiments
[0023] The present invention will be described in detail below in conjunction with specific embodiments.
[0024] The first technical solution provided by the present invention is a temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs, which is composed of the following raw material components by weight:
[0025] 5-15 parts of aluminum-iron salt minerals, 10-25 parts of silicate high polymers, 5-10 parts of amine compounds, 1-5 parts of polyester fiber reinforcing agents, and 40-79 parts of water. The aluminum-iron salt minerals, silicate high polymers, and amine compounds, together with the polyester fiber reinforcing agents, react chemically to generate a functional structure and are dispersed in the prepared water. At a certain temperature and time, the temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs of the present invention is formed. Among them, the aluminum-iron salt minerals and silicate high polymers are inorganic materials with good high-temperature resistance, high salinity resistance, good thermal stability, and are easily soluble in water. They will not solidify in a flowing state, which is convenient for injection. The amine compounds react with the aluminum-iron salt minerals and silicate high polymers at 100-150 °C to generate a gel water shutoff agent, which plays a role in water shutoff. The polyester fiber is used to further increase the strength of the gel water shutoff agent through the coiling and bridging action of the polyester fiber, and has the characteristics of being resistant to erosion.
[0026] The aluminum-iron salt mineral is any one or more of aluminum chloride, iron chloride, polyferric sulfate, and alum.
[0027] The silicate high polymer is any one or more of silicon dioxide powder, water glass, polysilicic acid, and silica sol.
[0028] The amine compound is any one or more of urea, thiourea, ammonium chloride, ammonium sulfate, and amino-containing compounds.
[0029] The polyester fiber reinforcing agent is any one or more of polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate.
[0030] The salinity of the water is 20×10 4 mg / L.
[0031] The second technical solution provided by the present invention is a preparation method of a temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs, which is specifically implemented according to the following steps:
[0032] Step 1: Weigh the following raw materials by weight:
[0033] 5-15 parts of aluminum-iron salt minerals, 10-25 parts of silicate high polymers, 5-10 parts of amine compounds, 1-5 parts of polyester fiber reinforcing agents, and 40-79 parts of water;
[0034] Step 2: Add water and aluminum-iron salt minerals into the reactor, stir and dissolve them. Then continue to add the high-silicate polymer, heat up to the first reaction temperature, keep the temperature constant for reaction, and then add the amine compound and stir to dissolve it. The amine compound reacts with the aluminum-iron salt minerals and the high-silicate polymer at 100 - 150 °C to form a gel plugging agent. Then continue to add the polyester fiber reinforcing agent, heat up to the second reaction temperature, stir and react for a set time, cool down to the set temperature. Through the coiling and bridging action of the polyester fiber, the strength of the gel plugging agent is further increased. Finally, the product is discharged to obtain a temperature-resistant and salt-resistant chemical plugging agent for low-permeability oil reservoirs. The raw material composition in the whole technological process is simple, the batching is convenient, the process is convenient, and the production cost is low.
[0035] In Step 2: The first reaction temperature is 100 °C - 150 °C, the constant-temperature reaction time is 1 - 3 hours, the second reaction temperature is 75 °C - 90 °C, and the set stirring reaction time is 2 - 4 hours. It can be seen that this temperature-resistant and salt-resistant chemical plugging agent for low-permeability oil reservoirs can only initiate gelation under high-temperature conditions, will not solidify in the low-temperature flowing state, is easy to pump, and has a high adhesion force on the rock surface.
[0036] The preparation method of the temperature-resistant and salt-resistant chemical plugging agent for low-permeability oil reservoirs of the present invention is specifically as follows:
[0037] Example 1
[0038] Add 70 parts of water into the reactor, stir, add 5 parts of polyaluminum chloride, stir and dissolve it. Then continue to add 15 parts of polysilicic acid, continue to stir, heat up to 110 °C, keep the temperature constant for 1 hour, then add 5 parts of ammonium chloride, stir and dissolve it. Then continue to add 5 parts of polybutylene naphthalate, heat up to 90 °C again, stir and react for 4 hours, cool down to 20 °C, and discharge to obtain the temperature-resistant and salt-resistant chemical plugging agent for low-permeability oil reservoirs corresponding to Example 1.
[0039] Example 2
[0040] Add 68 parts of water into the reactor, stir, add 10 parts of aluminum chloride, stir and dissolve it. Then continue to add 15 parts of silica sol, continue to stir, heat up to 100 °C, keep the temperature constant for 1.5 hours, then add 4 parts of thiourea, stir and dissolve it. Then continue to add 3 parts of polyethylene terephthalate, heat up to 75 °C again, stir and react for 3 hours, cool down to 40 °C, and discharge to obtain the temperature-resistant and salt-resistant chemical plugging agent for low-permeability oil reservoirs corresponding to Example 2.
[0041] Example 3
[0042] Add 57 parts of water to the reactor, stir, add 15 parts of polymeric ferric sulfate, stir until dissolved, then continue to add 20 parts of silicon dioxide, continue to stir, heat up to 120 °C, keep the temperature constant and react for 2 hours, then add 3 parts of hexamethylenetetramine, stir until dissolved, continue to add 5 parts of polyethylene terephthalate, heat up to 85 °C again, stir and react for 4 hours, cool down to 20 °C, and discharge to obtain the temperature and salt resistant chemical plugging agent for low permeability reservoirs corresponding to Example 3.
[0043] Example 4
[0044] Add 55 parts of water to the reactor, stir, add 15 parts of polyaluminum chloride, stir until dissolved, then continue to add 25 parts of sodium silicate, continue to stir, heat up to 120 °C, keep the temperature constant and react for 2 hours, then add 3 parts of urea, stir until dissolved, continue to add 2 parts of polyethylene naphthalate, heat up to 90 °C again, stir and react for 3 hours, cool down to 20 °C, and discharge to obtain the temperature and salt resistant chemical plugging agent for low permeability reservoirs corresponding to Example 4.
[0045] Example 5
[0046] Add 81 parts of water to the reactor, stir, add 15 parts of ferric chloride, stir until dissolved, then continue to add 0 parts of high-silica polymer, continue to stir, heat up to 120 °C, keep the temperature constant and react for 1.5 hours, then add 4 parts of urea, stir until dissolved, continue to add 0 parts of polybutylene terephthalate, heat up to 85 °C again, stir and react for 4 hours, cool down to 20 °C, and discharge to obtain the temperature and salt resistant chemical plugging agent for low permeability reservoirs corresponding to Example 5.
[0047] Example 6
[0048] Add 66 parts of water to the reactor, stir, add 15 parts of polyaluminum chloride, stir until dissolved, then continue to add 15 parts of sodium silicate, continue to stir, heat up to 105 °C, keep the temperature constant and react for 3 hours, then add 4 parts of urea, stir until dissolved, continue to add 0 parts of polyethylene terephthalate, heat up to 90 °C again, stir and react for 4 hours, cool down to 20 °C, and discharge to obtain the temperature and salt resistant chemical plugging agent for low permeability reservoirs corresponding to Example 6.
[0049] Comparative Example 1
[0050] Add 75 parts of water to the reactor, stir, add 5 parts of polyaluminum chloride, stir until dissolved, then continue to add 15 parts of polymeric silicic acid, continue to stir, heat up to 120 °C, keep the temperature constant and react for 1 hour, then add 5 parts of thiourea, stir until dissolved, continue to add 0 parts of polyethylene terephthalate, heat up to 75 °C again, stir and react for 4 hours, cool down to 20 °C, and discharge to obtain the chemical plugging agent corresponding to Comparative Example 1.
[0051] Comparative Example 2
[0052] Add 73 parts of water to the reaction kettle, stir, add 10 parts of polyferric chloride, stir and dissolve it, then continue to add 0 part of silica sol, continue to stir, heat up to 100 °C, keep the temperature constant and react for 1.5 hours, then add 4 parts of thiourea, stir and dissolve it, then continue to add 3 parts of polybutylene terephthalate, heat up to 85 °C again, stir and react for 3 hours, cool down to 40 °C, and discharge to obtain the chemical water plugging agent corresponding to Comparative Example 2.
[0053] Comparative Example 3
[0054] Add 57 parts of water to the reaction kettle, stir, add 0 part of polyaluminium chloride, stir and dissolve it, then continue to add 20 parts of sodium silicate, continue to stir, heat up to 105 °C, keep the temperature constant and react for 2 hours, then add 3 parts of urea, stir and dissolve it, then continue to add 5 parts of polyethylene terephthalate, heat up to 75 °C again, stir and react for 4 hours, cool down to 30 °C, and discharge to obtain the chemical water plugging agent corresponding to Comparative Example 3.
[0055] Comparative Example 4
[0056] Add 61 parts of water to the reaction kettle, stir, add 15 parts of polyaluminium chloride, stir and dissolve it, then continue to add 15 parts of sodium silicate, continue to stir, heat up to 100 °C, keep the temperature constant and react for 4 hours, then add 4 parts of urea amine compound, stir and dissolve it, then continue to add 5 parts of polyethylene terephthalate, heat up to 80 °C again, stir and react for 3 hours, cool down to 20 °C, and discharge to obtain the chemical water plugging agent corresponding to Comparative Example 4.
[0057] Comparative Example 5
[0058] Add 81 parts of water to the reaction kettle, stir, add 15 parts of polyferric chloride, stir and dissolve it, then continue to add 0 part of sodium silicate, continue to stir, heat up to 120 °C, keep the temperature constant and react for 1.5 hours, then add 4 parts of urea, stir and dissolve it, then continue to add 0 part of polyethylene terephthalate, heat up to 90 °C again, stir and react for 3 hours, cool down to 20 °C, and discharge to obtain the chemical water plugging agent corresponding to Comparative Example 5.
[0059] Comparative Example 6
[0060] Add 66 parts of water to the reaction kettle, stir, add 15 parts of polyaluminium chloride, stir and dissolve it, then continue to add 15 parts of sodium silicate, continue to stir, heat up to 110 °C, keep the temperature constant and react for 2 hours, then add 4 parts of urea, stir and dissolve it, then heat up to 85 °C again, stir and react for 3.5 hours, cool down to 20 °C, and discharge to obtain the chemical water plugging agent corresponding to Comparative Example 6.
[0061] Comparative Example 7
[0062] Select any one of the existing polymer plugging agents in the chemical plugging agents.
[0063] The comparison of the components and contents of Examples 1-6 and Comparative Examples 1-6 is shown in Table 1 below:
[0064] Table 1 Components and Contents of Examples 1-6 and Comparative Examples 1-6
[0065]
[0066]
[0067] For the above Examples 1-6 and Comparative Examples 1-6, a plugging experiment was carried out on the sandstone core at 150 °C in an indoor core plugging experiment, and the experiment was carried out according to the permeability test method, as follows:
[0068] Step 1, Core production: Use sands of different meshes, and measure the water-phase permeability after filling.
[0069] Step 2, Inject the plugging agent obtained from each of the above examples and comparative examples into the core and place it in a constant temperature drying oven at 150 °C for 72 h of curing, and measure the water flooding permeability.
[0070] Step 3, Calculate the core plugging rate according to Darcy's law, and the experimental results are as follows:
[0071] Table 2 Comparison of the effects of each example
[0072]
[0073]
[0074] It can be clearly seen from the experimental data of the above Examples 1-6 and Comparative Examples 1-6 that compared with Comparative Examples 1-6 in which there are differences in the raw material components of the plugging agent and other plugging agents, the plugging agent for low-permeability oil reservoirs with temperature and salt resistance of the present invention in Examples 1-6 has a lower permeability after plugging, a higher plugging rate, is easier to inject, and is difficult to wash away. It can be seen that the plugging agent for low-permeability oil reservoirs with temperature and salt resistance prepared by the present invention using aluminum-iron salt minerals, silicic acid polymers, amine compounds and polyester fiber reinforcing agents has obvious advantages of good plugging effect, erosion resistance and easy injection in the high-temperature and high-salt environment of low-permeability oil reservoirs.
[0075] The performance comparison between any one of the plugging agents for low-permeability oil reservoirs with temperature and salt resistance in Examples 1-6 above and the polymer plugging agent in Comparative Example 7 is shown in Table 3 below:
[0076] Table 3 Performance Comparison between Examples and Comparative Example 7
[0077]
[0078]
[0079] It can be seen that compared with ordinary polymer plugging agents, the temperature- and salt-resistant chemical plugging agent for low-permeability reservoirs of the present invention has better temperature and salt resistance, thermal stability, plugging rate and injectability than ordinary polymer plugging agents, and is obviously more suitable for the high-temperature and high-salt environment of low-permeability reservoirs.
Claims
1. A temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs, characterized in that, It consists of the following raw material components by weight parts: 5 - 15 parts of aluminum - iron salt minerals, 10 - 25 parts of silicate high - polymer, 5 - 10 parts of amine compounds, 1 - 5 parts of polyester fiber reinforcing agent, and 40 - 79 parts of water.
2. The temperature and salt resistant chemical water shutoff agent for low-permeability reservoirs according to claim 1, wherein The aluminum - iron salt minerals are any one or more of aluminum chloride, ferric chloride, polyferric sulfate, and alum.
3. The temperature and salt resistant chemical water shutoff agent for low-permeability reservoirs according to claim 1, characterized in that, The silicate high - polymer is any one or more of silicon dioxide powder, water glass, polysilicic acid, and silica sol.
4. The temperature- and salt-resistant chemical water shutoff agent for low-permeability reservoirs according to claim 1, wherein The amine compounds are any one or more of urea, thiourea, ammonium chloride, ammonium sulfate, and amino - containing compounds.
5. The temperature and salt resistant chemical water shutoff agent for low-permeability reservoirs according to claim 1, wherein The polyester fiber reinforcing agent is any one or more of polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate.
6. The temperature and salt resistant chemical water shutoff agent for low permeability reservoirs according to claim 1, wherein The salinity of the water is 20×10 4 mg / L.
7. Preparation method of temperature and salt resistant chemical plugging agent for low permeability reservoir, characterized in that, Specifically, it is implemented according to the following steps: Step 1: Weigh the following raw materials by weight parts respectively: 5 - 15 parts of aluminum - iron salt minerals, 10 - 25 parts of silicate high - polymer, 5 - 10 parts of amine compounds, 1 - 5 parts of polyester fiber reinforcing agent, and 40 - 79 parts of water; Step 2: Add water and aluminum - iron salt minerals into the reaction kettle, stir and dissolve, then continue to add silicate high - polymer, heat up to the first reaction temperature, keep the temperature constant for reaction, then add amine compounds, stir and dissolve, continue to add polyester fiber reinforcing agent, heat up to the second reaction temperature, stir and react for a set time, cool down to the set temperature, and discharge to obtain the temperature - resistant and salt - resistant chemical plugging agent for low - permeability reservoirs.
8. The preparation method of the temperature and salt resistant chemical plugging agent for low permeability reservoirs according to claim 7, characterized in that In Step 2: The first reaction temperature is 100℃ - 150℃, the constant - temperature reaction time is 1 - 3 hours, the second reaction temperature is 75℃ - 90℃, and the set stirring reaction time is 2 - 4 hours.