CN116925716A - High-temperature-resistant high-salt inorganic precipitation plugging agent and preparation method thereof - Google Patents
High-temperature-resistant high-salt inorganic precipitation plugging agent and preparation method thereof Download PDFInfo
- Publication number
- CN116925716A CN116925716A CN202310923207.5A CN202310923207A CN116925716A CN 116925716 A CN116925716 A CN 116925716A CN 202310923207 A CN202310923207 A CN 202310923207A CN 116925716 A CN116925716 A CN 116925716A
- Authority
- CN
- China
- Prior art keywords
- plugging
- agent
- plugging agent
- solution
- auxiliary agent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/5045—Compositions based on water or polar solvents containing inorganic compounds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/5083—Compositions based on water or polar solvents containing organic compounds macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/5086—Compositions based on water or polar solvents containing organic compounds macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/514—Compositions based on water or polar solvents containing organic compounds macromolecular compounds of natural origin, e.g. polysaccharides, cellulose
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/52—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
- C09K8/528—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning inorganic depositions, e.g. sulfates or carbonates
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
Abstract
The invention relates to a high-temperature-resistant high-salt inorganic precipitation plugging agent and a preparation method thereof. The plugging agent consists of sodium sulfate, calcium chloride, an auxiliary agent A and an auxiliary agent B, wherein the auxiliary agent A is a tackifier, the auxiliary agent B is a scale inhibitor, no crystal precipitate is generated in 48 hours at room temperature, the plugging agent is heated for 2-3d at 60-90 ℃, the mass precipitation rate is higher than 50%, and the plugging rate is higher than 98%. The plugging agent disclosed by the invention has better injectability, better temperature resistance and salt resistance, is suitable for oilfield working conditions, has small environmental pollution, and is a plugging agent system of a pure solution type with huge potential under the conditions of high temperature and high salt.
Description
Technical Field
The invention belongs to the technical field of petroleum exploitation, and particularly relates to a high-temperature-resistant high-salt plugging agent and a preparation method thereof.
Background
The heavy oil (i.e. heavy crude oil) refers to crude oil with viscosity of 100-1000 mPa.s at original reservoir temperature or density of 0.9340-1.0000g/cm at 15.6deg.C and atmospheric pressure 3 . The thickened oil accounts for about 60% of the total petroleum resources. Because of the high viscosity of the thick oil, the thick oil is developed mainly through thermal recovery. At present, the main mode of thermal recovery is to inject high-temperature steam into a heavy oil reservoir, heat the heavy oil through heat conduction to reduce viscosity, and then pump the heavy oil to the ground. At present, the main problems of thick oil thermal recovery are: after high-pass throughput, the production effect is poor; high comprehensive water content and low extraction degree. The root cause of the main problems is that because the internal permeability of the heavy oil reservoir is inconsistent, when steam is injected, most of high-temperature steam enters the hypertonic channel, heated crude oil returns from the hypertonic channel during oil extraction, which is equivalent to bidirectional flow in the hypertonic channel, so that the heavy oil which can be extracted is limited to the periphery of the hypertonic channel.
Because of the high-temperature steam injection and the operation process of the exploitation process, steam channeling and water invasion are unavoidable problems in the development process of the thick oil field, and are also the main technical problems in the thermal exploitation development process. At present, the problem is increasingly remarkable in the thick oil thermal recovery process, and how to prevent and treat the problems of steam channeling and water invasion is one of the key problems restricting the development of the thick oil thermal recovery. In the development process of the oil field, the water injection developed oil field has the advantages that due to the heterogeneity of stratum and the complexity of oil reservoir stratum, the heterogeneity of water injection profile is increased along with the increase of water injection quantity, so that a large amount of water is discharged from the oil field, the development effect of steam huff and puff is seriously influenced, and the recovery ratio of the oil field is influenced. The current widely applied water shutoff technology is mainly polymer gel water shutoff technology, but the polymer gel system is limited by the temperature resistance of the high molecular polymer and the activity of the cross-linking agent, has larger limit on the use temperature, and can only be applied to stratum environment of 50-110 ℃ generally. In addition, the polymer has high resistance in the injection process, is easy to shear and degrade, and has high requirements on oil reservoir environment in the aspects of salt tolerance and the like. Although technological workers develop high-temperature gel systems such as humic acid, lignin and the like successively to improve the temperature resistance of polymer gel, no breakthrough progress is made in aspects such as injectability, salt resistance and the like
In addition, the existing plugging agent is prepared into suspension in advance and then injected into the stratum, the distance of the existing plugging agent in stratum gaps is relatively short due to the existence of particles in the suspension in the infiltration process, and part of the suspension is flushed away along with the development of the water injection process, so that the plugging effect is not ideal, and particularly the existing plugging agent can not meet the requirements of actual working conditions more in particular to high-temperature working conditions such as thick oil steam injection thermal recovery and high-salt working conditions such as deep oil gas recovery, but related researches in recent years are many, but no particularly good solution exists.
CN114214046a discloses a high temperature resistant modified manganese dioxide nano plugging agent and oil-based drilling fluid. The high-temperature resistant modified manganese dioxide nano plugging agent comprises nano manganese dioxide (50 nm), methyl styrene compounds, alkenyl phenylsilane compounds, phenylsulfonate compounds, silane coupling agents, surfactants, cross-linking agents and initiators; the drilling fluid comprises the high-temperature resistant modified manganese dioxide nano plugging agent. The high temperature resistant modified manganese dioxide nano plugging agent is used as a nano plugging agent, and the particle size distribution of the nano plugging agent is 80-305 nm. There is also the problem that the particles do not advance sufficiently in the formation slots.
CN114437685a discloses a degradable dynamic polymer plugging material, a preparation method and application thereof, the material comprises: flexible dynamic polyurea particles, rigid dynamic polyurea particles, dynamic polyurea fibers, tackifiers, weighting agents, and water. The degradable dynamic polymer plugging material in the technology takes flexible polyurea particles as a deformation material, rigid particles as a supporting material, polyurea fibers as a winding material, and guanidyl urea bonds generated by the reaction of guanidyl and isocyanate can undergo dissociation-association reaction, the dynamic polyurea particles and fiber materials can undergo self-adhesion in a bottom hole crack under high temperature and high pressure, and no gaps exist between the particles and the fibers. The method also has the problem that particles cannot be fully propelled in stratum gaps, and meanwhile, the problem of environmental pollution caused by organic matters is also accompanied, so that the method can not be applied to actual oilfield working conditions.
CN114686191A gel blocking agent, and preparation method and application thereof. The first aspect of the invention provides a preparation method of a gel blocking agent, which comprises the following steps: preparing a mixed solution of polymerized monomers, wherein the mixed solution of polymerized monomers comprises acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and hydrophobic monomers; and adding montmorillonite into the mixed solution of the polymerization monomers, stirring uniformly, and then sequentially adding a cross-linking agent and an initiator to enable the polymerization monomers to carry out polymerization reaction, wherein after the polymerization reaction is finished, the gel plugging agent is obtained. However, in the concrete use of the oil field working condition, the bentonite and other particles still need to be added, and the technical problem in the prior art can not be solved.
CN115058234a is a crystal self-growth system plugging agent. The invention provides a plugging agent for a crystal self-growth system, which comprises the following components in percentage by weight: 0.1-0.7% of polymer, 1-5% of auxiliary agent A, 2-4% of calcium chloride, 2-4% of auxiliary agent B and 4-8% of sodium carbonate; the construction operation is simple: the crystal growth spontaneously proceeds in the pores, the system does not contain particles, the viscosity is low, the injection is easy, and the high-efficiency blocking of the hypertonic pore canal can be realized by only reasonably calculating the formulation and the injection amount of the slug and reasonably controlling the injection speed in the construction operation. However, the system provided by the invention is calcium carbonate crystals, the crystallization speed is high, the control of the crystal growth process is not easy, the temperature resistant effect is unknown, and the blocking effect under the high temperature working condition is not facilitated.
In summary, although the plugging agent system applied at present plays a great role in guaranteeing stable production of oil fields, the technical bottleneck is very obvious, and how to provide a plugging agent with better injectability, better temperature resistance and salt resistance and suitable for high-temperature working conditions of oil field steam injection becomes a technical problem to be solved urgently.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides the inorganic precipitation type plugging agent which is inorganic calcium sulfate crystal precipitation, can resist high temperature (can resist high temperature working condition above 350 ℃) and high salt (can resist mineralization degree 25 ten thousand mg/L), and can grow and crystallize in a gap after being injected into a stratum in a pure liquid form in the use process, thereby thoroughly solving the defects that the plugging agent in the prior art has limited advancing distance in the stratum gap and has reduced plugging effect caused by reinjection water flushing.
The invention provides a high-temperature and high-salt resistant plugging agent which consists of sodium sulfate, calcium chloride, an auxiliary agent A and an auxiliary agent B, wherein the auxiliary agent A is a tackifier, and the auxiliary agent B is a scale inhibitor.
Further, based on the weight percentage of the plugging agent, the sodium sulfate accounts for 1-2%, the calcium chloride accounts for 1-2%, the auxiliary agent A accounts for 0.2-1%, the auxiliary agent B accounts for 0.002% -0.02%, and the balance is water.
Further, the auxiliary agent A is any one or any combination of guar gum, polyacrylamide and welan gum, and the molecular weight of the auxiliary agent A is 10-200 ten thousand.
Further, the auxiliary agent B is any one or any combination of polyaspartic acid, amino trimethylene phosphonic acid and phytic acid.
The invention also provides a preparation method of the plugging agent, which comprises the following steps:
(1) Preparing an auxiliary agent A solution: adding ultrapure water into a beaker, adding the auxiliary agent A while stirring, and fully dissolving to obtain a solution A;
(2) Adding the auxiliary agent B into the solution A to obtain a solution B;
(3) Dissolving calcium chloride in the solution B, and fully dissolving to obtain a solution C;
(4) And dissolving sodium sulfate in the solution C, and fully dissolving to obtain the plugging agent.
Further, the addition amount of the auxiliary A of the solution A in the step (1) is calculated by adding 0.5 to 2.5g of the auxiliary A per 250ml of ultrapure water.
Further, the addition amount of the auxiliary B in the solution B in the step (2) is calculated by adding 0.005g-0.05g of the auxiliary B per 250ml of ultrapure water.
Further, the amount of the calcium chloride added in the solution C in the step (3) is calculated by adding 2.5 to 5g of the calcium chloride per 250ml of ultrapure water.
Further, the amount of sodium sulfate added in the step (4) is calculated by adding 2.5 to 5g of sodium sulfate per 250ml of ultrapure water.
Further, the stirring time in the step (1) is 1-1.5h.
Further, in the step (3), the stirring time is 10-15min.
Further, in the step (4), the stirring time is 10-15min.
The plugging agent can be suitable for oil reservoirs with formation temperature of 60-90 ℃; heating at 60-90deg.C for 2-3d, with precipitation rate higher than 50% and blocking rate higher than 98%. The formed inorganic crystal can resist high temperature of above 350 ℃ and 25 ten thousand mg/L of mineralization degree.
The plugging agent provided by the invention has no crystal formation after being placed at room temperature for 48 hours, and calcium sulfate crystals with different morphologies can be observed after being placed at the formation temperature (60-90 ℃) for 48 hours. The specific principle is as follows: at room temperature, the auxiliary agent A has good suspension performance, provides microgravity environment for calcium sulfate crystal nuclei, and inhibits the calcium sulfate crystal nuclei from contacting each other, thereby inhibiting the growth of calcium sulfate crystals; meanwhile, the crystal can also react with calcium ions directly, for example, hydroxyl in guar gum can be complexed with the calcium ions, so that the concentration of free calcium ions is reduced, and the generation of crystals at room temperature is inhibited. The auxiliary agent B is a scale inhibitor, and can chelate calcium ions through self carboxyl groups or phosphoric acid groups in the crystal growth process, so that the concentration of free calcium ions is reduced, and meanwhile, the auxiliary agent B is coordinated on the surface of the crystal to inhibit the combination of free calcium ions and sulfate ions on the surface of the crystal, thereby further inhibiting the growth of the crystal. At high temperature, the auxiliary agent A easily loses suspension property, microgravity environment cannot be provided, and meanwhile, the auxiliary agent B is easily decomposed and deactivated at high temperature, so that the effect of inhibiting crystal growth cannot be achieved, a large amount of calcium sulfate crystals are generated at high temperature, and plugging is rapidly formed in a stratum. Compared with the prior art, the specific formula composition has better plugging effect, and can last for deeper parts.
The invention has the beneficial effects that:
1. compared with the plugging agent which needs to have particles to form suspension in the prior art, the plugging agent disclosed by the invention can penetrate and advance in the stratum far further, and water is injected after crystals grow in the stratum, so that the problem that the plugging agent for suspending particles in the prior art is scattered in the water injection process is avoided;
2. according to the invention, the single-liquid injection of the sodium sulfate solution is realized through a specific formula, and the specific polymer is adopted to be matched with the sodium sulfate solution, so that the high temperature resistance of the plugging agent is improved, the stability of the plugging agent is improved, the plugging effect is enhanced, and the recovery ratio of crude oil is improved;
3. the plugging agent disclosed by the invention is in a solution form, simple in components, free from complex operation in the preparation process, convenient for large-scale field application of oilfield working conditions, capable of adapting to various complex oil reservoir environments, high-temperature resistant and high-salt resistant, higher in temperature, higher in mineralization degree in the crystallization process, higher in salt saturation, higher in crystal growth speed, more grown crystals and better in plugging effect;
4. the plugging agent does not need to additionally add other catalysts, crystal nucleus, initiator and the like for promoting the growth of crystals, and can utilize the temperature condition and the salinity condition of the plugging agent in the stratum to form the growth of crystals by one-time injection, so that the plugging effect is achieved;
5. the plugging agent is an inorganic mineral, has natural advantages in the aspects of temperature resistance, salt resistance, injectability and the like, has little environmental pollution, and is a plugging agent system of a pure solution type with huge potential and development.
Drawings
Fig. 1 is a graph showing the morphology of the plugging agent sample 1 of example 1 after 48 hours of the high temperature resistant calcium salt crystal plugging agent at different temperatures.
FIG. 2 shows the crystallization amount of the plugging agent sample 1 of example 1 after 48 hours of high temperature resistant calcium salt crystal plugging agent at different temperatures.
FIG. 3 is an infrared spectrum of the crystal generated by the plugging agent sample 1 of example 1 after the plugging agent is high temperature resistant calcium salt crystal for 48 hours at different temperatures.
Fig. 4 is a plot of the plugging agent displacement process pressure at 60 ℃ for plugging agent sample 1 of example 1.
Fig. 5 is a plot of the plugging agent displacement process pressure at 90 ℃ for plugging agent sample 1 of example 1.
Fig. 6 is a graph showing the morphology of the plugging agent sample 2 of example 2 after 48 hours of the high temperature resistant calcium salt crystal plugging agent at different temperatures.
FIG. 7 is an infrared spectrum of the crystal generated after 48 hours of the high temperature resistant calcium salt crystal plugging agent of example 2.
Fig. 8 is a plot of the plugging agent displacement process pressure at 60 ℃ for plugging agent sample 2 of example 2.
Fig. 9 is a plot of the plugging agent displacement process pressure at 90 ℃ for plugging agent sample 2 of example 2.
Fig. 10 is a graph showing the morphology of the plugging agent sample 3 of example 3 after 48 hours of the high temperature resistant calcium salt crystal plugging agent at different temperatures.
FIG. 11 is an infrared spectrum of the crystal generated after the plugging agent sample 3 of example 3 was resistant to high Wen Gaiyan crystal plugging agent for 48 hours.
Fig. 12 is a plot of the plugging agent displacement process pressure at 60 ℃ for plugging agent sample 3 of example 3.
Fig. 13 is a plot of the plugging agent displacement process pressure at 90 ℃ for plugging agent sample 3 of example 3.
Fig. 14 is a graph showing the morphology of the plugging agent sample 4 of example 4 after 48 hours of the high temperature resistant calcium salt crystal plugging agent at different temperatures.
FIG. 15 is an infrared spectrum of the crystal generated after the plugging agent sample 4 of example 4 was resistant to high Wen Gaiyan crystal plugging agent for 48 hours.
Fig. 16 is a plot of the plugging agent displacement process pressure at 60 ℃ for plugging agent sample 4 of example 4.
Fig. 17 is a plot of the plugging agent displacement process pressure at 90 ℃ for plugging agent sample 4 of example 4.
Detailed Description
Experimental example 1
Plugging agent sample 1
A plugging agent consists of 5g of sodium sulfate, 5g of calcium chloride, 2.5g of polyacrylamide with an auxiliary agent A molecular weight of 200 ten thousand, and 0.05g of polyaspartic acid with an auxiliary agent B molecular weight of 1000-5000.
The preparation method comprises the following steps:
(1) Preparing an auxiliary agent A solution: 250ml of ultrapure water is added into a beaker, 2.5g of the auxiliary agent A polyacrylamide is added while stirring, and the solution A is fully dissolved to obtain;
(2) Adding 0.05g of the auxiliary agent B polyaspartic acid into the solution A to obtain a solution B;
(3) Dissolving 5g of calcium chloride in the solution B, fully stirring for 10min, and fully dissolving to obtain a solution C;
(4) Dissolving 5g of sodium sulfate in the solution C, fully stirring for 10min, fully dissolving to obtain the plugging agent,
(5) The calcium salt crystal plugging agents are respectively placed in glass bottles with good sealing performance, then are respectively placed at 30-120 ℃ to simulate stratum environment conditions, and the growth characteristics of the Gao Wendu resistant agent are analyzed.
The plugging characteristics of the high temperature resistant plugging agent of the invention are analyzed by experiments as follows:
(1) Selecting two cores (phi 10cm multiplied by 2.5 cm) with similar permeability (670 mD and 720 mD), and vacuumizing the cores for about 8 hours;
(2) Weighing dry weight of the core, weighing wet weight after soaking to saturation, calculating pore volume of the core, and placing the core into a core holder;
(3) Water flooding is carried out at the speed of 1ml/min, and the permeability K is carried out according to the Darcy formula 0 Is calculated;
(4) Injecting the plugging agent sample 1 (the formula of the calcium salt crystal plugging agent is 1% polyacrylamide, 0.02% polyaspartic acid, 2% sodium sulfate and 2% calcium chloride) into a rock core at the speed of 1ml/min by a single liquid method, wherein the injection amount is 1PV, and recording the pressure difference change at two ends of a rock core holder; then respectively placing the mixture in an incubator at 60 ℃ and 90 ℃ for standing for 2d;
(5) Performing water flooding at a speed of 1ml/min until the pressure is stable, and performing permeability K according to Darcy formula 1 Is calculated;
(6) Press (K) 0 -K 1 )/K 1 The plugging rate eta is calculated by 100 percent.
By recording the pressure difference change in the whole water flooding process, the water flooding permeability after being stabilized for 2 days at different temperatures is calculated, and the plugging rate of the plugging agent sample 1 is summarized in the following table.
| Water permeability measurement | Temperature (. Degree. C.) | Subsequent water drive permeability | Subsequent water flooding plugging rate | |
| Core 1 | 670mD | 60 | 6.78mD | 98.98 |
| Core 2 | 720mD | 90 | 1.78mD | 99.75 |
Experimental results and analysis
1. As can be seen from a combination of fig. 1 and 2, the crystallization amount of the plugging agent sample 1 also increases significantly with an increase in temperature. Compared with the published calcium carbonate plugging agent patent CN115058234A, the plugging agent of the invention adopts a specific formula, so that the generated crystal is calcium sulfate crystal, the crystallization speed of the calcium sulfate crystal is slower, the control of the crystal growth process is easier, and the carboxyl in the polyaspartic acid can chelate Ca on the surface of the crystal nucleus 2+ Therefore, the crystal is combined on the surface of the crystal, the growth of the crystal is restrained, the crystal cannot be crystallized and precipitated in a short time, and the crystal is slowly precipitated at a high temperature. Meanwhile, the invention has higher crystallization amount, and the crystal morphology is flaky or needle-shaped, so that the invention has better plugging effect.
2. As can be seen from the infrared spectrum of FIG. 3, the blocking agent 1 produced at different temperatures produced crystals of standard calcium sulfate.
3. The high-permeability core plugging parameters at 60 ℃ and 90 ℃ are shown in the table 1, and when the temperature is increased, precipitation of calcium salt crystals is facilitated, the plugging effect is good, and the plugging agent sample 1 has good temperature resistance.
4. As can be seen from fig. 4 and 5, the temperature was about 60 ℃, and after the pressure was broken through by 0.57MPa, the salt crystals precipitated in the plugging agent sample 1 were gradually stabilized at 0.5MPa, and part of the channels were plugged. After the temperature is about 90 ℃ and the pressure breaks through 1.8MPa, the pressure is reduced, and the final pressure is stabilized at 1.86MPa, which shows that the salt crystals precipitated in the plugging agent sample 1 of the invention have the processes of plugging, migration and re-plugging in a porous medium such as a rock core, which is favorable for plugging deeper parts of a stratum, and is the technical effect which cannot be achieved by the plugging agent with a granular suspension system in the prior art.
Experimental example 2
Blocking agent sample 2
A plugging agent consists of 5g of sodium sulfate, 5g of calcium chloride, 2.5g of guar gum with an auxiliary agent A molecular weight of 200 ten thousand and 0.05g of amino trimethylene phosphonic acid with an auxiliary agent B molecular weight of 1000-5000.
The preparation method comprises the following steps:
(1) Preparing an auxiliary agent A solution: 250ml of ultrapure water is added into a beaker, 2.5g of auxiliary agent A guar gum is added while stirring, and the auxiliary agent A guar gum is fully dissolved to obtain solution A;
(2) Adding 0.05g of the auxiliary B amino trimethylene phosphonic acid to the solution A to obtain a solution B;
(3) Dissolving 5g of calcium chloride in the solution B, fully stirring for 10min, and fully dissolving to obtain a solution C;
(4) Dissolving 5g of sodium sulfate in the solution C, stirring for 10min, and dissolving to obtain the plugging agent
(5) The calcium salt crystal plugging agents are respectively placed in glass bottles with good sealing performance, then are respectively placed at 30-120 ℃ to simulate stratum environment conditions, and the growth characteristics of the Gao Wendu resistant agent are analyzed.
The plugging characteristics of the high temperature resistant plugging agent of the invention are analyzed by experiments as follows:
(1) Selecting two cores (phi 10cm multiplied by 2.5 cm) with similar permeability (660 mD and 610 mD), and vacuumizing the cores for about 8 hours;
(2) Weighing dry weight of the core, weighing wet weight after soaking to saturation, calculating pore volume of the core, and placing the core into a core holder;
(3) Water flooding is carried out at the speed of 1ml/min, and the permeability K is carried out according to the Darcy formula 0 Is calculated;
(4) Injecting the plugging agent sample 2 (calcium salt crystal plugging agent formula is 1% guar gum, 0.02% amino trimethylene phosphonic acid, 2% sodium sulfate and 2% calcium chloride) into a rock core at a speed of 1ml/min by a single liquid method, wherein the injection amount is 1PV, and recording the pressure difference change at two ends of a rock core holder; then respectively placing the mixture in an incubator at 60 ℃ and 90 ℃ for standing for 2d;
(5) Performing water flooding at a speed of 1ml/min until the pressure is stable, and performing permeability K according to Darcy formula 1 Is calculated;
(6) Press (K) 0 -K 1 )/K 1 The plugging rate eta is calculated by 100 percent.
By recording the pressure difference change in the whole water flooding process, the water flooding permeability after being stabilized for 2 days at different temperatures is calculated, and the plugging rate of the plugging agent sample 2 is summarized in the following table.
| Water permeability measurement | Temperature (. Degree. C.) | Subsequent water drive permeability | Subsequent water flooding plugging rate | |
| Core 1 | 660mD | 60 | 2.82mD | 99.57 |
| Core 2 | 610mD | 90 | 1.41mD | 99.76 |
Experimental results and analysis
1. From FIG. 6 and the results, compared with the calcium carbonate plugging system of patent CN115058234A, the crystal morphology of sample 2 is mainly needle-shaped, since the hydroxyl groups in the guar gum can be matched with Ca in the solution 2+ The phosphoric acid group in the amino trimethylene phosphonic acid can complex Ca in the solution 2+ Or bound to the surface of the crystal nucleus, so that the generation of crystals at room temperature can be significantly suppressed. As the temperature increases, the amount of crystallization of the sealant sample 2 also increases significantly.
2. As can be seen from the infrared spectrum of fig. 7, the crystal obtained by growth of the plugging agent 2 is a standard calcium sulfate crystal.
3. The high permeability core plugging parameters at 60 ℃ and 90 ℃ are shown in the table 2, and when the temperature is increased, precipitation of calcium salt crystals is facilitated, the plugging effect is good, and the good temperature resistance of the plugging agent sample 2 is proved.
4. As can be seen from the results of FIGS. 8 and 9, the salt crystals precipitated in the plugging agent sample 2 gradually stabilized at 1.14MPa after the pressure of the plugging agent breaks through 1.9MPa at about 60℃to plug part of the channels. After the temperature is about 90 ℃, the pressure breaks through 3.1MPa, the pressure has a descending trend, and the final pressure is stabilized at 2.5MPa, which indicates that the salt crystals precipitated by the plugging agent sample 2 of the invention have the processes of plugging, migration and re-plugging in a porous medium such as a rock core, which is beneficial to the plugging of the deep part of a stratum, and is the technical effect which cannot be achieved by the plugging agent with a granular suspension system in the prior art.
Experimental example 3
Blocking agent sample 3
A plugging agent consists of 5g of sodium sulfate, 5g of calcium chloride, 2.5g of an auxiliary agent A hydroxypropyl guar gum and 0.05g of an auxiliary agent B, wherein the molecular weight of the auxiliary agent B is 1000-5000.
The preparation method comprises the following steps:
(1) Preparing an auxiliary agent A solution: 250ml of ultrapure water is added into a beaker, 2.5g of the auxiliary agent A polyacrylamide is added while stirring, and the solution A is fully dissolved to obtain;
(2) Adding 0.05g of the auxiliary agent B polyaspartic acid into the solution A to obtain a solution B;
(3) Dissolving 5g of calcium chloride in the solution B, fully stirring for 10min, and fully dissolving to obtain a solution C;
(4) Dissolving 5g of sodium sulfate in the solution C, stirring for 10min, and dissolving to obtain the plugging agent
(5) The calcium salt crystal plugging agents are respectively placed in glass bottles with good sealing performance, then are respectively placed at 30-120 ℃ to simulate stratum environment conditions, and the growth characteristics of the Gao Wendu resistant agent are analyzed.
The plugging characteristics of the high temperature resistant plugging agent of the invention are analyzed by experiments as follows:
(1) Selecting two cores (phi 10cm multiplied by 2.5 cm) with similar permeability (650 mD and 710 mD), and vacuumizing the cores for about 8 hours;
(2) Weighing dry weight of the core, weighing wet weight after soaking to saturation, calculating pore volume of the core, and placing the core into a core holder;
(3) Water flooding is carried out at the speed of 1ml/min, and the permeability K is carried out according to the Darcy formula 0 Is calculated;
(4) Injecting the plugging agent sample 3 (calcium salt crystal plugging agent formula is 1% hydroxypropyl guar gum, 0.02% polyaspartic acid, 2% sodium sulfate and 2% calcium chloride) into a rock core at a speed of 1ml/min by a single liquid method, wherein the injection amount is 1PV, and recording the pressure difference change at two ends of a rock core holder; then respectively placing the mixture in an incubator at 60 ℃ and 90 ℃ for standing for 2d;
(5) Performing water flooding at a speed of 1ml/min until the pressure is stable, and calculating the permeability K1 according to a Darcy formula;
(6) The blocking rate η was calculated as (K0-K1)/K1X100%.
By recording the pressure difference change in the whole water flooding process, the water flooding permeability after being stabilized for 2d at different temperatures is calculated, and the plugging rate of the plugging agent sample 3 is summarized in the following table.
| Water permeability measurement | Temperature (. Degree. C.) | Subsequent water drive permeability | Subsequent water flooding plugging rate | |
| Core 1 | 650mD | 60 | 2.62mD | 99.59 |
| Core 2 | 710mD | 90 | 2.12mD | 99.70 |
Experimental results and analysis
1. As can be seen from fig. 10, compared with the calcium carbonate plugging system of patent CN115058234A, the crystal morphology of the present sample 3 is mainly dendritic. As the temperature increases, the amount of crystallization of the plugging agent sample 3 also increases significantly.
2. As can be seen from the IR spectrum of FIG. 11, the crystal obtained by growth of the plugging agent 3 is a standard calcium sulfate crystal.
3. The high permeability core plugging parameters at 60 ℃ and 90 ℃ are shown in the table 3, and when the temperature is increased, precipitation of calcium salt crystals is facilitated, the plugging effect is good, and the plugging agent sample 3 has good temperature resistance.
4. As can be seen from fig. 12 and 13, the salt crystals precipitated in the plugging agent sample 3 gradually stabilized at 1.3Mpa after the pressure was broken through at about 1.5Mpa at 60 ℃. After the temperature is about 90 ℃, the pressure breaks through 2.5MPa, the pressure has a descending trend, and the final pressure is stabilized at 1.6MPa, which shows that the salt crystals precipitated by the plugging agent sample 3 of the invention have the processes of plugging, migration and re-plugging in a porous medium such as a rock core, which is beneficial to the plugging of the deep part of a stratum, and is the technical effect which cannot be achieved by the plugging agent with a granular suspension system in the prior art.
Experimental example 4
Blocking agent sample 4
A plugging agent consists of 5g of sodium sulfate, 5g of calcium chloride, 2.5g of polyacrylamide with an auxiliary agent A molecular weight of 200 ten thousand and 0.05g of amino trimethylene phosphonic acid with an auxiliary agent B molecular weight of 1000-5000.
The preparation method comprises the following steps:
(1) Preparing an auxiliary agent A solution: 250ml of ultrapure water is added into a beaker, 2.5g of auxiliary agent A guar gum is added while stirring, and the auxiliary agent A guar gum is fully dissolved to obtain solution A;
(2) Adding 0.05g of the auxiliary agent B polyaspartic acid into the solution A to obtain a solution B;
(3) Dissolving 5g of calcium chloride in the solution B, fully stirring for 10min, and fully dissolving to obtain a solution C;
(4) Dissolving 5g of sodium sulfate in the solution C, stirring for 10min, and dissolving to obtain the plugging agent
(5) The calcium salt crystal plugging agents are respectively placed in glass bottles with good sealing performance, then are respectively placed at 30-120 ℃ to simulate stratum environment conditions, and the growth characteristics of the Gao Wendu resistant agent are analyzed.
The plugging characteristics of the high temperature resistant plugging agent of the invention are analyzed by experiments as follows:
(1) Selecting two cores (phi 10cm multiplied by 2.5 cm) with similar permeability (640 mD and 590 mD), and vacuumizing the cores for about 8 hours;
(2) Weighing dry weight of the core, weighing wet weight after soaking to saturation, calculating pore volume of the core, and placing the core into a core holder;
(3) Water flooding is carried out at the speed of 1ml/min, and the permeability K is carried out according to the Darcy formula 0 Is calculated;
(4) Injecting the plugging agent sample 4 (the formula of the calcium salt crystal plugging agent is 1% polyacrylamide, 0.02% of amino trimethylene phosphonic acid, 2% of sodium sulfate and 2% of calcium chloride) into a rock core at the speed of 1ml/min by a single liquid method, wherein the injection amount is 1PV, and recording the pressure difference change at two ends of a rock core holder; then respectively placing the mixture in an incubator at 60 ℃ and 90 ℃ for standing for 2d;
(5) Performing water flooding at a speed of 1ml/min until the pressure is stable, and performing permeability K according to Darcy formula 1 Is calculated;
(6) According to (K0-K) 1 ) The blocking rate η is calculated as K1×100%.
By recording the pressure difference change in the whole water flooding process, the water flooding permeability after being stabilized for 2d at different temperatures is calculated, and the plugging rate of the plugging agent sample 4 is summarized in the following table.
| Water permeability measurement | Temperature (. Degree. C.) | Subsequent water drive permeability | Subsequent water flooding plugging rate | |
| Core 1 | 640mD | 60 | 2.98mD | 99.53 |
| Core 2 | 590mD | 90 | 1.35mD | 99.76 |
Experimental results and analysis
1. As can be seen from fig. 14, compared with the calcium carbonate plugging system of patent CN115058234A, the crystal morphology of the present sample 4 is mainly irregular needle-like. As the temperature increases, the amount of crystallization of the plugging agent sample 4 also increases significantly.
2. As can be seen from the infrared spectrum of fig. 15, the crystal obtained by growth of the plugging agent 4 is a standard calcium sulfate crystal.
3. The high permeability core plugging parameters at 60 ℃ and 90 ℃ are shown in the table, and when the temperature is increased, precipitation of calcium salt crystals is facilitated, the plugging effect is good, and the plugging agent sample 4 has good temperature resistance.
4. As can be seen from fig. 16 and 17, the salt crystals precipitated in the plugging agent sample 4 gradually stabilized at 1.14Mpa after the pressure was broken through at about 1.8Mpa at 60 ℃. After the temperature is about 90 ℃, the pressure breaks through 3.0MPa, the pressure has a descending trend, and the final pressure is stabilized at 2.5MPa, which indicates that the salt crystals precipitated by the plugging agent sample 4 of the invention have the processes of plugging, migration and re-plugging in a porous medium such as a rock core, which is beneficial to the plugging of the deep part of a stratum, and is the technical effect which cannot be achieved by the plugging agent with a granular suspension system in the prior art.
Tests show that the growth characteristics and the blocking characteristics of the high-temperature-resistant calcium salt crystal blocking agent prepared in the experimental examples 2-4 are similar to those of the high-temperature-resistant calcium salt crystal blocking agent prepared in the experimental example 1.
The above description is only of the preferred embodiment of the present invention, and is not intended to limit the present invention in any other way, but is intended to cover any modifications or equivalent variations according to the technical spirit of the present invention, which fall within the scope of the present invention as defined by the appended claims.
Claims (12)
1. The inorganic precipitation type plugging agent is characterized by comprising sodium sulfate, calcium chloride, an auxiliary agent A and an auxiliary agent B, wherein the auxiliary agent A is a tackifier, the auxiliary agent B is a scale inhibitor, no crystal is generated in the plugging agent at room temperature for 48 hours, the plugging agent is heated for 2-3d at 60-90 ℃, the mass precipitation rate is higher than 50%, and the plugging rate is higher than 98%.
2. The plugging agent according to claim 1, wherein the plugging agent comprises, based on the weight of the plugging agent, 1-2% of sodium sulfate, 1-2% of calcium chloride, 0.2-1% of auxiliary agent A, 0.002% -0.02% of auxiliary agent B, and the balance water.
3. The plugging agent according to claim 1, wherein the auxiliary agent a has a molecular weight of 10-200 ten thousand, and is any one or any combination of guar gum, polyacrylamide and welan gum.
4. The plugging agent according to claim 1, wherein the auxiliary agent B is any one or any combination of polyaspartic acid, aminotrimethylene phosphonic acid and phytic acid.
5. A process for the preparation of a plugging agent according to any one of claims 1 to 4, comprising the steps of:
(1) Preparing an auxiliary agent A solution: adding ultrapure water into a beaker, adding the auxiliary agent A while stirring, and fully dissolving to obtain a solution A;
(2) Adding the auxiliary agent B into the solution A to obtain a solution B;
(3) Dissolving calcium chloride in the solution B, and fully dissolving to obtain a solution C;
(4) And dissolving sodium sulfate in the solution C, and fully dissolving to obtain the plugging agent.
6. The method according to claim 5, wherein the addition amount of the auxiliary A of the solution A in the step (1) is calculated by adding 0.5 to 2.5g of the auxiliary A per 250ml of ultrapure water.
7. The process according to claim 5, wherein the addition amount of the auxiliary B in the solution B in the step (2) is calculated by adding 0.005g to 0.05g of the auxiliary B per 250ml of ultrapure water.
8. The method according to claim 5, wherein the calcium chloride is added to the solution C in the step (3) in an amount of 2.5 to 5g per 250ml of ultrapure water.
9. The method according to claim 5, wherein the sodium sulfate is added in the step (4) in an amount of 2.5 to 5g of sodium sulfate per 250ml of ultrapure water.
10. The method according to claim 5, wherein the stirring time in the step (1) is 1 to 1.5 hours.
11. The method according to claim 5, wherein the stirring time in the step (3) is 10 to 15 minutes.
12. The method according to claim 5, wherein the stirring time in the step (4) is 10 to 15 minutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310923207.5A CN116925716A (en) | 2023-07-26 | 2023-07-26 | High-temperature-resistant high-salt inorganic precipitation plugging agent and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310923207.5A CN116925716A (en) | 2023-07-26 | 2023-07-26 | High-temperature-resistant high-salt inorganic precipitation plugging agent and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116925716A true CN116925716A (en) | 2023-10-24 |
Family
ID=88393910
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310923207.5A Pending CN116925716A (en) | 2023-07-26 | 2023-07-26 | High-temperature-resistant high-salt inorganic precipitation plugging agent and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116925716A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5244043A (en) * | 1991-11-19 | 1993-09-14 | Chevron Research And Technology Company | Method for reducing the production of liquids from a gas well |
| RU2186940C2 (en) * | 2000-09-13 | 2002-08-10 | Закрытое акционерное общество "Технология-99" | Method of isolation of formation water-encroached parts |
| CN102797442A (en) * | 2011-05-27 | 2012-11-28 | 中国石油化工股份有限公司 | Deep fluid diversion method |
| CN108003855A (en) * | 2017-11-10 | 2018-05-08 | 中国石油大学(华东) | A kind of single-fluid process inorganic precipitation type blocking agent, Its Preparation Method And Use |
| CN108624310A (en) * | 2018-06-15 | 2018-10-09 | 吉林石油集团兴业石油化学技术服务有限公司 | A kind of single-fluid process silicate plugging agent and preparation method |
| WO2019086864A1 (en) * | 2017-10-31 | 2019-05-09 | Mostafa Eslam A Salam | A method for reducing water flow in a subterranean formation |
| US20200032126A1 (en) * | 2016-10-21 | 2020-01-30 | Halliburton Energy Services | CONSOLIDATION AND WELLBORE STRENGTH ENHANCEMENT WITH CaCO3 PRECIPITATION |
-
2023
- 2023-07-26 CN CN202310923207.5A patent/CN116925716A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5244043A (en) * | 1991-11-19 | 1993-09-14 | Chevron Research And Technology Company | Method for reducing the production of liquids from a gas well |
| RU2186940C2 (en) * | 2000-09-13 | 2002-08-10 | Закрытое акционерное общество "Технология-99" | Method of isolation of formation water-encroached parts |
| CN102797442A (en) * | 2011-05-27 | 2012-11-28 | 中国石油化工股份有限公司 | Deep fluid diversion method |
| US20200032126A1 (en) * | 2016-10-21 | 2020-01-30 | Halliburton Energy Services | CONSOLIDATION AND WELLBORE STRENGTH ENHANCEMENT WITH CaCO3 PRECIPITATION |
| WO2019086864A1 (en) * | 2017-10-31 | 2019-05-09 | Mostafa Eslam A Salam | A method for reducing water flow in a subterranean formation |
| CN108003855A (en) * | 2017-11-10 | 2018-05-08 | 中国石油大学(华东) | A kind of single-fluid process inorganic precipitation type blocking agent, Its Preparation Method And Use |
| CN108624310A (en) * | 2018-06-15 | 2018-10-09 | 吉林石油集团兴业石油化学技术服务有限公司 | A kind of single-fluid process silicate plugging agent and preparation method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2190942B1 (en) | Methods of using colloidal silica based gels | |
| CN106479465B (en) | Profile control water shutoff agent and preparation method and application thereof | |
| AU2013405891B2 (en) | A fiber suspending agent for lost-circulation materials | |
| US9771785B2 (en) | Methods for enhancing and maintaining fracture conductivity after fracturing shale formations without proppant placement | |
| US4332297A (en) | Selectively controlling fluid flow through the higher permeability zones of subterranean reservoirs | |
| US3817038A (en) | Method for heating a fluid | |
| CN104927805A (en) | High-density water-based drilling fluid applicable to continental deposit sensitive shale formation | |
| CN109294539B (en) | Fire flooding well environment-friendly channeling sealing agent and preparation method and application thereof | |
| CN102533240B (en) | High-temperature oil reservoir composite modifying and flooding agent and preparing method and application thereof | |
| CN109294541A (en) | Fire flooding well self-degradation temporary plugging agent and preparation method and application thereof | |
| CN104314540A (en) | Method for preventing and treating steam channeling of steam-injected oil reservoir | |
| CN101235182A (en) | Intramolecular Cr3+ cross-linked polymer gel and its preparation method | |
| CN112852398B (en) | High-temperature foam profile control agent for offshore heavy oil steam flooding and application thereof | |
| CA2754554A1 (en) | Process for producing mineral oil from underground mineral oil deposits | |
| US11459500B2 (en) | Foamed treatment fluids comprising nanoparticles | |
| US20120080187A1 (en) | Process for producing mineral oil from underground mineral oil deposits | |
| CN107556996B (en) | CO (carbon monoxide)2Response in-situ gel channeling sealing agent and preparation method and application thereof | |
| CN111087998A (en) | Slow-expansion particles and preparation method thereof | |
| CN111648741A (en) | Chemical flooding method for medium-permeability reservoir | |
| CN111087997A (en) | Method for blocking water in oil reservoir and oil well | |
| CN112442342B (en) | Using and maintaining method of upper stratum collapse-preventing drilling fluid | |
| Qing et al. | Study and application of gelled foam for in-depth water shutoff in a fractured oil reservoir | |
| CN118685158A (en) | A high-temperature and high-density silicate water-based drilling fluid | |
| CN116925716A (en) | High-temperature-resistant high-salt inorganic precipitation plugging agent and preparation method thereof | |
| CN102153994B (en) | High-temperature miscible phase temporary plugging channeling sealing agent and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |