CN113322053B - Temporary blocking steering system and preparation method thereof - Google Patents
Temporary blocking steering system and preparation method thereof Download PDFInfo
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- CN113322053B CN113322053B CN202110402499.9A CN202110402499A CN113322053B CN 113322053 B CN113322053 B CN 113322053B CN 202110402499 A CN202110402499 A CN 202110402499A CN 113322053 B CN113322053 B CN 113322053B
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- 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
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- 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
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- 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
- C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
- C09K2208/26—Gel breakers other than bacteria or enzymes
Abstract
The application discloses a temporary plugging steering system and a preparation method thereof, and belongs to the technical field of oil field fracturing. According to the temporary blocking steering system provided by the embodiment of the application, the temporary blocking steering agent of the system comprises acrylamide, acrylic acid, N-methylene bisacrylamide, N-hydroxymethyl acrylamide, Tween 80, sodium dodecyl sulfate and ethylene diamine tetraacetic acid disodium, and vinyl trimethoxy silane is introduced into a main chain by adding the vinyl trimethoxy silane, so that the generated temporary blocking steering agent has good elasticity, compressibility recovery and water absorption expansion performance. Therefore, when stress acts on the temporary plugging agent, the stress is forced to turn, so that the aim of temporary plugging turning is fulfilled; the temporary plugging steering system prepared according to the temporary plugging steering agent can also adapt to cracks of different shapes, thereby greatly improving the plugging steering effect.
Description
Technical Field
The application relates to the technical field of oil field fracturing. In particular to a temporary blocking steering system and a preparation method thereof.
Background
At present, a temporary plugging steering system is mainly adopted to temporarily plug old cracks in a stratum and open new cracks in the fracturing process of an oil field, so that the oil drainage area is enlarged and the oil production is improved. Wherein, the temporary blocking steering system mainly comprises a temporary blocking steering agent and carrier fluid.
The temporary plugging diversion agent in the temporary plugging diversion system used in the related technology is a particle type temporary plugging diversion agent, and the particle type temporary plugging diversion agent is prepared by crosslinking different materials to obtain high-viscosity crosslinking liquid, and then performing processes such as drying, shearing, granulating and the like. The carrying fluid is mainly clear water. When a crack is plugged, the particle type temporary plugging diversion agent is mixed with clean water and then pumped into a stratum through a pump truck to temporarily plug perforation holes.
However, most of the particle type temporary plugging diverter is rigid particles, has no elasticity and no deformability, and force acts on the rigid particles, so that the force cannot be effectively transferred, and the plugging diversion effect is poor.
Disclosure of Invention
The embodiment of the application provides a temporary plugging steering system and a preparation method thereof, which can improve the plugging steering effect. The specific technical scheme is as follows:
in one aspect, an embodiment of the present application provides a temporary plugging steering system, where the temporary plugging steering system includes: temporarily blocking the diverter and the carrier fluid;
the temporary blocking steering agent comprises the following components in percentage by mass:
10 to 13 percent of acrylamide, 0.5 to 1 percent of acrylic acid, 0.01 to 0.02 percent of N, N-methylene bisacrylamide, 0.005 to 0.01 percent of N-hydroxymethyl acrylamide, 1 to 1.5 percent of Tween 80, 0.1 to 0.2 percent of sodium dodecyl sulfate, 0.002 percent of disodium ethylene diamine tetraacetate, 3 to 5 percent of vinyl trimethoxy silane and the balance of water.
In one possible implementation mode, the particle size of the temporary plugging diversion agent is 3-10 mm.
In one possible implementation, the carrier fluid includes: 0.6 percent of emulsion polymer, 0.6 to 0.7 percent of polyvinyl alcohol fiber and the balance of water;
the emulsion polymer comprises: an oil phase, a water phase and an alkaline regulator;
the oil phase comprises: white oil, span 80 and tween 80 in a mass ratio of 35:7: 1;
the aqueous phase comprises: 12 to 15 percent of acrylamide, 8 to 10 percent of acrylic acid, 5 to 7 percent of 2-acrylamide-2-methylpropanesulfonic acid, 1 to 3 percent of 12-allyloxy sodium dodecyl carboxylate and the balance of water;
the alkaline regulator is used for regulating the pH value of the hydrogen ion concentration index of the water phase to 6-8.
In a possible implementation manner, the mass fraction of the temporary plugging diversion agent is 5% -7%, and the balance is the carrier fluid.
In another possible implementation manner, the particle size of the temporary blocking diverting agent is 100-200 meshes.
In another possible implementation manner, the carrying fluid comprises the following components in percentage by mass: 0.4 to 0.55 percent of hydroxypropyl guar gum, 0.5 to 0.7 percent of alkaline regulator, 0.15 to 0.2 percent of buffer solution, 0.003 to 0.005 percent of gel breaker and the balance of water.
In another possible implementation manner, the alkaline regulator is a sodium hydroxide solution or a potassium hydroxide solution with the mass fraction of 15% -20%;
the buffer solution is a sodium carbonate solution;
the gel breaker is ammonium persulfate or potassium persulfate.
In another possible implementation manner, the temporary blocking steering system further includes: ceramsite of 70-140 meshes;
the mass fraction of the temporary plugging diverter is 3-8%, the mass fraction of the ceramsite is 6-8%, and the balance is the carrying fluid.
In another aspect, an embodiment of the present application provides a method for preparing a temporary blocking steering system, where the method includes:
according to the mass fraction of each component, dissolving acrylamide, acrylic acid, N-methylene bisacrylamide, N-hydroxymethyl acrylamide, tween 80, sodium dodecyl sulfate and disodium ethylene diamine tetraacetate into water;
adding vinyl trimethoxy silane into the water, emulsifying and dispersing for a first preset time, introducing nitrogen for a second preset time, adding 0.02% of ammonium persulfate and 0.02% of sodium bisulfite respectively, introducing nitrogen for a third preset time, heating to a first preset temperature, carrying out polymerization reaction at the first preset temperature, and reacting for 4-6 hours to obtain a copolymerization product;
granulating and drying the copolymerization product to obtain a temporary blocking steering agent;
and adding the temporary plugging diverting agent into the carrier fluid, and fully stirring to obtain a temporary plugging diverting system.
In one possible implementation, the preparation method of the carrier fluid comprises:
preparing white oil, span 80 and tween 80 in a first container according to the mass ratio of 35:7:1, and stirring at the speed of 1000r/min to uniformly mix the white oil, the span 80 and the tween 80 to obtain an oil phase;
sequentially adding acrylamide, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and 12-allyloxy sodium dodecyl carboxylate into water according to the mass fraction of each component, and fully stirring and dissolving to obtain a water phase;
adjusting the pH value of the water phase to 6-8 by using an alkaline regulator, emulsifying the oil phase and the water phase for a fourth preset time, introducing nitrogen for a fifth preset time, respectively adding 0.05-0.2% of sodium bisulfite and 0.05-0.2% of ammonium persulfate, initiating reaction between the sodium bisulfite and the sodium persulfate, and reacting for 4-8 hours at 70-80 ℃ to obtain an emulsion polymer;
adding 0.6% of the emulsion polymer and 0.6% -0.7% of polyvinyl alcohol fiber into water to obtain the carrying fluid.
The technical scheme provided by the embodiment of the application has the following beneficial effects:
the temporary blocking steering system provided by the embodiment of the application comprises a temporary blocking steering agent of the system, wherein the temporary blocking steering agent comprises acrylamide, acrylic acid, N-methylene bisacrylamide, N-hydroxymethyl acrylamide, Tween 80, sodium dodecyl sulfate and ethylene diamine tetraacetic acid disodium, and vinyl trimethoxy silane is introduced into a main chain by adding the vinyl trimethoxy silane, so that the temporary blocking steering agent has very strong elasticity and strong deformability, and is not easy to lose water and is structurally damaged even under the action of high pressure. Therefore, the temporary plugging steering system prepared according to the temporary plugging steering agent has stronger steering capacity, thereby improving the plugging steering effect.
Drawings
FIG. 1 is a schematic illustration of a product of copolymerization provided in the examples herein, being capable of stretching deformation;
FIG. 2 is a schematic illustration of a particulate diverting agent of various shapes and sizes provided in accordance with an embodiment of the present application;
FIG. 3 is a schematic diagram of the displacement pressure and flow rate changes during the anti-compression experiment of the particulate diverting agent provided by the embodiment of the present application;
FIG. 4 is a schematic diagram of a displacement pressure change during a compression test of a powder temporary plugging diverting agent provided by an embodiment of the application;
FIG. 5 is a schematic illustration of a powder diverting agent solidified from a powder into a filter cake according to embodiments of the present application;
FIG. 6 is a construction graph of a particle temporary plugging diverting agent applied between horizontal well clusters according to the embodiment of the application;
FIG. 7 is a schematic illustration of pressure and displacement changes as particulate diverting agent is pumped into a horizontal well according to embodiments of the present application;
FIG. 8 is a schematic illustration of the pressure and displacement changes during pumping of a particulate diverting agent into a directional well according to embodiments of the present application;
FIG. 9 is a graph of a construction profile for a directional well using a particulate diverting agent according to an embodiment of the present application.
Detailed Description
In order to make the technical solutions and advantages of the present application more clear, the following describes the embodiments of the present application in further detail.
The embodiment of the application provides a temporary blocking steering system, and the temporary blocking steering system comprises: temporarily blocking the diverter and the carrier fluid;
the temporary blocking steering agent comprises the following components in percentage by mass:
10 to 13 percent of acrylamide, 0.5 to 1 percent of acrylic acid, 0.01 to 0.02 percent of N, N-methylene bisacrylamide, 0.005 to 0.01 percent of N-hydroxymethyl acrylamide, 1 to 1.5 percent of Tween 80, 0.1 to 0.2 percent of sodium dodecyl sulfate, 0.002 percent of disodium ethylene diamine tetraacetate, 3 to 5 percent of vinyl trimethoxy silane and the balance of water.
According to the temporary blocking steering system provided by the embodiment of the application, the temporary blocking steering agent of the system comprises acrylamide, acrylic acid, N-methylene bisacrylamide, N-hydroxymethyl acrylamide, Tween 80, sodium dodecyl sulfate and ethylene diamine tetraacetic acid disodium, and vinyl trimethoxy silane is added to react with the comonomer and is introduced into a main chain, so that the temporary blocking steering agent has strong elasticity and strong deformability, and is not easy to lose water and is structurally damaged even under the action of high pressure. Therefore, the temporary plugging steering system prepared according to the temporary plugging steering agent has stronger steering capacity, thereby improving the plugging steering effect. In addition, the temporary plugging steering agent has adjustable water absorption expansion performance, so that the temporary plugging steering system can adapt to cracks of different shapes, and the plugging steering effect is further improved.
In the present embodiment, the mass fraction of acrylamide may be 10%, 11%, 11.5%, 12%, 12.5% and 13%, the mass fraction of acrylic acid may be 0.5%, 0.6%, 0.7%, 0.8%, 0.9% and 1%, the mass fraction of N, N-methylene bisacrylamide may be 0.01%, 0.015%, 0.02%, the mass fraction of N-methylolacrylamide may be 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, the mass fraction of tween 80 may be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, the mass fraction of sodium dodecylsulfonate may be 0.1%, 0.11%, 0.13%, 0.15%, 0.18%, 0.2%, the mass fraction of vinyltrimethoxysilane may be 3%, 3.5%, 3.8%, 4%, 4.5%, 4.8%, 5%.
Introduction of temporary blocking diverter and carrier fluid: in the embodiment of the application, the particle size of the temporary plugging diverting agent can be set and changed according to the process requirements, for example, the temporary plugging diverting agent can be particle temporary plugging diverting agents with different particle sizes and different shapes, and can also be powder temporary plugging diverting agents with different mesh numbers.
In a possible implementation manner, when the temporary plugging diversion agent is a particle temporary plugging diversion agent, the particle size of the particle temporary plugging diversion agent can be 3-10 mm.
In the embodiment of the application, due to the introduction of the vinyltrimethoxysilane, the composite material has good elasticity and compressibility recovery in addition to the original advantage of rigid compression resistance. Because the particle temporary plugging diverter has good elasticity and compressibility recovery, when stress acts on the temporary plugging diverter, the stress is forced to divert, thereby achieving the purpose of temporary plugging diversion. The residual organosilicon monomer or self-assembly which is not entered into the main chain of the comonomer is highly dispersed in the polymer matrix and can play a role of hydrophobicity.
In the embodiment of the application, the particle temporary blocking diverting agent is a temporary blocking material which can expand when meeting water, the water absorption speed is adjustable, the water absorption expansion speed is increased along with the increase of the concentration of acrylamide, is increased along with the increase of the concentration of N, N-methylene-bisacrylamide and is increased along with the decrease of the concentration of vinyl trimethoxy silane. Therefore, the water absorption expansion speed can be adjusted by adjusting the concentration, namely the mass fraction, of the acrylamide, the N, N-methylene bisacrylamide and the vinyl trimethoxy silane, so as to adapt to the temporary plugging diversion fracturing under the conditions of different well depths, different temperatures, different pumping output capacities and different fracturing process requirements. The higher the temperature, the higher the water absorption expansion rate, and the lower the temperature, the lower the water absorption expansion rate. When the water absorption multiple is less than or equal to 20 times, the elasticity of the particle temporary blocking diverting agent is the highest; when the water absorption multiple is more than or equal to 20 times, the elasticity is reduced along with the increase of the expansion multiple, and the maximum water absorption multiple can reach 100 times. The particle temporary plugging steering agent can fill and fill cracks in various shapes without gaps in the process of water absorption and expansion, and is compounded with polyvinyl alcohol fibers, so that the crack and the hole are further filled due to strong flexibility and crimpness, and the plugging steering effect can be greatly improved.
In the embodiment of the application, the particle temporary blocking steering agent can resist high temperature, and can resist the temperature up to 160 ℃. In addition, the particle temporary plugging diversion agent can be degraded at high temperature, the degradation time can be adjusted by adjusting the mass fractions of acrylamide, acrylic acid, N-methylene bisacrylamide and N-hydroxymethyl acrylamide, and the content of insoluble substances in water after degradation is less than or equal to 1%, so that the particle temporary plugging diversion agent has no damage to cracks.
In the embodiment of the application, the particle temporary blocking steering agent can resist high pressure, and the maximum breakthrough pressure reaches 54 MPa.
For the particle temporary blocking diverter, the carrying fluid can be clear water or a liquid with certain viscosity, 1m 3 The carrying fluid can carry 5 to 7 mass percent of particle temporary plugging diverter. When the carrying fluid is a fluid with certain viscosity, the carrying fluid can be a mixture of emulsion polymer, polyvinyl alcohol fiber and water, wherein the mass fraction of the emulsion polymer is 0.6%, and the mass fraction of the polyvinyl alcohol fiber is 0.6% -0.7%. The fiber can physically suspend a certain amount of the particle temporary plugging diverting agent, is easy to degrade, has good softness and swelling performance, and cannot cause damage to a reservoir stratum.
In embodiments of the present application, the emulsion polymer comprises: an oil phase, a water phase and an alkaline regulator; the oil phase comprises: white oil, span 80 and tween 80 in a mass ratio of 35:7: 1; the aqueous phase comprises: 12 to 15 percent of acrylamide, 8 to 10 percent of acrylic acid, 5 to 7 percent of 2-acrylamide-2-methylpropanesulfonic acid, 1 to 3 percent of 12-allyloxy sodium dodecyl carboxylate and the balance of water; the alkaline regulator is used for regulating the pH value (Hydrogen ion concentration index) of the water phase to 6-8.
Wherein the span 80 is sorbitan fatty acid ester, and the tween 80 is polymerized by sorbitan monooleate and ethylene oxide.
It should be noted that when the steering agent is temporarily blocked by particles carried by clear water, the particles temporarily block the steering agent, and the particle size of the steering agent is large, so that the pump may be blocked during pumping by the pump truck, even the pump truck cannot work normally, and the fracturing construction is seriously affected. When the particle temporary plugging diverting agent is carried by the mixture of the emulsion polymer, the polyvinyl alcohol fiber and water, the hydrophobic functional monomer is introduced into the emulsion polymer, so that the apparent viscosity is not high, the viscoelasticity is good, the fluidity is good, and the particle temporary plugging diverting agent carried by the particle temporary plugging diverting agent is matched with the physical suspension performance of the polyvinyl alcohol fiber, so that the pump effect is not influenced, and the pump blockage and the damage to a pump head can be avoided when the particle temporary plugging diverting agent passes through a pump truck. Moreover, the emulsion polymer is prepared by clear water, swelling is not needed, the emulsion polymer can be used after being prepared, the adhesion can be quickly realized, the working procedure is simple and convenient, and the field operability is strong.
In a possible implementation manner, when the temporary blocking diverting agent is a powder temporary blocking diverting agent, the particle size of the powder temporary blocking diverting agent can be 100-200 meshes. Compared with the particle temporary blocking diverting agent, the powder temporary blocking diverting agent and the particle temporary blocking diverting agent are different mainly in particle size and similar in other properties.
For powdered temporary blocking diverters, the carrier fluid in the temporary blocking diverting system may be an alkaline carrier fluid. The alkaline carrying fluid comprises the following components in percentage by mass: 0.4 to 0.55 percent of hydroxypropyl guar gum, 0.5 to 0.7 percent of alkaline regulator, 0.15 to 0.2 percent of buffer solution, 0.003 to 0.005 percent of gel breaker and the balance of water. Wherein the alkaline regulator is a sodium hydroxide solution or a potassium hydroxide solution with the mass fraction of 15-20%, the buffer solution is a sodium carbonate solution, and the gel breaker is ammonium persulfate or potassium persulfate.
In the embodiment of the present application, when the temporary plugging diversion agent is a powder temporary plugging diversion agent, the temporary plugging diversion system further includes: the proppant is 70-140 meshes of ceramsite; the mass fraction of the temporary plugging steering agent is 3-8%, the mass fraction of the ceramsite is 6-8%, and the balance is carrying fluid.
In the embodiment of the application, due to the introduction of the vinyltrimethoxysilane, the silicon-oxygen bonds in the vinyltrimethoxysilane can be subjected to condensation polymerization in the alkaline environment provided by the carrier fluid, so that the powder temporary plugging diversion agent can be completely dissolved in the carrier fluid. The carrier fluid after the powder temporary blocking diverter is dissolved can promote the powder temporary blocking diverter to be solidified to form a high-strength filter cake under the buffering and synergistic action of other additives in the carrier fluid at the temperature of over 60 ℃. The curing time can be adjusted within the range of 20-120 min according to the reservoir temperature, the pumping speed and the reservoir burial depth, and the curing speed is faster when the temperature is higher, so that the powder temporary plugging diverter can automatically form a filter cake under the reservoir condition that the temperature is higher than or equal to 60 ℃, the filter cake can be completely filled in natural cracks or old cracks as a whole, and the effective rate of plugging in the cracks and the possibility of forming branch cracks can be greatly improved.
It should be noted that the cake strength increases with increasing concentration of powder diverting agent and increases with increasing concentration of hydroxypropyl guar.
In summary, the particle size of the particle temporary plugging diversion agent provided by the embodiment of the application is large, and the particle temporary plugging diversion agent can be used as a seam temporary plugging diversion agent for plugging a seam opening, wherein the seam opening is a perforation hole, the average size of the general perforation hole is 7-12 mm, the hole density is 16 holes/meter, and the original hole is plugged, so that a new seam is cracked. The powder temporary plugging diversion agent has small particle size, is used for plugging natural fractures and branch fractures of fractures in the reservoir extension process, improves the net pressure of the fractures, complicates main fractures in the extension process, improves the fracture complexity and enlarges the swept volume of the fractures. Therefore, the temporary plugging diverter provided by the embodiment of the application can be used for plugging crack openings and also can be used for improving the complexity of main cracks in the reservoir, so that the exploitation degree of the reservoir is improved from the transverse direction and the longitudinal direction. In addition, the temporary plugging diverter is resistant to high temperature and high pressure, has high elasticity and high rigidity, is resistant to temperature, water absorption expansion and has adjustable degradation performance, so that the temporary plugging diverter can meet different requirements of well depth, well temperature and fracturing process, can greatly improve the effectiveness of temporary plugging diversion, is operable on site, is easy to degrade after fracturing, can greatly reduce construction risk, has small residue content, is harmless to cracks, and has wide application range.
The embodiment of the application provides a preparation method of a temporary blocking steering system, which comprises the following steps:
step 1: according to the mass fraction of each component, acrylamide, acrylic acid, N-methylene bisacrylamide, N-hydroxymethyl acrylamide, Tween 80, sodium dodecyl sulfate and disodium ethylene diamine tetraacetate are dissolved in water.
Wherein the water may be deionized water.
Step 2: adding vinyl trimethoxy silane into water, emulsifying and dispersing for a first preset time, introducing nitrogen for a second preset time, adding 0.02% of ammonium persulfate and 0.02% of sodium bisulfite respectively, introducing nitrogen for a third preset time, heating to a first preset temperature, carrying out polymerization reaction at the first preset temperature, and reacting for 4-6 hours to obtain a copolymerization product.
In this step, the first preset time, the second preset time and the third preset time may all be set and changed as needed, for example, the first preset time, the second preset time and the third preset time may all be 15 minutes. The first preset temperature can also be set and changed as required, for example, the first preset temperature can be 50-60 ℃. Correspondingly, the step can be: adding vinyl trimethoxy silane into water for dissolving the components, quickly stirring, emulsifying and dispersing for 15 minutes, introducing 15 minutes of nitrogen, respectively adding ammonium persulfate and sodium bisulfite, introducing 15 minutes of nitrogen, sealing, heating to 50-60 ℃ for micelle copolymerization, and reacting for 4-6 hours to obtain a copolymerization product.
Referring to fig. 1, the upper panel of fig. 1 is an original unstretched state after synthesis of a copolymerization product prepared by the above-described method, and the middle and lower panels of fig. 1 are schematic diagrams of stretching the copolymerization product, as can be seen from the middle and lower panels: the copolymerization product has larger elasticity and strong deformability, can be stretched by a longer multiple, and can be completely restored to the original shape after stress is relieved. Therefore, after the stress is pumped into a reservoir, when stress acts on the temporary plugging diverting agent, the stress can be transferred so as to achieve the purpose of forced diversion of the stress. In addition, the temporary plugging diverting agent can absorb water to expand and deform, so that the temporary plugging diverting agent can adapt to cracks with different shapes, and fills the cracks with different shapes, thereby improving the plugging diverting effect.
And step 3: and granulating and drying the copolymerization product to obtain the temporary blocking steering agent.
In the step, if the crack is plugged, the copolymerization product can be directly granulated and dried to obtain the temporary plugging diversion agent with particles of 3-10 mm and different particle sizes. Referring to fig. 2, fig. 2 shows the state of the copolymerization product after granulation and drying.
If the cracks in the storage layer are blocked, the copolymerization product can be granulated and dried, and then the operations such as crushing, sieving and the like can be carried out, so that the powder temporary blocking diverting agent with the particle size of 100-200 meshes is obtained.
And 4, step 4: and adding the temporary plugging diverting agent into the carrier fluid, and fully stirring to obtain a temporary plugging diverting system.
If the temporary plugging diversion agent prepared in the step 3 is a particle temporary plugging diversion agent, the carrier fluid in the step can be water, or the carrier fluid obtained by mixing emulsion polymer, polyvinyl alcohol fiber and water.
The preparation method of the carrier fluid obtained by mixing the emulsion polymer, the polyvinyl alcohol fiber and water comprises the following steps:
step 4-1: preparing white oil, span 80 and tween 80 in a first container according to the mass ratio of 35:7:1, and stirring at the speed of 1000r/min to uniformly mix the white oil, the span 80 and the tween 80 to obtain an oil phase.
In this step, the first container may be a beaker, and the size of the beaker may be selected as required.
Step 4-2: according to the mass fraction of each component, acrylamide, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and 12-allyloxy sodium dodecyl carboxylate are sequentially added into water, and fully stirred and dissolved to obtain a water phase.
In the step, the mass fraction of acrylamide is 12-15%, the mass fraction of acrylic acid is 8-10%, the mass fraction of 2-acrylamide-2-methylpropanesulfonic acid is 5-7%, and the mass fraction of 12-allyloxy sodium dodecyl carboxylate is 1-3%.
Step 4-3: adjusting the pH value of the water phase to 6-8 by using an alkaline regulator, emulsifying the oil phase and the water phase for a fourth preset time, adding 0.05-0.2% of sodium bisulfite and 0.05-0.2% of ammonium persulfate respectively by using nitrogen for a fifth preset time, initiating a reaction by using the sodium bisulfite and the sodium persulfate, and reacting for 4-8 hours at 70-80 ℃ to obtain the emulsion polymer.
The alkaline regulator can be sodium hydroxide solution or potassium hydroxide solution. The fourth preset time and the fifth preset time may be set and changed as needed, for example, the fourth preset time may be 5 minutes, and the fifth preset time may be 1 hour.
Step 4-4: adding 0.6% of emulsion polymer and 0.6% -0.7% of polymer fiber into water to obtain the carrying fluid.
If the temporary plugging diversion agent prepared in the step 3 is a powder temporary plugging diversion agent, the carrier fluid in the step can be alkaline carrier fluid, and the preparation method of the alkaline carrier fluid comprises the following steps: adding 0.4-0.55% of hydroxypropyl guar gum, 0.5-0.7% of alkaline regulator, 0.15-0.2% of buffer solution and 0.003-0.005% of gel breaker into water, and uniformly stirring to obtain the alkaline carrier fluid.
In summary, the temporary plugging steering system provided by the embodiment of the application has the advantages of simple preparation method, good elasticity, adaptability to cracks of different shapes, good plugging steering effect and easiness in degradation.
The technical solution of the present application will be described in detail by specific examples below.
Example 1
This example is primarily an evaluation of the performance of a particulate diverting agent.
First, a particulate temporary blocking diverter is prepared.
The preparation method of the particle temporary plugging diversion agent comprises the following steps: completely dissolving 10% of acrylamide, 0.8% of acrylic acid, 0.015% of N, N-methylene bisacrylamide, 0.005% of N-hydroxymethyl acrylamide, 1% of Tween 80, 0.15% of sodium dodecyl sulfate and 0.002% of disodium ethylene diamine tetraacetate into deionized water, adding 3% of vinyl trimethoxy silane into the solution, quickly stirring, emulsifying and dispersing for 15 minutes, introducing nitrogen for 15 minutes, respectively adding 0.02% of ammonium persulfate and 0.02% of sodium bisulfite, introducing nitrogen for 15 minutes, heating to 50-60 ℃ for micelle copolymerization, and reacting for 4-6 hours to obtain a copolymerization product. Uniaxial rock mechanics experiments are carried out on the copolymerization product, and the elastic modulus of 80MPa and the Poisson ratio of 0.48 are obtained through a stress-strain curve, which shows that the copolymerization product has stronger elastic deformation capability.
And granulating and drying the copolymerization product to obtain the particle temporary plugging diverter with different particle sizes of 3-10 mm and different shapes.
Second, the water swelling property of the particulate temporary plugging diverting agent was evaluated.
The particle temporary plugging diverter is put into water, can absorb water to expand, takes the reservoir temperature of 120 ℃ as an example, and adopts the low discharge capacity of 1-1.5 m 3 The particle temporary plugging diversion agent is pumped in per minute, the outer diameter of an oil pipe is 88.9mm, the wall thickness is 6.45mm, the buried depth of a reservoir is 3500m, the average temperature of a shaft is about 80 ℃, the time for reaching a target layer is about 18-20 min, and the particle temporary plugging diversion agent can linearly expand by 5-6 times.
And thirdly, filling the particle temporary plugging diverting agent in the simulated crack by adopting a multifunctional chemical core physical simulation system, and evaluating the compression resistance of the particle temporary plugging diverting agent.
The core model was a sand-filled pipe to simulate fractures in the reservoir, the sand-filled pipe having a diameter of 8cm and a length of 20 cm. The experimental temperature was set at 90 ℃, the displacement was performed with clean water at a flow rate of 0.2ml/min, and the effluent was collected with a balance. The lower layer of the sand filling pipe is made of 70-140 meshes of quartz sand, the thickness of the sand filling pipe is 5cm, in the sand filling process, a jack is used for compacting, the compacting pressure is 15MPa, and the holding time is 20 min. Adding the particle temporary plugging diverting agent into the upper layer of the sand filling pipe, wherein the thickness is 10cm, screwing the cover, putting the cover into the core holder, and slowly injecting clear water. With the injection of clear water, the particles temporarily block the diversion agent to absorb water and expand, and gradually fill the sand filling pipe.
The change in displacement pressure and flow during this experiment can be seen in figure 3. As can be seen in fig. 3: the displacement pressure is gradually increased along with the time, and the flow is gradually kept stable, which shows that the particles temporarily block the diverting agent to block the whole sand-filled pipe, so that the displacement pressure is increased sharply.
Fourth, the degradability of the particulate temporary plugging diverter in the presence of water was evaluated.
When the dosage of the gel breaker is 0.01 percent, the particle can be completely degraded after temporarily blocking the diverter for 24 hours at the temperature of 90 ℃. When the dosage of the gel breaker is 0.005 percent, the gel breaker can be completely degraded within 20 hours at 120 ℃, the viscosity after degradation is less than or equal to 3 mPa.s, and the solid phase content after degradation is less than 1 percent. When the dosage of the gel breaker is 0.005 percent, the gel breaker can be completely degraded within 5 hours at the temperature of 130 ℃, the viscosity after degradation is less than or equal to 3 mPa.s, and the solid phase content after degradation is less than 1 percent. And (3) adding no gel breaker, and completely degrading at 120 ℃ for 28 hours, wherein the viscosity after degradation is less than or equal to 3mPa & s, and the solid phase content after degradation is less than 1%.
The evaluation of the high-temperature degradation performance shows that: this stifled steering agent temporarily easily degrades because seam temporary closure turns to fracturing and generally all can cooperate mechanical partial pressure to implement together, on the work progress, can appear in the pump income temporary closure steering agent's in-process unavoidably, can block on supporting tools such as packer, hydraulic anchor, results in the tubular column can not play out smoothly, causes the construction accident, adopts the stifled steering agent temporarily of easy degradation risk that can greatly reduced be under construction on the one hand, and on the other hand can not cause the injury to the stratum.
Example 2
This example evaluates the performance of a powder blocking diverter.
First, a powder temporary blocking diverter was prepared.
The particle size of the powder temporary plugging diversion agent is 100-200 meshes, and the preparation method of the powder temporary plugging diversion agent is similar to that of the particle temporary plugging diversion agent in the embodiment 1, and is not repeated herein.
Secondly, the powder temporary blocking diverter can be dissolved in alkaline carrier fluid and can be automatically solidified into filter cakes after 20min at the temperature of 100 ℃.
And thirdly, filling the powder temporary plugging diverting agent in the simulated crack by adopting a multifunctional chemical core physical simulation system, and evaluating the compression resistance of the powder temporary plugging diverting agent.
The core model is a sand filling pipe, the diameter of the sand filling pipe is 8cm, and the length of the sand filling pipe is 20 cm. The experimental temperature is set to be 90 ℃, the lower layer of the sand filling pipe is made of 70-140 meshes of quartz sand, the sand filling thickness is 5cm, in the sand filling process, a jack is used for compacting, the compacting pressure is 15MPa, and the holding time is 20 min. Adding the powder temporary plugging diverting agent into the upper layer of the sand filling pipe, wherein the thickness is 5cm, screwing the cover, and vertically placing the sand filling pipe into the core holder. Slowly adding 0.5% hydroxypropyl guar gum into 1000mL clear water, stirring until the mixture becomes sticky, adding 0.5% sodium hydroxide and 0.18% sodium carbonate, and adding the prepared carrying fluid into an intermediate container for later use. Then displaced by the carrier fluid at a flow rate of 0.2mL/min, and as the displacement process proceeded, the powder diverting agent dissolved in the carrier fluid, slowly solidified to form a filter cake, and the pressure rose. The change in displacement pressure during this experiment can be seen in figure 4. The schematic diagram of the powder temporary plugging diversion agent solidified from powder into filter cake can be seen in fig. 5.
Fourth, the degradability of the powder temporary plugging diverting agent was evaluated.
When the dosage of the gel breaker is 0.003 percent, the gel can be completely broken in 90min at the temperature of 90 ℃, and the viscosity after gel breaking is less than or equal to 3mPa & s. And meanwhile, the easily degradable temporary blocking steering agent is adopted, so that the risk of constructing a pipe clamping column can be greatly reduced on one hand, and the reservoir can not be damaged on the other hand.
Example 3
This example evaluates a temporary block steering system consisting of a mixture of emulsion polymer, polymer fiber and water as the carrier fluid with a particulate temporary block steering agent.
First, the pumping condition of the temporary steering system is evaluated.
Pumping into a sand mixing tank for 1.5m 3 Pouring 9kg of emulsion polymer with the apparent viscosity of 40mPa & s into clean water while stirring, pouring 5kg of polymer fiber during stirring, adding 100kg of particle temporary blocking diverting agent, pouring 5kg of polymer fiber, and stirring for more than 10 min. At a discharge capacity of 0.8m 3 And/min, pumping the liquid in the sand mixing tank into a target layer, and keeping the pressure and the discharge capacity stable in the pumping process, which shows that the particle temporary plugging diverting agent is smooth when passing through a pump head, and the pump efficiency is not influenced and the pump blockage phenomenon is not caused.
And secondly, evaluating the application of the temporary blocking steering system in temporary blocking steering between horizontal well clusters.
After the mixture of emulsion polymer, polymer fiber and water is used as carrier fluid to be pumped into the particle temporary plugging diversion agent among clusters of the GXX horizontal well, the casing pressure rises by 17MPa, the first cluster fracture pressure is 62MPa, and the second cluster fracture pressure is 66MPa, which shows that the diversion occurs among the clusters, and a new crack is opened, and the method is shown in figure 6. And a mixture of emulsion polymer, polymer fiber and water is used as carrier fluid to pump the particle temporary plugging diverter, and the pressure and the displacement are kept balanced, as shown in figure 7. The well is divided into 3 sections and 8 clusters of fracturing production, and the daily production fluid at the initial stage is 47.6m 3 35.1t of daily oil, and 26 percent of water; the daily fluid production is 32.5m 3 19.6t of daily oil, 40 percent of water and 4500t of accumulative oil which has effect for 203 days.
And thirdly, evaluating the application of the temporary blocking steering system in a water injection well.
An interlayer steering field test is carried out in an LXX well of a water injection well (a directional well), reservoirs No. 179, No. 180 and No. 181 are fractured, and the permeability difference of the reservoirs No. 179, No. 180 and No. 181 is large, the shale content of the reservoir No. 181 is high and is about 39%, and the fracturing is not easy to occur. In order to realize uniform reconstruction of No. 179-181 reservoir and implement the diversion fracturing, a mixture of emulsion polymer, polymer fiber and water is used as a carrier fluid, 150kg of particle temporary plugging diversion agent is carried, 5kg of polymer fiber is carried, and the construction pressure and the discharge capacity are stable in the process of injecting the particle temporary plugging diversion agent, as shown in FIG. 8. After the particle temporary plugging diverting agent is pumped, the pressure is increased by 22MPa, the first layer rupture pressure is 65MPa, and the pump stopping pressure is 28.43 MPa; the second layer rupture pressure is 60MPa, the pump stopping pressure is 17.85MPa, and the two completely different construction parameters are known as follows: after the diversion is temporarily blocked, the new reservoir is opened longitudinally as shown in fig. 9. The pressure of water injected before the pressure is 11.5MPa, and the daily water injection is 50m 3 After pressing, the oil pressure of bottom pouring water is 10.2MPa, and water is injected into the water tank for 110m 3 The accumulated augmented injection is 1.2 ten thousand square, the effect is achieved for 197 days, the effect is continuously achieved, 3 layers of the water absorption profile measured before pressing do not absorb water due to the difference of physical properties, the water absorption profile measured after pressing and water absorption of No. 180 and No. 181 are achieved, the feasibility of interlayer turning fracturing is effectively demonstrated, the water absorption profile is effectively improved, and the water driving degree is improved.
The above description is only for facilitating the understanding of the technical solutions of the present application by those skilled in the art, and is not intended to limit the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (8)
1. A temporary blocking steering system, comprising: temporarily blocking the diverter and the carrier fluid;
the temporary blocking steering agent comprises the following components in percentage by mass:
10% -13% of acrylamide, 0.5% -1% of acrylic acid, 0.01% -0.02% of N, N-methylene bisacrylamide, 0.005% -0.01% of N-hydroxymethyl acrylamide, 1% -1.5% of Tween 80, 0.1% -0.2% of sodium dodecyl sulfate, 0.002% of disodium ethylene diamine tetraacetate, 3% -5% of vinyl trimethoxy silane and the balance of water;
the preparation method of the temporary blocking steering system comprises the following steps:
according to the mass fraction of each component, dissolving acrylamide, acrylic acid, N-methylene bisacrylamide, N-hydroxymethyl acrylamide, tween 80, sodium dodecyl sulfate and disodium ethylene diamine tetraacetate into water;
adding vinyl trimethoxy silane into the water, emulsifying and dispersing for a first preset time, introducing nitrogen for a second preset time, adding 0.02% of ammonium persulfate and 0.02% of sodium bisulfite respectively, introducing nitrogen for a third preset time, heating to a first preset temperature, carrying out micelle polymerization at the first preset temperature, and reacting for 4-6 hours to obtain a copolymerization product;
granulating and drying the copolymerization product to obtain a temporary plugging diverting agent, wherein the temporary plugging diverting agent is a granular temporary plugging diverting agent or a powder temporary plugging diverting agent;
adding the temporary plugging diverting agent into a carrier fluid, and fully stirring to obtain a temporary plugging diverting system;
if the temporary plugging diverting agent is a particle temporary plugging diverting agent, the particle size of the particle temporary plugging diverting agent is 3-10 mm.
2. The temporary plugging diversion system of claim 1, wherein if said temporary plugging diversion agent is a particulate temporary plugging diversion agent, said carrier fluid comprises: 0.6% of emulsion polymer, 0.6-0.7% of polyvinyl alcohol fiber and the balance of water;
the emulsion polymer comprises: an oil phase, a water phase and an alkaline regulator;
the oil phase comprises: white oil, span 80 and tween 80 in a mass ratio of 35:7: 1;
the aqueous phase comprises: 12-15% of acrylamide, 8-10% of acrylic acid, 5-7% of 2-acrylamide-2-methylpropanesulfonic acid, 1-3% of sodium 12-allyloxy dodecyl carboxylate and the balance of water;
the alkaline regulator is used for regulating the pH value of the hydrogen ion concentration index of the water phase to 6-8.
3. The temporary plugging diversion system of claim 1, wherein said particulate temporary plugging diversion agent comprises a mass fraction of 5% to 7% and the balance of said carrier fluid.
4. The temporary plugging diverting system according to claim 1, wherein if said temporary plugging diverting agent is a powdered temporary plugging diverting agent, the particle size of said powdered temporary plugging diverting agent is 100-200 mesh.
5. The temporary plugging steering system of claim 4, wherein if said temporary plugging steering agent is a powdered temporary plugging steering agent, said carrier fluid comprises the following components in mass fraction:
0.4-0.55% of hydroxypropyl guar gum, 0.5-0.7% of alkaline regulator, 0.15-0.2% of buffer solution, 0.003-0.005% of gel breaker and the balance of water.
6. The temporary plugging steering system according to claim 5, wherein the alkaline modifier is 15-20% by mass of sodium hydroxide solution or potassium hydroxide solution;
the buffer solution is a sodium carbonate solution;
the gel breaker is ammonium persulfate or potassium persulfate.
7. The temporary plugging steering system of claim 5, further comprising: ceramsite of 70-140 meshes;
the mass fraction of the powder temporary plugging diversion agent is 3-8%, the mass fraction of the ceramsite is 6-8%, and the balance is the carrying fluid.
8. The temporary plugging diversion system of claim 2, wherein said carrier fluid is prepared by a method comprising:
preparing white oil, span 80 and tween 80 in a first container according to the mass ratio of 35:7:1, and stirring at the speed of 1000r/min to uniformly mix the white oil, the span 80 and the tween 80 to obtain an oil phase;
sequentially adding acrylamide, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and 12-allyloxy sodium dodecyl carboxylate into water according to the mass fraction of each component, and fully stirring and dissolving to obtain a water phase;
adjusting the pH value of the water phase to 6-8 by using an alkaline regulator, emulsifying the oil phase and the water phase for a fourth preset time, introducing nitrogen for a fifth preset time, respectively adding 0.05-0.2% of sodium bisulfite and 0.05-0.2% of ammonium persulfate, initiating reaction of the sodium bisulfite and the ammonium persulfate, and reacting for 4-8 hours at 70-80 ℃ to obtain an emulsion polymer;
and adding 0.6% of the emulsion polymer and 0.6% -0.7% of polyvinyl alcohol fiber into water to obtain the carrying fluid.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104861953A (en) * | 2015-04-17 | 2015-08-26 | 四川捷贝通能源科技有限公司 | Oil field fracture temporary plugging agent and preparation method thereof |
| CN106867487A (en) * | 2015-12-10 | 2017-06-20 | 中国石油天然气股份有限公司 | A kind of temporarily stifled diversion agent for reservoir reconstruction and preparation method thereof |
| CN111548779A (en) * | 2020-04-14 | 2020-08-18 | 中国石油化工股份有限公司 | Temporary plugging agent and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104861953A (en) * | 2015-04-17 | 2015-08-26 | 四川捷贝通能源科技有限公司 | Oil field fracture temporary plugging agent and preparation method thereof |
| CN106867487A (en) * | 2015-12-10 | 2017-06-20 | 中国石油天然气股份有限公司 | A kind of temporarily stifled diversion agent for reservoir reconstruction and preparation method thereof |
| CN111548779A (en) * | 2020-04-14 | 2020-08-18 | 中国石油化工股份有限公司 | Temporary plugging agent and preparation method thereof |
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