CN114075959A - Fracturing fluid pad fluid for reservoir pulse fracturing and application thereof - Google Patents
Fracturing fluid pad fluid for reservoir pulse fracturing and application thereof Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
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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
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/62—Compositions for forming crevices or fractures
- C09K8/66—Compositions based on water or polar solvents
- C09K8/68—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
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/62—Compositions for forming crevices or fractures
- C09K8/72—Eroding chemicals, e.g. acids
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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
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/62—Compositions for forming crevices or fractures
- C09K8/72—Eroding chemicals, e.g. acids
- C09K8/74—Eroding chemicals, e.g. acids combined with additives added for specific purposes
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- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Geochemistry & Mineralogy (AREA)
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Abstract
The invention provides a fracturing fluid pad fluid for reservoir pulse fracturing and application thereof. The pad fluid comprises the following components in parts by weight: 0-0.12 part of HPG hydroxypropyl guar gum, 1-2 parts of KCl, 12-26 parts of pulse fracturing composition and 100 parts of water; the pulse fracturing composition comprises at least one chemical agent capable of releasing gas under acidic conditions, and at least one slow-release acid; the mass ratio of the chemical reagent capable of releasing gas under acidic condition to the slow-release acid is 11: 2 to 22: 10. the technology enables the fracturing fluid to have the characteristic of secondary fracture formation, a chemical agent capable of delaying energy release is added into the fracturing pad fluid, the chemical agent is characterized in that the chemical agent can be controlled to react and delay energy release, the pumping rate and the construction pressure of the pad fluid are controlled according to the design requirements of a site fracturing process, and the chemical agent can be fractured along with the pad fluid in the fracturing process.
Description
Technical Field
The invention relates to the field of oil exploitation, in particular to a fracturing fluid pad fluid for reservoir pulse fracturing and application thereof.
Background
Along with the continuous use of unconventional reservoirs, the permeability of reservoirs facing oil and gas field development is lower and higher, the development difficulty is higher and higher, particularly for shale reservoirs, the permeability is as low as nanometer, the problem that low-permeability, particularly ultra-low-permeability reservoirs are difficult to use can be solved by the staged volume modification fracturing technology of large-scale horizontal wells, and the method is a technical core for realizing the economic and effective use of the unconventional reservoirs. The conventional hydraulic fracturing technology is to inject large-displacement fracturing fluid into a well under high pressure to fracture a stratum and establish a high-flow-guide channel, the conventional fracturing fluid is only carried into the stratum by pumping pressure drop energy, the fracturing fluid is quickly flowback after the stratum is fractured, the conventional large-scale horizontal well staged volume modification fracturing technology needs to face the technical problem of low flowback rate of the fracturing fluid after the fracturing, in the application process of unconventional reservoirs such as compact oil, shale gas and the like, the flowback rate after 1 month is only 10-15%, the flowback rate after the fracturing is not more than 50% and most of the fracturing fluid is sealed in a reservoir fracture network space, so that the technical problem which is always concerned by researchers in the industry is how to effectively utilize the part of the fracturing fluid, and by developing an induced fracturing method for releasing energy through a chemical agent to induce pulse in the fracture, the fracture can extend the fracture again or connect micro-fractures, the fracturing fluid may be caused to further promote fracture propagation within the fracture, as well as further promote fracture complication and fracture reticulation progression. The volume is reformed transform in the increase, links up more artifical cracks and natural fracture, increases oil gas seepage flow area, improves oil gas output by a wide margin, improves the oil gas recovery ratio.
The secondary opening technology of the crack belongs to the technical blank in the industry, and the repeated fracturing technology of the original old well only adopts the existing fracturing technology to inject fracturing fluid into the original interval at high pressure to carry out repeated fracturing transformation so as to obtain a new crack channel.
At present, an energy increasing chemical agent is used in an oil field for a heavy oil development thermal recovery technology and a low-pressure oil reservoir fracturing production increasing technology to increase the temperature and the liquid back drainage pressure in a shaft, and a secondary opening technology capable of realizing fractures in a fractured reservoir is not reported.
Disclosure of Invention
One object of the present invention is to provide a fracturing fluid pad for pulsed fracturing of a reservoir;
another object of the present invention is to provide a method of impulse fracturing a reservoir.
In order to achieve the above purpose, in one aspect, the invention provides a fracturing fluid pad fluid for pulsed fracturing of a reservoir, wherein the pad fluid comprises the following components in parts by weight: 0-0.12 part of HPG hydroxypropyl guar gum, 1-2 parts of KCl, 12-26 parts of pulse fracturing composition and 100 parts of water;
the pulse fracturing composition comprises at least one chemical agent capable of releasing gas under acidic conditions, and at least one slow-release acid; the mass ratio of the chemical reagent capable of releasing gas under acidic condition to the slow-release acid is 11: 2 to 22: 10.
according to some embodiments of the invention, the acidic condition is an acidic condition with a pH of less than 5.
The chemical agent capable of releasing a gas under acidic conditions may be a conventional chemical agent capable of reacting with an acid to release a gas, and according to some embodiments of the present invention, the chemical agent capable of releasing a gas under acidic conditions is selected from a carbonate, a bicarbonate, or a combination of chemical agents capable of releasing a gas under acidic conditions;
the chemical combination reagent is NaNO2And NH4A combination of Cl or a combination of chromium trioxide and glucose.
According to some of these specific embodiments of the present invention, wherein the carbonate is selected from sodium carbonate and/or potassium carbonate.
According to some specific embodiments of the invention, wherein the bicarbonate is selected from sodium bicarbonate and/or potassium bicarbonate.
According to some embodiments of the invention, wherein, NaNO2And NH4The mass ratio of Cl is (5-10): (5-10.6).
According to some embodiments of the invention, wherein, NaNO2And NH4The molar ratio of Cl is (1: 1) - (1: 1.2).
According to some embodiments of the invention, the molar ratio of chromium trioxide to glucose is (1: 2) - (1: 2.5).
According to some embodiments of the present invention, the pulse fracturing composition comprises the following components in parts by weight: 5-10 parts of NaNO26-12 parts of NH4Cl and 1-4 parts of slow-release acid.
NaNO contained in the fracturing fluid-containing pad fluid2And NH4Cl is a substance which can generate chemical reaction under acidic condition, and NaNO is generated under the condition that the pH value is lower than 52And NH4The Cl can react to form hydrogen and release heat,the reaction is followed by a decrease in pH and an increase in temperature.
According to some embodiments of the invention, the mass ratio of the chemical agent capable of releasing gas under acidic conditions and the slow-release acid is 11: 4 to 22: 1.
according to some embodiments of the invention, the mass ratio of the chemical agent capable of releasing gas under acidic conditions and the slow-release acid is 11: 2 to 11: 5.
according to some embodiments of the invention, the sustained release acid is comprised of a solid acid and a sustained release material.
According to some embodiments of the invention, the sustained release acid comprises a core layer consisting of a solid acid and a shell layer consisting of a sustained release material.
According to some embodiments of the invention, the mass ratio of the solid acid to the sustained-release substance is 10: 1 to 5: 1.
according to some embodiments of the invention, the solid acid is selected from hydrazine hydrochloride, citric acid and ethylenediamine tetraacetic acid.
According to some embodiments of the invention, wherein the slow release substance is selected from an inert wear destroying substance, or a water slow dissolving substance.
The water-slowly-soluble substance refers to a substance capable of slowly decomposing in water, which may be a substance capable of slowly decomposing in water, which is conventional in the art, and according to some embodiments of the present invention, the water-slowly-soluble substance is selected from one or more of acrylic resin (acrylic resin IV), ethyl cellulose, polyvinylpyrrolidone, and polyvinyl chloride.
The inert wear-out breaking substance is a substance which achieves a slow release effect by friction with the outside so as to gradually lose the substance, and can be an inert wear-out breaking substance which is conventional in the field, and according to some specific embodiments of the invention, the wear-out slow release substance is a mixture of talcum powder and chlorine partial emulsion.
According to some embodiments of the present invention, the mass-to-volume ratio of the talc powder to the chlorometaemulsion is 100 g: 600-; preferably 100 g: 800 ml.
The polyvinylidene chloride emulsion may be obtained commercially, such as a 40% strength polyvinylidene chloride emulsion.
It is understood that, in the preparation of the sustained-release acid, one skilled in the art can select a suitable sustained-release substance according to the form of the acid.
The main raw materials of the solid acid are white crystalline solid hydrochloric acid and hydrazine hydrochloride (a monohydrochloride), an inert film is wrapped outside the solid acid, and the inert film mainly comprises the following components: talc powder and vinylidene chloride emulsion.
According to some embodiments of the present invention, wherein the sustained release acid is prepared according to prior art film forming processes.
According to some embodiments of the invention, wherein the slow release acid is prepared by: at 35-45 deg.C, placing the granules of acid substance into boiling spray drying granulator, and introducing slow-release substance to obtain solid acid granules with delayed release of acidity.
According to some embodiments of the invention, wherein the slow release acid is prepared by: at the temperature of 35-45 ℃, the granules of the acid substance are put into a boiling spray drying granulator, and the mixed solution of talcum powder and metachloro-emulsion is introduced to prepare the solid acid granules capable of delaying the release of acidity.
The slow-release acid is a solid acid capable of delaying the release of acidic substances, and comprises the following components: the inner part mainly consists of hydrazine hydrochloride particles, the outer layer inert film mainly comprises talcum powder and chlorine meta-emulsion, the film coating process mainly adopts a boiling spray drying granulator, the temperature is set to be 35-45 ℃, firstly, a proper amount of hydrazine hydrochloride crystal particles are placed into the boiling spray drying granulator, the mixed liquid of the talcum powder and the chlorine meta-emulsion is slowly introduced under the boiling condition for 1 hour, and finally, solid acid particles capable of delaying release of acidity are prepared.
In another aspect, the invention also provides a reservoir pulse fracturing method, wherein the method comprises the step of reforming the reservoir by using the fracturing fluid pad fluid of any item of the invention when reforming the reservoir.
According to some specific embodiments of the invention, the method comprises injecting the fracturing fluid pad of any one of the embodiments of the invention into a formation during reservoir modification, and injecting the fracturing fluid after the fracturing fluid pad reaches a micro-fracture of the reservoir and a chemical reaction is carried out to generate gas.
According to some embodiments of the invention, the method comprises selecting the release-delaying substance according to the depth and location of the reservoir microfracture, such that when the front pad reaches the reservoir microfracture, the release-delaying acid releases acid which reacts with the chemical agent capable of releasing gas to generate gas.
According to some embodiments of the present invention, the method includes controlling the pumping rate and the construction pressure of the pad fluid, during the fracturing process, the chemical agent can enter the front end of the fracture and partially enter the reservoir matrix and the micro-fracture of the reservoir along with the pad fluid, controlling the reaction time of the chemical agent according to the time arrangement of the fracturing design, after the fracturing process, controlling the initiation of the chemical reaction, the chemical agent can rapidly release energy, the volume expansion increases the local pressure, the local stress field is changed, the fracture is further extended in a pulse mode, and a new fracture is generated.
In conclusion, the invention provides a fracturing fluid pad fluid for reservoir pulse fracturing and application thereof. The technical scheme of the invention has the following advantages:
the technology enables the fracturing fluid to have the characteristic of secondary fracture formation, a chemical agent capable of delaying energy release is added into the fracturing pad fluid, the chemical agent is characterized in that the chemical agent can be controlled to react and delay energy release, the pumping rate and the construction pressure of the pad fluid are controlled according to the design requirement of an on-site fracturing process, the chemical agent can enter the front end of a fracture and part of the fracture enters a reservoir matrix and a reservoir microcrack along with the pad fluid in the fracturing process, the reaction time of the chemical agent is controlled according to the time arrangement of fracturing design, the chemical reaction is controlled to start after fracturing, the chemical agent can rapidly release energy, the volume expands to increase the local pressure, a local stress field is changed, the fracture is further extended in a pulse mode, a new fracture is generated, the new fracture is communicated with a natural fracture, and the reconstruction volume is further increased. Therefore, the fracturing modification effect of an unconventional compact reservoir is improved, the oil and gas yield is increased, and the core recovery ratio can be improved by 10% by adopting the technology according to the verification of a core displacement experiment.
Drawings
FIG. 1 is a graph of the pressure change of the released energy of fracturing fluid in a chemically induced pulse fracturing method;
FIG. 2 is a graph showing the temperature change of the released energy of the fracturing fluid in the chemical induced pulse fracturing method;
FIG. 3 is a comparison diagram of a chemical induced pulse fracturing method and a conventional fracturing method comparing a rock mechanical fracture initiation mechanism.
Fig. 4 shows the imaging result of CT scan of core before reaction.
Fig. 5 shows that CT scan imaging of the core after the chemical reaction started produces a plurality of new microcracks.
Detailed Description
The following detailed description is provided for the purpose of illustrating the embodiments and the advantageous effects thereof, and is not intended to limit the scope of the present disclosure.
Example 1
The embodiment provides a chemical induction pulse fracturing method suitable for unconventional reservoir transformation, which mainly comprises the steps of adding a chemical agent capable of delaying energy release into a fracturing fluid pad fluid, wherein the pad fluid comprises the following raw materials in parts by mass:
0.12 part of HPG hydroxypropyl guar gum, 2 parts of KCl and 10 parts of NaNO212 parts of NH4Cl, 4 parts of slow-release acid and 100 parts of water.
The sustained-release acid in the embodiment comprises the following raw materials in parts by mass:
1 kg of hydrazine hydrochloride;
25g of talcum powder;
200ml of chlorine partial emulsion.
The hydrazine hydrochloride in this example was produced by Wuhan Co-creation science and technology, Inc., the product catalog number was 216194, and the polyvinylidene chloride emulsion was produced by Shanghai Tianyin Kogyo technology, Inc.
25g of talcum powder and 200ml of chlorine partial emulsion are mixed and stirred evenly to form mixed liquid.
A method of preparation comprising the steps of: putting hydrazine hydrochloride particles into a boiling spray drying granulator at the temperature of 35 ℃, keeping the boiling state, introducing mixed solution of 6.67ml/min of talcum powder and chlorometaemulsion into the boiling spray drying granulator, and after all mixed solution of the talcum powder and the chlorometaemulsion is completely injected, keeping the boiling state at the temperature of 35 ℃ and drying for 20min, and finally obtaining the solid slow-release acid particles capable of delaying release of acidity.
All the additives in the embodiment can not react with chemical agents in the fracturing process, after fracturing, the slow-release acid can release strong acid, and NaNO is generated in the acidic environment2And NH4Cl reacts rapidly, releasing a large amount of N2And the released gas can promote local pressure rise at the tail ends of the reservoir microfractures and the crude oil fractures, so that the fractures extend forwards again for opening, and new fractures can be generated at the same time.
Example 2
The embodiment provides a chemical induction pulse fracturing method suitable for unconventional reservoir transformation, which mainly comprises the steps of adding a chemical agent capable of delaying energy release into a fracturing fluid pad fluid, wherein the pad fluid comprises the following raw materials in parts by mass:
0.05 part of HPG hydroxypropyl guar gum, 1 part of KCl and 5 parts of NaNO27 parts of NH4Cl, 2 parts of slow-release acid and 100 parts of water.
All the additives in the embodiment can not react with chemical agents in the fracturing process, solid acid releases strong acid after fracturing, and NaNO is generated in an acid environment2And NH4Cl reacts rapidly, releasing a large amount of N2And the released gas can promote local pressure rise at the tail ends of the reservoir microfractures and the crude oil fractures, so that the fractures extend forwards again for opening, and new fractures can be generated at the same time.
Example 3
Pressure and temperature sensors are placed in a pressure-resistant container filled with the fracturing fluid pad fluid of example 1, pressure and temperature changes of the fracturing fluid pad fluid under closed and adiabatic conditions are tested, and the results are shown in figures 1 and 2, and it can be seen from experimental results that the fracturing fluid has no reaction within the first 2h, the temperature and the pressure are kept constant, and after 2h, the chemical reaction is rapidly started, heat is released, and the pressure is rapidly increased to 11.5 MPa.
Example 4
The pressure-resistant container filled with the fracturing fluid pad fluid of example 1 is used for a true triaxial rock mechanical fracture initiation performance analysis experiment, the experiment adopts the same experiment conditions, shale samples are adopted, and compared with a conventional fracturing fluid and a chemical induced pulse fracturing method for unconventional reservoir transformation, the experiment result is shown in figure 3, and compared with the conventional fracturing fluid (a and c in figure 3), the chemical induced pulse fracturing method for unconventional reservoir transformation (b and d in figure 3) can obtain more complex fractures. The chemical reaction is used for producing heat and gas and the local pressure capable of producing cracks around a shaft, the fracturing fluid containing the energizing chemical reactant is injected into a core sample of a slim hole, and the chemical reactant is mixed in the core sample, so that the chemical reaction is carried out to release heat and the gas pressure to produce large cracks. CT scan imaging of the core shows that effective cracks are formed in the pores of the core sample (see the results in figures 4 and 5)
Example 5
The embodiment provides a chemical induction pulse fracturing method suitable for unconventional reservoir transformation, which mainly comprises the steps of adding a chemical agent capable of delaying energy release into a fracturing fluid pad fluid, wherein the pad fluid comprises the following raw materials in parts by mass:
0.03 part of HPG hydroxypropyl guar gum, 1 part of KCl and 5 parts of NaNO27 parts of NH4Cl, 2 parts of ethylenediamine tetraacetic acid, 2 parts of citric acid and 100 parts of water.
The embodiment is used for the fracturing construction process with the stratum temperature exceeding 100 ℃, and because the added 2 parts of ethylenediamine tetraacetic acid and 2 parts of citric acid can not reduce the pH of the liquid to be below 5 to start chemical reaction to release gas and energy under the condition that the temperature is lower than 100 ℃, all additives are gasified in the fracturing processThe chemical agent can not react, and generally in the fracturing process that the formation temperature exceeds 100 ℃, after fracturing, along with the rise of the formation temperature, the temperature of the liquid retained in the formation gradually approaches to the formation temperature, so that the acidity of the ethylenediaminetetraacetic acid and the citric acid in the system is rapidly released, the pH of the liquid is rapidly reduced to be below 5, a chemical reaction is started, gas and energy are released, after fracturing, the acidic substance releases a strong acid, and NaNO in an acidic environment2And NH4Cl reacts rapidly, releasing a large amount of N2And the released gas can promote local pressure rise at the tail ends of the reservoir microfractures and the crude oil fractures, so that the fractures extend forwards again for opening, and new fractures can be generated at the same time.
Example 6
The technology enables the fracturing fluid to have the characteristic of secondary crack formation, the fracturing fluid preflush prepared in the embodiment 1 is adopted, an artificial rock core is selected, the data of the rock core are shown in a table 1, and the rock core is displaced by a conventional fracturing fluid gel breaking liquid without a chemical agent and the fracturing fluid gel breaking liquid in the embodiment 1.
The conventional fracturing fluid pad fluid and the fracturing fluid pad fluid prepared in example 1 were subjected to an oil displacement recovery test experiment, and two artificial cores with similar physical properties (the physical properties parameters are shown in table 1) were used, and the specific experimental method was as follows:
(1) firstly, respectively saturating the No. 1 rock core with water and oil (simulating the oil-water distribution under the formation condition);
(2) testing the oil-water distribution state by a nuclear magnetic resonance movable oil testing method;
(3) replacing the rock core with the fracturing fluid pre-fluid displacement, and calculating the oil extraction degree (namely the recovery ratio) of the fracturing fluid pre-fluid displacement;
(4) testing the oil-water distribution state by a nuclear magnetic resonance movable oil testing method;
(5) replacing and adopting the 2# rock core to repeat the displacement steps from (1) to (4), and calculating the extraction degree of the chemical pulse fracturing fluid;
(6) the nuclear magnetic resonance movable oil testing method tests the oil-water distribution state in the rock core.
Wherein, the nuclear magnetic resonance movable oil test method is shown in figure 4; the artificial core parameters and the two liquid displacement recovery results are shown in table 1:
TABLE 1 core data parameters
From table 1 and fig. 4, it can be seen that the addition of the chemical pulse fracturing fluid pad fluid is different from the conventional pad fluid, the chemical agent which can delay the release of energy and is contained in the fracturing fluid pad fluid, the agent is characterized in that the agent can control the chemical agent to react and delay the release of energy, the pumping rate and the construction pressure of the pad fluid are controlled according to the design requirements of the site fracturing technology, in the fracturing process, the chemical agent can enter the front end of the crack and part of the chemical agent enters the reservoir matrix and the reservoir microfracture along with the fracturing of the pad fluid, the reaction time of the chemical agent is controlled according to the time arrangement of fracturing design, after fracturing, chemical reaction is controlled to start, chemical agents can quickly release energy, volume expansion increases local pressure, local stress field is changed, further extending the fracture in a pulsed fashion and creating new fractures, communicating more natural fractures, further increasing the reconstruction volume. Therefore, the fracturing modification effect of an unconventional compact reservoir is improved, the oil and gas yield is increased, and the core recovery ratio can be improved by 10% by adopting the technology according to the verification of a core displacement experiment.
Claims (13)
1. The fracturing fluid pad fluid for the pulse fracturing of the reservoir comprises the following components in parts by weight: 0-0.12 part of HPG hydroxypropyl guar gum, 1-2 parts of KCl, 12-26 parts of pulse fracturing composition and 100 parts of water;
the pulse fracturing composition comprises at least one chemical agent capable of releasing gas under acidic conditions, and at least one slow-release acid; the mass ratio of the chemical reagent capable of releasing gas under acidic condition to the slow-release acid is 11: 2 to 22: 10.
2. the fracturing fluid pad of claim 1, wherein the acidic conditions are acidic conditions having a pH of less than 5.
3. The fracturing fluid pad of claim 1, wherein the chemical agent capable of releasing gas under acidic conditions is selected from a carbonate, a bicarbonate, or a combination of chemical agents capable of releasing gas under acidic conditions;
the chemical combination reagent is NaNO2And NH4A combination of Cl or a combination of chromium trioxide and glucose.
4. The fracturing fluid pad of claim 3, wherein the carbonate is selected from sodium carbonate and/or potassium carbonate; the bicarbonate is selected from sodium bicarbonate and/or potassium bicarbonate.
5. The fracturing fluid pad of claim 3, wherein NaNO2And NH4The molar ratio of Cl is (1: 1) - (1: 1.2); the molar ratio of chromium trioxide to glucose is (1: 2) - (1: 2.5).
6. The fracturing fluid pad of claim 1, wherein the pulse fracturing composition is comprised of, by weight: 5-10 parts of NaNO25-10.6 parts of NH4Cl and 1-4 parts of slow-release acid.
7. The fracturing fluid pad fluid of any one of claims 1 to 6, wherein the slow release acid is comprised of a solid acid and a slow release substance.
8. The fracturing fluid pad of claim 7, wherein the slow release acid comprises a core layer comprised of a solid acid and a shell layer comprised of a slow release substance.
9. The fracturing fluid pad of claim 7, wherein the solid acid is selected from a mixture of one or more of hydrazine hydrochloride, citric acid, or ethylenediaminetetraacetic acid.
10. The fracturing fluid pad of claim 8, wherein the slow release substance is selected from an inert wear-out-breaking substance or a water-slow dissolving substance.
11. The fracturing fluid pad of claim 10, wherein the inert wear-destroying substance is a mixture of talc and a chlorometaemulsion; the water slow-soluble substance is selected from one or more of acrylic resin, ethyl cellulose, polyvinylpyrrolidone and polyvinyl chloride.
12. A method of pulsed fracturing of a reservoir, wherein the method comprises using the fracturing fluid pad of any one of claims 1 to 11 to reform the reservoir.
13. The method according to claim 12, wherein the method comprises the steps of injecting the fracturing fluid pad fluid of any one of claims 1 to 11 into a stratum during reservoir modification, and injecting the fracturing fluid after the fracturing fluid pad fluid reaches a micro-crack of the reservoir and is subjected to chemical reaction to generate gas.
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| CN102676150A (en) * | 2012-05-28 | 2012-09-19 | 中国石油天然气股份有限公司 | Solid acid for acid fracturing capacity increasing revamping |
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| US20170369768A1 (en) * | 2016-06-24 | 2017-12-28 | Cleansorb Limited | Shale Treatment |
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| CN102676150A (en) * | 2012-05-28 | 2012-09-19 | 中国石油天然气股份有限公司 | Solid acid for acid fracturing capacity increasing revamping |
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