CN114085662A - Preparation method and application of chemical self-heating energizing fracturing fluid suitable for low-pressure low-permeability oil and gas reservoir - Google Patents
Preparation method and application of chemical self-heating energizing fracturing fluid suitable for low-pressure low-permeability oil and gas reservoir Download PDFInfo
- Publication number
- CN114085662A CN114085662A CN202111396370.8A CN202111396370A CN114085662A CN 114085662 A CN114085662 A CN 114085662A CN 202111396370 A CN202111396370 A CN 202111396370A CN 114085662 A CN114085662 A CN 114085662A
- Authority
- CN
- China
- Prior art keywords
- fracturing
- fracturing fluid
- self
- low
- solution
- 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
- 239000012530 fluid Substances 0.000 title claims abstract description 180
- 238000010438 heat treatment Methods 0.000 title claims abstract description 106
- 239000000126 substance Substances 0.000 title claims abstract description 36
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 238000000034 method Methods 0.000 claims abstract description 78
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 76
- 239000007788 liquid Substances 0.000 claims abstract description 46
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 40
- 238000002156 mixing Methods 0.000 claims abstract description 25
- 239000000654 additive Substances 0.000 claims abstract description 22
- 230000000996 additive effect Effects 0.000 claims abstract description 22
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims abstract description 19
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 11
- 235000019270 ammonium chloride Nutrition 0.000 claims abstract description 9
- 230000007797 corrosion Effects 0.000 claims abstract description 9
- 238000005260 corrosion Methods 0.000 claims abstract description 9
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Substances [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 claims abstract description 9
- 239000003112 inhibitor Substances 0.000 claims abstract description 8
- 239000003381 stabilizer Substances 0.000 claims abstract description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052742 iron Inorganic materials 0.000 claims abstract description 7
- -1 iron ion Chemical class 0.000 claims abstract description 7
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical group [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims description 78
- 229910001870 ammonium persulfate Inorganic materials 0.000 claims description 39
- 239000004576 sand Substances 0.000 claims description 31
- 238000005554 pickling Methods 0.000 claims description 7
- 239000012190 activator Substances 0.000 claims description 6
- 230000000844 anti-bacterial effect Effects 0.000 claims description 6
- 239000003899 bactericide agent Substances 0.000 claims description 6
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 239000000839 emulsion Substances 0.000 claims 2
- 238000004132 cross linking Methods 0.000 abstract description 18
- 238000006243 chemical reaction Methods 0.000 abstract description 13
- 230000008901 benefit Effects 0.000 abstract description 8
- 239000002131 composite material Substances 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 65
- 239000007789 gas Substances 0.000 description 52
- 239000003795 chemical substances by application Substances 0.000 description 48
- 238000010276 construction Methods 0.000 description 37
- 239000007864 aqueous solution Substances 0.000 description 34
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 31
- 230000008569 process Effects 0.000 description 28
- 238000012360 testing method Methods 0.000 description 28
- 239000002585 base Substances 0.000 description 26
- 239000000499 gel Substances 0.000 description 26
- 125000006850 spacer group Chemical group 0.000 description 14
- 230000000694 effects Effects 0.000 description 12
- 238000002347 injection Methods 0.000 description 12
- 239000007924 injection Substances 0.000 description 12
- 230000006378 damage Effects 0.000 description 11
- 239000002994 raw material Substances 0.000 description 11
- 239000004568 cement Substances 0.000 description 10
- 239000006260 foam Substances 0.000 description 10
- 238000007664 blowing Methods 0.000 description 9
- 239000003153 chemical reaction reagent Substances 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 9
- 230000001965 increasing effect Effects 0.000 description 9
- 238000005755 formation reaction Methods 0.000 description 8
- 239000002356 single layer Substances 0.000 description 8
- 239000000725 suspension Substances 0.000 description 8
- 238000011161 development Methods 0.000 description 6
- 238000002955 isolation Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 229920013818 hydroxypropyl guar gum Polymers 0.000 description 5
- 230000003068 static effect Effects 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 239000003054 catalyst Substances 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000003814 drug Substances 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 239000000706 filtrate Substances 0.000 description 3
- 230000020169 heat generation Effects 0.000 description 3
- 238000011065 in-situ storage Methods 0.000 description 3
- 235000015110 jellies Nutrition 0.000 description 3
- 239000008274 jelly Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 229910021538 borax Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 239000004328 sodium tetraborate Substances 0.000 description 2
- 235000010339 sodium tetraborate Nutrition 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- 229920002907 Guar gum Polymers 0.000 description 1
- 239000006004 Quartz sand Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- KHSLHYAUZSPBIU-UHFFFAOYSA-M benzododecinium bromide Chemical compound [Br-].CCCCCCCCCCCC[N+](C)(C)CC1=CC=CC=C1 KHSLHYAUZSPBIU-UHFFFAOYSA-M 0.000 description 1
- 239000013043 chemical agent Substances 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229910001447 ferric ion Inorganic materials 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000012065 filter cake Substances 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 239000000665 guar gum Substances 0.000 description 1
- 229960002154 guar gum Drugs 0.000 description 1
- 235000010417 guar gum Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 230000009545 invasion Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 235000010288 sodium nitrite Nutrition 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
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
- C09K8/60—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
- C09K8/665—Compositions based on water or polar solvents containing inorganic compounds
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
- E21B43/2405—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection in association with fracturing or crevice forming processes
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
- E21B43/2605—Methods for stimulating production by forming crevices or fractures using gas or liquefied gas
Abstract
A preparation method and application of a chemical self-heating energizing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir are disclosed, wherein ammonium chloride, hydrochloric acid, CF-5D (composite cleanup additive), an iron ion stabilizer and a corrosion inhibitor are mixed to prepare a solution A; adding NaNO2Mixing hydrochloric acid and CF-5D to prepare solution B; uniformly mixing the solution A and the solution B according to the volume ratio of 1:1-1:8, and then adding active water, a gel breaker and a crosslinking liquid to obtain a self-heating energy-increasing fracturing system; and introducing the self-heating energy-increasing fracturing system into the fracturing fluid under the formation condition to obtain the self-heating energy-increasing fracturing fluid. The fracturing fluid has the advantages of self-generation of gas, release of a large amount of reaction heat, realization of energizing fracturing and reinforced flowback. The reaction is easy to control, the reaction is rapid at the formation temperature, the fracturing fluid can be fully and effectively utilized, no harmful gas is generated, and the method is safeThe method is environment-friendly and has little influence on the reservoir in the near wellbore area.
Description
Technical Field
The invention belongs to the technical field of petrochemical industry, and particularly relates to a preparation method and application of a chemical self-heating energizing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir.
Background
The fracturing fluid is a working fluid in the process of modifying an oil-gas layer by hydraulic fracturing, provides a means of hydraulic fracturing construction operation, and plays the roles of transferring pressure, forming formation cracks, carrying a propping agent to go deep into artificial cracks, and after fracturing is completed, chemically decomposing or breaking glue to low viscosity, and ensuring that most of the fracturing fluid is returned to the ground to purify the cracks. The performance of fracturing fluid is an important factor related to success or failure of fracturing construction and influencing the yield-increasing effect after fracturing, so the improvement of the performance is a subject of research.
Along with the development of the petroleum industry, the development of the fracturing technology and the continuous deepening of the research on the fracturing mechanism, the types of the fracturing fluid are increased, particularly, the large-scale fracturing technology, the foam fracturing technology and the like have new requirements on a fracturing fluid system, and the new requirements have great promotion effects on the development of the fracturing fluid.
The oil fields at home and abroad are widely researched in the aspect of fracturing fluid technology, various fracturing fluid systems from initial thickened water fracturing fluid to later gel fracturing fluid, foam fracturing fluid, acid-based fracturing fluid, emulsified fracturing fluid, oil-based fracturing fluid, clean fracturing fluid and the like are developed, the problem of low recovery rate in oil-gas field development is solved, and the oil-gas-field fracturing fluid makes outstanding contribution to exploration, development and production increase and storage increase of the oil fields. The performance of various chemicals forming the fracturing fluid in the fracturing fluid technology is the key directly related to the economic benefit of the fracturing technology.
The fracturing fluid systems widely used at home and abroad can be divided into water-based fracturing fluid, foam fracturing fluid, oil-based fracturing fluid and emulsified fracturing fluid. It has the following disadvantages:
1. the biggest problems with water-based fracturing fluid systems are damage to water-sensitive formations and loss of conductivity due to residues, unbroken gel, filter cake, etc.
2. The oil-based fracturing fluid is mainly used for water-sensitive strata, the oil-based fracturing is an effective method for modifying low-permeability oil and gas wells, and the oil-based fracturing fluid has high viscosity and strong sand carrying capacity, is deeply concerned at home and abroad, and has great development in the aspects of research and application. However, the research on the oil-based fracturing fluid is limited to a certain extent because the technology is limited by factors such as the structure of the thickening agent, the properties of the oil-based fluid, construction conditions and the like.
3. The foam fracturing fluid has the advantages of low hydrostatic column pressure, small filtration loss, good sand carrying performance, strong drainage assisting capability, small damage to stratum and the like, so that the foam fracturing fluid is widely used as drilling fluid, completion fluid, fracturing fluid, gravel filling sand carrying fluid and the like of low-pressure low-permeability, leakage and water-sensitive stratum in various oil and gas fields in the world. However, the rheological properties of the foamed fracturing fluid cannot be measured accurately, and thus, in-situ quality control and pressure analysis are difficult.
4. The emulsified fracturing fluid is a fracturing fluid between water base and oil base, is suitable for oil wells, gas wells and compact sandstones, is good in fluid loss control, small in damage to stratums, high in sand carrying capacity, difficult to prepare and expensive.
At present, fracturing construction is an important measure for increasing yield of oil and gas fields, and conventional water-based fracturing fluid increases flowback capacity by taking thorough gel breaking as a means and reduces damage of the fracturing fluid to a reservoir. The method has the problems that for a low-pressure low-permeability reservoir, the more thorough the gel breaking of the fracturing fluid is in the fracturing modification process, the higher the possibility that the filtrate enters the reservoir to cause damage is. Meanwhile, because the stress sensitivity of the low-permeability reservoir is strong, after cold fluid enters the reservoir, the temperature of a zone near a crack is reduced, so that the permeability of the reservoir is reduced, the flow conductivity of the reservoir is reduced, the fracturing effect is delayed or the expected yield cannot be achieved, the defects of incomplete gel breaking, poor flowback capability and the like exist in the conventional water-based fracturing fluid adopted in the fracturing transformation process of a low-temperature, low-pressure and low-permeability oil-gas reservoir, the retention time of the fracturing fluid in the stratum is long, the filtration loss is increased, the damage is enhanced, the fracturing yield-increasing construction effect is poor, and the effective period is short. Therefore, the improvement of the low-temperature gel breaking and low-pressure flowback capability of the conventional water-based fracturing fluid becomes a key for improving the fracturing construction effect of the low-pressure low-permeability oil and gas reservoir.
Fracturing modification is the most main means for developing low-pressure and low-permeability oil and gas reservoirs, and the method is of great importance in reducing the damage of fracturing fluid to reservoir layers to the greatest extent in the fracturing operation process. Among the properties of fracturing fluids, low fluid loss, low residue, rapid flowback are the basis for low damage to the reservoir. For low pressure, low permeability reservoirs, pressureThe damage of the fracturing fluid to the oil-gas layer is not only the blockage of the pore space caused by residues after gel breaking, but also more importantly the water lock effect (especially a low-pressure and low-permeability oil-gas reservoir) caused by the invasion of the filtrate, thereby obviously reducing the seepage capability. In order to enlarge the application range of the water-based fracturing fluid and improve the application effect of the water-based fracturing fluid, compressible CO is added2、N2Gas such as LPG is dispersed into water-based fracturing fluid to form ground energizing foam fracturing fluid, but the fracturing fluid system has poor foam high-temperature stability, high friction resistance in the pumping and injecting process, CO2The corrosion to ground equipment and a pipe column is large, and the ground pumping equipment needs to be specially made.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a preparation method and application of a chemical self-heating energizing fracturing fluid suitable for a low-pressure low-permeability oil and gas reservoir.
In order to realize the purpose, the technical scheme of the invention is as follows:
a preparation method of a chemical self-heating energized fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir comprises the following steps:
mixing ammonium chloride with hydrochloric acid, a demulsification cleanup additive, an iron ion stabilizer and an IS-156 hydrochloric acid pickling corrosion inhibitor to prepare solution A;
adding NaNO2Mixing hydrochloric acid and demulsifying and cleanup additive to prepare solution B;
uniformly mixing the solution A and the solution B according to the volume ratio of 1:1-1:8 to obtain a fracturing pad fluid, and then adding a base fluid, active water and a gel breaker to obtain a self-heating energy-increasing fracturing system;
and introducing the self-heating energy-increasing fracturing system into the fracturing fluid under the formation condition to obtain the self-heating energy-increasing fracturing fluid.
Further, the mass percent of ammonium chloride in the solution A IS 10-20%, the mass percent of hydrochloric acid IS 0.6-1%, the mass percent of demulsification cleanup additive IS 0.5-1%, the mass percent of ferric ion stabilizer IS 0.1-0.2%, and the mass percent of IS-156 hydrochloric acid pickling corrosion inhibitor IS 0.01-0.02%.
Further, NaNO in the B liquid2The mass percent of the demulsifying and cleanup additive is 13-26%, and the mass percent of the demulsifying and cleanup additive is 0.5-1.0%.
Further, the mass fraction of hydrochloric acid was 31%.
The application method of the chemical self-heating energized fracturing fluid prepared according to the method comprises the following steps:
(1) injecting the liquid A and the liquid B into a shaft according to the volume ratio of 1:1-1:8, and mixing the liquid A and the liquid B at a well head to enter a stratum;
(2) then injecting active water, then constructing according to a fracturing procedure, and adding 10-15 Kg of a gel breaker before the sand adding is finished;
(3) replacing by adopting base liquid;
(4) and closing the well for 30 minutes, and then gradually releasing and spraying.
Furthermore, the active water is prepared by adding KCl and a demulsifying cleanup additive into water, wherein the mass concentration of the KCl is 1%, and the mass concentration of the CF-5D is 0.5%.
Further, the gel breaker is ammonium persulfate or potassium persulfate.
Furthermore, the dosage ratio of the solution A, the active water and the gel breaker is 5-10 m3：1～2m3：10～15Kg。
Further, the base fluid is prepared by adding HPG, KCl, a demulsification cleanup additive, a bactericide and a low-temperature gel breaking activator into water; wherein, the mass concentration of HPG is 0.25%, the mass concentration of KCl is 1.0%, the mass concentration of demulsification cleanup additive is 0.5%, the mass concentration of bactericide is 0.05%, and the mass concentration of low-temperature gel-breaking activator is 0.1%.
Compared with the prior art, the sodium nitrite and the ammonium chloride which have high heat generation and air release efficiency and are harmless to the stratum are selected as a heat generation pressurization system through screening, both have high solubility in water, and the reaction product sodium chloride is not only easy to dissolve in water, but also is nontoxic and harmless and does not harm the stratum. The volume of the self-heating energizing fracturing fluid gel can be expanded to more than 4-5 times within 1-2 hours at normal temperature and normal pressure, so that the density of the self-heating energizing fracturing fluid gel is reduced, and flowback is facilitated. The fracturing fluid has the advantages of self-generation of gas, release of a large amount of reaction heat, realization of energizing fracturing and reinforced flowback. The fracturing fluid is easy to control in reaction, rapid in reaction at the formation temperature, safe and environment-friendly, and has small influence on a reservoir layer in a near wellbore area, and the fracturing fluid can be fully and effectively utilized, no harmful gas is generated. Compared with the fracturing construction process accompanied by liquid nitrogen or liquid carbon dioxide injection, the autogenous gas heat agent energizing technology has the characteristics of no increase of original fracturing construction equipment (liquid nitrogen or carbon dioxide tank cars, booster pumps and auxiliary fracturing vehicles), no occupation of the original fracturing construction ground space, no change of the original fracturing construction ground equipment connection flow and construction process procedures, little economic investment, multiple functions, strong operability, simple and convenient process and the like, thereby being suitable for the fracturing energizing construction requirements of low-pressure and low-permeability gas reservoirs. The self-heating energizing fracturing fluid is simple in fluid preparation and convenient to construct, can be completely constructed by utilizing the conventional fracturing equipment, and is a novel fracturing fluid with ideal technical and economic comprehensive benefits. The fracturing fluid is automatically heated and pressurized, automatically reduces the density by in-situ foaming, has excellent gel breaking performance, sand carrying performance, filtrate loss reduction performance and drainage assisting performance, has the technical advantages of the foaming fracturing fluid and the economy of the conventional water-based fracturing fluid, and meets the requirements of the fracturing fluid of a low-pressure low-permeability oil-gas reservoir. The self-heating energizing fracturing fluid is a novel fracturing fluid between conventional water-based fracturing fluid and foam fracturing fluid, has the economy of the water-based fracturing fluid and many advantages of the foam fracturing fluid, improves the low-temperature gel breaking effect of the fracturing fluid, increases the flow-back energy of the fracturing fluid, and reduces the damage of the fracturing fluid to a reservoir.
Drawings
FIG. 1 is a figure of the morphology of the crosslinked jelly.
FIG. 2 is a structural view of a cross-linked system under a cryoelectron microscope.
FIG. 3 is a structural view of a cryo-electron microscope of the system after gel breaking.
FIG. 4 is a static sand suspension performance test chart.
Detailed Description
The present invention is further illustrated by, but is not limited to, the following specific examples.
A chemical self-heating energized fracturing fluid suitable for low pressure low permeability hydrocarbon reservoirs is prepared by the following processes: and introducing the self-heating energy-increasing fracturing system into the conventional fracturing fluid under the formation condition to obtain the self-heating energy-increasing fracturing fluid.
The two heat generating agents adopted by the invention are NaNO2And NH4And Cl, after the two heat generating agents are mutually dissolved in the aqueous solution, the two heat generating agents react in the presence of a catalyst to release a large amount of heat energy and gas.
The autogenous heat energized fracturing system is prepared by the following processes: reacting NH4Mixing Cl (ammonium chloride) with hydrochloric acid (industrial grade, 31 mass percent), CF-5D (demulsification cleanup additive), IRON ion stabilizer (IRON-2066A) and IS-156 hydrochloric acid pickling corrosion inhibitor to prepare solution A, wherein NH in solution A4The mass percent of Cl (ammonium chloride) IS 10-20%, the mass percent of hydrochloric acid (industrial grade, mass fraction IS 31%) IS 0.6-1%, the mass percent of CF-5D (demulsification cleanup additive) IS 0.5-1%, the mass percent of IRON ion stabilizer (IRON-2066A) IS 0.1-0.2%, and the mass percent of IS-156 hydrochloric acid pickling corrosion inhibitor IS 0.01-0.02%.
Then adding NaNO2Mixing with hydrochloric acid (industrial grade, 31 wt%) and CF-5D (demulsifying and cleanup additive) to obtain solution B, wherein NaNO is contained in solution B2The mass percent of the catalyst is 13-26 percent, and the mass percent of the CF-5D is 0.5-1.0 percent.
And then uniformly mixing the solution A and the solution B according to the volume ratio of 1:1-1:8 to obtain a fracturing pad fluid, and then adding a base fluid, active water, a gel breaker and a crosslinking liquid for compatibility to obtain a self-heating energy-increasing fracturing system.
The application method of the chemical self-heating energy-increasing fracturing fluid comprises the following steps:
(1) firstly, injecting a self-heating energy-increasing fracturing system: selecting 3 wells on the autogenous thermal fracturing construction site for testing, adopting the processes of reagent separate injection and well mouth mixing, namely mixing two prepared autogenous thermal agent aqueous solutions (the solution A and the solution B are respectively 5-10 m in length)3) Are respectively injected by two cement trucks with the same discharge capacityThe shaft is mixed at the wellhead to enter the stratum, so that the influence of the medicament on the sand mixing truck is solved.
(2) Then injecting a spacer fluid (active water) 1-2 m3Then, constructing according to a normal fracturing procedure, and adding 10-15 Kg of a gel breaker before sand adding is finished;
(3) replacing by adopting base liquid;
(4) and closing the well for 30 minutes, and then gradually releasing and spraying.
The active water is prepared by adding KCl and CF-5D into water, wherein the mass concentration of KCl is 1%, and the mass concentration of CF-5D is 0.5%.
The gel breaker is 10-15 kg of gel breaker according to the proportion of 0.05%, 0.1% and 0.2% in the later stage of sand addition;
preferably, the gel breaker is Ammonium Persulfate (APS) or potassium persulfate; preferably, the breaker is Ammonium Persulfate (APS).
Preferably, NH in solution A4The mass percent of Cl (ammonium chloride) IS 20 percent, the mass percent of CF-5D (demulsification cleanup additive) IS 0.5 percent, the mass percent of IRON ion stabilizer (IRON-2066A) IS 0.1 percent, and the mass percent of IS-156 hydrochloric acid pickling corrosion inhibitor IS 0.01 percent. NaNO in B liquid2The mass percent of (B) was 26%, and the mass percent of CF-5D was 0.5%.
Preferably, the liquid A and the liquid B are mixed according to the volume ratio of 1: 1.
Preferably, the crosslinking ratio of the crosslinking liquid is 100: 5-8; preferably, the crosslinking ratio is 100: 8.
The heat generation principle of the fracturing fluid chemical self-heat generation pressurization system is as follows:
the self-generating gas heating agent can release N under certain chemical composition proportion and conditions2Etc. and a large amount of heat. The gas component has the functions of increasing the formation energy, reducing the liquid density, changing the fluid flowing form, protecting the formation, reducing pollution and improving the process effect in the fracturing construction and post-pressure liquid drainage processes of low-pressure and low-permeability oil and gas reservoirs. The heat effect can raise the temperature of stratum and change the physical properties of gas and liquid in stratum to some extent, so that it is favorable for the constructed liquidAnd (5) quick backflow. In addition, the organic acid in the self-gas-generating heat agent composition can be reduced into an original substance after the reaction is finished, so that the self-gas-generating heat agent energizing technology is a measure for utilizing a chemical agent to generate a large amount of gas and heat through oxidation reduction and decomposition reaction under the action of formation conditions and a catalyst, thereby improving the reservoir production conditions and improving the process effect.
The formula of the self-heating energizing fracturing fluid mostly adopts the following principle:
NaNO2+NH4Cl+H+→N2↑+NaCl+2H2O
ΔH0＝-332.58kJ/mol
the reaction can be slowed down to a certain extent by adding alkali, and the reaction can be promoted by adding acid and the like serving as an initiator.
The two kinds of water solution of self-heating agent are mixed and reacted chemically under the control of catalyst to release great amount of heat energy and gas. According to the chemical reaction equation of the two heat generating agents, the following formula is shown: every 1m3NaNO concentration of 1mol/L2Aqueous solution and per 1m3NH concentration of 1mol/L4When Cl aqueous solution is mixed, 332.58MJ heat can be generated theoretically, if 4.184KJ heat is needed for 1Kg of water to raise the temperature by 1 ℃ in the case of pure water, 1m3The temperature of the mixture was increased to 119 ℃ by heating pure water. At atmospheric pressure, water boils at 100 ℃, and steam will carry away a large amount of heat, and if a large amount of superheated water is obtained, the ambient pressure should be greater than the saturated vapor pressure of water at that temperature. The manual consults that: the saturated vapor pressure of water is related to temperature by:
wherein, A is 7.96681, B is 1668.21, and C is 228, calculated at 104 ℃:
P＝875.19mmHg(0.1175MPa)
in the fracturing construction process, the injection pressure is far higher than the calculated pressure, so that the temperature of the reaction liquid can completely reach more than 100 ℃. Can also be used for treating hepatitisTo 33.6m3The inert gas (under the conditions of 0.1MPa and 25 ℃) can be used for fracturing fluid in a gas lift shaft and the like, and is favorable for flowback of the fracturing fluid after fracturing of an oil-gas well.
The method for implementing the self-heating energizing fracturing fluid under different amounts of self-heating agent aqueous solution, spacer fluid (activated water) and APS (ammonium persulfate) in the preparation scheme of the self-heating energizing reaction fluid (self-heating agent) is not limited to the mode.
The raw materials used in the examples are conventional raw materials and can be obtained commercially; the methods are prior art unless otherwise specified. The experimental procedure described in the present invention is a field-implemented process, i.e., an application method, and examples 1, 4 and 7 are varied according to the amount of the self-heating agent added.
On the basis of the above-mentioned operation, the sand-adding quantity and active water quantity are respectively changed, and they are respectively added up for nine working examples. Finally, the average single-layer use of the obtained self-generated medicament is 16m3Average single-layer sand addition of 25m3The average single-layer fracture pressure is 25MPa, the field construction is smoothly carried out, and the self-heating fracturing construction process is completely feasible.
Example 1
A chemical self-heating energizing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energizing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energy-increasing fracturing system comprises the following raw materials:
self-heating agent aqueous solution (A solution 6 m)36m for B solution3) Isolation liquid (active water) 1m310kg of APS (ammonium persulfate) and 100m of base fluid320m of crosslinking solution320m of active water3。
The base fluid is prepared by adding HPG (hydroxypropyl guar gum), KCl, CF-5D (demulsification cleanup additive), bactericide which is dodecyl dimethyl benzyl ammonium bromide and YCYH04-20182 low-temperature gel breaking activator into water; wherein, the mass concentration of HPG is 0.25%, the mass concentration of KCl is 1.0%, the mass concentration of CF-5D is 0.5%, the mass concentration of bactericide is 0.05%, and the mass concentration of YCYH04-20182 low-temperature gel breaking activator is 0.1%.
The cross-linking solution is prepared by adding borax and APS into water; wherein, the concentration of borax is 0.4 percent, and the mass concentration of APS is 0.6 percent; the crosslinking ratio is 100: 8;
the application method of the chemical self-heating energy-increasing fracturing fluid of the low-pressure low-permeability oil and gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells on the autogenous thermal fracturing construction site for testing, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the prepared solution A and solution B of the autogenous thermal agent are weighed to be 6m each3The method adopts the processes of medicament separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter a stratum.
Step two: injecting spacer fluid (active water) 1m into the well bore3Then, the construction was carried out according to the normal fracturing procedure, and 10Kg of APS (ammonium persulfate) was added thereto before the completion of the addition of the sand.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 2
A chemical self-heating energy-increasing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energy-increasing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
self-heating agent aqueous solution (A solution 6 m)36m for B solution3) Isolation liquid (active water) 1.5m312kg of APS (ammonium persulfate) and 100m of base fluid320m of crosslinking solution320m of active water3。
The application method of the chemical self-heating energy-increasing fracturing fluid of the low-pressure low-permeability oil and gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells on the autogenous thermal fracturing construction site for testing, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the solution A and the solution B of the autogenous thermal agent aqueous solution prepared in the example 1 are weighed6m3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: injecting spacer fluid (active water) 1.5m into the well bore3Then, the construction was carried out according to the normal fracturing procedure, and 12KgAPS (ammonium persulfate) was added thereto before the completion of the sand addition.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 3
A chemical self-heating energizing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energizing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
self-heating agent aqueous solution (A solution 6 m)36m for B solution3)2m of spacer fluid (active water)314kg of APS (ammonium persulfate) and 100m of a base liquid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil-gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells on the autogenous thermal fracturing construction site for testing, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the solution A and the solution B of the autogenous thermal agent aqueous solution prepared in the example 1 are weighed to be 6m each3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: 2m spacer fluid (active water) is injected into the shaft3Then, construction was carried out according to a normal fracturing procedure, and 14Kg of APS (ammonium persulfate) was added thereto before completion of the addition of the sand.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing for flowback.
Example 4
A chemical self-heating energy-increasing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energy-increasing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
aqueous autothermic solution (solution A8 m)38m for B liquid3) Isolation liquid (active water) 1m310kg of APS (ammonium persulfate) and 100m of base fluid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil-gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells for testing on the autogenous thermal fracturing construction site, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the prepared solution A and solution B of the autogenous thermal agent are weighed to be 8m each3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: 1m spacer fluid (active water) is injected into a well bore3Then, the construction was carried out according to the normal fracturing procedure, and 10KgAPS (ammonium persulfate) was added thereto before the completion of the sand addition.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 5
A chemical self-heating energy-increasing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energy-increasing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
aqueous autothermic solution (solution A8 m)38m for B liquid3) Isolation fluid (Living)Water of sex) 1.5m312kg of APS (ammonium persulfate) and 100m of base fluid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil-gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells for testing on the autogenous thermal fracturing construction site, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the solution A and the solution B of the autogenous thermal agent aqueous solution prepared in the example 4 are weighed, and the solution A and the solution B are 8m in length3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: 1.5m spacer fluid (active water) is injected into the well bore3Then, the construction was carried out according to the normal fracturing procedure, and 12KgAPS (ammonium persulfate) was added thereto before the completion of the sand addition.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 6
A chemical self-heating energy-increasing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energy-increasing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
aqueous autothermic solution (solution A8 m)38m for B liquid3)2m of spacer fluid (active water)314kg of APS (ammonium persulfate) and 100m of a base liquid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil-gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells on the autogenous thermal fracturing construction site for testing, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the autogenous thermal agent water prepared in the example 4 is weighedSolution A and solution B each 8m3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: 2m spacer fluid (active water) is injected into the well bore3Then, construction was carried out according to a normal fracturing procedure, and 14KgAPS (ammonium persulfate) was added before completion of the sand addition.
Step three: using 100m3And displacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 7
A chemical self-heating energy-increasing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energy-increasing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
self-heating agent aqueous solution (A liquid 10 m)3Solution B10 m3) Isolation liquid (active water) 1m310kg of APS (ammonium persulfate) and 100m of base fluid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil-gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells for testing on the autogenous thermal fracturing construction site, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the prepared solution A and solution B of the autogenous thermal agent are weighed and respectively 10m3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: injecting spacer fluid (active water) 1m into the well bore3Then, the construction was carried out according to the normal fracturing procedure, and 10KgAPS (ammonium persulfate) was added thereto before the completion of the sand addition.
Step three: using 100m3Carrying out topping with base liquidAnd (4) replacing.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 8
A chemical self-heating energizing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energizing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
self-heating agent aqueous solution (A liquid 10 m)3Solution B10 m3) Isolation liquid (active water) 1.5m312kg of APS (ammonium persulfate) and 100m of base fluid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil-gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells on the autogenous thermal fracturing construction site for testing, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the solution A and the solution B of the autogenous thermal agent aqueous solution prepared in the example 7 are weighed, and the solution A and the solution B are 10m in length3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: injecting spacer fluid (active water) 1.5m into the well bore3Then, the construction was carried out according to the normal fracturing procedure, and 12KgAPS (ammonium persulfate) was added thereto before the completion of the sand addition.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Example 9
A chemical self-heating energy-increasing fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is obtained by introducing a self-heating energy-increasing fracturing system into a conventional fracturing fluid under the condition of a stratum; the self-heating energizing fracturing system comprises the following raw materials in parts by weight:
self-heating agent aqueous solution (A solution 10 m)3Solution B10m3)2m of spacer fluid (active water)314kg of APS (ammonium persulfate) and 100m of a base liquid320m of crosslinking solution320m of active water3。
The preparation method of the chemical self-heating energizing fracturing fluid of the low-pressure low-permeability oil and gas reservoir comprises the following steps:
the method comprises the following steps: selecting 7 wells on the autogenous thermal fracturing construction site for testing, wherein 3 wells are selected as test wells, the other 4 wells are selected as comparison wells, each well is subjected to autogenous thermal fracturing for 1 interval, and the solution A and the solution B of the autogenous thermal agent aqueous solution prepared in the example 7 are weighed, and the solution A and the solution B are 10m in length3The method adopts the processes of reagent separate injection and wellhead mixing, namely, two weighed self-heating agent aqueous solutions are respectively injected into a shaft by two cement trucks at the same discharge capacity, so that the two weighed self-heating agent aqueous solutions are mixed at the wellhead and enter the stratum.
Step two: 2m spacer fluid (active water) is injected into the shaft3Then, construction was carried out according to a normal fracturing procedure, and 14KgAPS (ammonium persulfate) was added before completion of the sand addition.
Step three: using 100m3And replacing the base liquid.
Step four: and closing the well for 30 minutes, and then gradually blowing to carry out flowback.
Analysis of field test results
Examples 1-9 Co-operative autogenous fracturing in-situ test 3 wells, 3 wells in total having autogenous fracturing in 3 intervals, with a minimum of 1 interval per well, an average monolayer thickness of 2m, and an average monolayer of autogenous agent of 16m3Average single-layer sand addition of 25m3The average single-layer fracture pressure is 25MPa, the field construction is smoothly carried out, and the self-heating fracturing construction process is completely feasible.
By analysis, the implementation process has the following advantages:
1. the flow-back rate of the fracturing fluid can be improved, and the stratum pollution is reduced.
The self-heating reaction can generate high-pressure gas and heat, part of the high-temperature high-pressure gas acts on a rock system and pores, and part of the high-temperature high-pressure gas acts on fracturing fluid entering the cracks to form a reverse jacking effect. From field tests, the average flowback rate of 3 wells is 40%, the average flowback rate of the other 4 wells is less than 30% measured by the same method, and the flowback rate of the test well is 10% higher than that of the comparative well.
2. The seepage capability can be improved, and the productivity can be increased.
The self-heating reaction releases a large amount of heat energy to heat the blockage of residual oil and organic matters in tiny pores in the area near the crack, thereby improving the flow guiding capability of the crack, improving the seepage capability and improving the productivity. The 3 test wells all obtain better yield increasing effect, the daily oil production is more than 2t, and the oil production intensity of a single well is improved by 0.5t/(d.m) compared with that of a contrast well.
The field test result shows that: the average single-layer fracture pressure is 25MPa, the average flowback rate of 3 wells is 40%, the average flowback rate of the other 4 wells is less than 30% measured by the same method, and the flowback rate of the test well is 10% higher than that of the comparative well. The 3 test wells all obtain better yield increasing effect, the daily oil production is more than 2t, and the single well oil production intensity is improved by 0.5t/(d.m) compared with a contrast well in field test.
The results show that the properties of the fracturing fluid are as follows:
as shown in figure 1, certain modified guar gum can be crosslinked under acidic conditions, the formed crosslinked jelly has uniform appearance, high viscosity and good integral hanging performance, and the appearance of the crosslinked jelly is shown in figure 1.
FIG. 2 is a cryo-electron microscope structure of a system after fracturing fluid crosslinking under a magnification of 100000x by using an H-600 microscope, and it can be seen that the fracturing fluid after crosslinking presents a high molecular group with a network structure.
FIG. 3 is a cryo-electron microscope structure of a system after fracturing fluid gel breaking with an H-600 microscope at a magnification of 30000x, showing that the fracturing fluid breaks chemical bonds of high molecular groups connected into a network structure after gel breaking and degrades the high molecular groups into smaller molecular groups.
Fig. 4 is an appearance diagram of the fracturing fluid subjected to a static sand suspension performance test, and it can be seen that the sand suspension capacity of the fracturing fluid is mainly determined by the viscosity of the fracturing fluid. The viscosity of the self-heating energizing fracturing fluid is increased after the self-heating energizing fracturing fluid is filled with gas to form foam liquid, and the viscosity is reduced smoothly under high-speed shearing, so that the self-heating energizing fracturing fluid is very favorable for improving the sand carrying performance of the fracturing fluid. Measuring the self-heating energizing fracturing fluid sand suspension performance by using a static sand suspension instrument to obtain single quartz sand, wherein the static sand suspension speed is less than 0.1 cm/min; when the sand ratio is 35 percent, the static sand suspension speed is less than 0.3cm/min, and the result shows that the sand suspension performance of the fracturing fluid is good.
Claims (9)
1. A preparation method of a chemical self-heating energized fracturing fluid suitable for a low-pressure low-permeability oil-gas reservoir is characterized by comprising the following steps:
mixing ammonium chloride with hydrochloric acid, a demulsification cleanup additive, an iron ion stabilizer and an IS-156 hydrochloric acid pickling corrosion inhibitor to prepare solution A;
adding NaNO2Mixing hydrochloric acid and demulsifying and cleanup additive to prepare solution B;
uniformly mixing the solution A and the solution B according to the volume ratio of 1:1-1:8 to obtain a fracturing pad fluid, and then adding a base fluid, active water and a gel breaker to obtain a self-heating energy-increasing fracturing system;
and introducing the self-heating energy-increasing fracturing system into the fracturing fluid under the formation condition to obtain the self-heating energy-increasing fracturing fluid.
2. The preparation method of the chemical self-heating energizing fracturing fluid suitable for the low-pressure low-permeability oil and gas reservoir as claimed in claim 1, wherein the mass percent of ammonium chloride in the fluid A IS 10% -20%, the mass percent of hydrochloric acid IS 0.6% -1%, the mass percent of demulsification cleanup additive IS 0.5% -1%, the mass percent of iron ion stabilizer IS 0.1% -0.2%, and the mass percent of IS-156 hydrochloric acid pickling corrosion inhibitor IS 0.01% -0.02%.
3. The method for preparing the chemical self-heating energized fracturing fluid suitable for the low-pressure low-permeability oil and gas reservoir as claimed in claim 1, wherein NaNO in the B fluid2The mass percent of the emulsion breaking and cleanup additive is 13% -26%, and the mass percent of the emulsion breaking and cleanup additive is 0.5% -1.0%.
4. The method of claim 1, wherein the hydrochloric acid comprises 31% by weight of the chemical autogenous heat energized fracturing fluid.
5. A method of using a chemically autogenous, heat-energized fracturing fluid prepared according to the method of claim 1, comprising the steps of:
(1) injecting the liquid A and the liquid B into a shaft according to the volume ratio of 1:1-1:8, and mixing the liquid A and the liquid B at a well head to enter a stratum;
(2) then injecting active water, then constructing according to a fracturing procedure, and adding 10-15 Kg of a gel breaker before the sand adding is finished;
(3) replacing by adopting base liquid;
(4) and closing the well for 30 minutes, and then gradually releasing and spraying.
6. The use of claim 5, wherein the active water is prepared by adding KCl and a demulsifying cleanup additive to water, wherein the mass concentration of KCl is 1% and the mass concentration of CF-5D is 0.5%.
7. Use according to claim 5, wherein the breaker is ammonium persulfate or potassium persulfate.
8. The use of claim 5, wherein the dosage ratio of the solution A, the active water and the gel breaker is 5-10 m3：1～2m3：10～15Kg。
9. The use of claim 5, wherein the base fluid is prepared by adding HPG, KCl, a demulsifying cleanup additive, a bactericide and a low temperature gel breaking activator to water; wherein, the mass concentration of HPG is 0.25%, the mass concentration of KCl is 1.0%, the mass concentration of demulsification cleanup additive is 0.5%, the mass concentration of bactericide is 0.05%, and the mass concentration of low-temperature gel-breaking activator is 0.1%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111396370.8A CN114085662A (en) | 2021-11-23 | 2021-11-23 | Preparation method and application of chemical self-heating energizing fracturing fluid suitable for low-pressure low-permeability oil and gas reservoir |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111396370.8A CN114085662A (en) | 2021-11-23 | 2021-11-23 | Preparation method and application of chemical self-heating energizing fracturing fluid suitable for low-pressure low-permeability oil and gas reservoir |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114085662A true CN114085662A (en) | 2022-02-25 |
Family
ID=80303480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111396370.8A Pending CN114085662A (en) | 2021-11-23 | 2021-11-23 | Preparation method and application of chemical self-heating energizing fracturing fluid suitable for low-pressure low-permeability oil and gas reservoir |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114085662A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114806536A (en) * | 2022-05-10 | 2022-07-29 | 重庆科技学院 | Fluid for enhancing gel breaking and flowback of low-temperature oil reservoir polymer fracturing fluid and preparation method thereof |
| CN115012897A (en) * | 2022-06-29 | 2022-09-06 | 西南石油大学 | Method for improving shale oil recovery ratio |
| CN116426264A (en) * | 2023-04-23 | 2023-07-14 | 延长油田股份有限公司 | Self-heating supercritical carbon dioxide guanidine gum fracturing fluid and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103265938A (en) * | 2013-05-07 | 2013-08-28 | 四川省博仁达石油科技有限公司 | Foam-like fracturing system, preparation method and filling method thereof |
| CN104312570A (en) * | 2014-09-30 | 2015-01-28 | 延安大学 | Low-corrosion chemical themogenic pressurizing gel breaker and preparation method thereof |
| CN109281643A (en) * | 2018-10-11 | 2019-01-29 | 中国石油化工股份有限公司 | Delay spontaneous hot system and preparation method thereof |
| CN110847871A (en) * | 2018-08-20 | 2020-02-28 | 中国石油天然气股份有限公司 | Self-heating agent and application thereof |
| CN110847852A (en) * | 2019-10-22 | 2020-02-28 | 中国石油天然气股份有限公司 | Electrochemical method for accelerating dissolution of soluble bridge plug |
| CN111944511A (en) * | 2020-09-04 | 2020-11-17 | 西南石油大学 | Self-heating gas-generating foam fracturing fluid and preparation method thereof |
| CN113530515A (en) * | 2021-07-14 | 2021-10-22 | 中国石油大学(华东) | Process method for increasing yield of thick oil layer of phase-change fracturing fluid by exciting with ultrasonic-assisted heat generating agent |
-
2021
- 2021-11-23 CN CN202111396370.8A patent/CN114085662A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103265938A (en) * | 2013-05-07 | 2013-08-28 | 四川省博仁达石油科技有限公司 | Foam-like fracturing system, preparation method and filling method thereof |
| CN104312570A (en) * | 2014-09-30 | 2015-01-28 | 延安大学 | Low-corrosion chemical themogenic pressurizing gel breaker and preparation method thereof |
| CN110847871A (en) * | 2018-08-20 | 2020-02-28 | 中国石油天然气股份有限公司 | Self-heating agent and application thereof |
| CN109281643A (en) * | 2018-10-11 | 2019-01-29 | 中国石油化工股份有限公司 | Delay spontaneous hot system and preparation method thereof |
| CN110847852A (en) * | 2019-10-22 | 2020-02-28 | 中国石油天然气股份有限公司 | Electrochemical method for accelerating dissolution of soluble bridge plug |
| CN111944511A (en) * | 2020-09-04 | 2020-11-17 | 西南石油大学 | Self-heating gas-generating foam fracturing fluid and preparation method thereof |
| CN113530515A (en) * | 2021-07-14 | 2021-10-22 | 中国石油大学(华东) | Process method for increasing yield of thick oil layer of phase-change fracturing fluid by exciting with ultrasonic-assisted heat generating agent |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114806536A (en) * | 2022-05-10 | 2022-07-29 | 重庆科技学院 | Fluid for enhancing gel breaking and flowback of low-temperature oil reservoir polymer fracturing fluid and preparation method thereof |
| CN115012897A (en) * | 2022-06-29 | 2022-09-06 | 西南石油大学 | Method for improving shale oil recovery ratio |
| CN115012897B (en) * | 2022-06-29 | 2023-11-21 | 西南石油大学 | Method for improving shale oil recovery ratio |
| CN116426264A (en) * | 2023-04-23 | 2023-07-14 | 延长油田股份有限公司 | Self-heating supercritical carbon dioxide guanidine gum fracturing fluid and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114085662A (en) | Preparation method and application of chemical self-heating energizing fracturing fluid suitable for low-pressure low-permeability oil and gas reservoir | |
| CN107255027B (en) | Compound modification method for carbonate rock reservoir | |
| CN102952534B (en) | Low-damage fracturing fluid and fracturing method | |
| CN101323780B (en) | Low pervasion oilfield thermochemical cleanup additive and use thereof | |
| Nianyin et al. | Fracturing technology with carbon dioxide: A review | |
| CN111396017B (en) | Compact oil reservoir fracturing method with low porosity, low permeability and high shale content | |
| CA2528696C (en) | Method and composition for treating a subterranean formation with splittable foams | |
| CN102627960B (en) | Self-gas-generating foam fracturing fluid, its production method and application method | |
| US9752072B2 (en) | Propping compositions for enhancing fracture conductivity | |
| CN107216866B (en) | A kind of method of Carbonate Reservoir seam dictyosome product acidfracturing treatment | |
| CN112375557B (en) | Alcohol-soluble slickwater system for fracturing and preparation method and application thereof | |
| CN103265938A (en) | Foam-like fracturing system, preparation method and filling method thereof | |
| US20200308947A1 (en) | Supercritical carbon dioxide for fracking and hydrocarbon recovery | |
| Nianyin et al. | Recent advances in waterless fracturing technology for the petroleum industry: An overview | |
| CN108456511B (en) | In-layer generation of CO2System and use thereof | |
| CN108049855A (en) | A kind of MH acid construction technology suitable for sandstone reservoir transformation | |
| CN114940895A (en) | Clean high-performance carbon dioxide foam fracturing fluid and preparation method thereof | |
| WO2017074462A1 (en) | Peroxide containing formation conditioning and pressure generating composition and method | |
| CN104927830A (en) | Waterproof lock fracturing fluid and preparation method thereof | |
| CN108913115B (en) | Low-damage composite fracturing fluid and application method thereof | |
| CN112324411A (en) | Loose sandstone heavy oil reservoir vertical well complex long-seam fracturing process | |
| CA3086797C (en) | Methane hydrates improved hydrostatic pressure of foam fracturing | |
| CN110872508B (en) | Non-crosslinked fracturing fluid and preparation method and application thereof | |
| CN113249100A (en) | Nitrogen foam water control and plugging agent and use method thereof | |
| CN113356820A (en) | Fracturing method |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220225 |