CN116375413A - Thermal insulation well cementation cement for geothermal development - Google Patents
Thermal insulation well cementation cement for geothermal development Download PDFInfo
- Publication number
- CN116375413A CN116375413A CN202310230127.1A CN202310230127A CN116375413A CN 116375413 A CN116375413 A CN 116375413A CN 202310230127 A CN202310230127 A CN 202310230127A CN 116375413 A CN116375413 A CN 116375413A
- Authority
- CN
- China
- Prior art keywords
- cement
- heat
- retarder
- perlite
- well
- 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
- 239000004568 cement Substances 0.000 title claims abstract description 152
- 238000011161 development Methods 0.000 title claims abstract description 17
- 238000009413 insulation Methods 0.000 title description 13
- 239000011521 glass Substances 0.000 claims abstract description 45
- 239000011324 bead Substances 0.000 claims abstract description 40
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 38
- 241000209094 Oryza Species 0.000 claims abstract description 37
- 235000007164 Oryza sativa Nutrition 0.000 claims abstract description 37
- 235000009566 rice Nutrition 0.000 claims abstract description 37
- 239000010451 perlite Substances 0.000 claims abstract description 36
- 235000019362 perlite Nutrition 0.000 claims abstract description 36
- 239000000463 material Substances 0.000 claims abstract description 27
- 239000003129 oil well Substances 0.000 claims abstract description 18
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 15
- 239000002245 particle Substances 0.000 claims abstract description 12
- 239000000654 additive Substances 0.000 claims abstract description 10
- 230000000996 additive effect Effects 0.000 claims abstract description 9
- 235000013339 cereals Nutrition 0.000 claims abstract description 7
- AEQDJSLRWYMAQI-UHFFFAOYSA-N 2,3,9,10-tetramethoxy-6,8,13,13a-tetrahydro-5H-isoquinolino[2,1-b]isoquinoline Chemical group C1CN2CC(C(=C(OC)C=C3)OC)=C3CC2C2=C1C=C(OC)C(OC)=C2 AEQDJSLRWYMAQI-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000000176 sodium gluconate Substances 0.000 claims abstract description 6
- 229940005574 sodium gluconate Drugs 0.000 claims abstract description 6
- 235000012207 sodium gluconate Nutrition 0.000 claims abstract description 6
- 239000002253 acid Substances 0.000 claims abstract description 5
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 238000012360 testing method Methods 0.000 description 56
- 239000004575 stone Substances 0.000 description 22
- 239000012496 blank sample Substances 0.000 description 18
- 238000002156 mixing Methods 0.000 description 14
- 239000002002 slurry Substances 0.000 description 11
- 238000000034 method Methods 0.000 description 10
- 230000008719 thickening Effects 0.000 description 10
- 239000000523 sample Substances 0.000 description 9
- 239000010903 husk Substances 0.000 description 8
- 238000002347 injection Methods 0.000 description 6
- 239000007924 injection Substances 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 210000001503 joint Anatomy 0.000 description 5
- 239000011148 porous material Substances 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 238000011049 filling Methods 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000004321 preservation Methods 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 239000000378 calcium silicate Substances 0.000 description 2
- 229910052918 calcium silicate Inorganic materials 0.000 description 2
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 238000006703 hydration reaction Methods 0.000 description 2
- 238000013101 initial test Methods 0.000 description 2
- 239000012774 insulation material Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 241000251468 Actinopterygii Species 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- 229910000906 Bronze Inorganic materials 0.000 description 1
- 244000137852 Petrea volubilis Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000010974 bronze Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000003032 molecular docking Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229920005646 polycarboxylate Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/08—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by adding porous substances
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/40—Porous or lightweight materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/30—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values
- C04B2201/32—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values for the thermal conductivity, e.g. K-factors
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Porous Artificial Stone Or Porous Ceramic Products (AREA)
Abstract
The invention relates to a heat-insulating well cementation cement for geothermal development, which consists of G-level high-sulfate-resistance oil well cement, external admixture and additive, wherein the G-level high-sulfate-resistance oil well cement accounts for 82% by weight; the external admixture comprises glass beads, perlite and rice hull ash; the additive is retarder and water reducer, the weight ratio of the glass beads is 6%, and the particle size is 75-150 mu m; the weight ratio of the perlite is 4 percent, and the grain diameter is 18-28 mu m; the mass ratio of the rice hull ash is 8%, and the grain diameter is 18-28 mu m; the water reducer is 540P poly-countic acid, and the weight ratio is 0.15-0.2% of the total weight of the cement base material and the admixture; the retarder is sodium gluconate, and the weight ratio of the retarder to the retarder is 0.02-0.03% of the total weight of the cement base material and the external admixture. The heat-insulating well cementation cement improves the compressive strength of the cement paste and effectively reduces the heat conductivity coefficient of the cement paste; the problem of geothermal well heat loss is solved, and geothermal well production efficiency is improved.
Description
Technical Field
This patent belongs to geothermal drilling and completion field, relates to a thermal-insulated heat preservation well cementation cement for geothermal development.
Background
Geothermal energy is a green, clean and renewable clean energy source, and has the advantages of wide distribution, large reserves and the like. The geothermal resource is fully developed and utilized, so that the geothermal resource has important promotion significance for adjusting the energy structure of China, and is one of effective ways for realizing the double-carbon target in China.
At present, the geothermal energy is developed into two modes, namely a water-heating extraction recharging development mode, namely, hot water of an underground thermal reservoir is extracted to the ground for utilization through a manual drilling and completion, geothermal tail water after heat extraction is recharged to an underground appointed stratum through a recharging well, and the development mode is the most traditional and most direct development mode; secondly, in the development mode of underground heat exchange which is rising in recent years, a well is drilled into a deep heat reservoir in the underground through drilling, then an underground heat exchanger is installed, stratum heat is circularly absorbed in the heat exchanger through a medium, and the stratum heat is guided out to the ground for use.
The first mode is that the extraction recharging geothermal development mode shown in fig. 1 corresponds to a hydrothermal geothermal resource, the thermal reservoir 1 to be exploited is often at the lowest part of a geothermal well, high-temperature geothermal water is gathered and moved upwards in the well from the lowest part, the temperature of the geothermal water is higher than the temperature of an external stratum after the geothermal water is moved to a certain depth, and the heat of the geothermal water is transferred to the stratum, so that heat loss is caused. The conventional water-heating geothermal well completion process adopts ordinary oil well cement to perform well cementation after one or two well completion, has no good heat insulation effect, and is easy to cause heat transfer of high-temperature geothermal water to a stratum. Therefore, a certain heat preservation measure or process is adopted to the geothermal well above a certain depth so as to reduce heat loss.
The second is that the underground heat exchange development mode shown in fig. 2 does not produce groundwater, and two types of heat exchange modes of a coaxial sleeve and a U-shaped butt joint well exist in the market currently. The U-shaped butt joint well is formed by butt joint of a horizontal well and a vertical well, wherein the wellhead of the horizontal well is a medium water inlet, the wellhead of the vertical well is a medium water outlet, the whole well section is well cementation, a heat exchange medium enters from the horizontal well, and returns out from the vertical well after absorbing the heat of a stratum, and the heat exchange capacity is increased by enlarging the heat exchange area. In the process that the medium absorbs the heat of the stratum and then returns to the ground from the vertical well, the heat insulation effect is poor due to the common cement adopted in the vertical well section, the heat carried by the medium is transferred to the stratum, and the heat loss is caused, so that the efficiency can be improved only by locking the heat of the medium in the well.
To the explanation of the background art, this patent provides a thermal-insulated heat preservation well cementation cement for geothermal development, uses in hydrothermal type geothermal development and U type butt joint well heat transfer development mode in the pit for geothermal water and heat transfer medium can better save heat, reduce the heat loss, improve geothermal well production efficiency, extension geothermal well life-span.
Disclosure of Invention
The invention aims to develop heat-insulating well cementation cement for geothermal development, which reduces the heat conductivity coefficient of the well cementation cement on the premise of ensuring the strength by adding external admixture, solves the problem of heat loss of a geothermal well and improves the production efficiency of the geothermal well.
The invention provides a heat-insulating well cementation cement for geothermal development, which is characterized by comprising a cement base material, an external admixture and an additive;
the cement base material is G-level high-sulfate-resistant oil well cement; the external admixture comprises glass beads, perlite and rice hull ash; the additive is retarder and water reducer;
the weight ratio of the cement base material is 82%;
the weight ratio of the glass beads is 6%, and the particle size of the glass beads is 75-150 mu m;
the weight ratio of the perlite is 4%, and the particle size of the perlite is 18-28 mu m;
the mass ratio of the rice hull ash is 8%, and the grain diameter of the rice hull ash is 18-28 mu m;
the water reducer is polycarboxylic acid, and the weight ratio of the water reducer is 0.15% -0.2% of the total weight of the cement base material and the external admixture;
the retarder is sodium gluconate, and the weight ratio of the retarder to the retarder is 0.02-0.03% of the total weight of the cement base material and the external admixture.
The heat-insulating well cementation cement also comprises water, and the water cement ratio is 0.44.
The invention has the beneficial effects that:
1. in the added external admixture, the glass beads have the function of filling the pores, so that the compressive strength of the cement paste can be improved; meanwhile, the cement paste has a spherical hollow structure, and after a certain amount of glass beads are mixed with the cement base material, the heat conductivity coefficient of the cement paste is effectively reduced; however, the blending amount of the glass beads exceeds a certain amount, so that the particle continuity of the cement paste is increased, and the heat conductivity coefficient is also increased.
2. The internal structure of the perlite is loose and porous, so that the perlite has very low heat conductivity coefficient of 0.028-0.048W/m & ltK & gt, and is a good heat insulation material. After perlite powder is added into cement, harmful holes of the cement paste become small and uniform harmless holes, so that the compressive strength of the cement paste is increased, air is contained in the holes, the heat conductivity coefficient is low, and the heat conductivity coefficient of the cement paste can be effectively reduced; in addition, the addition of perlite can cause the cement slurry to produce more discrete crystals in the form of blocks, reducing the continuity of the cement slurry particles and thus reducing its thermal conductivity.
3. The main component of the rice hull ash is silicon dioxide, and the silicon dioxide can react with calcium hydroxide which is a cement hydration product to generate calcium silicate hydrate, wherein the calcium silicate hydrate is a main product of compressive strength of cement. After the rice hull ash is added into cement, the compressive strength of the cement paste is increased due to the action of filling pores and potential pozzolanic activity; the rice hull ash has loose structure and low heat conductivity, and harmful holes in the cement paste become more uniformly distributed harmless holes after being added into the cement paste, so that the compressive strength of the cement paste is not affected, and the heat conductivity of the cement paste can be reduced.
Drawings
Fig. 1 is a schematic drawing of drainage and recharge.
FIG. 2 is a schematic diagram of a U-shaped docking well.
FIG. 3 shows the compressive strength test result of cement stone under 8h curing condition of single glass bead.
FIG. 4 shows the compressive strength test result of cement stone under the 24-hour curing condition of the single glass bead.
FIG. 5 shows the result of the compressive strength test of cement stone under the 8-hour curing condition of singly doped perlite.
FIG. 6 shows the result of compressive strength test of cement stone under 24h curing condition of singly doped perlite.
FIG. 7 shows the results of compressive strength experiments of cement stones under 8h curing conditions by singly blending rice husk ash.
FIG. 8 shows the results of compressive strength experiments of cement stones under 24h curing conditions by singly doping rice husk ash.
FIG. 9 shows the results of thermal conductivity test of cement stones under curing conditions of different environmental temperatures and different content of single glass beads for 28 days.
FIG. 10 shows the results of thermal conductivity testing of set cement under 28-day curing conditions at different ambient temperatures with different levels of perlite alone.
FIG. 11 shows the results of thermal conductivity testing of set cement under 28-day curing conditions at different ambient temperatures with different levels of rice hull ash alone.
Reference numerals illustrate:
1. a thermal storage layer; 2. an aquifer; 3. a cover layer; 4. thermal insulation well cementation cement; 5. geothermal water; 6. a butt joint well; 7. a formation; 8. a geothermal destination layer; 9. and (3) a vertical well.
Detailed Description
The following detailed description, structural features and functions of the present invention are provided with reference to the accompanying drawings and examples in order to further illustrate the technical means and effects of the present invention to achieve the predetermined objects.
The thermal conductivity coefficient of the well cementation cement is reduced on the premise of ensuring the strength, so that the problem of heat loss of a geothermal well is solved, the production efficiency of the geothermal well is improved, and the embodiment provides the thermal insulation well cementation cement for geothermal development, which comprises the following materials:
1. cement base material: API standard G-grade high-sulfate-resistance (HSR) oil well cement with particle size of 35-40 mu m and manufacturer: ningxia bronze isthmus cement Co.Ltd.
2. And (3) external doping:
(1) Glass beads: particle size of 75-150 μm and density of 1.5g/cm 3 The heat conductivity coefficient is 0.21W/mK, and the components are as follows: 62.12% SiO 2 And 28.55% Al 2 O 3 The manufacturer: consolidating the market yuan to share the water purifying material factory.
(2) Perlite: particle size 18-28 μm and density 2.53g/cm 3 Thermal conductivity 0.048W/mK, composition: 89.08% SiO 2 And 1.38% Al 2 O 3 The manufacturer: limited mining industry for Henan Xinyang mansionCompanies.
(3) Rice hull ash: particle size of 18-28 μm and density of 2.12g/cm 3 The heat conductivity coefficient is 0.062W/mK, and the components are as follows: 76.55% SiO 2 And 12.8% Al 2 O 3 The manufacturer: fish table Hengdong insulation Co., ltd.
3. Additive agent
(1) Water reducer, polycarboxylic acid component, manufacturer: shanghai ministerial chemical engineering Co.Ltd.
(2) Retarder, ingredients: sodium gluconate, manufacturer: shandong Usox chemical technology Co.Ltd.
4. The preparation method of cement slurry and cement stone sample blocks comprises the following steps:
according to the weight ratio of the cement base material of 82 percent, the weight ratio of the glass beads of 6 percent, the grain diameter of 75-150 mu m, the weight ratio of perlite of 4 percent, the grain diameter of 18-28 mu m, the mass ratio of rice hull ash of 8 percent and the grain diameter of 18-28 mu m; the chemical components of the water reducer are polycarboxylic acid, and the addition amount is 0.15% -0.2% of the total weight of the cement base material and the external admixture; the retarder is prepared from sodium gluconate with the addition of 0.02-0.03% of the total weight of the cement base material and the external admixture.
According to the proportion, the weighed G-level high-sulfate-resistance (HSR) oil well cement, the external admixture and the additive are dry-mixed in a clean and dry cement paste mixer for 15min at a low speed, so that various external admixtures and additives are uniformly dispersed. Pouring the weighed mixing water into an OWC-9040A type constant-speed stirrer slurry cup, slowly pouring the dry-mixed cement admixture into the slurry cup within 15s under the low-speed stirring of 4000r/min, and stirring at a high speed of 12000r/min for 35s to complete the preparation of cement slurry.
The prepared slurry is stirred by a glass rod and poured into four copper test molds with the thickness of 50mm multiplied by 50mm twice, and the redundant cement paste is scraped by a scraper under the condition that the glass rod is required to vibrate 17 twice in each mold, so that the pouring work is completed within 5 minutes. And (3) placing the test die into a constant-temperature water bath curing box at 38 ℃ and 60 ℃ for curing for 8 hours and 24 hours, demolding, taking out, and wiping off the release agent on the surface of the test block.
5. Test method
(1) Compressive Strength test
The slurry prepared before is stirred by a glass rod and poured into four copper test moulds of 50mm multiplied by 50mm twice, each mould is required to be vibrated by the glass rod twice for 17 times, redundant cement paste is scraped by a scraper, and the pouring work is completed within 5 minutes. And (3) placing the test die into a constant-temperature water bath curing box at 38 ℃ and 60 ℃ for curing for 8 hours and 24 hours, demolding, taking out, and wiping off the release agent on the surface of the test block. Using a YAW-300 microcomputer control full-automatic pressure testing machine to test the compressive strength of the sample; the compression rate was 1.2kN/s, and the compression strength value was obtained by averaging four sets of data.
(2) Thermal conductivity testing
Pouring the prepared cement paste into a mold with the thickness of 50mm multiplied by 10mm, curing for 24 hours at room temperature, demolding, transferring into a curing box with the temperature of 20 ℃ and the humidity of 95% and curing for 28 days. And sequentially polishing the surface of the heat conduction test block by using 80-mesh, 180-mesh, 400-mesh and 800-mesh sand paper. A TC3100 thermal conductivity coefficient tester manufactured by Xian Xiaxi electronic technology Co., ltd. Is used, a transient plane hot wire method is adopted, the measuring range is 0.001-20W/(m.K), the measuring temperature is-30-120 ℃, and the accuracy and repeatability are both +/-3%. The test temperature is 30 ℃,60 ℃ and 90 ℃.
(3) Thickening time test
According to GB10238-2015 oil well Cement, the prepared cement paste is filled into a paste cup of a pressurizing and thickening instrument, and the final circulation temperature of the pressurizing and thickening instrument is set to be 65 ℃ and the circulation pressure is set to be 35MPa. The pressure and the temperature in the slurry cup are increased to the set values within 35min, and the temperature is enabled to fluctuate at the set values by continuously increasing and reducing the pressure. When the consistency value reaches 100Bc, the experiment is finished, and the change curves of pressure, temperature and consistency are recorded.
6. Test procedure
Test of the influence of the singly doped and externally doped Admixture on the compressive Strength
(1) Under the condition of singly doping glass beads
Referring to fig. 3, the curing time is 8 hours, and the test results of the compressive strength test blocks of the cement paste prepared by the mass ratio of the glass beads with different weight ratios of 0%, 5%, 10%, 15% and 20% are shown in table 1 under the curing temperature conditions of 38 ℃ and 60 ℃ respectively.
Referring to fig. 4, the curing time is 24 hours, and the cement paste compressive strength test blocks prepared by the mass ratio of 0%, 5%, 10%, 15% and 20% of different glass beads are tested under the curing temperature conditions of 38 ℃ and 60 ℃ respectively, and the test results are shown in table 1.
Table 1 compressive strength of set cement blocks with different glass bead contents
( And (3) injection: in brackets are the improvement or reduction of the compressive strength of the single glass beads compared with the blank sample )
(2) Under the condition of singly mixing perlite
Referring to fig. 5, the curing time is 8 hours, and the cement paste compressive strength test blocks prepared by the mass ratio of 0%, 5%, 10%, 15% and 20% of different perlite are respectively tested under the curing temperature conditions of 38 and 60 ℃, and the test results are shown in table 2.
Referring to fig. 6, the curing time is 24 hours, and the cement paste compressive strength test blocks prepared by the mass ratio of 0%, 5%, 10%, 15% and 20% of different perlite are respectively tested under the curing temperature conditions of 38 and 60 ℃, and the test results are shown in table 2.
Table 2 compressive strengths of set cement blocks with different perlite contents
( And (3) injection: in brackets are the increasing or decreasing amplitude of the compressive strength of the singly doped perlite compared with the blank sample )
(3) Under the condition of singly mixing rice husk ash
Referring to fig. 7, curing time is 8h, and the cement paste compressive strength test blocks prepared by 0%, 5%, 10%, 15% and 20% of different rice hull ash mass ratios are respectively tested under the curing temperature conditions of 38 and 60 ℃, and the test results are shown in table 3;
referring to fig. 8, the curing time is 24 hours, and the cement paste compressive strength test blocks prepared by the mass ratio of 0%, 5%, 10%, 15% and 20% of different rice hull ash are respectively tested under the curing temperature conditions of 38 and 60 ℃, and the test results are shown in table 3.
TABLE 3 compressive Strength of Cement stones with different Rice husk ash contents
( And (3) injection: in brackets are the increasing or decreasing amplitude of the compressive strength of the singly doped rice husk ash compared with the blank sample )
According to the national standard of oil well cement (GB/T102382015), the minimum compressive strength of 8h curing time at 38 ℃ is 2.1MPa, and the minimum compressive strength at 60 ℃ is 10.3MPa; the curing time for 24 hours is not specified.
According to tables 1, 2 and 3, in the case of singly blending glass beads, perlite and rice husk ash, the compressive strength of the cement paste is changed at 38 ℃ and 60 ℃ for 8 hours and 24 hours, but the compressive strength of the cement paste accords with the national standard within the range of 0-20% of singly blending amount.
(II) influence of singly doped external admixture on thermal conductivity of cement test block
(1) Under the condition of singly doping glass beads
Referring to FIG. 9, the cement test blocks prepared by the mass ratio of 0%, 5%, 10%, 15% and 20% of different glass beads were subjected to thermal conductivity tests at the ambient temperature of 30 ℃,60 ℃ and 90 ℃ respectively, and the test results are shown in Table 4.
TABLE 4 thermal conductivity coefficients of different glass bead thermal insulation cements
( And (3) injection: in brackets is the decrease in the thermal conductivity of the single glass beads compared with the blank )
As can be seen from the table, the glass bead content is from 0% to 15%, and when the ambient temperature is 30 ℃, the thermal conductivity of the cement stone sample is reduced by 21.31% compared with that of the blank sample; when the mixing amount is 15-20%, the thermal conductivity of the cement stone sample is increased from 0.9238W/(m.K) to 1.082W/(m.K), but the thermal conductivity is still reduced by 7.84% compared with that of a blank sample. When the ambient temperature is 60 ℃, the thermal conductivity of the cement stone is reduced from 1.023W/(m.K) to 0.7923W/(m.K), and compared with a blank sample, the thermal conductivity is reduced by 22.55%; when the mixing amount is 15-20%, the heat conductivity coefficient is increased from 0.7923W/(m.K) to 0.9531W/(m.K), but the heat conductivity coefficient is still reduced by 6.83% compared with that of a blank sample. When the ambient temperature is 90 ℃, the thermal conductivity of the cement stone is reduced from 0.9435W/(m.K) to 0.6953W/(m.K), and compared with a blank sample, the thermal conductivity of the cement stone is reduced by 26.31%; when the mixing amount is 15-20%, the heat conductivity coefficient is increased from 0.6953W/(m.K) to 0.8843W/(m.K), but the heat conductivity coefficient is still reduced by 6.27% compared with that of a blank sample.
The reason why the heat conductivity is firstly reduced and then increased is as follows: the glass beads have the function of filling the pores at the beginning, so that the compressive strength of the cement paste can be improved, and the spherical hollow structure of the glass beads can effectively reduce the heat conductivity coefficient of the cement paste; when the mixing amount of the glass beads is too large, the effect of filling the pores can not compensate the strength generated by hydration of cement replaced by the glass beads, and the compressive strength of cement paste is reduced; the glass beads fill the pores, so that the particle continuity of the cement paste is increased, and the heat conductivity coefficient is also increased.
(2) Under the condition of singly mixing perlite
Referring to FIG. 10, cement test pieces prepared with different mass ratios of perlite of 0%, 5%, 10%, 15% and 20% were subjected to thermal conductivity tests at ambient temperature conditions of 30 ℃,60 ℃ and 90 ℃ respectively, and the test results are shown in Table 5.
TABLE 5 thermal conductivity coefficients of thermal insulation cements with different perlite contents
( And (3) injection: in brackets is the degree of decrease in the coefficient of thermal conductivity of the singly doped perlite compared with the blank sample )
As can be seen from the table, the thermal conductivity coefficient gradually decreases along with the increase of the ash content of the rice hull, and the thermal conductivity coefficient of the cement stone sample in the environment of 30 ℃ is reduced by 27.36% compared with that of the blank sample; when the environment temperature is 60 ℃, the thermal conductivity of the cement stone is reduced by 25.37% compared with that of a blank sample; when the ambient temperature is 90 ℃, the thermal conductivity of the cement stone is reduced by 26.41 percent compared with that of a blank sample.
(3) Under the condition of singly mixing rice husk ash
Referring to FIG. 11, cement test pieces prepared at 30, 60, 90℃and different rice hull ash mass ratios of 0%, 5%, 10%, 15% and 20% were subjected to thermal conductivity tests, respectively, and the test results are shown in Table 6.
TABLE 6 thermal conductivity coefficients of thermal insulation cements with different rice hull ash contents
( And (3) injection: in brackets is the decrease of the heat conductivity coefficient of the singly doped rice husk ash compared with the blank sample )
As can be seen from the table, the thermal conductivity coefficient gradually decreases along with the increase of the ash content of the rice hull, and the thermal conductivity coefficient of the cement stone sample in the environment of 30 ℃ is reduced by 24.07% compared with that of the blank sample; when the environment temperature is 60 ℃, the thermal conductivity of the cement stone is reduced by 27.30% compared with that of a blank sample; when the ambient temperature is 90 ℃, the thermal conductivity of the cement stone is reduced by 27.78 percent compared with that of a blank sample.
(III) influence of the remixed external admixture on the well cementation cement performance
By singly doping glass beads, perlite and rice hull ash with different doping amounts, the law of influence of the thermal insulation material on the cement mechanics and thermal properties of the oil well can be obtained. For example, the heat conductivity coefficient of the oil well cement can be effectively reduced by adding glass beads; and under the condition that the curing time is 8 hours, the compressive strength can be greatly reduced when the glass bead doping amount is too large. Meanwhile, perlite and rice hull ash perlite have the greatest contribution to mechanical strength, and can effectively increase compressive strength and reduce heat conductivity under the condition of small mixing amount. The contribution of rice hull ash, whether it is resistant to compaction or thermal conductivity, is intermediate. The single-doped heat-insulating material can not meet the well cementation requirement, so that an orthogonal test is required to be designed to ensure that the compressive strength meets the related requirements of national standard GB10238-2015 oil well cement, namely, the compressive strength at 38 ℃ and 60 ℃ for 8 hours is more than 2.10MP and 10.3MPa.
(1) Orthogonal test analysis
Taking perlite A, glass beads B and rice hull ash C as three factors, wherein each factor is divided into three levels of 1, 2 and 3, wherein A1, A2 and A3 are respectively 2%, 4% and 6%, and represent the mass ratio of the glass beads to the cement system (the total mass of the cement base material and the external admixture); b1, B2 and B3 are respectively 4%, 6% and 8%, and represent the mass ratio of perlite to cement system (total mass of cement base material and external admixture); c1, C2 and C3 are respectively 4%, 6% and 8%, and represent the mass ratio of the rice hull ash to the cement system (the total mass of the cement base material and the external admixture); the cement systems of 9 groups of different influencing factors are designed by adopting an orthogonal analysis method, and the 9 groups are subjected to 8h compressive strength, heat conductivity coefficient and fluidity tests to obtain Table 7.
TABLE 7 results of orthogonal test table
Note that: the national standard requirements of free liquid content are as follows: <5.9%.
(2) Analytic hierarchy process
The analytic hierarchy process is to divide the analytic hierarchy process into a total target, sub targets of each layer, an evaluation criterion and specific alternative schemes according to different hierarchical structures, then to calculate the priority weight of each element of each layer to a certain element of the previous layer by solving the eigenvectors of the matrix, and finally to merge the final weights of each alternative scheme to the total target in a stepwise manner by a weighted sum method, wherein the highest weight is the optimal scheme.
Each index has a unit dimension, and in order to eliminate the dimension and conveniently evaluate each index, the data in table 5 is required to be subjected to standardized processing, namely: data standard value= (present value/present set maximum value) ×100. According to the method for determining the index weight of the AHP method, 4 performance indexes of the cement stone, namely the heat conductivity coefficient, the compressive strength at 38 ℃ for 8 hours, the compressive strength at 60 ℃ for 8 hours and the fluidity are divided into 4 layers, and the priority order of each index is determined according to the relative importance degree: thermal conductivity > 60 ℃ compressive strength > 38 ℃ compressive strength > 8h compressive strength = fluidity. Using yaahp12.2 software, AHP weights ω for thermal conductivity, 60 ℃ compressive strength, 38 ℃ compressive strength, and fluidity were calculated as 0.7198, 0.1318, 0.0755, and 0.0730, respectively; the consistency proportion factor CR=0.0123 is less than 0.10, namely the indexes are consistent with the comparison judgment priority matrix, and the weight coefficient is effective.
The overall score for each group of orthogonal experiments was calculated as follows: composite score = (thermal conductivity standard value x 0.7198+60 ℃ compressive strength standard value x 0.1318+38 ℃ compressive strength standard value x 0.0755 +fluidity standard value x 0.0730) ×100. The standard values and the comprehensive scores of the test groups are shown in Table 8.
Table 8 Standard value and comprehensive evaluation Table for each test group
Note that: the level of each factor is in brackets
Note that: the level of each factor is in brackets
Table 9 Standard values of various level experiment indexes and comprehensive evaluation Table
According to analysis of a comprehensive evaluation table, the larger the average value is, the larger the contribution to the comprehensive performance of the well cementation material is, so that the optimal external doping factor level of the heat insulation well cementation cement is A3B1C3, namely, the glass bead doping amount is 6%, the perlite doping amount is 4%, the rice hull ash doping amount is 8%, and the comprehensive performance of the heat insulation well cementation cement is the best when the cement base material is 82%. The optimal proportion (weight ratio) is 6% of glass beads, 4% of perlite, 8% of rice hull ash and 82% of cement base material.
(IV) thermal insulation optimal proportion verification test
Optimum ratio = 6% glass microsphere blend +4% perlite +8% rice hull ash +82% cement base.
The water to ash ratio was 0.44.
The additive is a water reducing agent and a retarder, wherein the addition amount of the water reducing agent is 0.15% of the total mass of the cement base material and the external admixture, and the chemical components are polycarboxylate water reducing agents; the retarder is added in an amount of 0.03% of the total mass of the cement base material and the external admixture, and the chemical composition is sodium gluconate.
Thermal insulation cement system = water + cement base + external admixture + admixture
The actual addition is as follows: 349g of water+47.52 g of glass beads+31.68 g of perlite+63.36 g of rice hull ash+ 649.44 cement+1.188 g of water reducer+ 0.0792g of retarder.
(1) Compressive Strength test results
Table 10 table of compressive strength results for set cement sample blocks at optimum proportions
The compressive strength of water curing at 38 ℃ and 60 ℃ for 8 hours is 3.76MPa, 12.56MPa, and the requirements of oil well cement standards are 2.1 and 10.3 respectively; the compressive strength of the water culture at 60 ℃ for 24 hours is 16.92MPa and 28.56MPa; the compressive strength reaches the standard required by oil well cement.
(2) Thermal conductivity test results
Table 11 optimum ratio sample block thermal conductivity results table
The thermal conductivity of the cement stone sample block with the optimal proportion is reduced to 0.5872W/(m.K) from 1.174W/(m.K) of a blank sample at 30 ℃, the reduction range is 50.0%, the thermal conductivity at 60 ℃ is reduced to 0.5363W/(m.K) from 1.023W/(m.K), the reduction range is 47.6%, and the thermal conductivity at 90 ℃ is reduced to 0.4974W/(m.K) from 0.9435W/(m.K), and the reduction range is 47.3%. In conclusion, the complex admixture can effectively reduce the heat conductivity coefficient of the cement paste.
(3) Thickening time test
The thickening time is the time elapsed from the start of the temperature rise and the pressure rise until the consistency reaches 100Bc, and the consistency of the cement slurry at the end of the thickening time test should be recorded. The minimum thickening time of the G-grade oil well cement is 90min according to the oil well cement requirement. After adding 1.188g of water reducer and 0.0792g of retarder into a cement system, performing a thickening test under the conditions of an initial test temperature of 27-28 ℃, an initial test pressure of 4.9MPa, a test circulation temperature of 65 ℃, a circulation pressure of 35MPa and a heating and boosting time of 40min to obtain a result
Table 12.
The cement slurry has the initial consistency of 10BC and the time for reaching 100BC is 119min, namely the thickening time is 119min, which meets the standard requirement of oil well cement. In practical engineering application, the retarder is increased or decreased according to practical requirements to adjust the thickening time.
In conclusion, various indexes such as compressive strength, heat conductivity coefficient and the like of the heat-insulating well cementation cement system proportion reach the standard of oil well cement, and the construction requirement is met.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (2)
1. The heat-insulating well cementation cement for geothermal development is characterized by comprising a cement base material, an external admixture and an additive;
the cement base material is G-level high-sulfate-resistant oil well cement; the external admixture comprises glass beads, perlite and rice hull ash; the additive is retarder and water reducer;
the weight ratio of the cement base material is 82%;
the weight ratio of the glass beads is 6%, and the particle size of the glass beads is 75-150 mu m;
the weight ratio of the perlite is 4%, and the particle size of the perlite is 18-28 mu m;
the mass ratio of the rice hull ash is 8%, and the grain diameter of the rice hull ash is 18-28 mu m;
the water reducer is polycarboxylic acid, and the weight ratio of the water reducer is 0.15% -0.2% of the total weight of the cement base material and the external admixture;
the retarder is sodium gluconate, and the weight ratio of the retarder to the retarder is 0.02-0.03% of the total weight of the cement base material and the external admixture.
2. The thermal insulating cement according to claim 1, further comprising water, and having a cement ratio of 0.44.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310230127.1A CN116375413A (en) | 2023-03-10 | 2023-03-10 | Thermal insulation well cementation cement for geothermal development |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310230127.1A CN116375413A (en) | 2023-03-10 | 2023-03-10 | Thermal insulation well cementation cement for geothermal development |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116375413A true CN116375413A (en) | 2023-07-04 |
Family
ID=86974128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310230127.1A Pending CN116375413A (en) | 2023-03-10 | 2023-03-10 | Thermal insulation well cementation cement for geothermal development |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116375413A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998054108A1 (en) * | 1997-05-26 | 1998-12-03 | Konstantin Sobolev | Complex admixture and method of cement based materials production |
| CN109265093A (en) * | 2018-11-27 | 2019-01-25 | 中国石油集团渤海钻探工程有限公司 | Ultra-Low Density Cement Slurries are used in well cementation |
| CN112714755A (en) * | 2018-09-18 | 2021-04-27 | 日产化学株式会社 | Silica-based additive for well cementing composition, well cementing composition and well cementing method |
| CN113045259A (en) * | 2019-12-26 | 2021-06-29 | 中国石油天然气股份有限公司 | Hydrophobic and breathable cement slurry adopted in natural gas well cementing and preparation method thereof |
-
2023
- 2023-03-10 CN CN202310230127.1A patent/CN116375413A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998054108A1 (en) * | 1997-05-26 | 1998-12-03 | Konstantin Sobolev | Complex admixture and method of cement based materials production |
| CN112714755A (en) * | 2018-09-18 | 2021-04-27 | 日产化学株式会社 | Silica-based additive for well cementing composition, well cementing composition and well cementing method |
| CN109265093A (en) * | 2018-11-27 | 2019-01-25 | 中国石油集团渤海钻探工程有限公司 | Ultra-Low Density Cement Slurries are used in well cementation |
| CN113045259A (en) * | 2019-12-26 | 2021-06-29 | 中国石油天然气股份有限公司 | Hydrophobic and breathable cement slurry adopted in natural gas well cementing and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 稽鹰 等: "玻璃微珠/珍珠岩/稻壳灰对固井水泥性能影响", 《非金属矿》, vol. 46, no. 1, 31 January 2023 (2023-01-31), pages 1 - 5 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103664114B (en) | Self-heat-insulating fly ash autoclaved aerated concrete block and preparation method thereof | |
| CN104829189B (en) | Phase-change energy-storing composite foam concrete block | |
| JP6871660B1 (en) | Oil shale slag concrete compounding ratio design method | |
| CN109336637B (en) | Foam concrete based on silicate-aluminosilicate composite adhesive material and preparation method thereof | |
| CN114315256A (en) | High-thermal-conductivity high-heat-insulation cement for geothermal well and preparation method thereof | |
| CN113620636A (en) | GBL concrete waterproof compacting agent | |
| CN103043970A (en) | Concrete for nuclear power station | |
| CN116375413A (en) | Thermal insulation well cementation cement for geothermal development | |
| CN112456878A (en) | Novel CO2High-temperature corrosion-resistant well cementation cement system for-EGS-mode hot dry rock | |
| CN111003988A (en) | C105 non-autoclaved tubular pile for cold area and preparation method thereof | |
| CN112321219B (en) | Heat-preservation well cementation cement system for dry hot rock production well | |
| CN116217193A (en) | Alkali-activated full-solid waste seawater sea sand coral concrete for island reefs and preparation process | |
| CN109574700A (en) | A kind of dispersion fibrous foam concrete and preparation method thereof | |
| CN114580200A (en) | Design method of high-performance recycled aggregate pervious concrete | |
| CN113603438A (en) | High-performance autoclaved aerated concrete material prepared from tailings and preparation method | |
| CN112321213A (en) | Heat insulation concrete and preparation method thereof | |
| CN113530242B (en) | Environment-friendly waterproof heat-preservation construction method | |
| CN113480247B (en) | Heat insulation concrete and preparation method thereof | |
| CN116084392B (en) | High-thermal-conductivity low-carbon energy pile and manufacturing method thereof | |
| CN118125757A (en) | Preparation process of light concrete | |
| CN115611586B (en) | Heat-insulating sound-insulating floor structure and preparation method thereof | |
| CN115403333B (en) | Durable cement mortar | |
| CN117809768B (en) | Method for evaluating compressive strength of fly ash foam concrete based on density | |
| CN117756456A (en) | SiO (silicon dioxide) 2 Aerogel composite vitrified microbead insulation board and preparation method thereof | |
| CN110577409B (en) | Building indoor energy storage and heat insulation material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |