A kind of composite particles, preparation method and applicationTechnical field
The present invention relates to oil gas well cementing operation technical field, in particular to a kind of composite particles, preparation method and application.
Background technique
As gas well annular space phenomenon with pressure is more and more common, the sealing quality and durability of cement sheath are increasingly by industryInterior attention.But traditional cements stone is a kind of fragile material, is easy to appear and splits in oil well long-term production or operation process cement sheathLine or microannulus, lead to wellheadpressure.The application of especially current shale oil gas, fine and close oil/gas well staged fracturing technology, it is rightBehavior of Hardened Cement Paste elastic deformation energy force request is higher, it is desirable that Behavior of Hardened Cement Paste can couple casing deformation.Therefore in order to effectively improve Behavior of Hardened Cement PasteLong term seal ability, need to be effectively improved the mechanical property of Behavior of Hardened Cement Paste, improve the deformability of Behavior of Hardened Cement Paste, cement is effectively reducedThe elasticity modulus of stone, and guarantee the enough intensity of Behavior of Hardened Cement Paste.The currently used material for improving Behavior of Hardened Cement Paste elastic property mainly has:The substances such as styrene-butadiene latex latex, styrene-acrylic latex, rubber grain and organic resin class, but latex and organic resin substance are because of priceHigh and limit being widely used for they, rubber grain and resin material are affected due to temperature resistance ability difference and the defect of itselfIts application in oil gas well cementing operation.Wherein rubber grain becomes many elastic cements slurries due to from a wealth of sources, cheapThe preferred material of system, but its surface hydrophobicity, and easily floating and temperature tolerance are poor, its application is caused to receive biggish limitSystem.
It is therefore desirable to develop a kind of novel elastic material based on core-shell structure, enable the cement slurry to be formedBehavior of Hardened Cement Paste elasticity modulus is reduced, Behavior of Hardened Cement Paste brittleness is reduced, increases Behavior of Hardened Cement Paste deformability, and rationally reduce cost.
Summary of the invention
One of present invention provides a kind of composite particles, and the composite particles are by the elastic granule as kernel and are coated onThe rigid particles as shell of the kernel outer surface form.
In addition, the possibility for carrying out physical modification to elastic granule is realized by mechanical coating technology, by elasticityThe material of grain surface physics cladding rigidity such as SILICA FUME, flyash, especially has the hydraulicity and/or alkali-activated carbonatite volcanic ashThe material of matter realizes non-porous cladding, can be effectively improved the water-wet behavior of inner nuclear material, further improves elastic granule and cementCementation between stone, improves the temperature resistant capability and stability of elastic granule, while can improve Mechanical Behavior of Hardened Cement Paste, effectively dropsLow Behavior of Hardened Cement Paste elasticity modulus increases Behavior of Hardened Cement Paste strain rate.Therefore, using the composite particles of core-shell structure of the invention, Neng GouyouEffect ground meets high temperature well cementing requirements.
It should be pointed out that the kernel of composite particles of the invention only has an elastic granule, and the number of the particle of shellAmount is far above one, but to reach the quantity of non-porous cladding and/or continuous cladding elastic granule.Wherein non-porous cladding refers to packetAfter being covered with the non-porous experimental test of the embodiment 7 of the composite particles of shell of the invention through the invention, fail to find diesel oil groupThe cladding divided；It is continuous to coat the non-porous examination for referring to the embodiment 7 of the composite particles for being coated with shell of the invention through the inventionAfter test examination, the cladding of diesel component can be found.
In a specific embodiment, the shell is coated on the outer layer of the kernel in non-porous form.Using non-porousCladding can effectively prevent water from penetrating by shell, prevent core water-swellable, while can reduce the ratio of mud in cement slurry, improve waterMudstone mechanical property.
When elastic material is in reasonable dosage proportional region, can guarantee Behavior of Hardened Cement Paste, elastic deformation amount exists under compressionBetween 0.1-0.5%, it at this moment can be effectively prevent the destruction of the factors to Behavior of Hardened Cement Paste such as staged fracturing and thermal expansion, to guarantee solidThe long term seal ability of Behavior of Hardened Cement Paste after well improves safety in production time and the Inter-zonal packing effect of oil/gas well.Therefore, have at oneIn body embodiment, the ratio of the thickness of the average grain diameter of the kernel and the shell is 2:1-8:1, preferably 2:1-5:1.
In a specific embodiment, the elastic granule includes the latex powder that elasticity modulus is less than 1.5GPa, preferably instituteStating elastic granule includes acrylonitrile-butadiene rubber powder and/or styrene butadiene rubber powder.
In a specific embodiment, the average grain diameter of the elastic granule is 100-180 microns, partial size d50=110-165 microns；It is preferred that 120-140 microns of the average grain diameter of the elastic granule, partial size d50=125-145 microns.
In a specific embodiment, the shore hardness of the elastic granule is 60-100, and in mass, phosphorus content is less thanOr it is equal to 1.0%；It is preferred that the shore hardness of the elastic granule is 70-85, phosphorus content is less than or equal to 0.5%.
In a specific embodiment, the rigid particles are the material with the hydraulicity and/or alkali-activated carbonatite volcano grey matter,It is preferred that the material includes at least one of silicon ash, flyash and metakaolin.
In a specific embodiment, the flat average grain diameter of the rigid particles is 1.0-10.0 microns, particle diameter distribution d50=1.35-8.5 microns；Preferably 1.3-5.6 microns, particle diameter distribution d50=1.35-5.4 microns.
The two of the present invention provide a kind of method for preparing composite particles as described above comprising following steps:
Air-flow carries the elastic granule secretly and the rigid particles do relative motion in confined conditions, thus described in being formedComposite particles.
In a specific embodiment, the mass ratio of the elastic granule and the rigid particles is 100:(10-50),Preferably 100:(20-30).
In a specific embodiment, the system revolving speed for controlling the air-flow is 1500-3000rpm；It is preferred that the systemRevolving speed is 2000-2500rpm.
In a specific embodiment, the elastic granule is carried secretly using air-flow and the rigid particles do relative motionTime is 20-30 minutes.
The three of the present invention provide a kind of application of composite particles as described above in oil gas well cementing operation.
Compared with prior art, the beneficial effects of the present invention are:
(1) composite particles temperature tolerance of the invention is high, improves the acidproof alkali ability of elastic granule；
(2) composite particles stability of the invention is good；
(3) composite particles of the invention are good with cement slurry compatibility, and in cement slurry maintenance processes, composite particles do not occurHydro-planing, while there is not thickening behavior in cement slurry, so that cement slurry property be made to be greatly improved；
(4) composite particles of the invention can be substantially reduced Behavior of Hardened Cement Paste elasticity modulus, increase the deformability of Behavior of Hardened Cement Paste；
(5) composite particles of the invention are spherical shape, are conducive to the mobility for increasing cement slurry.
Detailed description of the invention
The structural schematic diagram of core-shell structure composite particles is shown in Fig. 1, and wherein inner core is elastic granule, and outside is rigidProperty particles coat kernel formed shell.
The forming process schematic diagram of composite particles is shown in Fig. 2, can carry out ball to elastic material first as neededShape, then with spheroidization treated rigid particles, such as silicon ash is after mixing, impacts composite algorithm shape using dry type laterAt the particle of continuous and/or non-porous cladding.
PCS-1 system flow chart is shown in Fig. 3；Wherein, 1 is loading hopper, and 2 be sample injector, and 3 be processing system, and 4 be coldBut system, 5 be control system.
Microstructure of the composite particles under scanning electron microscope is shown in Fig. 4, as can be seen from the figure the ball of composite particlesShape degree is very high.
Specific embodiment
In the present invention, using compound particle hybrid system (Tsinghua University, PCS-1), composite algorithm, benefit are impacted using dry typeCarried under one's arms particle with the high-speed flow that equipment rotation generates and done high speed relative motion, by impact make elastic granule and rigid particles withVan der Waals force and electrostatic force generation are compound, form the elastic particle of core-shell structure.By adjusting system revolving speed in 1500-3000r/min, control system put into raw material, open row's powder switch by control cabinet again after running 20-30min, arrange powder 15-20min forms final products.
In the present invention, elasticity modulus, accepted standard GB/T are measured using instrument ToniPrax (Germany)23561.8.Poisson's ratio is measured using instrument ToniPrax (Germany), accepted standard is GB/T 50081-2002).Using beautyState instrument Instron2450-200 measures compression strength and tensile strength, and accepted standard is GB/T 50081-2002, whereinCompression strength and tensile strength use same device measuring).
Embodiment 1
By 100 parts by weight, average grain diameter is 120 microns, partial size d50=123 microns, elasticity modulus 0.6GPa, shore is hardDegree is 70, and (average grain diameter is 1.45 micro- in the silicon ash after 30 parts of the nitrile rubber particle addition ball-types that phosphorus content is 0.5wt%Rice, partial size d50It=1.40 microns, stirs evenly, and adjusts compound particle hybrid system (Tsinghua University, PCS-1) revolving speed 2500Rev/min, it controls charging rate 5kg/ minutes, coats the time 30 minutes, collecting average grain diameter is 180 microns, partial size d50=175The composite particles of micron.
Embodiment 2
By 100 parts by weight, average grain diameter is 180 microns, partial size d50=165 microns, elasticity modulus 0.8GPa, shore is hardDegree is 85, and 20 parts by weight after ball-type are added in the butadiene-styrene rubber particle that phosphorus content is 0.5%, and average grain diameter is 5.6 microns, grainDiameter d50=5.4 microns, phosphorus content is controlled to stir evenly, and adjust 2000 revs/min of PCS-1 revolving speed in 0.5% flyashIt charging rate 5kg/ minutes processed, coats the time 20 minutes, collects 250 microns of product average grain diameter, partial size d50=240 microns answerClose particle.
Embodiment 3
By 100 parts by weight, average grain diameter is 120 microns, partial size d50=125 microns, elasticity modulus 0.5GPa, shore is hardDegree is 60, and 10 parts by weight after ball-type are added in the butadiene-styrene rubber particle that phosphorus content is 0.5%, and average grain diameter is 1.6 microns, grainDiameter d50It in=1.2 microns of metakaolin, stirs evenly, and adjusts 1000 revs/min of PCS-1 revolving speed, control charging rateIt 5kg/ minutes, coats the time 20 minutes, collects 215 microns of product average grain diameter, partial size d50=220 microns of composite particles.
Embodiment 4
By 100 parts by weight, average grain diameter is 100 microns, partial size d50=110 microns, elasticity modulus 1GPa, shore hardnessIt is 90,50 parts by weight after ball-type are added in the butadiene-styrene rubber particle that phosphorus content is 0.5%, and average grain diameter is 1.0 microns, partial sized50=1.35 microns, phosphorus content controls to stir evenly, and adjust 3000 revs/min of PCS-1 revolving speed in 0.5% flyashIt charging rate 5kg/ minutes, coats the time 20 minutes, collects 200 microns of product average grain diameter, partial size d50=189 microns compoundParticle.
Embodiment 5
By 100 parts by weight, average grain diameter is 120 microns, and particle diameter distribution index is d50=125 microns, elasticity modulus is25 parts by weight after ball-type, average grain is added in 1.5GPa, shore hardness 100, the butadiene-styrene rubber particle that phosphorus content is 0.5%Diameter is 1.3 microns, partial size d50=1.35 microns, phosphorus content be 0.5% flyash in, stir evenly, and adjust PCS-1 revolving speedIt 2000 revs/min, controls charging rate 5kg/ minutes, coats the time 20 minutes, collect 233 microns of product average grain diameter, partial sized50=240 microns of composite particles.
Embodiment 6
By 100 parts by weight, average grain diameter is 141 microns, partial size d50=145 microns, elasticity modulus 0.7GPa, shore is hardDegree is 80, and 40 parts by weight after ball-type are added in the butadiene-styrene rubber particle that phosphorus content is 1.0%, and average grain diameter is 10.0 microns,Partial size d50=8.5 microns, phosphorus content be 0.5% flyash in, stir evenly, and adjust 2000 revs/min of PCS-1 revolving speed,Control charging rate 5kg/ minutes coats the time 20 minutes, collects 215 microns of product average grain diameter, partial size d50=210 micronsComposite particles.
Embodiment 7
30 sample of composite particles grab sample that will be prepared in embodiment 1, divides 3 groups, every group of 10 samples impregnate diesel oil respectivelyIn 24 hours, room temperature is air-dried 2 hours using air-dry machine, destroy core-shell structure, take core carry out spectrofluorimetry, first group 99 sample, second group of 10 sample, third group samples, do not find diesel component, illustrate to realize 90% or more non-porous cladding.
Also, other embodiments also play similar effect.
Comparative example 1
For the improvement for comparing addition composite particles with being not added with compound particle Mechanical Behavior of Hardened Cement Paste, make firstOrdinary water mudstone test sample, that is, be not added with compound particle, using 100 parts of cement (good G grades of China, Dezhou continental shelf company), drop filterIt loses 5 parts of agent (DZJ-Y, Dezhou continental shelf company), 1.2 parts of dispersing agent (DZS, Dezhou continental shelf company), retarder (DZH-2, moralState continental shelf company) 1.5 parts, 40 parts of water, 0.2 part of defoaming agent (DZX, Dezhou continental shelf company) configures the water of traditional performanceMud system, density 1.9g/cm3, conserve 72 hours under 80 DEG C and 20MPa environment, measurement elasticity modulus, Poisson's ratio, resistance to compressionIntensity and tensile strength.It the results are shown in Table 1.
Embodiment 8
Using 100 parts of cement (good G grades of China, Dezhou continental shelf company), fluid loss additive (DZJ-Y, Dezhou continental shelf company) 5Part, 1.2 parts of dispersing agent (DZS, Dezhou continental shelf company), 1.5 parts of retarder (DZH-2, Dezhou continental shelf company), 40 parts of water,6 parts of the composite particles prepared in embodiment 1- embodiment 7,0.2 part of defoaming agent, configuring density is 1.9g/cm3, 80 DEG C andIt is conserved 72 hours under 20MPa environment, measurement elasticity modulus, Poisson's ratio, compression strength and tensile strength.It the results are shown in Table 1.
Compared with comparative example 1, Behavior of Hardened Cement Paste elasticity modulus obviously drops after adding the composite particles in embodiment 1- embodiment 7Low, deformability is most strong.
The present embodiment the results show that composite particles can effectively improve the temperature tolerance of original elastic granule, stability withAnd it is cementing with cement, while Behavior of Hardened Cement Paste elasticity modulus is greatly reduced.The effective hard crisp characteristic for improving Behavior of Hardened Cement Paste, improves cementThe durability of stone is conducive to the long-term sealing ability for improving gas well Behavior of Hardened Cement Paste, and meets the segmentation of the unconventional oil and gas such as shale gasDemand of the pressure break to Behavior of Hardened Cement Paste.
Table 1
| Embodiment | Behavior of Hardened Cement Paste elasticity modulus | Poisson's ratio | Compression strength | Tensile strength |
| Embodiment 1 | 3.2GPa | 0.20 | 14.5MPa | 2.0MPa |
| Embodiment 2 | 3.0GPa | 0.21 | 10.5MPa | 1.7MPa |
| Embodiment 3 | 2.8GPa | 0.22 | 8.4MPa | 1.45MPa |
| Embodiment 4 | 3.8GPa | 0.20 | 16.2MPa | 2.1MPa |
| Embodiment 5 | 3.2GPa | 0.20 | 15.4MPa | 2.1MPa |
| Embodiment 6 | 2.8GPa | 0.21 | 8.2MPa | 1.7MPa |
| Comparative example 1 | 11.5GPa | 0.19 | 28.5MPa | 2.4MPa |