Summary of the invention
Main purpose of the present invention is to provide a kind of double-decker well fracturing pressure break ball and preparation method thereof, to overcome deficiency of the prior art.
For realizing aforementioned invention object, the technical solution used in the present invention comprises:
A kind of double-decker well fracturing pressure break ball, it comprises hard macromolecule matrix and is coated on the elastic material layer on described matrix.
Comparatively preferred, described matrix forms primarily of thermoplastic, but is not limited thereto.
Comparatively preferred, be distributed with reinforcing material in described spherical substrate.
Comparatively preferred, described elastic material layer can be made up of the various elastomer being applicable to fracturing fluid environment.
Additionally provide a kind of method preparing described double-decker well fracturing pressure break ball among some embodiments of the present invention, it comprises:
Injection molding process is adopted by thermoplastic to make described matrix;
Elastic material is adopted to make spherical shell type structure;
The gap place that spherical substrate is reserved in described spherical shell type structure is pressed in described spherical shell type structure, carries out sealing process afterwards, thus form described pressure break ball to reserving gaps.
Compared with prior art, advantage of the present invention comprises: the double-decker well fracturing pressure break ball proportion provided is less, requirement on machining accuracy is low, during sealing, pressurize is respond well, and because having the double-decker of high resiliency skin+rigid core, there will not be the situation that pressure break ball damages because regional area stress concentrates, therefore the situation that underground pressure blastomere lost efficacy can significantly be reduced, and effectively improve the reliability of multi-level pressure break corollary equipment, simultaneously, this pressure break ball preparation technology is simple, is easy to control, with low cost.
Detailed description of the invention
Hereafter do more detailed explanation explanation by technical scheme of the present invention.But, should be appreciated that within the scope of the present invention, above-mentioned each technical characteristic of the present invention and can combining mutually between specifically described each technical characteristic in below (eg embodiment), thus form new or preferred technical scheme.As space is limited, tiredly no longer one by one to state at this
One aspect of the present invention provides a kind of double-decker well fracturing pressure break ball, and its skin is elastic material, can improve the problem sealing and improve stress and concentrate situation to bring.
Among some embodiments, described double-decker well fracturing pressure break bag is drawn together hard macromolecule matrix and is coated on the elastic material layer on described matrix.
Refer to Fig. 1, among an exemplary embodiments, described pressure break bag is drawn together as the hard macromolecule spherical substrate 1 of core and the elastic material clad 2 as shell.
Preferably, the material in order to form described matrix comprises the thermoplastic of compressive strength at more than 70MPa, such as polypropylene, polyester, polyamide, polyvinyl alcohol, polyether-ether-ketone, polyethersulfone resin, polystyrene, polybutylene terephthalate (PBT), Merlon, polytetrafluoroethylene (PTFE), Kynoar, any one or two or more combinations in ethylene-tetrafluoroethylene copolymer and ethylene-chlorotrifluoro-ethylene copolymer, and be not limited thereto.
Among some comparatively preferred embodiments, in described matrix, be also distributed with reinforcing material and/or density controlling material.
Further, described reinforcing material comprises fortifying fibre if glass fiber, carbon fiber etc. or graininess reinforcing material are as hollow glass bead etc.
Further, described fortifying fibre comprises carbon fiber and/or glass fiber.
Comparatively preferred, described matrix comprises 10wt% ~ 60wt% carbon fiber and/or glass fiber.
Preferably, the diameter of described fortifying fibre is 0.01-50 μm, is especially preferably 1-10 μm, more preferably 5-8 μm.
Preferably, the modulus of elasticity of described fortifying fibre is greater than 5GPa, is especially preferably greater than 10GPa.
Further, described graininess reinforcing material can select hollow glass bead etc.
Further, described density controlling material comprises hollow beads, such as hollow glass bead.
Among some embodiments, described matrix can comprise: thermoplastic 60wt% ~ 70wt%, fortifying fibre 5wt% ~ 30wt%, hollow glass bead 5wt% ~ 25wt%.
Preferably, the diameter of described hollow glass bead is 0.1-200 μm, is especially preferably 1-100 μm.
Preferably, the density of described hollow glass bead is 0.2-1.5g/cm3, be preferably less than 1.4g/cm further3, be especially preferably 0.4-1.0g/cm3.
Comparatively preferred, the Shore A hardness value of described elastic material is more than 70, such as can be selected from one or both and the above combination in general purpose rubber or specific rubber and modified product thereof, modified natural rubber can be selected from more specifically, modified butadiene acrylonitrile rubber, modified hydrogenated acrylonitrile-butadiene rubber, fluorubber, modified polyurethane etc., but be not limited thereto.
Comparatively preferred, the diameter of described matrix is 10mm ~ 146.1mm.
Comparatively preferred, the thickness of described elastic material layer is 0.1mm ~ 140mm.
Comparatively preferred, the density of described pressure break ball is 1.14g/cm3~ 1.46g/cm3.
Comparatively preferred, the compressive strength of described pressure break ball, at more than 27MPa, is preferably greater than 70MPa further.
Comparatively preferred, the compressive strength of described pressure break ball is not less than 70MPa.
Another aspect of the present invention provides a kind of method preparing described double-decker well fracturing pressure break ball, and it comprises:
Injection molding process is adopted by thermoplastic to make described matrix;
Elastic material is adopted to make spherical shell type structure;
The gap place that spherical substrate is reserved in described spherical shell type structure is pressed in described spherical shell type structure, carries out sealing process afterwards, thus form described pressure break ball to reserving gaps.
Comparatively preferred, described preparation method comprises:
After fully mix as the material such as nylon 6/6, polyether-ether-ketone (PEEK) of base material and carbon fiber, glass fiber etc., the method for employing injection mo(u)lding, particularly high-pressure injection molding makes spherical substrate;
The elastic material such as modified hydrogenated acrylonitrile-butadiene rubber, fluorubber are adopted to make spherical shell;
By in gap place press-in spherical shell reserved on described spherical shell for spherical substrate, afterwards sealing process is carried out to reserving gaps, thus form described pressure break ball.
Below in conjunction with some embodiments, more specifically explanation is explained to technical scheme of the present invention.
Embodiment 1:
The pressure break bag of the present embodiment draws together spheroidal nylon 6/6 matrix, carbon fiber (diameter 1-10 μm is distributed with in described spheroidal nylon 6/6 matrix, intensity 5-10GPa), and described spheroidal nylon 6/6 matrix is enclosed with the modified hydrogenated acrylonitrile-butadiene rubber layer of tensile modulus of elasticity at about 30MPa.The diameter of described spheroidal nylon 6/6 matrix is about 44.45mm, and the thickness of described modified hydrogenated acrylonitrile-butadiene rubber layer is about 3mm.
Further, described spheroidal nylon 6/6 matrix comprises (in wt%): nylon 9 0%, carbon fiber 10%.
Further, the molding shrinkage of described spheroidal nylon 6/6 matrix is about 0.05%-0.2%.
The proportion about 1.14 of the pressure break ball of the present embodiment, compressive strength is about 230MPa.
Spheroidal nylon 6/6 matrix of the present embodiment is prepared by Shooting Technique, and molding proces s parameters is: injection molding temperature 280 DEG C ~ 310 DEG C, pressure 120MPa ~ 140MPa, mould temperature 70 DEG C ~ 120 DEG C.
And modified hydrogenated acrylonitrile-butadiene rubber layer makes spherical shell by common process, and can reserving gaps on this spherical shell.
Afterwards, can spheroidal nylon 6/6 matrix be pressed in this spherical shell from this gap, afterwards sealing process be carried out to this gap, form described pressure break ball.
When applying the pressure break ball of the present embodiment and carrying out pressure break test, can find, this pressure break ball can be used for temperature not higher than 135 DEG C of most of chemical environments except strong acid-base, and applicable fracturing fluid density range is not higher than 1.14g/cm3, the down-hole pressurize of at least 90MPa can be reached.
Embodiment 2:
The pressure break bag of the present embodiment draws together spheroidal polyether-ether-ketone matrix, is distributed with that length is about 11mm, diameter is about the long glass fibres of 7-13 μm in described spheroidal polyether-ether-ketone matrix.And described spheroidal polyether-ether-ketone matrix is enclosed with fluororubber layer.The diameter of described spheroidal polyether-ether-ketone matrix is about 44.45mm, and the thickness of described fluororubber layer is about 3mm.
Further, described polyether-ether-ketone matrix comprises (in wt%): polyether-ether-ketone 60%, long glass fibres 40%.
The proportion about 1.40 of the pressure break ball of the present embodiment, compressive strength is about 270MPa.
The present embodiment pressure break ball can reference example 1 technique preparation.
Embodiment 3:
The difference of the present embodiment and embodiment 1 is, (diameter is about 12-48 μm, and density is about 0.6g/cm also to include the hollow glass bead of 16wt% in matrix3), elastic material layer adopts natural rubber to form.
The proportion about 1.14 of the pressure break ball of the present embodiment, compressive strength is about 230MPa.
The present embodiment pressure break ball can reference example 1 technique preparation.
Embodiment 4:
The difference of the present embodiment and embodiment 2 is, matrix mainly adopts PDVF to become, and (diameter is about 8-24 μm, and density is about 0.6g/cm wherein also to include the hollow glass bead of 23wt%3), the polyurethane that elastic material layer adopts hardness to be about 80HA is formed.
The proportion about 1.18 of the pressure break ball of the present embodiment, compressive strength is about 100MPa.
The present embodiment pressure break ball can reference example 1 technique preparation.
In addition, inventor also utilizes the corresponding raw material in the alternate embodiment 1-4 such as other listed raw material and other process conditions and process conditions to carry out similar test above, obtain the compressive strength of pressure break ball all at more than 100MPa, density is all at 1.0g/cm3left and right, these pressure break balls substantially can both the most of chemical environment of tolerable temperature more than 120 DEG C except strong acid-base etc.
It should be noted last that, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted.Although with reference to embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that, modify to technical scheme of the present invention or equivalent replacement, do not depart from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.