阅读说明：本技术 固井系统及套管接头 (Cementing system and casing joint ) 是由 李军 连威 汪伟 张辉 席岩 于 2019-08-23 设计创作，主要内容包括：本发明公开了一种固井系统及套管接头,所述套管接头包括沿轴向延伸的本体,所述本体沿轴向具有相对的第一端和第二端；设于所述第一端的第一接头,所述第一接头用于与固井套管相连接；设于所述第二端的第二接头,所述第二接头用于与固井套管相连接；贴合套设于所述本体外的缓冲套,所述本体设有对所述缓冲套进行轴向限位的限位部；所述缓冲套的弹性模量小于所述本体的弹性模量,所述缓冲套的弹性模量小于水泥环的弹性模量,所述缓冲套用于对所述本体沿径向的形变进行缓冲；所述缓冲套外壁的外径大于所述本体的最大外径。本发明所提供的固井系统及套管接头,能够在不增加固井成本的同时,有效避免环空带压。(The invention discloses a kind of cementing system and casing joint, described sleeve pipe connector includes the ontology axially extended, and the ontology has opposite first end and second end along axial；Set on the first connector of the first end, first connector with well cementing casing pipe for being connected；Set on the second connector of the second end, second connector with well cementing casing pipe for being connected；Fitting sle is set to described external cushion collar, and the ontology is equipped with the limiting section that axial limiting is carried out to the cushion collar；The elasticity modulus of the cushion collar is less than the elasticity modulus of the ontology, and the elasticity modulus of the cushion collar is less than the elasticity modulus of cement sheath, and the cushion collar is for buffering the deformation of the ontology radially；The outer diameter of the cushion collar outer wall is greater than the maximum outside diameter of the ontology.Cementing system provided by the present invention and casing joint can effectively avoid annular space with pressure while not increasing well cementation cost.)

1. a kind of cementing system characterized by comprising

Multiple well cementing casing pipes, there is cement to inject gap between the well cementing casing pipe and stratum, and cement injection gap is used for It injects cement slurry and forms cement sheath；At least two adjacent well cementing casing pipes are connected by casing joint, described sleeve pipe connector packet It includes:

The ontology axially extended, the ontology have opposite first end and second end along axial；

Set on the first connector of the first end, first connector with well cementing casing pipe for being connected；

Set on the second connector of the second end, second connector with well cementing casing pipe for being connected；

Fitting sle is set to described external cushion collar, and the ontology is equipped with the limit that axial limiting is carried out to the cushion collar Portion；The elasticity modulus of the cushion collar is less than the elasticity modulus of the ontology, and the elasticity modulus of the cushion collar is less than cement sheath Elasticity modulus, the cushion collar is for buffering the deformation of the ontology radially；The outer diameter of the cushion collar outer wall Greater than the maximum outside diameter of the ontology；The cushion collar is between the ontology and the cement sheath；Outside the cushion collar Wall is equipped with multiple insertion protrusions, and the insertion protrusion is inserted into the cement slurry in cement injection gap, and in the cement slurry Solidification is fixed in the cement sheath when forming the cement sheath.

2. a kind of casing joint characterized by comprising

The ontology axially extended, the ontology have opposite first end and second end along axial；

Set on the first connector of the first end, first connector with well cementing casing pipe for being connected；

Set on the second connector of the second end, second connector with well cementing casing pipe for being connected；

Fitting sle is set to described external cushion collar, and the ontology is equipped with the limit that axial limiting is carried out to the cushion collar Portion；The elasticity modulus of the cushion collar is less than the elasticity modulus of the ontology, and the elasticity modulus of the cushion collar is less than cement sheath Elasticity modulus, the cushion collar is for buffering the deformation of the ontology radially；The outer diameter of the cushion collar outer wall Greater than the maximum outside diameter of the ontology.

3. casing joint according to claim 2, which is characterized in that the limiting section includes being set to the body outer wall Groove, along axial length and the cushion collar along axial equal length, the cushion collar is sheathed on described recessed the groove In slot, the inner wall of the cushion collar is bonded with the groove surfaces.

4. casing joint according to claim 3, which is characterized in that the upper end of the cushion collar protrudes from the groove Part is equipped with the first water conservancy diversion inclined-plane；The outer diameter of first water conservancy diversion inclined-plane from top to bottom is gradually expanded；First water conservancy diversion inclined-plane Inclination extends to the outside wall surface that the ontology is located on the upside of the groove upwards.

5. casing joint according to claim 4, which is characterized in that the lower end of the cushion collar protrudes from the groove Part is equipped with the second water conservancy diversion inclined-plane；The outer diameter of second water conservancy diversion inclined-plane from top to bottom is gradually reduced；Second water conservancy diversion inclined-plane It tilts down and extends to the outside wall surface that the ontology is located on the downside of the groove.

6. casing joint according to claim 2, which is characterized in that the outer wall of the cushion collar is equipped with multiple for being inserted into Insertion protrusion in cement sheath；The material of the cushion collar is vulcanization anticorrosion rubber.

7. casing joint according to claim 2, which is characterized in that be equipped with more inside the cushion collar from upper end under The steel wire extended is held, at least two steel wires, which intersect, extends.

8. casing joint according to claim 7, which is characterized in that the upper end of the cushion collar has multiple circumferentially equal First steel wire endpoint of even distribution；The lower end of the cushion collar has multiple and the first steel wire endpoint one-to-one second Steel wire endpoint；The every steel wire extends to second steel being staggered with it along axial direction from the first steel wire endpoint Silk point；Central angle size corresponding to the every steel wire is identical；Corresponding to circumferentially adjacent two the first steel wire endpoints Two steel wire extending directions it is opposite.

9. casing joint according to claim 2, which is characterized in that first connector be pin thread screw thread, described second Connector is female thread screw thread；The internal diameter of described sleeve pipe connector is identical as the internal diameter of adjacent well cementing casing pipe, the internal diameter of described sleeve pipe connector For 104.8mm-121.36mm.

10. casing joint according to claim 2, which is characterized in that the length of described sleeve pipe connector is 1000mm- 2000mm；The outer diameter of the cushion collar is 160mm-195mm.

Technical field

The present invention relates to petrol resources exploitation technical field, in particular to a kind of cementing system and casing joint.

Background technique

The description of this part only provides and discloses relevant background information to the application, without constituting the prior art.

One of the important technical that hydraulic fracturing is developed as shale gas, by into formation at target locations inject fracturing fluid with And proppant to be to form artificial seam net, so that allowing shale gas to be changed into free state from adsorbed state ultimately forms business air-flow.

However hydraulic fracturing pump pressure is high, discharge capacity is big, and the casing, cement sheath, stratum of nearly near wellbore is made to bear higher set Pipe internal pressure and temperature change are unfavorable for cementing concrete ring and keep leakproofness.When casing internal pressure is higher, cement sheath may go out It is now plastically deformed and even destroys, eventually lead to downhole fluid causes annular space with pressure by cement sheath channelling to the well head to fail. Annular space is with pressure to will lead to that security risk in shale gas well production process is high, and cost dramatically increases, and subsequent improvements difficulty, serious shadow Well yield and the production cycle for having rung shale gas well greatly hinder the safe and efficient exploitation of shale gas.

Avoiding annular space main method with pressure at present is the mortar architecture using low elastic modulus.However this method is very big Ground increases well cementation cost, and it avoids the effect of annular space phenomenon with pressure not significant.

It should be noted that the above description of the technical background be intended merely to it is convenient to technical solution of the present invention carry out it is clear, Complete explanation, and facilitate the understanding of those skilled in the art and illustrate.Cannot merely because these schemes of the invention Background technology part is expounded and thinks that above-mentioned technical proposal is known to those skilled in the art.

Summary of the invention

In view of the deficiencies in the prior art, the object of the present invention is to provide a kind of cementing system and casing joint, with can be While not increasing well cementation cost, effectively avoid annular space with pressure.

Following technical proposal can be used to realize in above-mentioned purpose of the invention:

A kind of cementing system, comprising:

Multiple well cementing casing pipes, there is cement to inject gap between the well cementing casing pipe and stratum, and the cement injects gap Cement sheath is formed for injecting cement slurry；At least two adjacent well cementing casing pipes are connected by casing joint, and described sleeve pipe connects Head include:

The ontology axially extended, the ontology have opposite first end and second end along axial；

Set on the first connector of the first end, first connector with well cementing casing pipe for being connected；

Set on the second connector of the second end, second connector with well cementing casing pipe for being connected；

Fitting sle is set to described external cushion collar, and the ontology is equipped with the limit that axial limiting is carried out to the cushion collar Position portion；The elasticity modulus of the cushion collar is less than the elasticity modulus of the ontology, and the elasticity modulus of the cushion collar is less than cement The elasticity modulus of ring, the cushion collar is for buffering the deformation of the ontology radially；Outside the cushion collar outer wall Diameter is greater than the maximum outside diameter of the ontology；The cushion collar is between the ontology and the cement sheath；The cushion collar Outer wall is equipped with multiple insertion protrusions, and the insertion protrusion is inserted into the cement slurry in cement injection gap, and in the cement Slurry solidification is fixed in the cement sheath when forming the cement sheath.

A kind of casing joint, comprising:

The ontology axially extended, the ontology have opposite first end and second end along axial；

Set on the first connector of the first end, first connector with well cementing casing pipe for being connected；

Set on the second connector of the second end, second connector with well cementing casing pipe for being connected；

Fitting sle is set to described external cushion collar, and the ontology is equipped with the limit that axial limiting is carried out to the cushion collar Position portion；The elasticity modulus of the cushion collar is less than the elasticity modulus of the ontology, and the elasticity modulus of the cushion collar is less than cement The elasticity modulus of ring, the cushion collar is for buffering the deformation of the ontology radially；Outside the cushion collar outer wall Diameter is greater than the maximum outside diameter of the ontology.

In one preferred embodiment, the limiting section includes the groove set on the body outer wall, the groove Along axial length and the cushion collar along axial equal length, the cushion collar is sheathed in the groove, the buffering The inner wall of set is bonded with the groove surfaces.

In one preferred embodiment, the part that the upper end of the cushion collar protrudes from the groove is equipped with first and leads Flow inclined-plane；The outer diameter of first water conservancy diversion inclined-plane from top to bottom is gradually expanded；First water conservancy diversion inclined-plane tilts upwards to be extended to The ontology is located at the outside wall surface on the upside of the groove.

In one preferred embodiment, the part that the lower end of the cushion collar protrudes from the groove is equipped with second and leads Flow inclined-plane；The outer diameter of second water conservancy diversion inclined-plane from top to bottom is gradually reduced；Second water conservancy diversion inclined-plane, which tilts down, to be extended to The ontology is located at the outside wall surface on the downside of the groove.

In one preferred embodiment, the outer wall of the cushion collar is equipped with multiple insertions for being inserted into cement sheath Protrusion；The material of the cushion collar is vulcanization anticorrosion rubber.

In one preferred embodiment, the more steel wires extended from upper end to lower end are equipped with inside the cushion collar, At least two steel wires, which intersect, extends.

In one preferred embodiment, the upper end of the cushion collar has multiple the first steel being uniformly distributed circumferentially Silk endpoint；The lower end of the cushion collar has the multiple and one-to-one second steel wire endpoint of the first steel wire endpoint；Every The steel wire extends to the second steel wire point being staggered with it along axial direction from the first steel wire endpoint；Described in every Central angle size corresponding to steel wire is identical；Two steel wires corresponding to circumferentially adjacent two the first steel wire endpoints extend It is contrary.

In one preferred embodiment, first connector is pin thread screw thread, and second connector is female thread screw thread； The internal diameter of described sleeve pipe connector is identical as the internal diameter of adjacent well cementing casing pipe, and the internal diameter of described sleeve pipe connector is 104.8mm- 121.36mm。

In one preferred embodiment, the length of described sleeve pipe connector is 1000mm-2000mm；The cushion collar Outer diameter is 160mm-195mm.

The features and advantages of the invention are: the casing joint that the application embodiment provides, for connecting adjacent two Well cementing casing pipe, casing joint are externally provided with the cushion collar, can protect the cement sheath between cushion collar and stratum, make cement sheath Leakproofness, integrality are guaranteed, and the annular space as caused by cement sheath seal failure is with pressure when scientifically avoiding hydraulic fracturing Problem.Meanwhile described sleeve pipe joint structure it is simple, without complicated matching piece or driving device, and it is easy for installation, be suitble to scene quickly Installation.

Referring to following description and accompanying drawings, specific implementations of the present application are disclosed in detail, specify the original of the application Reason can be in a manner of adopted.It should be understood that presently filed embodiment is not so limited in range.

The feature for describing and/or showing for a kind of embodiment can be in a manner of same or similar one or more It uses in a other embodiment, is combined with the feature in other embodiment, or the feature in substitution other embodiment.

It should be emphasized that term "comprises/comprising" refers to the presence of feature, one integral piece, step or component when using herein, but simultaneously It is not excluded for the presence or additional of one or more other features, one integral piece, step or component.

Detailed description of the invention

Fig. 1 is a kind of structural schematic diagram of the casing joint provided in the application embodiment；

Fig. 2 is the sectional view in Fig. 1 at A-A；

Fig. 3 is the sectional view in Fig. 1 at B-B；

Fig. 4 is a kind of structural perspective of the cushion collar provided in the application embodiment；

Fig. 5 is that the structural schematic diagram at underground is applied in a kind of casing joint provided in the application embodiment.

Description of symbols:

1, ontology；2, groove；3, the first connector；4, cushion collar；5, the first water conservancy diversion inclined-plane；6, insertion protrusion；7, steel wire；8, Cement slurry；9, stratum；10, well cementing casing pipe；11, the second connector；12, the second water conservancy diversion inclined-plane.

Specific embodiment

In order to make those skilled in the art better understand the technical solutions in the application, below in conjunction with the application reality The attached drawing in example is applied, the technical scheme in the embodiment of the application is clearly and completely described, it is clear that described implementation Example is merely a part but not all of the embodiments of the present application.Based on the embodiment in the application, this field is common The application guarantor all should belong in technical staff's every other embodiment obtained without making creative work The range of shield.

It should be noted that it can directly on the other element when element is referred to as " being set to " another element Or there may also be elements placed in the middle.When an element is considered as " connection " another element, it, which can be, is directly connected to To another element or it may be simultaneously present centering elements.Term as used herein " vertical ", " horizontal ", "upper", "lower", "left", "right" and similar statement for illustrative purposes only, are not meant to be the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein and the technical field for belonging to the application The normally understood meaning of technical staff is identical.The term used in the description of the present application is intended merely to description tool herein The purpose of the embodiment of body, it is not intended that in limitation the application.Term as used herein "and/or" includes one or more Any and all combinations of relevant listed item.

Fig. 1 is please referred to Fig. 5.The application embodiment provides a kind of casing joint, is used to connect two sections of well cementing casing pipes 10.Described sleeve pipe connector includes the buffering that ontology 1, the first connector 3, the second connector 11 and fitting sle are set to outside the ontology 1 Set 4.

Wherein, the ontology 1 axially extends, and has opposite first end and second end along axial.Described first connects First 3 are set to the first end, and second connector 11 is set to the second end, first connector 3 and second connector 11 For being connected with the well cementing casing pipe 10.The ontology 1 is equipped with the limiting section that axial limiting is carried out to the cushion collar 4.Institute The elasticity modulus for stating cushion collar 4 is less than the elasticity modulus of the ontology 1, and the elasticity modulus of the cushion collar 4 is less than cement sheath Elasticity modulus, the cushion collar 4 can buffer the deformation of the ontology 1 radially.The outer diameter of 4 outer wall of cushion collar Greater than the maximum outside diameter of the ontology 1, cushion collar 4 and cement slurry 8 can be made to come into full contact with, after cement slurry 8 forms cement sheath, Cushion collar 4 can protect the cement sheath, and the leakproofness of cement sheath and integrality is made to be guaranteed, thus when avoiding hydraulic fracturing Annular space problem with pressure.

The casing joint that the application embodiment provides, for connecting two adjacent well cementing casing pipes 10, outside casing joint Equipped with the cushion collar 4, the cement sheath between cushion collar 4 and stratum 9 can be protected, obtains the leakproofness of cement sheath, integrality To guarantee, the problem with pressure of the annular space as caused by cement sheath seal failure when scientifically avoiding hydraulic fracturing.Cushion collar 4 can Occur adaptivity deformation, absorb casing joint ontology 1 deformation, so as to avoid cement sheath radially generate compression damage with And tensile failure is generated in the circumferential.Meanwhile described sleeve pipe joint structure it is simple, without complicated matching piece or driving device, and pacify Dress is convenient, is suitble to scene Fast Installation.The casing joint that the application embodiment provides can not increase the same of well cementation cost When, effectively avoid annular space with pressure.

It should be noted that for ease of description, the axial direction of described sleeve pipe connector is defined as in present specification Lower direction.Specifically, 3 direction of the first connector is defined as "upper", 11 direction of the second connector is defined For "lower".

In the application embodiment, the limiting section includes the groove 2 set on 1 outer wall of ontology, 2 edge of groove Axial length and the cushion collar 4 are along axial equal length, and the groove 2 is for accommodating the cushion collar 4 and to described Cushion collar 4 carries out axial limiting.The cushion collar 4 is sheathed in the groove 2, the inner wall of the cushion collar 4 and the groove 2 Surface fitting, preferably to absorb the deformation of casing joint ontology 1, thus avoid cement sheath radially generate compression damage and Tensile failure is generated in the circumferential.

Specifically, the part that the upper end of the cushion collar 4 protrudes from the groove 2 is equipped with for keeping cement slurry 8 smoothly logical The the first water conservancy diversion inclined-plane 5 crossed.As shown in Fig. 2, the outer diameter of first water conservancy diversion inclined-plane 5 from top to bottom is gradually expanded, and described Inclination extends to the outside wall surface that the ontology 1 is located at 2 upside of groove upwards on the first water conservancy diversion inclined-plane 5.I.e. described first water conservancy diversion Inclined-plane 5 is in contact with the part that the ontology 1 is not provided with the groove 2.First water conservancy diversion inclined-plane 5 can allow in well cementing process Cement slurry 8 passes through the cushion collar 4 and is in close contact with the cushion collar 4.

More specifically, the part that the lower end of the cushion collar 4 protrudes from the groove 2 is equipped with for keeping cement slurry 8 smooth By the second water conservancy diversion inclined-plane 12.The outer diameter of second water conservancy diversion inclined-plane 12 from top to bottom is gradually reduced.Second water conservancy diversion is oblique Face 12, which tilts down, extends to the outside wall surface that the ontology 1 is located at 2 downside of groove.That is second water conservancy diversion inclined-plane 12 and institute It states ontology 1 and is not provided with the part of the groove 2 and be in contact.First water conservancy diversion inclined-plane 5 and the second water conservancy diversion inclined-plane 12 can cement the well Cement slurry 8 is allowed to pass through the cushion collar 4 and be in close contact with the cushion collar 4 in the process.

In the application embodiment, it is convex that the outer wall of the cushion collar 4 is equipped with multiple insertions for being inserted into cement sheath 6 are played, for contacting with cement slurry 8.When cement slurry 8 is liquid, insertion protrusion 6 is interspersed in 8 inner wall of cement slurry of liquid；Work as water After mud 8 forms cement sheath, insertion protrusion 6 then forms one with cement sheath, increases the cementing strong of cushion collar 4 and cement sheath Degree, so as to preferably protect cement sheath.The application to it is described insertion protrusion 6 distribution mode with no restrictions, can be equal On the even outer wall for being distributed in cushion collar 4, to guarantee that cushion collar 4 is uniformly contacted with cement sheath.Or as needed, make insertion protrusion 6 somewhere (such as cushion collar 4 is along axial both ends) distribution is more intensive, to increase the cementing of cushion collar 4 and cement sheath at this Intensity.

In the application embodiment, the material of the cushion collar can be rubber or the lesser material of other elasticity modulus Material.Preferably, the material of the cushion collar 4 is the vulcanization anticorrosion rubber with high deformability, preferably to absorb casing The deformation of joint body 1, so that cement sheath be avoided radially to generate compression damage and generating tensile failure in the circumferential.It is described The outer diameter of cushion collar 4 is 160mm-195mm.

In the application embodiment, the more high strength steels extended from upper end to lower end are equipped with inside the cushion collar 4 Silk 7, at least two steel wires 7, which intersect, extends, for increasing the intensity of cushion collar 4.

With no restrictions to the distribution mode of the steel wire 7, more steel wires 7 can be in cushion collar 4 for the application embodiment The distribution of part layer wound form.Preferably, the intensity of cushion collar 4 in order to further increase, as shown in figure 4, the cushion collar 4 is upper End has multiple the first steel wire endpoints being uniformly distributed circumferentially.The lower end of the cushion collar 4 has multiple and first steel The silk one-to-one second steel wire endpoint of endpoint.The every steel wire 7 extends to and its edge from the first steel wire endpoint The the second steel wire point being axially staggered.Central angle size corresponding to the every steel wire 7 is identical.Circumferentially adjacent two Two 7 extending directions of steel wire corresponding to the first steel wire endpoint are opposite.

In the application embodiment, the length of described sleeve pipe connector is 1000mm-2000mm.First connector 3 can Think that pin thread screw thread, second connector 11 can be female thread screw thread, is connected respectively with the screw thread of well cementing casing pipe 10.Screw thread connects The mode of connecing allows to that casing joint is mounted on to different well depth positions according to live needs.It can be square using being threadedly coupled Just the installation and removal of casing joint.The internal diameter of described sleeve pipe connector is identical as the internal diameter of adjacent well cementing casing pipe 10, described sleeve pipe The internal diameter variation range of connector is 104.8mm-121.36mm.

In the application embodiment, the rigid grade of 1 material of ontology is higher than the well cementing casing pipe 10.Such as well cementing casing pipe When 10 rigid grade is TP125V, the rigid grade for being shorted ontology 1 should be TP140V.

As shown in figure 5, the first connector 3, second connect when the casing joint that the application embodiment is provided is applied to underground First 11 are separately connected well cementing casing pipe 10, and to cement slurry 8 is injected between well cementing casing pipe 10 and stratum 9, cement slurry 8 passes through cushion collar 4 The first water conservancy diversion inclined-plane 5 and the second water conservancy diversion inclined-plane 12 smoothly flow down.Insertion protrusion 6 is interspersed in 8 inner wall of cement slurry of liquid, works as water After mud 8 forms cement sheath, insertion protrusion 6 then forms one with cement sheath.In practical fracturing process, even if casing internal pressure makes admittedly Casing 10 is expanded to cement sheath direction, and adaptivity deformation can occur for cushion collar 4, absorbs the deformation of casing joint ontology 1, It is radially generating compression damage so as to avoid cement sheath and is generating tensile failure in the circumferential.

A kind of cementing system is also provided in the application embodiment, the cementing system includes multiple well cementing casing pipes 10, institute Stating between well cementing casing pipe 10 and stratum, there is cement to inject gap, and the cement injection gap forms cement for injecting cement slurry Ring.At least two adjacent well cementing casing pipes 10 are connected by casing joint.Described sleeve pipe connector includes ontology 1, the first connector 3, the second connector 11 and fitting sle are set to the cushion collar 4 outside the ontology 1.Wherein, the ontology 1 axially extends, and edge It is axial that there is opposite first end and second end.First connector 3 is set to the first end, and second connector 11 is set to institute Second end, first connector 3 and second connector 11 are stated for being connected with the well cementing casing pipe 10.The ontology 1 is set There is the limiting section that axial limiting is carried out to the cushion collar 4.The elasticity modulus of the cushion collar 4 is less than the elasticity of the ontology 1 Modulus, the elasticity modulus of the cushion collar 4 are less than the elasticity modulus of cement sheath, and the cushion collar 4 can be to the ontology 1 along diameter To deformation buffered.The outer diameter of 4 outer wall of cushion collar is greater than the maximum outside diameter of the ontology 1.The cushion collar is located at Between the ontology and the cement sheath.The outer wall of the cushion collar is equipped with multiple insertion protrusions, the insertion protrusion insertion institute The cement slurry in cement injection gap is stated, and is fixed on the cement sheath when the cement slurry sets form the cement sheath In.

It during hydraulic fracturing job, is influenced by ground high pressure pump group and liquid column hydrostatic pressure, well cementing casing pipe 10 needs Bear high casing internal pressure.Under the effect of high casing internal pressure, well cementing casing pipe 10 is expanded to cement sheath direction, may cause cement Ring is radially generating compression damage and is generating tensile failure in the circumferential.The application embodiment by well cementing casing pipe 10 with Increase sealing sleeve pipe connector between well cementing casing pipe 10, in practical fracturing process, even if casing internal pressure makes well cementing casing pipe 10 to cement The expansion of ring direction, cushion collar 4 can occur adaptivity deformation, the deformation of casing joint ontology 1 be absorbed, so as to avoid cement Ring is radially generating compression damage and is generating tensile failure in the circumferential.

The cementing system includes at least a casing joint, it is proposed that installs described in one between every two well cementing casing pipes 10 Casing joint reduces a possibility that altering on downhole oil air water utmostly to protect cement sheath.

Casing joint in the cementing system can be casing joint described in any embodiment or embodiment as above, In This is repeated no more.

It should be noted that term " first ", " second " etc. are used for description purposes only and distinguish in the description of the present application Similar object between the two and is not present sequencing, can not be interpreted as indication or suggestion relative importance.In addition, In In the description of the present application, unless otherwise indicated, the meaning of " plurality " is two or more.

Herein cited any digital value all include between lower limit value to upper limit value with the lower value of an incremented and The all values of upper value, there are the intervals of at least two units between any lower value and any much higher value.For example, such as Fruit elaborates that the quantity an of component or the value of process variable (such as temperature, pressure, time etc.) are from 1 to 90, preferably from 20 To 80, more preferably from 30 to 70, then purpose is arrived in order to illustrate also clearly listing such as 15 to 85,22 in the specification 68,43 to 51,30 to 32 is equivalent.For the value less than 1, suitably think that a unit is 0.0001,0.001,0.01,0.1. These are only intended to the example clearly expressed, it is believed that all possibility for the numerical value enumerated between minimum and peak Combination is all expressly set forth in the specification in a similar manner.

Unless otherwise indicated, all ranges all include all numbers between endpoint and endpoint.It is used together with range " about " or " approximation " be suitable for two endpoints of the range.Thus, " about 20 to 30 " are intended to cover that " about 20 to about 30 ", including at least the endpoint indicated.

All articles and reference disclosed, including patent application and publication, for various purposes by quoting knot Together in this.Describing combined term " substantially by ... constitute " should include identified element, ingredient, component or step and reality Other elements, ingredient, component or the step of the basic novel feature of the combination are not influenced in matter.Using term "comprising" or " comprising " describes the combination of element here, ingredient, component or step it is also contemplated that substantially by these elements, ingredient, component Or the embodiment that step is constituted.Here by using term " can with ", it is intended to illustrate that " can with " includes described any Attribute is all optional.

Multiple element, ingredient, component or step can be provided by single integrated component, ingredient, component or step.Optionally Ground, single integrated component, ingredient, component or step can be divided into multiple element, ingredient, component or the step of separation.It is used to The open "a" or "an" for describing element, ingredient, component or step is not said to exclude other elements, ingredient, component Or step.

The foregoing is merely several embodiments of the invention, although disclosed herein embodiment it is as above, institute Content is stated only to facilitate the embodiment for understanding the present invention and using, is not intended to limit the present invention.