CN206655664U - A kind of arc form flexibility slip insert long-life casing head - Google Patents

Abstract

The utility model discloses a kind of arc form flexibility slip insert long-life casing head, including bottom plate, annular backup pad, manual flat valve, anti-shock pressure meter, WE type arc form flexibility slips hanger assemblies, c-type composite sealing ring, casing head body, H type metal o-ring assemblies, lower curved formula flexibility slips assembly, gasket ring I, stud, nut, gasket ring II.Arc form flexibility slip insert described in the utility model compares conventional spur type slip insert, bearing capacity is bigger, make bushing outer surface uniform force, therefore the occlusion to sleeve pipe will not be caused to damage, the corrosion resistance of the slip insert of titanium alloy be common alloy steel nearly a hundred times, intensity increase, the weight saving of hanger, casing head integral seal structure uses metal sealing coil structures substantially, high temperature resistant, ability resistant to chemical etching is stronger, ensure the long-life of slips hanger, it is suitable for the combination of existing deep-well and ultradeep well casing head of well head, extend slips hanger uses field.

Description

A kind of arc form flexibility slip insert long-life casing head

Technical field

It the utility model is related to drilling technology field, and in particular to a kind of arc form for ultra-deep high-pressure oil-gas well is flexible Slip insert long-life casing head.

Background technology

Casing head is the necessary equipment of connection sleeve pipe and wellhead assembly during oil, natural gas drilling.Casing head works Principle is interacted by casing head slips and sleeve pipe and hanger, and lower going-into-well middle sleeve weight is hanged by slips, slips Hanging device is delivered to casing head pedestal so that casing head all bears casing wt, now casing head shell, slips hanger, card Watt and sleeve pipe will bear compared with noticeable effort, it is desirable to each several part laser intensity must is fulfilled for requiring.

At present, casing head is usually split type and monoblock type, all configures anti-slip-type hanger or mandrel formula hanger, point Body formula casing head is installed inconvenience, wasted time and energy in use；Integral casing head is rational in infrastructure, saves material, and can letter The installation procedure of chemoprevention spray apparatus, is easily assembled.Inverted slips formula hanger, easily occur obvolvent loosely phenomenon in use, Play above and below sleeve pipe meeting, sealing property and security reliability are poor, also easy damaged sleeve pipe；Using the mandrel formula of the airtight closures of PT-CQ Hanger is big for hanging although sealing property, pressure-resistant performance and the more anti-slip type casing head of functional reliability increase The larger surface pipe of caliber, by its structure is limited, in the confined space of casing head bottom, mandrel formula hanger is difficult to pacify Put, thus it is inconvenient for use.And casing head will reach the fixed well head of control when oil, gas and water well carry out drilling well, and support, be fixed The casing string of G.I.H, the purpose of preventer group is installed, therefore the sealing of casing head is critically important for construction safety, particularly Occur to play a key effect during the blowout phenomenons such as overflow, well kick in well.For existing 95/8 " -24 " casing hanger assembly The stress and contact force for hanging various conventional steel-grade bushings are analyzed, and are found to be only applicable to shallow-layer with each steel-grade bushing and are discontented with 300 tons of ultimate loads of foot, sleeve pipe maximum unilateral force occurs in slips indentation, there, and slips and slips hanger contact force are maximum Value also occurs in indentation, there, and it is uneven that slip insert contacts with sleeve outer wall face, and main cause is that slips is by circumferential receipts Contracting clamping sleeve pipe so that slips, casing-contact power are asymmetric.Due to slips asymmetry so that slips, casing stress distributed pole Uneven, slips breach opposite stress value is maximum.

Therefore, the problem of slips is primarily present at present be：The casing head of prior art is single layer sealing structure, only in slips The lower end of hanger is sealed provided with a BT sealing ring, borehole pressure occur it is unstable in the case of, sealing ring it is close Envelope effect can be affected, and be unfavorable for the blowout phenomenon of quick control well head, slip insert is uneven to the extruding force of sleeve pipe, causes Casing strength decline and early stage failure, common alloy slip insert gets rusty easily under severe work condition environment, tooth stress not It is easily damaged, it is necessary to often change.

Utility model content

The defects of for above-mentioned slips structure and sealing structure, the utility model devises a kind of arc form flexibility slip insert The long-life casing head of structure and metal sealing bearing structure.

The technical solution of the utility model is as follows：

A kind of arc form flexibility slip insert long-life casing head, the utility model support gasket ring I, annular brace by bottom plate Plate, support gasket ring II, greasing check valve, manual flat valve, thread flange, plug, right-angle type stop valve, anti-shock pressure meter, instrument Table flange, WE type arc form flexibility slips hanger assemblies, jackscrew assembly, screw one, c-type composite sealing ring, wedge metal are close Seal ring I, soket head cap screw, joint, casing head body, metal o-ring assembly, lower curved formula flexibility slip insert, wedge metal Sealing ring II, slips housing, screw two, spring washer, gasket ring I, stud, gasket ring II form, the bottom plate Top be welded and fixed with supporting pad ring, support gasket ring above be connected with turn annular backup pad, support gasket ring II, casing head sheet Body, described sleeve pipe head body middle part are provided with horizontal through hole pipeline, and greasing check valve is arranged at the through hole pipeline of casing head body Lower section, middle vehicle have screw thread, and casing head body side is drilled with screwed hole, and greasing check valve uses screw thread with casing head body Connection, described sleeve pipe head body are symmetrically arranged two manual flat valves, and the manual flat valve is oil field standard PFF78- 70 sulfur resistive flap types, the left and right partially manual flap type of casing head body by thread flange and casing head body by stud, Nut is fastenedly connected, and the gasket ring I is embedded in the annular groove of manual flat valve and casing head body, the metal sealing Circle assembly is installed in the rectangular channel of casing head body, and casing head body inner ring is machined with the square coordinated with metal o-ring assembly Shape groove, anti-shock pressure meter, right-angle type stop valve are connected with instrument flange by NPT taper pipe threads, and anti-shock pressure meter is connected to directly In the screwed hole of angle stop valves, the jackscrew assembly is arranged in the tapped through hole of casing head body radial direction processing, close Packing ring II is arranged in the seal groove being pre-machined of casing head body upper surface, and the joint screw thread is connected to casing head sheet Body left end thread flange end face, plug are welded on the thread flange end face on the right of casing head body.

Further, the WE type slips shell inner surfaces of the WE types arc form flexibility slips hanger assembly are machined with three Layer step, arc form flexibility slip insert outer surface is machined with three layers of step, and is installed with WE type slips housings with step, interior Hex screw circumferential directions fasten WE type slips shells on WE type slips housings and arc form flexibility slip insert circumferencial direction Body and arc form flexibility slip insert, WE type slips housings upper surface circumferencial direction are threaded hole, pass through screw three, metal gasket Circle is connected with support gasket ring, and wedge metal sealing ring I and wedge metal sealing ring are embedded in arc form flexibility slip insert In the wedge-shaped slot of outer surface, the soket head cap screw compresses WE type arc form flexibility slips hanger assembly arc form flexibility slips Tooth, WE type arc form flexibility slips hangers assembly coordinate on the endoporus taper surface of casing head body.

Further, the lower curved formula flexibility slip insert outer surface is machined with quadruple board platform rank, and slips housing is machined with Quadruple board platform rank, lower curved formula flexibility slip insert are installed with slips housing with step, slips housing lower surface circumferencial direction Hole is threaded, by screw, spring washer, is connected with support gasket ring II, wedge metal sealing ring II is embedded in down In the wedge-shaped slot of the outer surface of portion's arc form flexibility slip insert.

Further, the metal o-ring assembly is by the metal o-ring seat of honour, H types metal o-ring and metal o-ring Lower seat composition, H type metal o-rings are arranged under the metal o-ring seat of honour and metal o-ring among seat, and compression fit, gold The category sealing ring seat of honour is made up with seat under metal o-ring of 12Cr13 machine-shapings, H type metal o-rings of 15CrNiMo.

Further, it is characterised in that the c-type composite sealing ring is molded into O-ring seal and c-type rubber ring Type, c-type rubber ring can bear space six direction pressure-bearing function by lip-type packing Structure Improvement Design, compound from c-type Sealing ring selects HNBR hydrogenated nitrile-butadiene rubber materials, and its relatively common rubber ring intensity is higher, resistance to oxidation, ageing-resistant, high temperature resistant, Chemically-resistant acid and alkali corrosion performance is stronger, ensures that the sealing structure life-span is longer.

Further, the lower curved formula flexibility slip insert along the circumferential direction processes cylinder slips structure, then indulges again To piecemeal slips is cut into, it is installed on slips casing step, exploitativeness identical with the installation method of ordinary straight slip insert By force, it is easy to utilize.

Further, in the course of work, the plug of casing head body right end portion is blocked, casing head body left end portion Joint can connect external high pressure pipeline.

Integral sealing part of the present utility model uses shape metallic leak-proof structure substantially, few rubber sealing element, high temperature resistant, Corrosion-resistant, service life extends, and reduces the maintenance cost and labor intensity for changing rubber seal.

The beneficial effects of the utility model are：

1) rubber sealing element is substituted using the compound sealing structure of shape metallic leak-proof structure, ensures pressure-bearing effect, extension makes With the life-span, replacement frequency is reduced, sealing effectiveness is superior, and wedge metal sealing ring is designed between slips housing and slip insert, is subtracted The relative wear of small slips housing and slips centric stop；

2) upper seal is replaced by c-type composite sealing ring, relatively common O-ring seal or rectangular seal, protected Card multidirectional pressure-bearing and sealing property, c-type composite sealing ring under external load effect select HNBR hydrogenated nitrile-butadiene rubber materials Material, its relatively common rubber ring intensity is higher, and resistance to oxidation, ageing-resistant, high temperature resistant, chemically-resistant acid and alkali corrosion performance are stronger, ensures The sealing structure life-span is longer；

3) arc form flexibility slip insert is used, compared to conventional spur type slip insert, bearing capacity is bigger, makes sleeve pipe appearance Face uniform force, therefore hardly cause the occlusion to sleeve pipe to damage, the corrosion resistance of the slip insert of titanium alloy is common Steel alloy is nearly a hundred times；

4) the arc form flexibility slip insert of the utility model design is titanium alloy material, and corrosion-resistant and resistance to elevated temperatures is more By force, and there is stronger elastic deformation so that slips, casing stress are evenly distributed, and will not cause to slips housing and slips The step surface stress value that tooth coordinates is excessive, will not also form the damage to the sleeve surface of contact, while will not cause itself tooth The damage of tooth；

5) by using the slip insert of titanium alloy material, mitigate casing head overall weight, and then reduce lifting and remove Dynamic labor intensity, it is easier to which processing and assembling, exploitativeness is strong, promotes the use.

Brief description of the drawings

, below will be to embodiment in order to illustrate more clearly of the utility model embodiment or technical scheme of the prior art Or the required accompanying drawing used is briefly described in description of the prior art, it should be apparent that, drawings in the following description are only It is some embodiments of the utility model, for those of ordinary skill in the art, before creative labor is not paid Put, other accompanying drawings can also be obtained according to these accompanying drawings.

Fig. 1 is a kind of structural representation of arc form flexibility slip insert long-life casing head；

Fig. 2 a are 3-D solid structure figure of the present utility model；

Fig. 2 b are the 3-D solid structure figure of prior art；

Fig. 3 a are the mounting structure schematic diagram of conventional spur type slip insert；

Fig. 3 b are the mounting structure schematic diagram of arc form flexibility slip insert；

Fig. 4 is a kind of H type metal o-ring assembly structure schematic diagrames of arc form flexibility slip insert long-life casing head；

Fig. 5 is a kind of two kinds of structure slip insert scheme of installations of arc form flexibility slip insert long-life casing head；

Fig. 6 is a kind of WE type arc form flexibility slips hanger assembly knots of arc form flexibility slip insert long-life casing head Structure schematic diagram；

Fig. 7 a are slip insert stress change schematic diagram of the present utility model；

Fig. 7 b are the slip insert stress change schematic diagram of prior art.

Shown in figure：

1- bottom plates, 2- gasket rings, 3- annular backup pads, 4- greasings hole, 5- greasing check valves, 6- manual flat valves, 7- screw threads Flange, 8- plugs, 9- right-angle type stop valves, 10- anti-shock pressure meters, 11- instrument flanges, 12-WE type arc form flexibility slips hang Hanging device assembly, 13- jackscrew assemblies, 14- screws, 15-C type composite sealing rings, 16- wedge metals sealing ring I, hexagonal spiral shell in 17- Nail, 18- joints, 19- casing head bodies, 20- metal o-ring assemblies, 21- wedge metals sealing ring II, 22- lower curved formulas Flexible slip insert, 23- slips housings,

A1, A2- screw spring washer,

A3- gasket rings I,

A4, A5, A6, A7- stud,

A8- gasket rings II,

121-WE type slips housings, 122- arc form flexibility slip inserts, 123- metal washers, 124- support gasket rings, 125- Screw,

151-O type sealing rings, 152-C type rubber rings.

Embodiment

The utility model is further illustrated with reference to the accompanying drawings and examples, but is not limited to the utility model.

As shown in Fig. 1~Fig. 7, a kind of arc form flexibility slip insert long-life casing head, it is characterised in that the utility model By bottom plate 1, gasket ring I 2 is supported, annular backup pad 3 supports gasket ring II 4, greasing check valve 5, manual flat valve 6, thread flange 7, Plug 8, right-angle type stop valve 9, anti-shock pressure meter 10, instrument flange 11, WE type arc form flexibility slips hangers assembly 12, top Silk assembly 13, screw 1, c-type composite sealing ring 15, wedge metal sealing ring I 16, soket head cap screw 17, joint 18, sleeve pipe Head sheet 19, metal o-ring assembly 20, lower curved formula flexibility slip insert 21, wedge metal sealing ring II 22, slips housing 23, Screw, spring washer A1, A2, the A3 of gasket ring I, stud, nut A4, A5, A6, A7, the A8 of gasket ring II compositions；Bottom plate 1 top is welded and fixed with support gasket ring 2, for supporting top parts, the upper surface of annular backup pad 3 and support gasket ring II 4 Contact, the car of greasing check valve 5 have screw thread, and casing head body 19 is drilled with screwed hole, greasing check valve 5 and casing head body 19 Threaded connection, described sleeve pipe head body 19 are symmetrically arranged two manual flat valves 6, and the manual flat valve 6 is oil field mark Quasi- PFF78-70 sulfur resistive flap type, the left and right partially manual flap type 6 of casing head body 19 pass through thread flange 7 and casing head sheet Body 19 is fastenedly connected by stud, nut A4, A5, and the A3 of gasket ring I is embedded in manual flat valve 6 and casing head body In 19 annular groove, the metal o-ring assembly 20 is installed in the rectangular channel of casing head body 19, in casing head body 19 Circle is machined with the rectangular channel coordinated with metal o-ring assembly 20, anti-shock pressure meter 10, right-angle type stop valve 9 and instrument flange 11 Connected by NPT taper pipe threads, anti-shock pressure meter 10 is connected in the screwed hole of right-angle type stop valve 9, the jackscrew assembly 13 In the tapped through hole of the radial direction of casing head body 19 processing, the A8 of gasket ring II is arranged on the upper end of casing head body 19 In the seal groove being pre-machined in face, the joint 18 is threaded in the end face of 19 left end thread flange of casing head body 7, plug 8 are welded on the end face of thread flange 7 on the right of casing head body 19；The WE type cards of WE type arc form flexibility slips hangers assembly 12 Watt inner surface of housing 121 is machined with three layers of step, and the outer surface of arc form flexibility slip insert 122 is machined with three layers of step, arc form Flexible slip insert 122 is that axially cutting pintongs mutual cooperation is symmetrically installed, and is pacified with WE type slips housing 121 with step Dress, the circumferential directions of soket head cap screw 17 on WE type slips housing 121 and the circumferencial direction of arc form flexibility slip insert 122, Fastening WE type slips housing 121 and arc form flexibility slip insert 122, the upper surface circumferencial direction of WE type slips housing 121 are machined with Screwed hole, it is connected by screw 3 125, metal washer 123 and support gasket ring 124, wedge metal sealing ring I 16 and wedge shape Metallic packing ring 161 is embedded in the wedge-shaped slot of the outer surface of arc form flexibility slip insert 122, and the soket head cap screw 17 compresses The arc form flexibility slip insert 122 of WE type arc form flexibility slips hangers assembly 12, WE type arc form flexibility slips hangers are total Coordinate into 12 and be arranged on the endoporus taper surface that casing head body 19 is pre-machined；The outer surface of lower curved formula flexibility slip insert 21 Be machined with quadruple board platform rank, slips housing 23 is machined with quadruple board platform rank, lower curved formula flexibility slip insert 21 and slips housing 23 by Step coordinates installation, and the lower surface circumferencial direction of slips housing 23 is threaded hole, by screw, spring washer A1, A2, with branch Stake pad ring II 4 is connected, and wedge metal sealing ring II 22 is embedded in the wedge of the outer surface of lower curved formula flexibility slip insert 21 In shape groove；Metal o-ring assembly 20 is by seat under the metal o-ring seat of honour 201, H types metal o-ring 202 and metal o-ring 203 compositions, H types metal o-ring 202 is arranged under the metal o-ring seat of honour 201 and metal o-ring among seat 203, and is compressed Coordinate, under the metal o-ring seat of honour 201 and metal o-ring seat 203 by 12Cr13 machine-shapings, H types metal o-ring 202 by 15CrNiMo is made；

As best shown in figures 3 a and 3b, c-type composite sealing ring 15 is molded into O-ring seal 151 and c-type rubber ring 15 Type, c-type rubber ring 152 can bear space six direction pressure-bearing function, from c-type by lip-type packing Structure Improvement Design Composite sealing ring 15 use HNBR hydrogenated nitrile-butadiene rubber materials, its relatively common rubber ring intensity is higher, resistance to oxidation, it is ageing-resistant, High temperature resistant, chemically-resistant acid and alkali corrosion performance are stronger, ensure that the sealing structure life-span is longer；Lower curved formula flexibility slip insert 21 is along circle Circumferential direction processes cylinder slips structure, and then longitudinally cutting again is piecemeal slips, is installed on the step of slips housing 23, and commonly The installation method of straight slip insert is identical, and exploitativeness is strong, easy to utilize.

In the course of work, the plug 8 of the right end portion of casing head body 19 is blocked, the left end portion of casing head body 19 connects Head can connect external high pressure pipeline；Casing head integral sealing part uses shape metallic leak-proof structure, few rubber seal member substantially Part, high temperature resistant is corrosion-resistant, and service life extends, and reduces the maintenance cost and labor intensity for changing rubber seal；It is in Fig. 7 The contrast of the arc form flexibility slips stress of straight thread tooth slips and this patent effect, it is found that straight thread tooth slips is local to sleeve pipe Influence huge, and stress distribution is uneven, and upper and lower ends are big, middle small, arc form flexible thread tooth slips sleeve pipe is influenceed it is smaller, And stress distribution is uniform.

A kind of arc form flexibility slip insert long-life casing head provided by the utility model, its arc form flexibility slip insert All it is made of titanium alloy material, compared to conventional spur type slip insert, bearing capacity is bigger, makes bushing outer surface stress equal It is even, therefore hardly cause the occlusion to sleeve pipe to damage, the corrosion resistance of the slip insert of titanium alloy is common alloy steel Nearly a hundred times, sealing structure uses metal sealing coil structures substantially, ensures the long-life of slips hanger, is suitable for existing depth The combination of well and ultradeep well casing head of well head, extend slips hanger uses field.

It is described above, only it is preferred embodiment of the present utility model, not the utility model is made any formal Limitation, although the utility model is disclosed above with preferred embodiment, but be not limited to the utility model, it is any ripe Professional and technical personnel is known, is not being departed from the range of technical solutions of the utility model, when in the technology using the disclosure above Hold the equivalent embodiment made a little change or be modified to equivalent variations, as long as being without departing from technical solutions of the utility model Hold, any simple modification, equivalent change and modification made according to the technical essence of the utility model to above example, still Belong in the range of technical solutions of the utility model.

Claims (7)

1. a kind of arc form flexibility slip insert long-life casing head, it is characterised in that the utility model is by bottom plate (1), supporting pad It is ring I (2), annular backup pad (3), support gasket ring II (4), greasing check valve (5), manual flat valve (6), thread flange (7), stifled Head (8), right-angle type stop valve (9), anti-shock pressure meter (10), instrument flange (11), WE type arc form flexibility slips hangers are total Into (12), jackscrew assembly (13), screw one (14), c-type composite sealing ring (15), wedge metal sealing ring I (16), interior hexagonal spiral shell Follow closely (17), joint (18), casing head body (19), metal o-ring assembly (20), lower curved formula flexibility slip insert (21), wedge Shape metallic packing ring II (22), slips housing (23), screw two, spring washer (A1, A2), gasket ring I (A3), stud (A4, A5, A6, A7), gasket ring II (A8) composition, top and the support gasket ring (2) of the bottom plate (1) are welded and fixed, supported It is connected with annular backup pad (3), support gasket ring II (4), casing head body (19), described sleeve pipe head sheet above gasket ring (2) in turn Horizontal through hole pipeline is provided with the middle part of body (19), greasing check valve (5) is arranged at below the through hole pipeline of casing head body (19) Inner side, middle vehicle have screw thread, and casing head body (19) is drilled with screwed hole, greasing check valve (5) and casing head body (19) Threaded connection, described sleeve pipe head body (19) are symmetrically arranged two manual flat valves (6), and the manual flat valve (6) is Oil field standard PFF78-70 sulfur resistive flap types, the left and right partially manual flap type (6) of casing head body (19) pass through thread flange (7) it is fastenedly connected with casing head body (19) by stud, nut (A4, A5), the gasket ring I (A3) is embedded in manually In the annular groove of flap type (6) and casing head body (19), the metal o-ring assembly (20) is installed in casing head body (19) in rectangular channel, casing head body (19) inner ring is machined with the rectangular channel coordinated with metal o-ring assembly (20), antidetonation Pressure gauge (10), right-angle type stop valve (9) are connected with instrument flange (11) by NPT taper pipe threads, and anti-shock pressure meter (10) is even It is connected in the screwed hole of right-angle type stop valve (9), the jackscrew assembly (13) adds installed in casing head body (19) radial direction In the tapped through hole of work, gasket ring II (A8) is arranged in the seal groove being pre-machined of casing head body (19) upper surface, The joint (18) is threaded in casing head body (19) left end thread flange (7) end face, and plug (8) is welded on casing head sheet Thread flange (7) end face on the right of body (19).

A kind of 2. arc form flexibility slip insert long-life casing head according to claim 1, it is characterised in that the WE types WE type slips housing (121) inner surface of arc form flexibility slips hanger assembly (12) is machined with three layers of step, and arc form is soft Property slip insert (122) outer surface is machined with three layers of step, and is installed with WE type slips housings (121) with step, interior hexagonal Screw (17) circumferential directions are on WE type slips housings (121) and arc form flexibility slip insert (122) circumferencial direction, fastening WE type slips housings (121) and arc form flexibility slip insert (122), the processing of WE type slips housing (121) upper surface circumferencial direction There is screwed hole, be connected by screw three (125), metal washer (123) and support gasket ring (124), wedge metal sealing ring I (16) it is embedded in wedge metal sealing ring (161) in the wedge-shaped slot of the outer surface of arc form flexibility slip insert (122), it is described interior Hex screw (17) compresses WE type arc form flexibility slips hanger assembly (12) arc form flexibility slip insert (122), WE type arcs Form flexibility slips hanger assembly (12), which coordinates, to be arranged on the endoporus taper surface that casing head body (19) is pre-machined, described Slip insert selects titanium alloy material.

A kind of 3. arc form flexibility slip insert long-life casing head according to claim 1, it is characterised in that the bottom Arc form flexibility slip insert (21) outer surface is machined with quadruple board platform rank, and slips housing (23) is machined with quadruple board platform rank, lower curved Formula flexibility slip insert (21) is installed with slips housing (23) with step, and slips housing (23) lower surface circumferencial direction is machined with Screwed hole, by screw, spring washer (A1, A2), it is connected with support gasket ring II (4), wedge metal sealing ring II (22) It is embedded in the wedge-shaped slot of the outer surface of lower curved formula flexibility slip insert (21).

A kind of 4. arc form flexibility slip insert long-life casing head according to claim 1, it is characterised in that the metal Sealing ring assembly (20) is by seat (203) group under the metal o-ring seat of honour (201), H types metal o-ring (202) and metal o-ring Into H types metal o-ring (202) is arranged under the metal o-ring seat of honour (201) and metal o-ring among seat (203), and is pressed Tight fit, the metal o-ring seat of honour (201) are with seat (203) under metal o-ring by 12Cr13 machine-shapings, H type metal o-rings (202) it is made up of 15CrNiMo.

A kind of 5. arc form flexibility slip insert long-life casing head according to claim 1, it is characterised in that the c-type Composite sealing ring (15) injection molding with O-ring seal (151) and c-type rubber ring (152), from c-type composite sealing ring (15) HNBR hydrogenated nitrile-butadiene rubber materials are selected.

A kind of 6. arc form flexibility slip insert long-life casing head according to claim 1, it is characterised in that the bottom Arc form flexibility slip insert (21) along the circumferential direction processes cylinder slips structure, and then longitudinally cutting again is piecemeal slips, installation In on slips housing (23) step.

A kind of 7. arc form flexibility slip insert long-life casing head according to claim 1, it is characterised in that the course of work In, the plug (8) of casing head body (19) right end portion is blocked, the joint connection of casing head body (19) left end portion is outside High pressure line.