CN101539010A - Thermal-prestressed fusion casing for heavy-oil thermal recovery process, and using method thereof - Google Patents
Thermal-prestressed fusion casing for heavy-oil thermal recovery process, and using method thereof Download PDFInfo
- Publication number
- CN101539010A CN101539010A CN200810017740A CN200810017740A CN101539010A CN 101539010 A CN101539010 A CN 101539010A CN 200810017740 A CN200810017740 A CN 200810017740A CN 200810017740 A CN200810017740 A CN 200810017740A CN 101539010 A CN101539010 A CN 101539010A
- Authority
- CN
- China
- Prior art keywords
- casing
- tubing
- thermal
- prestressed
- oil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Earth Drilling (AREA)
- Reinforcement Elements For Buildings (AREA)
Abstract
The invention provides a thermal-prestressed fusion casing for heavy-oil thermal recovery process, and a using method thereof. A plurality of slits (2) penetrating through the wall of an oil casing are evenly distributed on the surface periphery of seal grooves at two ends of the oil casing (1); the interval between every two slits is 60 millimeters; the slits (2) are at an equidirectional-dislocation angle of 60 degrees, are evenly distributed on the peripheral surface of the oil casing (1), and are filled with filler material; a structure surplus gap is arranged reserved between the oil casing (1) and a steel sheath (3); and a wound pipe (4) is arranged outside the steel sheath (3). When the thermal-prestressed fusion casing is arranged at the lower end of a thermal packer (13) of an oil pipe (11), the axial and radial thermal stress of the oil pipe (11) can be fully digested and absorbed, so the interface integrity of the casing can be effectively protected; steam leap and water leap caused by cracked or crushed of cement sheaths are avoided; and the casing can also be prevented from integrally leaping up to destroy wellhead equipment and collar connection. The thermal-prestressed fusion casing has the characteristics of simple structure, practicability and good effects.
Description
One, technical field
A kind of cover that the present invention relates in the petroleum production engineering field decreases the control device, specifically is a kind of heat-prestressed fusion casing and using method thereof that is used for heavy crude heat extraction technology.
Two, background technology
Along with the day of the energy is becoming tight and the oil recovery by heating technological progress, thickened oil recovery more and more comes into one's own.Karamay oilfield six, nine district's shallow layer thick oil oil reservoirs are important component parts of xinjiang viscous crude oil at present; The Liaohe River and Shengli Oil Field also are distributed with viscous crude, and annual capacity reaches more than 4,500,000 tons, mainly rely on steam injection heating exploitation method, i.e. steam soak and steam drive.
Because the specific (special) requirements of viscous crude oil recovery by heating, make heavy crude heat extraction casing well damage.The reason that correct study and cognition sleeve pipe damages is taked necessary renovation technique and preventive action, and in time recovering the casing damaged well ordinary production has become a important topic in the current oil field development.Around reducing the sleeve pipe loss, improving and annotate the vapour thermal efficiency, improve crude output and be the theme, derived many new technologies and new technology have also produced favorable economic benefit and social benefit in recent years.But, because thermal stress effect, the sleeve pipe that steam flush corrosion (the especially enforcement of sleeve pipe steam injection technology) causes damages and still is not solved, the cover of heavy crude heat extraction decreases problem sternness still, further strengthen the cost and the cycle of thickened oil recovery, become problem that presses for solution in the petroleum industry.
Because cover damage situation is serious, technology and technical research have been launched in oil fields such as Xinjiang, the Liaohe River, triumph, and have obtained some achievements in research, and major technology is summed up as follows:
The prestressing force measure that A, well head promote
Cooperate earth anchor to promote tubing and casing, can partly alleviate the axial thermal stress in the sleeve pipe, but amplitude is very limited, have only the effect of improving of a little at well head.Do not consider the radial compressive loads of sleeve pipe in addition yet.So be not the technical measures that a kind of complete cover decreases control.
B, the hot stretching device of employing gas injection well
In notification number is the Chinese patent of CN2849162, the hot expansion bend of a kind of gas injection well has been proposed, adopt this expansion bend, the expansion coupling that just uses during setting of casing, can eliminate axial thermal stress to the utmost, but because the existence of casing coupling, the thermal stretching of well cementation rear sleeve greatly is subjected to the restriction of cement sheath, makes this technology can not bring into play the technical advantage of himself.In addition, also be the radial load of not considering sleeve pipe.So the result of use of this patent will be affected.
C, thickening tubing and casing treatment measures
This treatment measures are the simplest a kind of and methods intuitively, are mainly used to increase stability of structure.If temperature gradient is little, then thermal stress is not high, prevents that casing damage from having effect preferably; If temperature gradient is bigger, then cement sheath destruction, sleeve pipe eject well head, casing damage or the like problem and all are difficult to avoid.
Three, summary of the invention
Damage problem for solving at present again the sleeve pipe that exists in the thermodynamic oil extraction process, comprise on cement sheath interface damage and the sleeve pipe well head and scurrying, influence the problem of the process implementing of oil recovery by heating, the present invention proposes a kind of heat-prestressed fusion casing and using method thereof that is used for heavy crude heat extraction technology.
For achieving the above object, the present invention is by loosening the heat-prestressing force fusion method with the radial structure surplus in axial rigidity, make thermal recovery section sleeve pipe self can digest and absorb the side effect that the thermal stress in the sleeve pipe is brought, keep the due stability of sleeve pipe and resist the radial pressure that stratum high-temperature expands and produces.
The present invention includes tubing and casing, steel sheath, wind pipe.Wherein, after the distance that box cupling installs is reserved at the sleeve pipe two ends, process seal groove, be embedded with high-temperature seal ring in the sealing groove, be used for the inside and outside isolation of well shaft fixing technology middle sleeve; Some tube wall slots that penetrate tubing and casing distribute on the sleeve pipe between the sealed at both ends groove; Slot is uniform 3-84 ° * wide 5mm, and 60mm at interval, and the 60 ° of angles that misplace in the same way each other is evenly distributed on the circumferential surface of tubing and casing, up to sealed at both ends groove place; Slot two ends fillet slows down stress with transition and concentrates.In slot, fill the packing material of temperature characterisitic, charge into to prevent cementing concrete with 120 ℃ of thermal deformations and 360 ℃ of hot flowages.Steel sheath is enclosed within outside the tubing and casing, is the critical piece of realizing sealing and guaranteeing the radial structure surplus, and its thickness is 2.0 millimeters, and length surpasses the sealed at both ends slot pitch of tubing and casing from 50mm.For alleviating the pressure of rock stratum to tubing and casing, outside steel sheath, be wound with composite material, form the composite material wind pipe, and by this wind pipe axial restraint steel sheath; The thickness of this wind pipe is 3 millimeters.Between steel sheath and sleeve pipe, possess 0.15 millimeter-0.50 millimeter structure surplus gap.The radial structure surplus principle is to guarantee that the gap value of steel sheath and sleeve pipe under the 250K temperature difference is greater than sleeve pipe bulging amount;
When use is of the present invention,
At first, when transferring tubing and casing,, be installed in the heavy oil tested layer bottom to hot packer lower end with the needs length of heat-prestressed fusion casing according to thermal recovery technology.Secondly, cooperate the earth anchor service condition to determine maximum lift load according to the well shaft fixing technology requirement; And, determine the lifting load lower limit according to the thermal recovery temperature gradient; Once more, consider under the influence condition of deadweight and cementing concrete density, by the value of load-optimised definite lifting load, before cementing concrete solidifies, with the slips locking lifting load in the well head prestressing force envelope pressure device.At last, after cement sheath solidifies, seal well head, wait oil pipe and hot packer in production tree to be installed and the thermal recovery technology with the envelope platen press orchid in the well head prestressing force envelope pressure device.
Axial rigidity is loosened, the sleeve structure of radial structure surplus because the present invention has utilized, cooperate the heat flow of macromolecular material and the flow behavior of liquid, according to the temperature gradient on sleeve pipe, stratum and the coefficient of thermal expansion of material, the rigidity of design stress fusion casing structure and surplus amount, guarantee sleeve pipe on the basis that prestressing force promotes, axially can digestive fever stress, radially can absorb thermal stress, keep self good radial stability, with the radial compressive loads of opposing stratum heat expansion to sleeve pipe.The present invention can fully digest and assimilate axially and thermal stress radially, ensures sleeve pipe thermal stress state minimum, keeps the stability of casing stress, and has effectively protected the integrality of ferrule interface, and the vapour of avoiding cement sheath cracking, conquassation to bring is scurried and water breakthrough.Can prevent also that simultaneously sleeve pipe from scurrying on the whole, destroy the well head equipment and be connected with box cupling.It is simple in structure, practical that the present invention has, good effectiveness.
Four, description of drawings
Fig. 1 is the structural representation of heat-prestressed fusion casing.
Fig. 2 is the partial structurtes enlarged diagram of heat-prestressed fusion casing.
Fig. 3 is the application installation site schematic diagram of heat-prestressed fusion casing.Wherein:
1. tubing and casing 2. slots 3. steel sheaths 4. wind pipe 5. high-temperature seal rings 6. radial structure surpluses 7. production trees 8. envelope pressure devices 9. surface pipes 10. production casings 11. oil pipes 12. cement sheaths 13. hot packer 14. stress fusion pipe 15. heavy oil heat production stratum 16. earth anchors
Five, the specific embodiment
Embodiment one
Present embodiment is 7 " heat-prestressing force fusion pipe, with the 10m of API standard (american petroleum TIA standard) long 7 " tubing and casing is as turned blank, comprises tubing and casing 1, steel sheath 3, wind pipe 4.Wherein, the distance that the box cupling installation is reserved at the two ends of tubing and casing 1 processes seal groove afterwards, is embedded with high-temperature seal ring 5 in the sealing groove, is used for the inside and outside isolation of well shaft fixing technology tubing and casing; The some slots 2 of distribution between the seal groove at tubing and casing 1 two ends, and filling has the packing material of the temperature characterisitic of 100 ℃ of thermal deformations and 300 ℃ of hot flowages.External surface in tubing and casing 1 is set with steel sheath 3, and the external surface of steel sheath has wind pipe 4, and by this wind pipe axial restraint steel sheath 3.In the specific implementation process:
Go out seal groove in the 1 two ends 1.5m place turning of distance tubing and casing, and " O " RunddichtringO 5 of in seal groove, high temperature being installed.Within sealed at both ends groove, the surface of tubing and casing 1 is evenly distributed with the slot 2 of the wide tube wall that penetrates tubing and casing 1 of some 3-84 ° * 5mm; Between the slot 2 along tubing and casing 1 axially spaced-apart 60mm, arrange at misplace 60 ° of angles in the same way; In slot 2, fill organic glass PMMA.With roll bending machine that steel plate is round along tubing and casing 1 cylindrical roller, and, form steel sheath 3 with the opposite joint welding; Between tubing and casing 1 and the steel sheath 3 radial structure surplus 6 is arranged, and this radial structure surplus is in the tolerance range scope of 0.20mm～0.50mm; The length of steel sheath 3 is slightly larger than the length between the seal groove at tubing and casing 1 two ends.Adopt the winding process of composite material, twining thickness outside steel sheath 3 is the bisphenol A epoxide resin base glass fibre composite material 4 of 3.0mm, and the length of winding should be slightly larger than the length of steel sheath; Bisphenol A epoxide resin base glass fibre composite material solidify to form wind pipe 4 through normal temperature.
Embodiment two
Present embodiment is 7 " heat-prestressing force fusion pipe, with the 10m of API standard (american petroleum TIA standard) long 7 " tubing and casing is as turned blank, comprises tubing and casing 1, steel sheath 3, wind pipe 4.Wherein, the distance that the box cupling installation is reserved at the two ends of tubing and casing 1 processes seal groove afterwards, is embedded with high-temperature seal ring 5 in the sealing groove, is used for the inside and outside isolation of well shaft fixing technology tubing and casing; The some slots 2 of distribution between the seal groove at tubing and casing 1 two ends, and filling has the packing material of the temperature characterisitic of 100 ℃ of thermal deformations and 300 ℃ of hot flowages.External surface in tubing and casing 1 is set with steel sheath 3, and the external surface of steel sheath has wind pipe 4, and by this wind pipe axial restraint steel sheath 3.In the specific implementation process:
Go out seal groove in the 1 two ends 1.5m place turning of distance tubing and casing, and " O " RunddichtringO 5 of in seal groove, high temperature being installed.Within sealed at both ends groove, the surface of tubing and casing 1 is evenly distributed with the slot 2 of the wide tube wall that penetrates tubing and casing 1 of some 3-84 ° * 5mm; Between the slot 2 along tubing and casing 1 axially spaced-apart 60mm, arrange at misplace 60 ° of angles in the same way; Filled nylon PA-6 in slot 2.With roll bending machine that steel plate is round along tubing and casing 1 cylindrical roller, and, form steel sheath 3 with the opposite joint welding; Between tubing and casing 1 and the steel sheath 3 radial structure surplus 6 is arranged, and this radial structure surplus is in the tolerance range scope of 0.20mm～0.50mm; The length of steel sheath 3 is slightly larger than the length between the seal groove at tubing and casing 1 two ends.Adopt the winding process of composite material, twining thickness outside steel sheath 3 is the bisphenol A epoxide resin base glass fibre composite material 4 of 3.0mm, and the length of winding should be slightly larger than the length of steel sheath 3; Bisphenol A epoxide resin base glass fibre composite material solidify to form wind pipe 4 through normal temperature.
Embodiment three
Present embodiment is 7 " heat-prestressing force fusion pipe, with the 10m of API standard (american petroleum TIA standard) long 7 " tubing and casing is as turned blank, comprises tubing and casing 1, steel sheath 3, wind pipe 4.Wherein, the distance that the box cupling installation is reserved at the two ends of tubing and casing 1 processes seal groove afterwards, is embedded with high-temperature seal ring 5 in the sealing groove, is used for the inside and outside isolation of well shaft fixing technology tubing and casing; The some slots 2 of distribution between the seal groove at tubing and casing 1 two ends, and filling has the packing material of the temperature characterisitic of 100 ℃ of thermal deformations and 300 ℃ of hot flowages.External surface in tubing and casing 1 is set with steel sheath 3, and the external surface of steel sheath 3 has wind pipe 4, and by these wind pipe 4 axial restraint steel sheaths 3.In the specific implementation process:
Go out seal groove in the 1 two ends 1.5m place turning of distance tubing and casing, and " O " RunddichtringO 5 of in seal groove, high temperature being installed.Within sealed at both ends groove, the surface of tubing and casing 1 is evenly distributed with the slot 2 of the wide tube wall that penetrates tubing and casing 1 of some 3-84 ° * 5mm; Between the slot 2 along tubing and casing 1 axially spaced-apart 60mm, arrange at misplace 60 ° of angles in the same way; Filled nylon PA-610 in slot 2.With roll bending machine that steel plate is round along tubing and casing 1 cylindrical roller, and, form steel sheath 3 with the opposite joint welding; Between tubing and casing 1 and the steel sheath 3 radial structure surplus 6 is arranged, and this radial structure surplus is in the tolerance range scope of 0.15mm～0.30mm; The length of steel sheath 3 is slightly larger than the length between the seal groove at tubing and casing 1 two ends.Adopt the winding process of composite material, twining thickness outside steel sheath 3 is the bisphenol-A epoxy base carbon fiber composite material of 3.0mm, and the length of winding should be slightly larger than the length of steel sheath; The bisphenol-A epoxy base carbon fiber composite material solidify to form composite material wind pipe 4 through normal temperature.
Install and use embodiment four
When using present embodiment, at first, when after surface pipe 10 installations, transferring production casing 9,, be installed in the heavy oil tested layer bottom to hot packer 13 lower ends with production casing 9 thread connection with the needs length of heat-prestressed fusion casing 14 according to thermal recovery technology.Secondly, cooperate earth anchor 16 service conditions to determine maximum lift load according to the well shaft fixing technology requirement; And, determine the lifting load lower limit according to the thermal recovery temperature gradient; Once more, consider under the influence condition of deadweight and cementing concrete ring 12 density, by the value of load-optimised definite lifting load, before cementing concrete ring 12 solidifies, with the slips locking lifting load in the well head prestressing force envelope pressure device 8.At last, after cement sheath 12 solidifies, seal well head, wait oil pipe 11 and hot packer 13 in production tree 7 to be installed and the thermal recovery technology with the envelope platen press orchid in the well head prestressing force envelope pressure device 8.
Claims (4)
1. a heat-prestressed fusion casing that is used for heavy crude heat extraction technology is characterized in that comprising tubing and casing (1), steel sheath (3) and wind pipe (4), wherein:
A. be embedded with high-temperature seal ring (5) in the seal groove at tubing and casing (1) two ends; Some slots (2) that penetrate the tube wall of tubing and casing (1) of on the tubing and casing between the sealed at both ends groove (1), evenly arranging, this slot (2) is uniform 3-84 ° * wide 5mm; Between the slot (2) along tubing and casing (1) axially spaced-apart 60mm, arrange at misplace 60 ° of angles in the same way; In slot (2), charge into packing material;
B. tubing and casing (1) external surface is with steel sheath (3), and 0.15 millimeter-0.50 millimeter structure surplus gap is arranged between tubing and casing and the steel sheath.
C., wind pipe (4) is arranged outside steel sheath (3), and by this wind pipe axial restraint steel sheath (3).
2. heat-the prestressed fusion casing that is used for heavy crude heat extraction technology according to claim 1 is characterized in that the material of filling in the slot (2) has the temperature characterisitic of 100 ℃ of thermal deformations and 300 ℃ of hot flowages.
3. heat-the prestressed fusion casing that is used for heavy crude heat extraction technology according to claim 1 is characterized in that described wind pipe (4) is that the external surface that composite material is wrapped in steel sheath (3) is formed after solidifying; The thickness of wind pipe (4) is 3 millimeters.
4. one kind is used the method for the heat-prestressed fusion casing of heavy crude heat extraction technology according to claim 1, it is characterized in that:
A. when transferring tubing and casing (1), heat-prestressed fusion casing (14) is installed in the heavy oil tested layer bottom to hot packer (13) lower end;
B. according to the well shaft fixing technology requirement, cooperate earth anchor (16) service condition to determine maximum lift load; And, determine the lifting load lower limit according to the thermal recovery temperature gradient;
C. consider under the influence condition of deadweight and cementing concrete ring (12) density, by the value of load-optimised definite lifting load, before cementing concrete ring (12) solidifies, with envelope pressure device (8) locking lifting load;
D. after cement sheath (12) solidifies, seal well head, wait oil pipe (11) and hot packer (13) in production tree to be installed (7) and the thermal recovery technology with the envelope platen press orchid in the envelope pressure device (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100177400A CN101539010B (en) | 2008-03-18 | 2008-03-18 | Thermal-prestressed fusion casing for heavy-oil thermal recovery process, and using method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008100177400A CN101539010B (en) | 2008-03-18 | 2008-03-18 | Thermal-prestressed fusion casing for heavy-oil thermal recovery process, and using method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101539010A true CN101539010A (en) | 2009-09-23 |
| CN101539010B CN101539010B (en) | 2012-07-04 |
Family
ID=41122382
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2008100177400A Expired - Fee Related CN101539010B (en) | 2008-03-18 | 2008-03-18 | Thermal-prestressed fusion casing for heavy-oil thermal recovery process, and using method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101539010B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106225760A (en) * | 2016-06-30 | 2016-12-14 | 广东技术师范学院 | A kind of Model For The Bush-axle Type Parts cuts the radial heat distortion measuring method caused |
| CN107313742A (en) * | 2017-05-27 | 2017-11-03 | 大庆市晟威机械制造有限公司 | A kind of repeatable expansion type casing external packer utilized |
| CN111362656A (en) * | 2020-03-19 | 2020-07-03 | 李建生 | Well cementing oil well cement composition and preparation method thereof |
| CN114856542A (en) * | 2022-05-09 | 2022-08-05 | 西南石油大学 | Device and method for testing integrity of cement ring under simulated prestress action |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN85108884B (en) * | 1985-12-03 | 1987-04-08 | 华东石油学院北京研究生部 | Protection equipment for injecting water sleeve in oil field |
| CN2224274Y (en) * | 1995-07-18 | 1996-04-10 | 石油大学(北京) | Hot oil-extracting casing column covered with protection ring |
| CN2622377Y (en) * | 2003-05-23 | 2004-06-30 | 辽河石油勘探局工程技术研究院 | Contact real type thermal stress compensator |
| CN200958368Y (en) * | 2006-10-20 | 2007-10-10 | 张超 | Vacuum thermal-insulating double pipe of oil well |
-
2008
- 2008-03-18 CN CN2008100177400A patent/CN101539010B/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106225760A (en) * | 2016-06-30 | 2016-12-14 | 广东技术师范学院 | A kind of Model For The Bush-axle Type Parts cuts the radial heat distortion measuring method caused |
| CN106225760B (en) * | 2016-06-30 | 2019-04-23 | 广东技术师范学院 | A kind of caused radial heat distortion measurement method of Model For The Bush-axle Type Parts cutting |
| CN107313742A (en) * | 2017-05-27 | 2017-11-03 | 大庆市晟威机械制造有限公司 | A kind of repeatable expansion type casing external packer utilized |
| CN111362656A (en) * | 2020-03-19 | 2020-07-03 | 李建生 | Well cementing oil well cement composition and preparation method thereof |
| CN111362656B (en) * | 2020-03-19 | 2022-09-13 | 保定保兴油田固井材料制造有限公司 | Well cementing oil well cement composition and preparation method thereof |
| CN114856542A (en) * | 2022-05-09 | 2022-08-05 | 西南石油大学 | Device and method for testing integrity of cement ring under simulated prestress action |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101539010B (en) | 2012-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104373145B (en) | Embedded classification constant-resistance shearing resistance large deformation anchor and method | |
| CN101539010B (en) | Thermal-prestressed fusion casing for heavy-oil thermal recovery process, and using method thereof | |
| CN110397453B (en) | Assembly type advanced stress release pilot tunnel supporting structure capable of being recycled and construction method | |
| CN103883263A (en) | Aerogel composite heat insulation sleeve | |
| CN104374637B (en) | Water sealing device applied to hydraulic fracture experiment under high-temperature and high-pressure condition | |
| CN107387041A (en) | One kind note critical medium oil shale single well stimulation conversion process | |
| CN105605335A (en) | Large-caliber prestressed steel cylinder concrete pipe for jacking construction | |
| CN105298433B (en) | A kind of waterpower pressure, rush, take out integrated hole sealing device and method | |
| CN209855832U (en) | Self-rotating anchoring pipe | |
| CN202117615U (en) | Combined structure of packer tools outside pipe for well cementation | |
| CN204729046U (en) | Prestressed thermal production casing head | |
| CN203796215U (en) | Packer | |
| CN210238512U (en) | Concrete high dam full dam storehouse surface-free consolidation grouting structure | |
| Lepper | Production casing performance in a thermal field | |
| CN209129621U (en) | Intelligent prestressed concrete liner tunnel | |
| CN105952381A (en) | Anchor rod drill bit capable of recycling anchor cable | |
| CN103174398A (en) | Drilling type fracture bridge plug | |
| CN206158637U (en) | Well cementation earth anchor device | |
| CN106090460A (en) | A kind of novel seabed oil-gas transportation compound tube | |
| CN114856542B (en) | Cement ring integrity testing device and method under simulated prestressing force effect | |
| CN112483008B (en) | Special-shaped casing and application thereof in preventing gas well annulus pressure | |
| Burkowsky et al. | Cemented pipe-in-pipe casing strings solve field problems | |
| CN217481257U (en) | Releasing device for thermal stress of completion pipe column of thickened oil thermal production well and casing string | |
| CN219412536U (en) | Wellhead sleeve reinforcing device | |
| CN109404008A (en) | Intelligent prestressed concrete liner tunnel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120704 Termination date: 20140318 |