A kind of high-pressure blocking-sealing gas injection leak detection tool with anti-jump function
Technical field
The utility model belongs to high-voltage tube string sealing detection range, industrial gas oil oil casing sealing detection range especially, but a kind of leak detection tool of high-pressure blocking-sealing gas injection of fast detecting oil casing sealing is provided.
Background technology
Pressure duct is after pipe couples together or repairs, often need the sealing detection is carried out in its connection or reparation position, for example need to finish the conveying of oil gas in the petroleum industry with oil casing, oil casing is made up of tubing and casing and aid, and tubing and casing and aid thereof couple together and constitute the passage that oil gas flows.In order to guarantee that the oil gas in oil well and the gas well flows out oil well or gas well according to the channel security of designing requirement, oil casing just needs good sealing.
The way that detects the oil casing sealing in the prior art is: in the laboratory the pin thread of every tubing and casing and aid and box, be connected with male joint with the box of standard respectively, set up confined space, in the tubing and casing confined space, inject a certain amount of high pressure detected gas then, water immersion oil string of casing again, tubing and casing and aid do not emit bubble within a certain period of time, and the sealing of tubing and casing or aid screw thread is described.Detect qualified after, again the oil jacket aid is unloaded from standard spiral shell snapping head, be transported to the working-yard respectively and use.In the working-yard, oil field, tubing and casing or aid are joined together to form the tubing string string by root.Above-mentioned detection method can not be used at the scene, just play for the connecting thread on the tubing and casing in the check of setting the sealing after whether can satisfying connection under the high pressure, promptly check screw thread whether qualified, and the sealing of the actual oil casing junction screw thread that couples together in scene is not tested, breadboard detection conclusion can only illustrate that connecting thread can meet the requirements of seal degree, but can not guarantee that but the sealing situation of reality that the scene is lowered to the screw thread of tubing and casing in the oil gas well or aid is good.
The utility model content
The purpose of this utility model is to improve prior art and has circumscribed problem, a kind of on-the-spot needs that satisfy are provided, carry out the high-pressure blocking-sealing gas injection leak detection tool that sealing detects for the devices such as oil casing that couple together at the scene with anti-jump function, it can detect the sealing situation of the oil casing junction that couples together on the spot, and this testing tool is pulled down Shi Buhui and is upwards gone out tubing and casing because of the impact of gases at high pressure from devices such as oil casing after detection finishes, and forms potential safety hazard.
The purpose of this utility model is achieved in that
The high-pressure blocking-sealing gas injection leak detection tool with anti-jump function that the utility model provides comprises a card envelope instrument, and it comprises two cover card sealing and newels;
Described newel is the hollow tubular of axial tool tube chamber, and the two ends up and down of this hollow tubular are provided with shutoff and seal this tube chamber;
Two cover card sealings are sleeved on both sides on the newel of rigidity.Every cover card sealing comprises the packer of a rigidity sliding sleeve and elastic material system, and it is a packing element.Described packing element and described sliding sleeve in every cover card sealing are set on the described newel slidably, and packing element is near the end of newel, and sliding sleeve is away from this end and the packing element adjacency that offsets; The outer end of described sliding sleeve and packing element is axially arranged with position limiting structure in the newel upper edge, this position limiting structure can make this sliding sleeve and packing element on the newel outer wall vertically at the setpoint distance intrinsic displacement, one end of described packing element is near sliding sleeve, and its other end leans against on the position limiting structure on the newel; Be set as a cavity between described sliding sleeve and the newel adjacently situated surfaces, this cavity is by being installed in the O-ring seal sealing on described sliding sleeve inwall and/or the described newel cylinder; On the newel of described cavity correspondence, be provided with a through hole and be communicated with formation one gas access with described tube chamber, make described cavity be communicated with described tube chamber; On the tube wall of the hollow tubular at the middle part between two described sliding sleeve position limiting structures, be provided with two through holes on the described newel, make the tube chamber of described hollow tubular be in communication with the outside, in these two passages, a retaining valve is set respectively, it is opposite by conducting direction, and this retaining valve is conducting under the pressure reduction of setting on this conducting direction, thereby form a pressurization passageway and a pressure release passage, but this pressurization passageway is being set conducting under the pressure reduction to extraneous direction, otherwise ending forever; But this pressure release passage is to the conducting under set pressure of described tube chamber direction, otherwise ends forever.Through hole also is set as leak detection medium input duct on the hollow tubular tube wall of described newel, be used for to the tube chamber input of the hollow tubular of newel or and output detected gas medium;
In addition, be provided with through hole in the set shutoff in the described lower end of described newel, anti-jump ball-and-seat is set in this through hole, this ball-and-seat is from the intraluminal direction of extroversion, but setting conducting under the pressure reduction, otherwise ends forever;
Described ball-and-seat comprises the valve seat that is arranged in the described through hole, on the aperture of the through hole in the connection external world of this valve seat valve member is set, and an end of a spring is pressed against in the described through hole, and the other end is provided with a valve member casting die, and it is pressed against on the described valve member.
This ball-and-seat comprises a ball-and-seat shell that is tightly connected with described newel, be provided with described valve seat on the axial passage in this ball-and-seat shell, on this valve seat, be provided with valve member and spring, one end of this spring is pressed against on this valve member by described valve member casting die, make the through hole that is in communication with the outside on the valve member closed valve seat, the other end of spring is pressed against on this shell.
Further, described valve seat be included in the pressure cap that is spirally connected on the described axial passage and be pressed on this pressure cap and with the flange seat of described axially extending bore sealing, establish axially extending bore on described pressure cap and the flange seat and be communicated with, described valve member is pressed on the aperture of axially extending bore of this flange seat.
But the valve seat that described pressure cap and flange seat constitute forms pressuring adjusting valve base, the conducting set pressure of scalable ball-and-seat.
Particularly, this ball-and-seat comprises an anti-jump ball-and-seat shell, its described tube chamber that has in an axial step through hole and the described newel is communicated with, the axial step through hole hole Duan Weiyi threaded hole section that this shell is corresponding with the newel link, ground matches, the end of described newel has the connection external thread, and described shell of ball-and-seat and newel are spirally connected, and the external thread section sealing of the termination of threaded hole section and downslide loop bar is spirally connected; In described threaded hole section back is a thinner transitional pore section, be the ball-and-seat containing hole section thick than transition section thereafter, wherein, an end of described spring is against on the convex shoulder between described transition section and the containing hole section, and it is described valve member casting die that the other end of this spring is provided with ball seat; Have the diameter adjusting screw section big than the containing hole section in the shell of the other end of described containing hole section, the pressure cap that is spirally connected in this adjusting screw section plugs a flange seat hermetically by O-ring seal and its sidewall in this containing hole section; Described pressure cap and flange seat are provided with axially extending bore makes the tube chamber of described newel and the external world be communicated with, and pressure cap and flange seat constitute adjustable seating; Described valve member is that steel ball is arranged between described ball seat and the flange seat, is pressed in this axial passage of sealing on the axial passage mouth of flange seat by spring, has constituted anti-jump ball-and-seat.
Be respectively equipped with the flange and the pit that are complementary on described pressure cap and the flange seat adjacent face and constitute the chimeric structure that compresses, the degree of depth of this pit or the axial height of flange or both differences form the adjustment structure of ball-and-seat spring pressure.
Originally the high-pressure blocking-sealing gas injection leak detection tool that has anti-jump function is work like this, this leak detection tool is promptly blocked envelope instrument lower end put into tubing and casing to be detected down, be positioned for example both sides of screw buckle, coupling part to be checked, to the chamber of described hollow tubular, feed gas from described leak detection medium input duct with certain pressure, gas enters described tube chamber between sliding sleeve and the newel by the gas access on the two cover card sealings, can promote to slide over the extruding packing element that slides on the newel, make packing element under axle pressure, be radially expanded, tighten the tube wall of oil casing threaded button both sides, in tubing and casing, form the confined space of a sealing, promptly finish setting.Set finish before, the pressure in the tube chamber of newel does not reach the set pressure of retaining valve in the pressurization passageway, so this not conducting of retaining valve.Set and finish, continue to feed gas in hollow tubular, after the set pressure of pressure above the described retaining valve on the pressurization passageway wherein, this retaining valve is opened, and gas flows into this confined space, this confined space can be full of then, and form certain pressure.At this moment, the not conducting of retaining valve in the pressure release passage is because the pressure of tube chamber and confined space is equal substantially.After static a period of time, can check whether screw thread has leakage.Whether promptly check has gas to flow to outside the tubing and casing from the junction of tubing and casing.If it is qualified no, to prove that then this connecting portion connects.Leak detection finishes, can be by emptying or the aspirator that on leak detection medium input duct, connects, gas in the hollow tubular is discharged, pressure in the hollow tubular tube chamber reduces, confined space between this card envelope instrument and the tubing and casing forms pressure reduction, after this pressure reduction reaches the set pressure of retaining valve in the pressure release passage, make retaining valve conducting in the pressure release passage, the pressure in the confined space reduces.Simultaneously, make that the pressure that packing element expands is also laid down, thereby, packing element shrinks and restores, this leak detection tool can be taken out from tubing and casing, when pressure release, if last packer be later than under packer restore, two packers are that the gases at high pressure between the packing element are when discharging downwards, run into the shaft bottom liquid level and conversely leak detection tool is formed impulsive force upwards, under this impulsive force, make described ball-and-seat open, after then downward gas rebounds through the shaft bottom liquid level, flow back to the instrument tube chamber by the single current passage, the emptying or the aspirator pressure release that connect on leak detection medium input duct thus, can prevent to jump on the testing tool.
The gas that charges into hollow tubular can change leak detection with pressure in the above-mentioned detection confined space.Can also outside tubing and casing, detection whether there be gas to spill and hunts leak.Thus, the leak detection tool of this high-pressure blocking-sealing gas injection also will comprise a gas collection cover, and this gas collection cover comprises two identical semicolumn housings, and a side seams of two halves cylindrical shell is provided with articulated structure and connects, and the padlock that coupling is set on the opposite side corresponding site connects firmly; The two ends of described gas collection cover are provided with a toroidal membrane of the two half ring plate compositions that are similarly identical, and the internal diameter of this toroidal membrane and the external diameter of tested tubing and casing are complementary, the gas collection space that makes a sealing of formation when the gas collection cover is set on the tubing and casing outer wall; On the wall of described gas collection cover, be provided with the detection hole that is in communication with the outside, be used for the detecting instrument that joint detection spills gas.Detecting instrument can be the highly sensitive instrument that can detect the search gas concentration change delicately.Correspondingly, search gas can be selected inert gas, for example helium.In order to reduce the leak detection cost, the combination gas that can use helium and nitrogen to mix, the content of helium is advisable can make detecting instrument detect, and common helium content is not less than 5% and gets final product.
Between two described dividing plates on the described housing of this gas collection cover, can also be provided with and be similarly the annular central dividing plate that identical two half ring plate are formed, the internal diameter of the described toroidal membrane that the internal diameter of this annular central dividing plate is provided with greater than two ends is complementary with the box cupling external diameter of two tubing and casing that are spirally connected on the tubing and casing.Put at described gas collection two described detection holes are set, it is located at the both sides of described central dividing plate respectively.Spacing between the relative plate face of the dividing plate at described two ends should be longer than the coupling length on the tubing and casing, and the length that grows is 5-50mm.If the too little collection that too mostly is unfavorable for spilling gas of this length that grows, the distance that grows usually are that 20mm is advisable, the thickness of each dividing plate can be 20mm, so, can guarantee the serviceable life of this gas collection cover.
During use, can establish pipeline on the leak detection medium input duct on the card sealing of this leak detection tool and be communicated with the gases at high pressure conveying device.Can also connect the pressure release branch road on this input duct.Perhaps, a through hole is set on described hollow tubular again, which is provided with atmospheric valve, use when being used for pressure release.
Usually, the tensimeter of precision of leak detection can be installed on the pipeline that is provided with on the leak detection medium input duct.
Further, on newel, an end of described packing element is near sliding sleeve, and its other end leans against on the newel.Be preferably in a sheathed elasticity control loop between the position limiting structure on described packing element and the newel.In gas compression packing element, also compress described elasticity control loop.When leak detection finished, the medium of will hunting leak was discharged from described tube chamber, and described control loop loses at sliding sleeve under the state of axial force, can provide enough auxiliary packing elements of elastic force axially to reset.
Described newel can be interconnected by upper sliding sleeve bar, downslide loop bar and venthole pipe nipple to be formed, and this venthole pipe nipple is a hollow short tube, respectively is provided with a screw socket at axial two ends; The axial hole that axially has perforation of described upper sliding sleeve bar, described downslide loop bar axially have an axial hole that does not connect, the respective end that is connected with venthole pipe nipple two ends of described slide down loop bar be provided with the venthole pipe nipple on the end that is spirally connected that is complementary of screw socket, be spirally connected with described venthole pipe nipple, seal by O-ring seal therebetween, and make axial hole on the slide down loop bar be connected and constitute the gas main channel with axial pipeline on the venthole pipe nipple, establish connector in the upper end of upper sliding sleeve bar and seal its upper port, and on the upper sliding sleeve bar, establish through hole as leak detection medium input duct.
On the sidewall of described venthole pipe nipple, be provided with two through holes and form described pressurization passageway and pressure release pressure passageway.
Particularly, the outer wall of described slide down loop bar is three grades of multidiameters, be connected an end with described venthole pipe nipple and be butt end, by it up or down, form four gradually thin ladder sections, hoop is provided with through hole on the slide down loop bar sidewall at the close convex shoulder position of inferior thin segment, two described sliding sleeves in the described two cover card sealings have with described slide down loop bar on the ladder axially extending bore that is complementary of multidiameter, be set on respectively on the slide down loop bar, one end of described sliding sleeve is spacing by the described axial limiting of the convex shoulder formation between the thickest section and inferior thick section on the described slide down loop bar, sheathed one described packer is packing element and described two the sliding sleeve ends adjacency that offsets on the thinnest shaft part of described slide down loop bar, between the shoulder hole hole wall of the inferior thin segment of described slide down loop bar and low sleeve correspondingly, form a gap and constitute described cavity, corresponding with the described through hole that is arranged circumferentially on the described slide down loop bar, on the described sliding sleeve up and down at the two ends in this gap and/or corresponding described slide down loop bar, be provided with O-ring seal, make that this gap is sealed.
Establish screw thread in the outer end of thin shaft part at described slide down loop bar, be spirally connected on it and cap constitutes the axial limiting structure that described packer is the packing element outside.
On described slide down loop bar, instrument connector that has perforation and instrument importing head that the outside described and cap is spirally connected respectively and is the sphere termination.
The high-pressure blocking-sealing gas injection leak detection tool that the utility model provides with anti-jump function, simple in structure, detecting reliability is high, can hunt leak for the tubing and casing that couples together by execute-in-place, and it is easy to operation, cooperate with the device that can produce the high pressure search gas fast, can hunt leak to each connecting portions such as oil pipes at the scene fast and efficiently, each connects the connecting portion leak detection of tubing and casing and can finish in 1-2 minute.By comparison, existing other detection technique each detection time all is no less than 10 minutes.Have again, owing to be provided with ball-and-seat, can effectively prevent to detect to finish and jump the potential safety hazard that causes on the testing tool in the pressure leak process.
Below by drawings and Examples the utility model is described further.
Description of drawings
The structural representation of the high-pressure blocking-sealing gas injection leak detection tool that Fig. 1 provides for the utility model with anti-jump function;
The leak detection tool sectional structure synoptic diagram of the high-pressure blocking-sealing gas injection that Fig. 2 provides for the utility model;
Fig. 2 a, Fig. 2 b and Fig. 2 c are respectively A, the B of Fig. 2 and the partial enlarged drawing at C three places;
The sectional structure synoptic diagram of the venthole pipe nipple in the leak detection tool of the high-pressure blocking-sealing gas injection that Fig. 3 provides for the utility model;
The sectional structure synoptic diagram of the gas collection cover in the leak detection tool of the high-pressure blocking-sealing gas injection that Fig. 4 provides for the utility model;
The side-looking structural representation of the leak detection tool of the high-pressure blocking-sealing gas injection that Fig. 5 provides for the utility model presents gas collection cover end face structure;
The structural representation of the anti-jump ball-and-seat of the lower end in the high-pressure clamped sealing gas injection tool that Fig. 6 provides for the utility model.
Embodiment
The utility model provides is used for leak detection of tube column and has the leak detection tool of the high-pressure blocking-sealing gas injection of anti-jump function, and it comprises card envelope instrument and gas collection cover,
Shown in Fig. 1,2,4 and 5, the high-pressure blocking-sealing gas injection leak detection tool with anti-jump function that the utility model provides comprises two cover card sealing and newels; Described newel is the hollow tubular of vertical tool central lumen, and the two ends of this hollow tubular are provided with shutoff blocked center tube chamber; Two cover card sealings are sleeved on both sides on the newel of rigidity.Every cover card sealing comprises the packer of a rigidity sliding sleeve and elastic material system, and it is a resilient material glue tube.
Particularly, as Fig. 1, shown in 2, newel 10 is by upper sliding sleeve bar 11, downslide loop bar 12 and venthole pipe nipple 13 interconnect composition, venthole pipe nipple 13 is a hollow short tube, as shown in Figure 3, respectively be provided with a screw socket 131 at the two ends of tube axial, be used to connect the slide down loop bar, as shown in Figure 2, the axial hole that axially has perforation of upper sliding sleeve bar 11, the axial hole that axially has perforation of downslide loop bar 12, the end 11a that is spirally connected of slide down loop bar, the screw socket 131 at 12a and venthole pipe nipple 13 two ends is spirally connected, O RunddichtringO 131a sealing is set therebetween, and makes axial hole on the slide down loop bar formation gas main channel P that is connected with pipeline on the venthole pipe nipple 13.On the sidewall of venthole pipe nipple 13, be provided with two through holes and form a pressurization passageway 132 and pressure release pressure passageway 133, on these two passages, a retaining valve is set respectively, it is opposite by conducting direction, but the retaining valve in the pressurization passageway 132 is to the conducting under certain pressure of extraneous direction, otherwise ends forever; But the retaining valve in the pressure release passage 133 is to the conducting under certain pressure of pipeline chamber direction, otherwise ends forever.
As Fig. 2, shown in Fig. 2 b, the outer wall of downslide loop bar 12 is three grades of multidiameters, it is connected an end and is butt end with venthole pipe nipple 13, by it left, form four gradually thin ladder sections, hoop is provided with through hole 121 on the downslide loop bar sidewall at the close convex shoulder position of inferior thin segment 12h, one low sleeve 14 have with downslide loop bar 12 on the ladder axially extending bore that is complementary of multidiameter, be set on the downslide loop bar 12, one end of low sleeve 14 is by the convex shoulder 12b axial limiting between the thickest section and inferior thick section on the downslide loop bar, a sheathed lower packet 15 is that resilient material glue tube 15 offsets and adjacency with low sleeve 14 ends on downslide loop bar 12 the thinnest axle 12c sections, between the shoulder hole hole wall of the inferior thin segment 12h of downslide loop bar 12 and low sleeve correspondingly 14, form a gap a, it is corresponding with described through hole 121 on the downslide loop bar 12, between the low sleeve at the two ends in this gap and downslide loop bar, be provided with O RunddichtringO 12a, 14a makes that this gap a is sealed.Screw thread is established in outer end at downslide loop bar 12 the thinnest shaft part 12c, be spirally connected on it and cap 16 as the axial limiting spare of packing element 15, and the outside downslide loop bar of cap on the be spirally connected instrument that is the sphere termination import 17.
With similarly above-mentioned, the outer wall of upper sliding sleeve bar 11 also is three grades of multidiameters, one section that is connected with the venthole pipe nipple is butt end, by it to the right, form four gradually thin ladder sections, hoop is provided with through hole on the upper sliding sleeve bar sidewall at the close convex shoulder position of inferior thin segment, one upper sliding sleeve 18 have with upper sliding sleeve bar 11 on the ladder axially extending bore that is complementary of multidiameter, be set on the upper sliding sleeve bar 11, one end of upper sliding sleeve 18 is by the convex shoulder axial limiting between the thickest section and inferior thick section on the upper sliding sleeve bar 11, and a sheathed upper packer 19 is that resilient material glue tube 19 offsets and adjacency with upper sliding sleeve 18 ends on the thinnest shaft part of upper sliding sleeve bar 11.Between the shoulder hole hole wall of the inferior thin segment of upper sliding sleeve bar 11 and upper sliding sleeve correspondingly 18, form a gap, corresponding with described hoop through hole on the upper sliding sleeve bar 11.On the upper sliding sleeve 18 at the two ends in this gap and upper sliding sleeve bar 11, be provided with the O RunddichtringO, make that this gap is sealed.Establish screw thread in the outer end of thin shaft part at upper sliding sleeve bar 11, be spirally connected on it and cap 16 as the axial limiting spare of packing element 19, and the outside upper sliding sleeve of cap do the instrument connector 17a that is spirally connected on 11, can have perforation on it, be used to wear steel wire, be convenient to this testing tool be put into tubing and casing by steel wire.A gas input duct also is set on described newel makes described gas main channel P be in communication with the outside, it is connected by for example high-pressure hose Q with the gases at high pressure feedway when using.
As Fig. 2,2a and shown in Figure 6, be provided with an axial single current passage at importing 17 1 end, it makes longitudinal center's tube chamber of newel be in communication with the outside, and outwards is provided with in this single current passage and ends forever, inwardly can be at the anti-jump ball-and-seat of conducting under the set pressure.The concrete structure of this ball-and-seat can be shown in Fig. 2,6.This ball-and-seat 300 comprises an anti-jump ball-and-seat shell 301, its tube chamber that has in an axial step through hole and the newel is communicated with, the axial step through hole hole Duan Weiyi threaded hole section 302 corresponding with the newel link, ground matches, the end of newel has the connection external thread, ball-and-seat shell 301 is spirally connected with newel, specific to structure shown in Figure 2, threaded hole section 302 is spirally connected with the external thread section sealing of the termination of downslide loop bar 12, and the convex shoulder of shell 301 spiro union portions is provided with O-ring seal 303 makes downslide loop bar and shell 301 seal.In threaded hole section 302 back is a thinner transitional pore section, be the ball-and-seat containing hole section thick than transition section thereafter, wherein, an end of the spring 310 in the ball-and-seat is against on the convex shoulder between transition section and the containing hole section, and the other end of spring 310 is provided with ball seat 311.
In the shell 301 of the other end of containing hole section, have the diameter adjusting screw section 314 big than the containing hole section, a pressure cap 316 is spirally connected in this adjusting screw section 314, plug a flange seat 313 hermetically by O-ring seal 315 and its sidewall in the containing hole section, O-ring seal 315 is realized the lateral seal of valve seat.Pressure cap 316 and flange seat 313 are provided with axially extending bore makes the tube chamber of newel and the external world be communicated with.Pressure cap 314 and flange seat 313 constitute adjustable seating.Valve member is that steel ball 312 is arranged between ball seat 311 and the flange seat, is pressed in this axial passage of sealing on the axial passage mouth of flange seat by spring 310, has constituted anti-jump ball-and-seat.Be respectively equipped with the flange and the pit that are complementary on pressure cap 316 and flange seat 313 adjacent faces and constitute the chimeric structure that compresses, the degree of depth of this pit or the axial height of flange or both differences form the adjustment structure of ball-and-seat 300 spring pressures.By inwardly with to inner rotary pressure cap 316, the degree that compresses that can regulating spring, thereby the unlatching set pressure that can regulate ball-and-seat within the specific limits.
The present embodiment using gases is as the leak detection medium.When using, the instrument that this leak detection tool is promptly blocked the envelope instrument imports 17 and puts into tubing and casing to be detected down, being positioned connecting thread button to be checked partly locates, two packing elements on it are positioned at the both sides of screw buckle, feed in described gas main channel P by high-pressure hose Q and to have the detected gas of certain pressure, gas enters described gap a (seeing Fig. 2 b) by the hoop passage on upper sliding sleeve bar 11 and the downslide loop bar 12, can promote slide down is enclosed within on the slide down loop bar and moves and i.e. two packing elements of extruding upper packer 15 and lower packet 19, make packing element under axle pressure, be radially expanded, the tube wall of chucking tubing and casing connecting thread both sides forms a confined space, promptly finishes setting.Set in the process in foundation, because the pressure among the P of gas main channel does not reach the conducting set pressure of retaining valve in the pressurization air flue 132, the not conducting of retaining valve in the pressurization passageway, and the retaining valve in the pressure release passage 133 is by can conducting outwards not leaking gas.Set end, continue in the hollow tubular of newel, to feed gas, after the set pressure of pressure wherein above the described retaining valve in the pressurization passageway 132, this retaining valve is opened, gas flows into this confined space, this confined space can be full of then, and form certain pressure.At this moment, the not conducting of retaining valve in the pressure release passage.After static a period of time, can check whether screw thread has leakage.For example, can block the inductive head that high-precision tensimeter or pressure transducer are set on the high-pressure hose that connects on the gas input duct of envelope instrument at this, detected pressures changes, if there is pressure to reduce, illustrates that then there is leakage the tubing and casing junction.Leak detection finishes, and high-pressure hose can be connected aspirator, and the gas in the gas main channel is discharged, pressure in the hollow tubular tube chamber reduces, itself and confined space form pressure reduction, can be so that the retaining valve conducting in the pressure release passage, and the pressure in the confined space can reduce.Simultaneously, make to cause the pressure that packing element expands also to be laid down, thereby, this leak detection tool can be taken out from tubing and casing.
Except can passing through pressure detection method leak detection as previously mentioned, can also hunt leak by detecting the method that whether has the leak detection dielectric leakage to come out in the tubing and casing outside.Like this, easily collecting detects for the gas that prevents to leak out flies away not, can a gathering-device be set in the tubing and casing outside.
Thus, originally the high-pressure blocking-sealing gas injection leak detection tool that has anti-jump function also comprises gas collection cover 20, shown in Fig. 4,5, this gas collection cover comprises two identical semicolumn cylindrical outer casings 21, one side shaft of two halves cylinder barrel shaped housing is provided with padlock 23 to being articulated and connected by hinge 22 on the opposite side corresponding site; Two ends are provided with a toroidal membrane 24 of the two half ring plate compositions that are similarly identical respectively on the described housing of described gas collection cover, and the external diameter of the internal diameter of this toroidal membrane 24 and tested leakage of oil sleeve pipe is complementary; Make when the gas collection cover be located on the tubing and casing outer wall, seal between two axial seams of two halves cylinder barrel shaped housing and dividing plate and dividing plate and the tube wall, form the gas collection space of a sealing between the outer wall of this gas collection cover and tubing and casing; On the wall of described gas collection cover, be provided with the detection hole that is in communication with the outside, be used for the detecting instrument that joint detection spills gas.Detecting instrument can be the high sensitivity instruments such as mass spectrometer that can detect detected gas delicately.Search gas can select inert gas as spike medium, for example helium.In order to reduce the leak detection cost, the combination gas that can use helium and nitrogen to mix, the content of helium is advisable can make detecting instrument to detect, and normally helium content can reach the spike effect more than 5%.Detect the concentrations of helium that detects in the space by detecting instrument and whether surpass normal concentrations of helium in the air, the decidable detected part has or not leakage according to this, and according to the variable quantity of concentrations of helium, the degree that quantitative test is leaked.
Between two described dividing plates on the described housing of this gas collection cover, can also be provided with and be similarly the annular central dividing plate 25 that identical two half ring plate are formed, the internal diameter of the described toroidal membrane that the internal diameter of this annular central dividing plate is provided with greater than two ends is complementary with the box cupling external diameter of two tubing and casing of screw thread on the tubing and casing.Put at described gas collection two described detection holes 26 are set, it is located at the both sides of described central dividing plate respectively.Spacing between the relative plate face of the dividing plate at described two ends should be longer than the coupling length on the tubing and casing, and the length that grows is 5-50mm.Usually the distance that grows is that 20mm is advisable, and the thickness of each dividing plate can be 20mm.
The toroidal membrane 24 that described gas collection cover two ends are provided with and central dividing plate 25 and shell 21 are connected with bolt, and for example, the relevant position is provided with through hole on described dividing plate and shell wall, wherein wears bolt dividing plate and shell are fixed together.
In said structure, last lower packet is described packing element one end near sliding sleeve up and down, the other end lean against and cap on.Further, when finishing to unload this card envelope instrument, leak detection can allow packing element restore as early as possible in order to make, can slide down loop bar upper sliding sleeve and and cap between a sheathed elasticity control loop (not shown), in search gas effect compression packing element, also compress described elasticity control loop.When leak detection finishes to pull down the card sealing, gas to be discharged from described main channel, described control loop loses at sliding sleeve under the state of axial force, can provide enough auxiliary packing elements of elastic force axially to reset.
When from oil casing, unloading this testing tool, from high-pressure hose Q gas bleeding, the conducting of pressure release passage retaining valve, seal cavity air pressure reduces, sliding sleeve and last lower rubber cylinder reset up and down, and when last packing element resetted than lower rubber cylinder evening, the gas in the seal cavity was downwards again to upper punch, can wash ball-and-seat 300 open, send out thereby effectively avoid upper punch gas that this leak detection tool has been dashed the danger of smashing relevant device and operating personnel.