The concentric tube hydraulic jet rushes the coal dust downhole hardware
Technical field:
The present invention relates to the solid particles such as a kind of coal dust for removing coal bed gas well deposition and shaft bottom, coal tar, coal slime, recover the equipment of production capacity, belong to oil gas field and coal bed gas field development technique field.
Background technology:
Coal-bed gas exploitation is the process of a drainage and step-down gas production.In the pump drainage process,, on the borehole wall and the impact in coal seam on every side, add the factors such as forced-ventilated water due to drilling well, well cementation and pressure break, can cause the coal dust of coal bed gas well output larger particles.Along with continuing that row adopts, cause producing pressure differential to become gradually greatly, can constantly encourage coal seam, the solid particles such as coal dust, coal grain, coal slime are come off from coal seam, the solidity particles such as the coal dust of generation are along with production fluid enters pit shaft.Adopt the initial stage row, when aquifer yield is higher, the solid particles such as coal dust that enter pit shaft can be discharged along with water, but when entering the steady production after date, the stratum aquifer yield reduces, cause the water discharge capacity less, the solidity particles such as coal dust that enter pit shaft can not effectively be discharged ground, under the effect of self gravitation, constantly precipitation, be deposited in the oil jacket annular space, thereby cause the phenomenon of burying pump, stifled pump and holddown, cause very large difficulty to production, in order to resume production, the solidity material that must will be deposited on shaft bottom is discharged ground.
The on-the-spot main mode that adopts machinery to drag for coal dust is carried out well workover at present, and this operating type need to constantly be lowered to, play flowline, and operating efficiency is low, activity duration is long, the continuous row who affects coal bed gas well adopts, and causes the wetting of coal seam and pollution, thereby affects the output of coal bed gas; , because coal dust is easy to suspend in water, therefore can't determine whether the coal dust in shaft bottom is all pulled out in addition, cause and drag for coal dust inefficiency and not thorough.
The process of the conventional hydraulic sand washing in oil field is inapplicable coal bed gas well also.Be mainly because the strata pressure of coal bed gas well is lower,, if adopt the mode of conventional hydrodynamic cleaning to arrange coal dust, can cause the sand cleaning fluid leakage serious, return output much smaller than inlet, thereby pollute stratum; It is large that coal seam has compressibilty, the characteristics of natural cranny development, and because the pressure of sand cleaning fluid is higher, sand cleaning fluid can penetrate in coal seam, destroys the structure in coal seam, and the destruction of causing the aerogenesis passage, affect the recovery of coal bed gas well production capacity.At the bottom of the foam flushing manhole, cost is higher, lifting solid material indifferent, also and be not suitable for coal bed gas well.
At present, still do not have a kind ofly both to have met coal bed gas and rush the coal dust needs, can protect again the workover process technology of the solid particles such as eliminating coal dust of reservoir, this device solves this difficult problem.
Summary of the invention
The objective of the invention is: the inefficient shortcoming that overcomes present coal bed gas well workover treatment; Change the single present situation of coal bed gas well workover treatment mode.The invention provides a kind of down-hole that completely newly rushes the coal dust operation and rush coal dust device, this device is connected to form circuit system with one group of concentric plain tubing, power fluid enters and rushes in coal dust device along the annulus access of inside and outside oil pipe, returning fluid returns on inner oil tube, avoided power fluid and returning fluid to enter into the oil jacket annular space, in the situation that do not injure coal seam, efficient fast with the coal dust discharge of shaft bottom deposition; And in the process of workover treatment, make the shaft bottom producing fluid level can not increase.
The technical solution adopted in the present invention is: the concentric tube hydraulic jet rushes the coal dust downhole hardware and mainly venturi anemostat, high pressure nozzle, stirring nozzle, high pressure chest, sleeve, urceolus, inner core, joint, copper backing, leather packing sheet and O-ring seals, consists of, it is characterized in that: high pressure chest upper/lower terminal inner headed face is connected with the stirring nozzle with high pressure nozzle with screw thread respectively, is provided with copper backing between high pressure chest and high pressure nozzle and stirring nozzle; Urceolus upper/lower terminal inner headed face is connected with high pressure chest, inner core with screw thread respectively, is respectively arranged with O-ring seals between urceolus and high pressure chest, inner core; Urceolus upper/lower terminal periphery is connected with sleeve, joint with screw thread respectively, is respectively arranged with O-ring seals between urceolus and sleeve, joint; Be provided with the leather packing sheet between sleeve and high pressure chest; The venturi anemostat is connected with inner core with screw thread, is provided with O-ring seals between venturi anemostat and inner core.
During use, upper end of joint is connected with the 3.5in plain tubing with screw thread, 3.5in plain tubing carries the concentric tube hydraulic jet and rushes under the coal dust downhole hardware to the precalculated position, down-hole, the 2in plain tubing carries the down-hole fastening means and is lowered into 3.5in oil pipe inside, under the effect of centralizer, the 2in plain tubing rushes the coal dust downhole hardware by down-hole fastening means and concentric tube hydraulic jet and is connected, and forms concentric pipeline.When coal bed gas well rushes the coal dust operation, from the high voltage power liquid of ground three plunger high pressure reciprocating pumps, through wellhead assembly, enter into inside and outside oil pipe annular space, power fluid flows downward and enters into high pressure chest inside along the annulus access of inside and outside oil pipe; Be divided into 2 tunnels at high pressure chest internally-powered liquid, a route stirs nozzle ejection ejection, impacts shaft bottom, stirs coal dust, and coal dust is fully mixed with formation fluid, and the duct of formation mixed liquid on urceolus circumference wall enters into the annular space of jet rows coal dust device.Another road power fluid sprays by high pressure nozzle, and the total head of power fluid almost all changes velocity head into, and the fluid column ambient pressure is reduced, and forms negative pressuren zone, under the differential pressure action between bottom pressure and negative pressuren zone, formation fluid is drawn in trunnion.Throat pipe diameter always is greater than nozzle diameter, and power fluid and formation mixed liquid are fully mixed in trunnion after, velocity head reduces, and pressure head gos up to some extent.In this process, power fluid loses momentum and kinetic energy, and formation mixed liquid obtains momentum and kinetic energy.Mixed liquid enters in anemostat,, along with the anemostat cross-sectional area increases gradually, makes velocity head again be converted to pressure head, thereby mixed liquor is given rise on ground., along with the concentric tube hydraulic jet rushes transferring gradually of coal dust downhole hardware, complete row's coal dust work of whole coal bed gas well.Stirring the nozzle place in addition, the total head of power fluid also almost all becomes velocity head, and the fluid column ambient pressure is reduced, and can avoid like this injury to shaft bottom fully.
This device is designed with the stirring nozzle, and the power fluid of nozzle ejection makes shaft bottom deposition coal dust fully mix with formation fluid, is conducive to whole discharges of shaft bottom coal dust.
In order to guarantee that the shaft bottom producing fluid level remains unchanged, consider that the coal seam aquifer yield is less, design concentric tube hydraulic jet rushes the flow that the coal dust downhole hardware entrainments formation fluid and is larger than the flow that stirs nozzle ejection power fluid.
Efficiency when the distance affects hydraulic jet between high pressure nozzle and trunnion rushes coal dust device work, find when larynx mouth distance is 7~10.5mm by calculating, hydraulic jet rushes the most effective of coal dust device, apart from being 7~10.5mm, this installs all connections and all adopts regular screw threads to connect for larynx mouth after guaranteeing to have assembled; Between nozzle and high pressure chest, copper backing is installed, is provided with O-ring seals between other parts, guarantee the sealing of this device.
Be designed with the sand washing tooth in the sleeve lower end, be mainly used in visiting the coal dust face, and prevent that the stirring nozzle is stopped up by coal dust in the process of visiting the coal dust face, affect hydraulic jet and rush the normal operation of coal dust device.
The invention has the beneficial effects as follows: the deficiency that overcomes that present coal bed gas well workover treatment efficiency is low, the well workover mode is single and can't the shaft bottom coal dust all pull out.The design of stirring nozzle makes the coal dust of shaft bottom deposition fully mix with formation fluid, is convenient to whole discharges of shaft bottom coal dust, has improved the efficiency of workover treatment; Contacting of power fluid and returning fluid and coal seam avoided in the design of concentric double pipe post, and protective effect has been played in coal seam.
Description of drawings
Fig. 1 is front view of the present invention, has mainly showed the overall structure that the concentric tube hydraulic jet rushes the coal dust downhole hardware.
Fig. 2 is the sectional view of Fig. 1, has showed that mainly the concentric tube hydraulic jet rushes annexation and the inner concrete structure of this device between each component of coal dust downhole hardware.
Fig. 3 is the structural representation of urceolus, and the axial duct of urceolus Surface Vertical is the formation fluid entrance, with the annulus of axially parallel be the runner of power fluid.
Fig. 4 is the structural representation of high pressure chest, and the high pressure chest Surface Vertical is the power fluid entrance in axial duct.
Fig. 5 is the structural representation of sleeve.
Fig. 6 is the two-dimensional structure schematic diagram of venturi anemostat.
The specific embodiment
The present invention is provided by following instance, and the present invention will be further described below in conjunction with accompanying drawing.
The present invention is comprised of venturi anemostat 1, O-ring seals 2,5,6,9,10, inner core 3, joint 4, high pressure nozzle 7, copper backing 8,15, urceolus 11, sleeve 12, high pressure chest 13, leather packing sheet 14 and stirring nozzle 16 as shown in the figure, its assembled relation is as follows: high pressure chest 13 upper and lower end inner headed faces are connected with stirring nozzle 16 with high pressure nozzle 7 with screw thread respectively, are respectively arranged with copper backing 8,15 between high pressure chest 13 and high pressure nozzle 7 and stirring nozzle 16; Urceolus 11 upper/lower terminal inner headed faces are connected with high pressure chest 13, inner core 3 with screw thread respectively, are respectively arranged with O-ring seals 5,9 between urceolus 11 and high pressure chest 13, inner core 3; Urceolus 11 upper/lower terminal peripheries are connected with sleeve 12, joint 4 with screw thread respectively, are respectively arranged with O-ring seals 6,10 between urceolus 11 and sleeve 12, joint 4; Be provided with leather packing sheet 15 between sleeve 12 and high pressure chest 13; Venturi anemostat 1 is connected with inner core 3 with screw thread, is provided with O-ring seals 5 between venturi anemostat 1 and inner core 3.Wherein be designed with duct on the circumference tube wall of urceolus 11 sides; Venturi anemostat 1 be internal diameter from top to bottom by the capillary base of thin chap, the venturi anemostat is connected with the 2in plain tubing by the down-hole fastening means, joint is connected with the 3.5in plain tubing.