CN201218066Y - Down-hole decompression tool - Google Patents

Abstract

An underground depressurizing tool applicable to the technical field of oil-gas drilling engineering comprises a multi-stage pump, a connector, a shaft joint, a hydraulic cylinder, a piston, a supporting bar, a sliding seal ring and a fixed seal ring. The multi-stage pump is provided with an inlet and an outlet on the lower part and the upper part respectively, and the fixed seal ring is fixed on the external wall of the shell of the multi-stage pump. The sliding seal ring is matched with the fixed seal ring to form sealing. The lower part of the sliding seal ring is connected with the supporting bar. The hydraulic cylinder is fixed on the lower external wall of the shell of the multi-stage pump, a ring piston is arranged inside the hydraulic cylinder, and the top of the piston is connected with the supporting bar. The utility model has the advantages that the bottom hole pressure can be effectively reduced by 1 to 3MPa and the problem of mud loss in the process of drilling is solved. Moreover, the sealing system of the patent is automatically controlled by hydraulic pressure, and therefore, excessive pressure fluctuations in the process of drill lifting and lowering are effectively avoided.

Description

The underground pressure reducing instrument

Technical field

The utility model relates to the oilfield drilling field of engineering technology, and particularly a kind of drilling well downhole tool is a kind of instrument that reduces bottom pressure under the circulation of drilling fluid state.

Background technology

Down-hole pressure control is the key link in the drilling process.In the conventional drilling process, drilling liquid pressure is to be used for suppressing strata pressure and to keep hole stability.Under the inactive state, bottom pressure P_BHOnly with drilling fluid liquid column hydrostatic pressure P_HydRelevant; Under the recurrent state, bottom pressure P_BHBe drilling fluid fluid pressure and annular pressure lost P_AFBoth sums.Yet annular pressure lost P_AFThe too high bottom pressure P that makes_BHGreater than formation fracture pressure, cause the leakage of drilling fluid.Because the selection of drilling fluid density by the strata pressure decision, therefore must solve the problem that the bottom pressure height is produced under the circulation of drilling fluid state by reducing annular pressure lost (equivalent mud circulation density ECD).The method that tradition is used for reducing equivalent circulating density in the drilling technology has: reach with the low drilling fluid of rheological characteristic and reduce the annular pressure loss; Adopt the reaming hole method to enlarge borehole size; Replace sleeve pipe with drilling liner; Reduction annular space discharge capacity reaches and reduces frictional resistance; Reduce the total amount that drilling speed reduces landwaste in the annular space.Yet adopt above-mentioned measure will reduce drilling efficiency, increase drilling cost.

Foreign literature has been introduced a kind of annular space pump that can be used to reduce bottom pressure at present, the annular space pump is driven by power motor, this annular space pump is lowered in the sleeve pipe with its potted component that matches, potted component is positioned between annular space pump case and internal surface of sleeve pipe, potted component is divided into upper and lower two disjunct spaces with annular space, the fluid that returns from drill bit and the mixture of landwaste must pass through annular space pump inner space, the annular space pump rotates under the driving of power motor, and the castering action of annular space pump is lifted to the face of land with the annular fluid of certain depth.Existing experimental result shows: this annular space pump can effectively reduce bottom pressure, avoids formation leakage.The subject matter of this instrument existence has two aspects at present: because potted component is in sealing state all the time, make the annular space pump cause very big surge pressure together with drilling rod in the process of making a trip; Potted component will move up and down with brill, causes potted component very easily to lose efficacy, and can not reach sealing effectiveness, makes Returning fluid directly return the face of land without the annular space pump, can not give full play to the castering action of annular space pump, can not effectively reduce bottom pressure.

Summary of the invention

The purpose of this utility model is: a kind of underground pressure reducing instrument is provided, can reduces down-hole pressure at circulation time, solve the problem that narrow mud density window strata drilling produces, reduce nonproductive timeliness, improve drilling efficiency.

The technical solution adopted in the utility model is: the underground pressure reducing instrument comprises multistage pump, connector, shaft coupling, hydraulic cylinder, piston, support bar, sliding ring and decides joint ring.

The multistage pump main shaft is positioned at the multistage pump enclosure interior, the upper/lower terminal of multistage pump main shaft by bearing fixing in the multistage pump enclosure interior.

The multistage pump lower housing portion has import, and import provides Returning fluid and landwaste enters usefulness in the multistage pump housing; The outlet of multistage pump housing top, Returning fluid and debris flow that outlet provides in the multistage pump housing are used to annular space.

On the outer wall of multistage pump housing, be fixed with and decide joint ring.It is circular deciding joint ring, and the internal diameter of deciding joint ring is identical with multistage pump housing external diameter, will decide on the outer wall that joint ring is fixed on the multistage pump housing by screw thread or welding, decide the position, position of joint ring in the import of the multistage pump housing, export between any position.

Sliding ring is an annular, and the external diameter of sliding ring is identical with casing inner diameter, and the internal diameter of sliding ring is with to decide seal outer diameter identical.Sliding ring with decide joint ring and cooperate the back to form sealing.The sliding ring bottom is connected with support bar, and the effect of support bar is to be used for supporting sliding ring, and can make sliding ring do upper and lower motion.

Outer wall is fixed with hydraulic cylinder in the lower end of multistage pump housing, forms annular space between the outer wall of hydraulic cylinder and multistage pump housing.Annular piston is arranged in hydraulic cylinder, and piston top connects described support bar.The drilling fluid inlet is arranged on the outer wall of multistage pump housing, and the high pressure drilling liquid in the multistage pump housing can enter annular space by the drilling fluid inlet, promotes piston and moves upward.

The position of described import and outlet is on the conical outer wall of multistage pump housing, and import is symmetrically distributed with outlet, and the quantity of import and outlet is respectively 2～10.Import and outlet are shaped as the fan annular, and fan ring arc corresponding angle is 0～180 °.

Describedly decide the joint ring height between 50～200mm, the vertical section of deciding joint ring is shaped as wedge shape, stairstepping, rectangle.

The vertical section of described sliding ring is shaped as wedge shape, stairstepping, rectangle.

The piston motion stroke can be controlled in the upper and lower dead point of hydraulic cylinder inside.Drilling liquid pressure hour, piston is positioned at the hydraulic cylinder lower dead point position, increase along with drilling liquid pressure, drilling fluid enters into hydraulic cylinder inside by the inlet of the drilling fluid on the multistage pump housing that links to each other with hydraulic cylinder, under drilling fluid promotes, piston moves upward, and drives coupled steady arm and sliding ring, always the motion sliding ring with decide the effect of joint ring fitted seal.Support bar quantity is 2～8.

The underground pressure reducing instrument that the utility model proposes, rise, in the going down process, piston is positioned at the hydraulic cylinder bottom dead centre, sliding ring decide joint ring below, be in not at cooperation position, can not form sealing, compare with this instrument is not installed, surge pressure does not have significant change; In normal drilling process, the promotion piston moved upward after drilling fluid entered hydraulic cylinder, piston drives sliding ring by support bar and moves upward and decide joint ring and cooperate, annular space between multistage pump housing and sleeve pipe forms sealing state, the drilling fluid that returns from the shaft bottom and the mixture of landwaste can not directly return the face of land by annular space, and must be by in the multistage pump, power motor drives the multistage pump main shaft and rotates together with top blade, the thrust that multistage pump produces is delivered to well head with fluid and the landwaste that returns, fluid pressure and this section annular pressure lost of the fluid of top, instrument installation site will be not counted in bottom pressure, therefore reduce the pressure in shaft bottom.The underground pressure reducing instrument can reduce bottom pressure in normal drilling process, avoid pressing the too high bottom pressure that makes of consumption and surpass strata pressure because of circulation, cause the leakage of drilling fluid, rise, going down process can reduce surge pressure, is very suitable for extended reach well, complicated deep-well, ocean deepwater and beach sea drilling well; The sealing of hydraulic cylinder and piston control can reduce the wearing and tearing of seal, the reliability and the life-span of raising sealing.This instrument cost is low, installation is convenient, easy and simple to handle, safe and reliable, can be used for the 9-5/8 inch to the sleeve pipe of 13-3/8 inch.

The beneficial effects of the utility model: the utility model underground pressure reducing instrument, can reduce bottom pressure 1-3MPa effectively, solve the lose returns problem that causes owing to circulation of drilling fluid in narrow mud density window strata drilling and the extended reach well drilling process; Simultaneously the sealing system of this patent is controlled automatically by hydraulic pressure, can effectively avoid, cause excessive surge pressure in the going down process, can improve the life-span and the reliability of potted component.

Description of drawings

Fig. 1 is the utility model underground pressure reducing tool construction generalized section.

Fig. 2 is the utility model underground pressure reducing execution of instrument mode schematic diagram.

Fig. 3 is the sectional drawing of multistage pump housing.

Fig. 4 is the vertical view of Fig. 3.

Among the figure, the 1st, power motor housing, the 2nd, power motor main shaft, the 3rd, connector, the 4th, shaft coupling, the 5th, bearing, the 6th, sealing ring, the 7th, multistage pump housing, the 8th, Returning fluid outlet, the 9th, the multistage pump main shaft, the 10th, decide joint ring, the 11st, sliding ring, the 12nd, Returning fluid inlet, the 13rd, support bar, the 14th, piston, the 15th, hydraulic cylinder, the 16th, hydraulic cylinder drilling fluid inlet, the 17th, drilling rod, the 18th, wellhead equipment, the 19th, wellhead equipment outlet, the 20th, sleeve pipe, the 21st, cement sheath, the 22nd, the stratum, the 23rd, annular space, the 24th, drill bit, the 25th, landwaste.

The specific embodiment

Embodiment 1: be applicable to that with onesleeve pipe 20 internal diameters are that 320.4 millimeters underground pressure reducing instrument is an example, are described in further detail the utility model.

Consult Fig. 1.The underground pressure reducing instrument comprises multistage pump, connector 3,shaft coupling 4,hydraulic cylinder 15,piston 14,support bar 13, slidingring 11 and decides joint ring 10.Multistage pump main shaft 9 is positioned atmultistage pump housing 7 inside, and the upper/lower terminal of multistage pump main shaft 9 is fixed inmultistage pump housing 7 inside by bearing 5.Multistage pump housing 7 maximum outside diameters are 280 millimeters, andmultistage pump housing 7 lower outer diameter are 240 millimeters.

Conical changeover portion is arranged on the outer wall of multistage pump housing 7.Import is arranged at the bottom ofmultistage pump housing 7; The outlet ofmultistage pump housing 7 tops.The position of import and outlet is on the conical outer wall ofmultistage pump housing 7, and import is symmetrically distributed with outlet, and the quantity of import and outlet is respectively 4, and high 45mm, corresponding circle round angle are 60 °.

On the outer wall ofmultistage pump housing 7, be welded with and decide joint ring.The distance of decidingjoint ring 10 and import is 200mm.Decidejoint ring 10 for circular, the internal diameter of decidingjoint ring 10 is identical withmultistage pump housing 7 external diameters, decidesjoint ring 10 and highly is 150mm, and the vertical section of decidingjoint ring 10 is shaped as stairstepping.Decide the position, position ofjoint ring 10 between the import of themultistage pump housing 7, outlet.

Sliding ring 11 is an annular, and the external diameter of slidingring 11 is identical with casing inner diameter, and the internal diameter of slidingring 11 is with to decide seal outer diameteridentical.Sliding ring 11 with decidejoint ring 10 and cooperate the back to form sealing.Sliding ring 11 bottoms are connected withsupport bar 13, and the effect ofsupport bar 13 is to be used for driving slidingring 11, and can make slidingring 11 do upper and lower motion.The quantity ofsupport bar 13 is 4.

Outer wall is welded withhydraulic cylinder 15 in the lower end ofmultistage pump housing 7, forms annular space between the outer wall ofhydraulic cylinder 15 and multistage pump housing 7.The length ofhydraulic cylinder 15 is 120 millimeters, and the width of the annular space in thehydraulic cylinder 15 is 40 millimeters.Annular piston 14 is arranged inhydraulic cylinder 15, and piston top connects described support bar 13.It is 8 millimetersdrilling fluid inlet 16 that 2 diameters are arranged on the outer wall ofmultistage pump housing 7, and the high pressure drilling liquid in themultistage pump housing 7 can enter the mouth by drilling fluid and 16 enter annular space, promotespiston 14 and moves upward.

The course of work of the underground pressure reducing instrument that the utility model proposes:

Consult Fig. 1.The underground pressure reducing instrument is connected the below of drilling well power horse.Power motor housing 1 is threaded by connector 3 with multistage pump housing 7.Power motor main shaft 2 is positioned atpower motor housing 1 inside, and multistage pump main shaft 9 is positioned atmultistage pump housing 7 inside, and the upper/lower terminal of multistage pump main shaft 9 is fixed inmultistage pump housing 7 inside by bearing 5.The hole that power motor main shaft 2 and multistage pump main shaft 9 all have drilling fluid to pass through, bore dia are 30～80mm, and power motor main shaft 2 links to each other with multistage pump main shaft 9 in the multistage pump housing byshaft coupling 4 and forms the mobile passage of drilling fluid.The bottom jointed rod of underground pressure reducing instrument anddrill bit 24.

Consult Fig. 2.Stratum 22 is drilled with well, is fixed withsleeve pipe 20 in the well.Instrument is lowered in the sleeve pipe 20.Directly be connected withdrilling rod 17 by the screw thread ofpower motor housing 7 upper ends and the lower end screw thread ofmultistage pump housing 7,drilling rod 17 lower ends are connected with drill bit 24.The circulation of drilling fluid direction is shown in arrow in 2, drilling fluid enters in thepower motor housing 1 bydrilling rod 17, power motor can also be turbine motor, screw motor or electro-motor or other form power motor, the lower space of flowing through then and enteringmultistage pump housing 7 after the perforate of multistage pump main shaft 9, part drilling fluid entershydraulic cylinder 15 inside by hydraulic cylinderdrilling fluid inlet 16, most of drilling fluid continues to flow downward by thedrilling rod 17 that is connected withmultistage pump housing 7, behinddrill bit 24, enterannular space 23, cuttingcarring 25 continues to return to the ground apparent bearing.When being back to the instrument installation position, because the sealing function of decidingjoint ring 10 and slidingring 11 7 ofsleeve pipe 20 and multistage pump housings, drilling fluid that returns and the landwaste that carries 25 enter the inner space ofmultistage pump housing 7 by the Returningfluid inlet 12 of multistage pump bottom, multistage pump main shaft 9 drives rotation by power motor main shaft 2, and the blade that drives above it applies active force upwards to fluid and thelandwaste 25 that returns, return the Returningfluid outlet 8 under the effect of the thrust that makes progress of liquid andlandwaste 25 and flow intoannular space 23 once more, continue to cycle throughwellhead equipment outlet 19 to drilling fluid pot bymultistage pump housing 7 tops.

Tool'spower motor shell 1,multistage pump housing 7 link to each other withdrilling rod 17, are drilled into drilled stratum down.In this process, circulating fluid not,piston 14 is positioned at the bottom dead centre ofhydraulic cylinder 15, thismoment sliding ring 11 with decidejoint ring 10 can not be atsleeve pipe 20 and 7 formation of multistage pump housing sealing function, therefore in going down process, effectively reduced the shaft bottom surge pressure.

When drillingrod 17 together with underground pressure reducing instrument anddrill bit 24 behind drilled stratum, drilling fluid begins circulation, treat that drill-in fluid is throughdrilling rod 17, power motor main shaft 2, after multistage pump main shaft 9 backs arrive the lower space ofmultistage pump housing 7, indivisible drilling fluid enters intohydraulic cylinder 15 by the inlet of the hydraulic cylinder drilling fluid on themultistage pump housing 7 16, promotionlower piston 14 at drilling liquid pressure moves upward, along with through going into the increase of drilling well liquid measure,piston 14 moves to top dead-centre together with its steady arm that connects above 13 and slidingring 11, at thismoment sliding ring 11 and decidejoint ring 10 will form sealing betweensleeve pipe 17 andmultistage pump housing 7 forms up and down two not spaces of UNICOM withannular space 23 at the sealing station place; Overwhelming majority drilling fluid continues to flow downward, flow through behind thedrill bit 24 bydrilling rod 17, cutting carring returns to the face of land, when being back to the instrument installation position, owing to decide the sealing function thatjoint ring 10 and slidingring 11 form, fluid that all return andlandwaste 25 all enter themouth 12 through going into the inner space ofmultistage pump housing 7 by the Returning fluid ofpower motor housing 7 bottoms.Power motormain shaft 1 drives 9 rotations of multistage pump main shaft, and multistage pump main shaft 9 drives the blade of installing on its top fluid and landwaste 25 throughmultistage pump housing 7 inside are produced upwards thrust, makes fluid andlandwaste 25 be back to the face of land.Because the instrument installation site is upper and lower to be two not UNICOM spaces, so the annular space frictional resistance the when fluid pressure of the above fluid of instrument installation position and circulation of fluid no longer is superimposed to bottom pressure, and this has just reached the purpose of reduction bottom pressure.

In the trip-out process, drilling fluid stops circulation, the pressure ofhydraulic cylinder 15 inner drilling fluids reduces, the thrust thatpiston 14 and thesteady arm 13 that links with it thereof and slidingring 11 are made progress reduces most zero thereupon, slidingring 11 produces under the downward friction with the inwall ofsleeve pipe 20, slidingring 11 moves downward to the bottom dead centre ofpiston 14 athydraulic cylinder 15 together withsteady arm 13,piston 14, sealing thatsleeve pipe 20 and multistage pump housing are 7 disappears, and has effectively like this eliminated the swabbing pressure in the trip-out process.

Claims (5)

1, a kind of underground pressure reducing instrument, comprise multistage pump, connector (3), shaft coupling (4), hydraulic cylinder (15), piston (14), support bar (13), sliding ring (11) and decide joint ring (10), multistage pump main shaft (9) is positioned at multistage pump housing (7) inside, the upper/lower terminal of multistage pump main shaft (9) is fixed in multistage pump housing (7) inside by bearing (5), it is characterized in that: import is arranged at multistage pump housing (7) bottom, and intake energy enters in the multistage pump housing (7) Returning fluid and landwaste; The outlet of multistage pump housing (7) top, outlet can make interior Returning fluid of multistage pump housing (7) and debris flow to annular space, on the outer wall of multistage pump housing (7), be fixed with and decide joint ring, decide joint ring (10) for circular, the internal diameter of deciding joint ring (10) is identical with multistage pump housing (7) external diameter, to decide joint ring (10) by screw thread or welding is fixed on the outer wall of multistage pump housing (7), decide of the import of the position, position of joint ring (10) in the multistage pump housing (7), between the outlet, sliding ring (11) is an annular, the external diameter of sliding ring (11) is identical with casing inner diameter, the internal diameter of sliding ring (11) is with to decide seal outer diameter identical, sliding ring (11) with decide joint ring (10) and cooperate the back to form sealing, sliding ring (11) bottom is connected with support bar (13), the effect of support bar (13) is to be used for driving sliding ring (11), and sliding ring (11) is done, following motion, lower end outer wall at multistage pump housing (7) is fixed with hydraulic cylinder (15), form annular space between the outer wall of hydraulic cylinder (15) and multistage pump housing (7), annular piston (14) is arranged in hydraulic cylinder (15), piston top connects described support bar (13), drilling fluid inlet (16) is arranged on the outer wall of multistage pump housing (7), high pressure drilling liquid in the multistage pump housing (7) can enter the mouth by drilling fluid (16) enter annular space, promote piston (14) and move upward.

2, underground pressure reducing instrument according to claim 1, it is characterized in that: the position of described import and outlet is on the conical outer wall of multistage pump housing (7), import is symmetrically distributed with outlet, the quantity of import and outlet is respectively 2～10, import and outlet are shaped as the fan annular, and fan ring arc corresponding angle is 0～180 °.

3, underground pressure reducing instrument according to claim 1 is characterized in that: the distance of deciding joint ring (10) and import is between 50～200mm, and the vertical section of deciding joint ring (10) is shaped as wedge shape, stairstepping or rectangle.

4, underground pressure reducing instrument according to claim 1 is characterized in that: the vertical section of described sliding ring (11) is shaped as wedge shape, stairstepping or rectangle.

5, underground pressure reducing instrument according to claim 1 is characterized in that: the quantity of described support bar (13) is 2～8.

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