CN107165577B - Screw underbalance pulse hydroscillator - Google Patents

Abstract

The invention discloses a hydraulic vibrator with the function of promoting chip removal, which is used in fields such as petroleum drilling. The technical solution is: the upper joint, the stator shell, the cardan shaft shell, the bearing support pup joint, and the lower joint are threaded sequentially; the power assembly includes the upper joint, the rotor compression cap, the screw rotor, the rubber stator and the stator shell; the screw The rotor, cardan shaft and transmission shaft are connected through threads in turn; the valve assembly includes the overcurrent transmission shaft, cam system, nozzle, spring system and lower joint, the overcurrent transmission shaft and the cam seat are connected through threads, and the cam is fixed on the cam through screws. On the seat, the valve core cooperates with the lower joint through the keyway; the cam system converts the rotary motion of the screw motor into the axial motion of the valve core, thereby realizing the opening and closing of the valve. The invention can effectively reduce the frictional resistance between the lower part of the horizontal well and the extended displacement well and the well wall, can improve the rock-carrying capacity of the drilling fluid, and can avoid downhole accidents such as sticking while improving the drilling efficiency.

Description

Screw type negative pressure pulse hydraulic oscillator

technical field

The invention belongs to a novel downhole tool in the field of petroleum and natural gas drilling engineering, in particular to a novel hydraulic oscillator with the function of promoting debris removal.

Background technique

The exploitation of new oil and gas wells makes drilling engineering more complex. In order to meet the needs of new drilling conditions (such as ultra-deep wells) or new oil and gas resources (such as coalbed methane, shale gas, offshore oil and gas, etc.), corresponding new drilling methods and tools Also evolving. During the development of these new drilling technologies, increasing the rate of penetration, reducing borehole wall friction, and increasing the borehole target diameter are important basic issues that need to be solved. Among the methods to solve these problems, downhole tools that work mechanically use drilling fluid to achieve energy conversion and generate certain expected vibrations, which have developed rapidly in recent years. Compared with other methods, downhole tools have the characteristics of high energy conversion efficiency, good economic benefits, and flexibility, thus gaining widespread attention and application. The types of related tools include rotary drilling tools, hydraulic impactors, etc. The specific implementation methods include valve plates, screws, turbines, centrifugal blades, etc. The emergence of these new methods and new tools has important applications for reducing friction and drag, increasing speed and increasing efficiency significance. The existing hydraulic oscillator will increase the pump pressure, which will adversely affect the service life of the mud pump, and the axial force generated by the screw will strengthen the friction between the movable valve plate and the static valve plate, thereby accelerating the dynamic The wear of the valve plate and the static valve plate will greatly shorten the service life of the hydraulic oscillator.

Based on this, on the basis of the existing research, this paper proposes a new type of oscillator, which uses drilling fluid to realize energy conversion and generates composite vibration mainly axial vibration. Due to its own structural characteristics, the axial force generated by the screw It will not be transmitted to the spool, and combined with the structural parameters of the fuselage and drilling parameters, it can achieve the purposes of reducing friction and resistance during drilling, increasing the effective drilling pressure of the drill bit, increasing the ROP and extending the drilling displacement of the drill string.

Contents of the invention

The purpose of the present invention is to overcome the problems of large drilling friction in existing horizontal wells and extended-reach wells, the inability of the drilling pressure at the wellhead to be effectively transmitted to the drill bit, the low rock-carrying capacity of the drilling fluid and the use effect of the existing axial vibration tools For unsatisfactory problems, design a new screw-type negative pressure pulse hydraulic oscillator.

Screw type negative pressure pulse hydraulic oscillator consists of upper joint, rotor compression cap, stator shell, screw rotor, rubber stator, cardan shaft, cardan shaft housing, drive shaft, overcurrent drive shaft, O-ring A , thrust bearing, O-ring seal B, bearing support pup joint, cam seat, positioning screw, cam, roller, valve core, nozzle, O-ring seal C, spring seat, spring, lower joint, characterized in that The upper joint, the stator housing, the cardan shaft housing, the bearing support nipple, and the lower joint are connected through threads in sequence; the rotor compression cap is located inside the stator housing, between the upper joint and the screw rotor, and the rotor compression cap and the stator housing adopt interference Fitting, used to limit the axial movement of the rotor; the rubber stator is poured inside the stator shell, and the surface is in the shape of an inner spiral, and is matched with the screw rotor. The ratio of the number of screw rotor heads to the number of rubber stator heads is 3:4; The axial shaft, transmission shaft, over-current transmission shaft and cam seat are threaded in turn; clearance fit is used between the over-current transmission shaft and the bearing support pup joint; O-ring A and O-ring B are located between the over-current transmission shaft and Between the bearing support pup joints, it is used to seal the bearing; the cam and the cam seat are connected by positioning screws; the roller is installed on the outside of the protrusion on the upper end of the valve core, and the outer circle of the roller is in contact with the cam surface; the middle of the valve core is along the There are two round holes separated by 180° in the radial direction, and two raised structures separated by 180° are arranged on the upper end of the valve core, and two round holes are opened in the radial direction. The round holes are connected with the rollers. Shaft fit, the lower end of the spool is provided with a sliding keyway, which is matched with the lower joint through the sliding keyway to achieve its circumferential positioning; the middle part of the lower joint is provided with two through holes at an interval of 180° in the radial direction. There are threads, and the inner wall of the lower joint is provided with a sliding keyway that matches the valve core; the outside of the nozzle is threaded, and the inner hole is a regular hexagon, and is matched with the radial hole on the lower joint through the threads; the spring seat is located at the lower end of the valve core, Its upper surface is in contact with the lower end of the valve core, and the lower surface of the large end of the spring seat is in contact with the spring, and is held up by the spring. There are 6 long holes spaced 180° apart in the radial direction of the small end; the spring is located between the spring seat and the lower joint.

Compared with the prior art, the present invention has the beneficial effects as follows: (1) the screw type negative pressure pulse hydraulic oscillator can provide a periodic low-frequency axial impact force; (2) the screw type negative pressure pulse hydraulic oscillator The drilled fluid has the ability to impact and stir the well wall, which is helpful for the migration of cuttings in the annulus and improves the rock-carrying ability of the drilling fluid; (3) Only a small standpipe pressure can generate negative pulses; (4) The conventional hydraulic oscillator will increase the pump pressure. The screw type negative pressure pulse hydraulic oscillator is equipped with a new bypass, which can reduce the pump pressure while increasing the drilling speed and improve the life of the surface mud pump.

Description of drawings

Fig. 1 is a structural schematic diagram of a screw-type negative pressure pulse hydraulic oscillator according to the present invention.

In the figure: 1-upper joint, 2-rotor compression cap, 3-stator shell, 4-screw rotor, 5-rubber stator, 6-cardan shaft, 7-cardan shaft shell, 8-transmission shaft, 9 - Overcurrent drive shaft, 10-O-ring A, 11-thrust bearing, 12-O-ring B, 13-bearing support pup, 14-cam seat, 15-set screw, 16-cam, 17 -Roller, 18-spool, 19-nozzle, 20-O type sealing ring C, 21-spring seat, 22-spring, 23-lower joint.

Fig. 2 is a schematic diagram of the valve opening structure of the screw-type negative pressure pulse hydraulic oscillator according to the present invention.

Fig. 3 is a partially enlarged view of area a in Fig. 1 of the present invention.

Fig. 4 is a partially enlarged view of area b in Fig. 2 of the present invention.

Fig. 5 is a sectional view of plane A-A in Fig. 1 of the present invention.

Fig. 6 is a sectional view of the B-B plane in Fig. 2 of the present invention.

Fig. 7 is a three-dimensional schematic diagram of the cam of the present invention.

Fig. 8 is a three-dimensional schematic diagram of the valve core of the present invention.

Fig. 9 is a three-dimensional schematic diagram of the spring seat of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

According to the drawings, the screw-type negative pressure pulse hydraulic oscillator is mainly composed of three parts: power assembly, transmission assembly and valve assembly. The power assembly consists of upper joint 1, rotor compression cap 2, stator housing 3. Screw rotor 4, rubber stator 5; transmission assembly is composed of cardan shaft 6, transmission shaft 8 and overcurrent transmission shaft; valve assembly is composed of cam seat 14, cam 16, roller 17, valve core 18, nozzle 19. Spring seat 21, spring 22, lower joint 23, etc.; upper joint 1, stator housing 3, cardan shaft housing 7, bearing support nipple 13, and lower joint 23 are sequentially connected by threads; rotor compression cap 2 is located on the stator Inside the casing 3, between the upper joint 1 and the screw rotor 4, the rotor compression cap 2 and the stator casing 3 adopt an interference fit to limit the axial movement of the rotor; the rubber stator 5 is injected inside the stator casing 3, and the surface is inner. Spiral, cooperate with screw rotor; screw rotor 4, cardan shaft 6, transmission shaft 8, overcurrent transmission shaft 9 and cam seat 14 are connected by threads in turn; overcurrent transmission shaft 9 and bearing support pup joint 13 adopt clearance Cooperate; O-ring A10 and O-ring B12 are located between the over-current transmission shaft 9 and the bearing support nipple 13, used to seal the bearing; the cam 16 and the cam seat 14 are connected by the set screw 15; the roller 17 is installed on the outside of the bulge on the upper end of the spool 18, and the outer circle of the roller 17 is in contact with the curved surface of the cam 16; the middle part of the spool 18 has two circular holes separated by 180° along its radial direction, and the upper end of the spool 18 is provided with There are two protruding structures separated by 180°, and two round holes are opened in the radial direction. The round holes are matched with the roller shaft. Cooperate to realize its circumferential positioning; the middle part of the lower joint 23 has two through holes spaced 180° apart in the radial direction, the through holes are provided with threads, and the inner wall of the lower joint 23 is provided with a slide that cooperates with the valve core 18. Keyway; Nozzle 19 is provided with threads outside, and the inner hole is a regular hexagon, and cooperates with the radial hole on the lower joint 23 by threads; The lower surface of the large end of the seat 21 is in contact with the spring 22 and is held up by the spring 22. The large end of the spring seat 21 has a sliding keyway, and the spring seat 21 cooperates with the lower joint through the keyway to realize its circumferential positioning. The small end of the spring seat 21 is radially There are 6 long holes spaced 180° apart in the direction; the spring 22 is located between the spring seat 21 and the lower joint 23 .

During the working process, the upper part of the screw-type negative pressure pulse hydraulic oscillator is used in conjunction with the shock absorber. The drilling fluid flowing out of the shock absorber flows into the tool directly from the upper joint 1, and then passes through the rotor compression cap 2 to drive the rotor to rotate. , the drilling fluid flows out from the gap between the screw rotor 4 and the rubber stator 5, passes through the annular space inside the cardan shaft housing 7, and flows into the flow channel inside the transmission shaft 8 from the radial through hole of the transmission shaft 8. At this time, If the through hole on the spool 18 communicates with the through hole on the lower joint 23, a part of the drilling fluid will flow out from the through hole, and a part will flow through the spool 18 and the spring seat 21 in sequence, and then flow out from the lower end of the lower joint 23 and flow into the lower part. Drill assembly. The rotary motion generated by the powertrain is transmitted to the cam combination through the cardan shaft 6 , the transmission shaft 8 and the overcurrent transmission shaft 9 , and the cam combination converts the rotary motion generated by the powertrain into the axial reciprocating motion of the spool 18 . As shown in Figure 1, when the roller 17 is at the low position of the cam 16, the spool 18 and the spring seat 21 are pushed up by the elastic force of the spring 22. The through holes are staggered, and the drilling fluid pressure in the pipe is at the maximum value at this time; when the roller 17 moves from the low position of the cam 16 to the high position of the cam 16, as shown in Figure 2, the spring 22 is compressed, and the valve core 18 and the spring seat 21 move downward, During the downward movement, the radial through hole on the spool 18 gradually coincides with the nozzle 19, and a part of the drilling fluid flows out from the nozzle 19. Due to the pressure difference of the drilling fluid inside and outside the tool, the pressure of the drilling fluid inside the tool decreases, and the outflowing drilling fluid can Flush the well wall; when the roller 17 moves from the high position of the cam 16 to the low position of the cam 16, the spool 18, the spring seat 21 and the spring 22 return to the initial position, the cam 16 rotates once and the spool 18 reciprocates twice, and the drilling in the tool The hydraulic pressure also fluctuates twice, and this repetition will cause a periodic fluctuation of the standpipe pressure, and the drilling fluid is used to realize energy conversion, resulting in composite vibration dominated by axial vibration.

Claims (3)

1. screw underbalance pulse hydroscillator, fixed by top connection, rotor clamping cap, stator casing, screw rotor, rubber Son, universal shaft, universal shaft housing, transmission shaft, overcurrent transmission shaft, O-ring seal A, thrust bearing, O-ring seal B, bearing branch Pipe nipple, cam chair, positioning screw, cam, roller, spool, nozzle, O-ring seal C, spring base, spring, lower contact composition are supportted, It is characterized in that top connection (1), stator casing (3), universal shaft housing (7), bearing support pipe nipple (13), lower contact (23) are successively It is connected through a screw thread；Rotor clamping cap (2) is located at stator casing (3) inside, between top connection (1) and screw rotor (4), rotor Clamping cap (2) is used with stator casing (3) and is interference fitted, the axial movement for limiting rotor；Elastomer stator (5) is cast in fixed Subshell (3) is internal, and surface is in spiral, is coordinated with screw rotor；Screw rotor (4), universal shaft (6), transmission shaft (8), Overcurrent transmission shaft (9) and cam chair (14) pass sequentially through threaded connection；Between overcurrent transmission shaft (9) and bearing support pipe nipple (13) It is gap-matched；O-ring seal A (10) and O-ring seal B (12) are located at overcurrent transmission shaft (9) and bearing support pipe nipple (13) between, for the sealing to bearing；Cam (16) is connected with cam chair (14) by positioning screw (15)；Roller (17) It is installed in the outside of spool (18) upper end protrusion, roller (17) outer circle and cam (16) curved face contact；Edge in the middle part of spool (18) It is opened in the radial direction there are two being separated by 180 ° of circular hole, and spool (18) upper end sets that there are two the bulge-structures for being separated by 180 °, and It is opened in the radial direction thereof there are two circular hole, circular hole coordinates with Roller Shaft, and spool (18) lower end is provided with sliding keyway, and passes through cunning Dynamic keyway coordinates with lower contact (23), realizes that its is circumferentially positioned；The middle part of lower contact (23) has been provided with two phases in the radial direction The mutually through-hole at 180 ° of interval, through-hole is interior to be equipped with screw thread, and lower contact (23) inner wall is provided with the sliding keyway with spool (18) cooperation；Spray Screw thread is equipped with outside mouth (19), endoporus is regular hexagon, and is coordinated by the radial hole on screw thread and lower contact (23)；Spring base (21) it is located at spool (18) lower end, upper surface and end in contact, spring base (21) big end lower surface and spring under spool (18) (22) it contacts, is held up by spring (22), spring base (21) big end is provided with sliding keyway, and spring base (21) passes through keyway and lower contact Cooperation, realizes that its is circumferentially positioned, spring base (21) small end is provided with 6 spaced 180 ° of slot holes in the radial direction；Spring (22) between spring base (21) and lower contact (23).

2. screw underbalance pulse hydroscillator according to claim 1, it is characterised in that use two cams (16) Using two protrusions, cam (16) uses the contour curve of " cycloid-straight line-cycloid-straight line " characteristics of motion.

3. screw underbalance pulse hydroscillator according to claim 1, it is characterised in that lower contact (23) inner wall is set There are two step, keyway is opened on first step, after the set-up mode of keyway must be such that spool (18) coordinates with lower contact (23), Two radial through-hole on two radial through-hole and lower contact (23) on spool (18) are in the same plane.