CN103321576A - Tubular column lowering power tractor with well grinding and repairing function - Google Patents

Abstract

The invention relates to a downpipe string power tractor with the function of grinding and repairing boreholes for oil and gas well cementing operations. The technical solution is: use a screw motor as the driving mechanism; connect the motor rotor and the crown of the tractor through the transmission shaft and the deflector; To drain the drilling fluid; the crown of the retractor is inlaid with carbide teeth. The invention can guide the casing into running without rotating the casing string; the crown of the tractor can break the rock and ream the hole, ensuring safe and efficient running of the casing to the designed position; the rotatable asymmetric retractor The crown has a strong ability to cross the shoulder obstacle in the wellbore; after the casing is run into the designed position, the milling bit can be used to drill through the tool within ten minutes, and then cement is injected into the well. The lower pipe string power tractor provided by the present invention with the function of grinding and repairing the wellbore can provide a large enough output torque, and can be used even in very complicated working conditions of the wellbore.

Description

Lower string dynamic tractor with grinding and workover function

technical field

The invention relates to a lower pipe string dynamic tractor for oil and natural gas drilling, in particular to a lower pipe string dynamic tractor with the function of grinding and repairing boreholes.

Background technique

Casing resistance is a common technical problem in cementing operations such as horizontal wells and highly deviated wells. Eccentric guide shoes are often used to guide the casing into the bottom of the well. However, due to the influence of wellbore irregularities, steps, subsidence and falling blocks, etc., even if eccentric guide shoes are used, problems such as casing running resistance, sticking, and even running failure often occur, which lead to a significant increase in construction period and construction cost .

When the diameter of the borehole shrinks, collapses due to geological formation problems, and the casing string cannot be rotated due to insufficient power of the drilling rig or limitation of the borehole trajectory, the use of traditional casing running tools is likely to be hindered or even unusable. The new self-rotating casing tool is designed with a unique driving mechanism inside, which can rely on the internal fluid to drive the tool to self-rotate under the condition of low displacement and low pump pressure, and guide it into the casing without rotating the casing string. ; and the reaming bit on the crown of the tool can be used to break the rock and ream the hole, stabilize the well wall, and ensure that the casing is run into the design position safely and efficiently; Drilling through the tool string within, and then starting cementing, the entire operation is cost-effective.

Contents of the invention

The purpose of the present invention is to solve the casing technical problems in the cementing operations of horizontal wells, deep wells, ultra-deep wells and other complex well structures, improve the cementing efficiency and quality, and reduce the cost and risk of well construction. In particular, a lower pipe string power tractor with the function of grinding and repairing the wellbore is provided.

In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve the above-mentioned problems is: a lower pipe string dynamic tractor with the function of grinding and repairing the wellbore mainly includes a screw motor stator casing, a rubber bush, a motor rotor, a transmission shaft, Deflectors, bearing support housings, deep groove ball bearing sets and tractor crowns. Its structural features are: the motor is used as the driving mechanism, which is composed of a screw motor stator, a rubber bush and a motor rotor. The upper end of the motor rotor is suspended, and the lower end is connected to the transmission shaft; the transmission shaft connects the motor rotor and the upper end of the deflector. There are diversion holes on the deflector; the lower end of the deflector is connected with the crown of the tractor; the asymmetric shape of the crown of the tractor can be designed as a wedge-shaped cylinder with a wedge-shaped surface of 30° or an arc-shaped wedge surface according to the wellbore wedge-shaped cylinder; the crown of the tractor has 1-3 dorsal water holes of 30°~45° on the back side of the inclined plane, one axial water eye is opened on the inclined plane side along the axial direction, and one water eye is opened on the circumferential direction. A circumferential water eye to discharge mud; the crown of the tractor is inlaid with carbide teeth.

The beneficial effects of the present invention are: (1) It can overcome the problem that the casing string cannot be rotated due to insufficient power of the drilling rig or the limitation of the wellbore trajectory; (2) The tool is powered by an efficient downhole motor to ream the hole without the need for drilling (3) The internal drive motor is made of drillable materials, which can work normally under low displacement and low pump pressure conditions. After the hole is reamed to the target depth, the drill bit can be used to The entire tool string can be drilled from the inside within ten minutes, and the construction process is fast, economical and has a high success rate.

Description of drawings

Fig. 1 is a structural schematic diagram of the first embodiment of the power tractor for downpipe string with the function of grinding and repairing wellbore in the wedge-shaped cylindrical shape of the crown of the tractor of the present invention.

Fig. 2 is a schematic view of the appearance of a wedge-shaped cylindrical crown with a wedge-shaped surface of 30° for a downpipe string dynamic tractor with the function of grinding and repairing the wellbore according to the present invention.

Fig. 3 is a structural schematic diagram of a second embodiment of the power tractor for downpipe string with the function of grinding and repairing wellbore, the crown of the tractor is wedge-shaped and the surface is an arc, which is wedge-shaped and cylindrical.

Fig. 4 is a schematic view of the appearance of a wedge-shaped cylindrical crown with an arc-shaped crown wedge-shaped surface of a lower pipe string dynamic tractor with the function of grinding and repairing the wellbore according to the present invention.

In the figure: 1. Screw motor stator housing, 2. Rubber bushing, 3. Motor rotor, 4. Transmission shaft, 5. Flow deflector, 6. Bearing support housing, 7. Deep groove ball bearing group, 8. Retractor crown, 9. Dorsal water eye, 10. Circumferential water eye, 11. Axial water eye, 12. Hard alloy teeth.

Detailed ways

Referring to the accompanying drawings 1 and 3, the lower pipe string power tractor with the function of grinding and repairing the wellbore of the present invention mainly includes a screw motor casing 1, a rubber bush 2, a motor rotor 3, a transmission shaft 4, and a deflector 5 , Bearing support shell 6, deep groove ball bearing set 7 and tractor crown 8. Its structural features are: the motor is used as the driving mechanism, which is composed of a screw motor housing 1, a rubber bush 2 and a motor rotor 3. The inner hole of the screw motor stator housing 1 is a vulcanized rubber bush 2, and the inner surface of the rubber bush 2 is continuous. Spiral curved surface; the motor rotor 3 is screwed into the inner hole of the rubber bush 2, the upper end of the motor rotor 3 is suspended, and the lower end is connected to the transmission shaft 4; the lower end of the transmission shaft 4 is connected to the deflector 5, and the deflector 5 is connected to the tractor crown 8 The deflector 5 is provided with diversion holes; the retractor crown 8 is inlaid with carbide teeth 12; the asymmetric shape of the retractor crown 8 can be designed as a wedge-shaped cylinder with a wedge-shaped surface of 30° or The wedge-shaped surface is an arc-shaped wedge-shaped cylinder.

Referring to accompanying drawing 2, embodiment 1 of the downpipe string dynamic tractor with the function of grinding and repairing the wellbore of the present invention, the crown 8 of the tractor is a wedge-shaped cylinder with a wedge-shaped surface of 30°, which has a strong ability to cross the shoulder obstacle capacity; the retractor crown 8 has 1 to 3 dorsal water holes 9 of 30°~45° on the back side of the slope, one axial water eye 11 is opened on the slope side along the axial direction, and 1 water hole is opened on the circumferential direction. A circumferential water eye 10 to discharge mud.

Referring to accompanying drawing 4, embodiment 2 of the power tractor of lower string with the function of grinding and repairing the wellbore of the present invention, its crown 8 of the tractor is a wedge-shaped cylindrical shape with a wedge-shaped surface; There are 1-3 dorsal water holes 9 of 30°~45° on the side, one axial water eye 11 is opened on the slope side along the axial direction, and one circumferential water eye 10 is opened on the circumferential direction to discharge mud.

This tool is connected to the lower end of the casing string. When it is lowered into the casing, the motor rotor 3 starts to rotate under the drive of the liquid in the casing string. The transmission shaft 4 is connected to the motor rotor 3 and the upper end of the deflector 5. The plane planetary motion of the deflector 5 is converted into fixed axis rotation, and the lower end of the deflector 5 is connected to the tractor crown 8, thereby driving the tractor crown 8 to rotate, and guiding it into the casing string without rotation, which can Greatly improve the casing running efficiency in the case of irregular well diameter; the surface of the tractor crown 8 is inlaid with carbide teeth 12, which can be used to ream the wellbore, repair the shoulder or repair the well wall, and make the casing Run into the designed position quickly and safely; after the casing is lowered to the designed position, the tool string can be drilled through the tool string within ten minutes with the milling bit, and then cement injection and cementing are started. The entire operation is cost-effective.

Claims (3)

1. The downpipe string dynamic tractor with the function of grinding and repairing the wellbore mainly includes the screw motor stator casing (1), rubber bushing (2), motor rotor (3), transmission shaft (4), deflector ( 5), bearing support shell (6), deep groove ball bearing group (7) and tractor crown (8), which are characterized by: screw motor stator shell (1) inner hole vulcanized rubber bushing (2), rubber The inner surface of the bushing (2) is a continuous spiral surface; the motor rotor (3) is screwed into the inner hole of the rubber bushing (2), the upper end of the motor rotor (3) is suspended, and the lower end is connected with the transmission shaft (4); the transmission shaft (4) The lower end is connected with the deflector (5), the deflector (5) is connected with the retractor crown (8), and the deflector (5) is provided with diversion holes; the retractor crown (8) is inlaid with hard Quality alloy teeth (12). 2. The downpipe string dynamic tractor with grinding and workover function according to claim 1, characterized in that: the asymmetric shape of the tractor crown (8) can be designed as a wedge with a wedge surface of 30° according to the wellbore Cylindrical or wedge-shaped cylindrical with curved surfaces. 3. The downpipe string dynamic tractor with grinding and workover function according to claim 2, characterized in that: the crown of the tractor (8) has 1 to 3 holes of 30° to 45° on the back side of the slope. The back side water eye (9) has an axial water eye (11) on the inclined plane side along the axial direction, and a circumferential water eye (10) on the circumferential direction.

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