CN204941345U - A kind of radial well transfer with packing function - Google Patents

Abstract

The utility model provides a radial well steering device with a sealing function. Composition; the upper and lower sides of the center steering chamber are respectively connected with the upper central tube and the lower central tube, the upper end of the upper central tube is connected with the upper joint, and the lower end of the lower central tube is connected with the lower joint; the upper sealing rubber tube is set outside the upper central tube, and the lower The sealing rubber tube is set outside the lower central pipe; the lower end of the upper joint and the upper end of the lower joint are respectively provided with fixing rings. The utility model is applied to realize the integration of radial well drilling and fracturing operation tools. It is a new downhole device that can realize flexible drill string steering and casing isolation. The device is easy to operate, safe and practical, and can greatly shorten the operating time time and cost savings.

Description

A Radial Well Steering Device with Isolation Function

technical field

The utility model relates to a radial well steering device with a sealing function, belonging to downhole tools for oilfields.

Background technique

Radial well drilling technology is a new type of drilling technology that has emerged in recent years. The radial well drilling technology uses a special steering device to realize the steering of the flexible drill string with an ultra-short radius of curvature, and uses the energy of high-pressure water jets to break rocks. Radial wells have small horizontal hole diameters, so radial wells are often used in the development of coalbed methane and shale gas to solve the problem of poor wellbore stability.

Coal seams and shale reservoirs have low permeability and strong heterogeneity, and fracturing must be carried out in the development process to achieve the purpose of increasing production. Due to the small diameter of the horizontal hole in radial wells and the short radius of curvature of the build-up section, conventional horizontal well fracturing string tools cannot be applied to radial wells. The fracturing fluid is pumped into the production layer at high pressure to increase the pressure of the fluid in the horizontal hole of the radial well. When the fluid pressure in the horizontal hole of the radial well is higher than the fracture pressure of the rock, the rock fractures and fractures are formed.

This fracturing method requires the radial well drilling tool to be raised from the downhole first, and then run into the packer. Frequent lifting and lowering of the pipe string not only increases the workload, but also increases the operating cost.

Utility model content

The technical problem to be solved by the utility model lies in overcoming the defects of the prior art, and providing a radial well steering device with an isolation function, which is applied to realize the integration of radial well drilling and fracturing operation tools, and is a new A downhole device that can realize flexible drill string steering and casing isolation. The device is easy to operate, safe and practical, and can greatly shorten operation time and save costs.

In order to achieve the above object, the utility model adopts the following technical solutions:

The utility model provides a radial well steering device with a sealing function. The upper and lower sides of the central steering chamber are respectively connected with the upper central pipe and the lower central pipe, the upper end of the upper central pipe is connected with the upper joint, the lower end of the lower central pipe is connected with the lower joint, and the upper sealant The sleeve is set outside the upper central tube, the lower sealing rubber tube is sleeved outside the lower central tube, and the lower end of the upper joint and the upper end of the lower joint are respectively provided with fixing rings.

The center steering chamber is provided with a flexible drill string steering channel and two liquid flow channels, the inner wall of the steering channel is inlaid with rotatable balls, each liquid flow channel is provided with a check valve at the inlet end, and each liquid flow channel is provided with three export.

The upper sealing rubber cylinder is composed of an inner rubber cylinder and an outer rubber cylinder. The joints of the upper ends of the inner rubber cylinder and the outer rubber cylinder are vulcanized as a whole by a heat vulcanization process. There is a cavity in the middle of the inner rubber cylinder and the outer rubber cylinder. The liquid inlet channel communicates with the outlet of the liquid flow channel in the center steering chamber, and the connection is provided with a sealing ring for sealing.

The lower sealing rubber cylinder is composed of an inner rubber cylinder and an outer rubber cylinder, and the joint of the lower end of the inner rubber cylinder and the outer rubber cylinder is vulcanized as a whole by a heat vulcanization process. There is a cavity in the middle of the inner rubber cylinder and the outer rubber cylinder, and a The liquid inlet channel communicates with the outlet of the liquid flow channel in the center steering chamber, and the connection is provided with a sealing ring for sealing.

Wherein, the cavities between the inner and outer rubber cylinders of the upper and lower packing rubber cylinders communicate with the liquid flow channel of the central steering chamber.

Further, an overflow channel is provided in the lower center pipe, and an unsealing pin is provided at the outlet of the overflow channel, and the gap between the overflow channel and the inner rubber tube and the outer rubber tube in the lower sealing rubber tube cavity connected. A shearing piston is arranged in the cavity of the lower central tube, and the shearing piston is connected to the bottom surface of the central steering chamber through a spring.

During the construction process, firstly, the device is lowered from the casing to the predetermined position, the lower end of the coiled tubing is connected to the flexible drill string, and the flexible drill string is turned from vertical to horizontal through the steering channel of the central steering chamber, and the flexible drill string is under the action of the internal high-pressure fluid Realize self-propelled drilling. After the drilling and well washing are completed, fluid is injected into the annular space between the coiled tubing and the center pipe at high pressure, and the fluid enters the flow channel through the check valve on the center steering chamber. On the one hand, the fluid flows into the flow channel through the flow channel. In the cavity in the lower central tube, the fluid pushes the shearing piston downward until the movement of the shearing piston is blocked by the unsealing pin; on the other hand, the fluid flows into the inner and outer rubber cylinders of the upper and lower sealing rubber cylinders through the liquid flow channel In the cavity between the coiled tubing and the center tube, the fluid gradually fills the cavity between the inner and outer rubber tubes under pressure, and forces the outer rubber tube to expand outward to realize the setting seal, and stops flowing to the annulus between the coiled tubing and the center tube. Inject liquid. After setting, the fracturing fluid is pumped into the horizontal hole through the coiled tubing. When the fracturing fluid in the horizontal hole is higher than the rock fracture pressure, the rock breaks and fractures are formed. After the fracturing process is completed, continue to inject high-pressure fluid into the annulus between the coiled tubing and the center pipe, and continuously increase the injection pressure until the fluid injection pressure reaches the pressure-bearing critical value of the unsealed pin, and the shear piston will shear the pin to achieve unblock.

Compared with the prior art, the utility model has the following beneficial effects:

(1) It can realize the integration of radial well drilling and fracturing operation tools, avoiding the defects of large operation volume, long operation period and high cost for the single tripping drilling steering device and fracturing isolation device.

(2) The device is easy to operate, safe and reliable.

Description of drawings

Fig. 1 is a front view of the structure of the utility model.

Fig. 2 is a left view of the structure of the utility model.

detailed description

As shown in Figure 1 and Figure 2, the utility model provides a radial well steering device with a sealing function, the device consists of an upper joint 2, an upper central pipe 7, an upper sealing rubber cylinder 3, and a central steering chamber 12. The lower central pipe 13, the lower sealing rubber tube 16, and the lower joint 17 are formed. The upper and lower sides of the central steering chamber 12 are respectively connected with the upper central pipe 7 and the lower central pipe 13. The upper end of the upper central pipe 7 is connected to the upper The lower end of the lower central pipe 13 is connected with the lower joint 17, the upper packing rubber tube 3 is set outside the upper central pipe 7, and the lower packing rubber tube 16 is set outside the lower central pipe 13. The lower end of the upper joint 2 and the upper end of the lower joint 17 are respectively provided with fixing rings.

The central steering chamber 12 is provided with a flexible drill string steering channel 10 and two liquid flow channels 11, the inner wall of the steering channel 10 is inlaid with rotatable balls 20, and the inlet end of each liquid flow channel 11 is provided with a one-way valve 8 , each liquid flow channel 11 is provided with three outlets.

The upper sealing rubber cylinder 3 is composed of an inner rubber cylinder 6 and an outer rubber cylinder 4. The joints at the upper ends of the inner rubber cylinder 6 and the outer rubber cylinder 4 are vulcanized as a whole by a thermal vulcanization process. The middle of the inner rubber cylinder 6 and the outer rubber cylinder 4 is There is a cavity, and the lower end is provided with a liquid inlet channel, which communicates with the outlet of the central steering chamber 12, the liquid flow channel 11, and the connection is provided with a sealing ring 9 for sealing.

The lower sealing rubber cylinder 16 is composed of an inner rubber cylinder 6 and an outer rubber cylinder 4. The lower end connection of the inner rubber cylinder 6 and the outer rubber cylinder 4 is vulcanized as a whole by a thermal vulcanization process. The middle of the inner rubber cylinder 6 and the outer rubber cylinder 4 is There is a cavity, and the upper end is provided with a liquid inlet channel, which communicates with the outlet of the central steering chamber 12, the liquid flow channel 11, and the connection is provided with a sealing ring 9 for sealing.

Wherein, the cavities between the inner and outer rubber cylinders of the upper packing rubber cylinder 3 and the lower packing rubber cylinder 16 communicate with the liquid flow channel 11 of the central turning chamber 12 .

Further, an overflow channel 14 is provided in the lower central pipe 13, and an unsealing pin 17 is provided at the outlet of the overflow channel 14, and the overflow channel 14 is connected to the inner rubber tube in the lower sealing rubber tube 16. 6 communicates with the cavity between the outer rubber cartridge 4. A shearing piston 21 is arranged in the cavity of the lower central tube 13 , and the shearing piston 21 is connected to the bottom surface of the central steering chamber through a spring 20 .

In the construction process, firstly, the device is lowered from the casing 1 to a predetermined position, the lower end of the coiled tubing 5 is connected to the flexible drill string 19, and the flexible drill string 19 is turned from vertical to horizontal through the central steering chamber 12 and the channel 10, and the flexible drill string 19 Self-propelled drilling is realized under the action of internal high-pressure fluid. After drilling, well washing and other processes are completed, fluid is injected into the annular space between the coiled tubing 5 and the center pipe 7 under high pressure, and the fluid enters the liquid flow channel through the check valve 8 on the center steering chamber. On the one hand, the fluid passes through the liquid The flow channel flows into the cavity in the lower central tube 13, and the fluid pushes the shear piston 21 downward until the movement of the shear piston 21 is blocked by the unsealing pin 15; on the other hand, the fluid flows into the upper and lower compartments through the liquid flow channel 11 In the cavity between the inner and outer rubber tubes of the rubber tube, under the action of pressure, the fluid gradually fills the cavity between the inner and outer rubber tubes, and forces the outer rubber tube 6 to expand outwards to realize setting and stop the continuous flow. Liquid is injected into the annular space between the oil pipe 5 and the central pipe 7 . After setting, the fracturing fluid is pumped into the horizontal hole through the coiled tubing 5, and when the fracturing fluid in the horizontal hole is higher than the rock fracture pressure, the rock breaks and fractures are formed. After the fracturing process is completed, continue to inject high-pressure fluid into the annulus between the coiled tubing 5 and the center pipe 7, and continuously increase the injection pressure until the fluid injection pressure reaches the pressure-bearing critical value of the unblocking pin 15, and the shear piston 21 Cut pin 15 to realize unsealing.

Finally, it should be noted that obviously, the above-mentioned embodiments are only examples for clearly illustrating the utility model, rather than limiting the implementation manner. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the protection scope of the present utility model.

Claims (6)

1. A radial well steering device with a pack-off function, characterized in that: the device consists of an upper joint, an upper central pipe, an upper packing rubber tube, a central steering chamber, a lower central pipe, a lower packing rubber tube, The upper and lower sides of the central steering chamber are respectively connected with the upper central pipe and the lower central pipe, the upper end of the upper central pipe is connected with the upper joint, the lower end of the lower central pipe is connected with the lower joint, and the upper packing The rubber tube is set outside the upper central tube, the lower sealing rubber tube is set outside the lower central tube, and the lower end of the upper joint and the upper end of the lower joint are respectively provided with fixing rings. 2. A radial well steering device with isolation function according to claim 1, characterized in that: said central steering chamber is provided with a flexible drill string steering channel and two liquid flow channels, and the inner wall of the steering channel is inlaid The rotatable ball is provided with a one-way valve at the inlet end of each liquid flow channel, and each liquid flow channel is provided with three outlets. 3. A radial well steering device with isolation function as claimed in claim 1, characterized in that: the upper isolation rubber tube is composed of an inner rubber tube and an outer rubber tube, and the inner rubber tube and the outer rubber tube The connection at the upper end is vulcanized as a whole by thermal vulcanization process. There is a cavity between the inner rubber tube and the outer rubber tube. The lower end is provided with a liquid inlet channel. The liquid inlet channel is connected with the outlet of the liquid flow channel in the center steering chamber. . 4. A radial well steering device with isolation function as claimed in claim 1, characterized in that: the lower isolation rubber tube is composed of an inner rubber tube and an outer rubber tube, and the inner rubber tube and the outer rubber tube The connection at the lower end is vulcanized as a whole by thermal vulcanization process. There is a cavity between the inner rubber tube and the outer rubber tube. The upper end is provided with a liquid inlet channel. The liquid inlet channel is connected with the outlet of the liquid flow channel in the center steering chamber, and the connection is provided with a sealing ring. . 5. A radial well steering device with isolation function as claimed in claim 1, 3 or 4, characterized in that: the cavities between the inner and outer rubber cylinders in the upper and lower isolation rubber cylinders are uniform. It communicates with the liquid flow channel of the center turning chamber. 6. A radial well steering device with isolation function as claimed in claim 1 or 4, characterized in that: an overflow passage is arranged in the lower central pipe, and a solution is arranged at the outlet of the overflow passage. Sealing pin, the overflow channel communicates with the cavity between the inner rubber tube and the outer rubber tube in the lower pack-off rubber tube, and a shearing piston is arranged in the cavity of the lower central tube, and the shearing piston is connected with the center steering chamber The bottom faces are connected by springs.