Boring or penetrating the earth – Means traveling with tool to constrain tool to bore along...
Reexamination Certificate
2000-05-01
2002-08-27
Bagnell, David (Department: 3672)
Boring or penetrating the earth
Means traveling with tool to constrain tool to bore along...
C166S117500, C166S155000, C166S383000
Reexamination Certificate
active
06439321
ABSTRACT:
FIELD OF INVENTION
The present invention relates to an actuator for an orienting device for orienting a borehole apparatus in a borehole and to an orienting device comprised of the actuator. The orienting device includes an orienting mechanism actuated by longitudinal movement.
BACKGROUND OF INVENTION
Directional drilling involves controlling the direction of a borehole as it is being drilled in order to drill along a predetermined path. It is often necessary to adjust the direction of the borehole frequently while directional drilling, either to accommodate a planned change in direction or to compensate for unintended or unwanted deflection of the borehole.
Directional drilling may involve the use of a drilling bit actuated by a downhole motor connected with the drill string and which is powered by the circulation of fluid, such as drilling mud, supplied from the surface. Typically, the downhole motor includes a bent housing or bent sub so that the resulting path drilled by the drilling bit is slightly curved. Further, the downhole motor actuates the drilling bit relative to the bent housing or bent sub and the drill string. In other words, the drill string itself need not be moved or rotated during the drilling operation in order to actuate the drilling bit.
The drilling operation will be intermittently interrupted in order to ascertain the path of the borehole in relation to the desired predetermined path. In the event that correction or adjustment of the path is required, the drill string may be rotated from the surface in order to rotate the bent motor housing or the bent sub downhole. This is possible due to the relatively rigid nature of a conventional drill string. Thus, rotation of the drill string from the surface orients the bent housing or bent sub in the desired direction to adjust the borehole towards the desired predetermined path.
However, coiled tubing may also be used for drilling operations such that the drill string is typically comprised of a single length of relatively flexible tubing which is inserted into the borehole. Various downhole tools, including a downhole motor and drilling bit, may be connected with the downhole end of the coiled tubing string. However, as a result of the nature of coiled tubing and the manner by which it is run into the borehole, it is not possible to rotate the bent housing or bent sub downhole, in order to adjust the direction of the borehole, by rotating the coiled tubing string from the surface.
As a result, various orienting devices or orienting subs have been developed for connection between the coiled tubing string and the bent housing or bent sub. These orienting devices are provided to rotate the bent housing or bent sub relative to the coiled tubing string in order to adjust the direction of the borehole. Typically, the orienting device rotates the bent housing or bent sub through a selected incremental amount in order to fix the angular orientation of the bend point in the bent housing or bent sub in relation to the axis of the borehole so that the borehole can be drilled along the predetermined path.
Several of these orienting devices are comprised of hydraulic systems connected to the surface for supply of the hydraulic fluid to actuate the device. For instance, U.S. Pat. No. 5,316,094 issued May 31, 1994 to Pringle and U.S. Pat. No. 5,894,896 issued Apr. 20, 1999 to Smith et. al. both describe an orienting device for use with coiled tubing for rotationally orientating a well tool to the proper direction in the well bore. The orienting device is comprised of a body or tubular housing, a mandrel rotatable within the body for providing rotation to the well tool and a hydraulic piston slidably positioned in the annulus between the body and the mandrel. The orienting device provides for the rotation of the mandrel within the body or housing in response to the longitudinal movement of the piston in the annulus.
In Pringle, a hydraulic control line is connected to a first side of the piston for moving the piston longitudinally in a first direction. A spring is provided against the second side of the piston for moving the piston longitudinally in an opposed second direction. The hydraulic control line is provided from the surface, through the coiled tubing to the orienting device to provide the hydraulic control fluid for operating the orienting device. Similarly, in Smith et. al., a flow path is provided for the selective delivery of pressurized hydraulic fluid to either side of the piston so that the mandrel may be rotated in either a clockwise or a counterclockwise direction or to both sides of the piston equally to maintain the piston in a fixed annular orientation. Further, the flow path is supplied with hydraulic fluid through two hydraulic lines which transfer fluid from the surface to the device with the lines alternating in function as either supply, relief or return lines.
Given the inherent disadvantages associated with the use of a hydraulic system including hydraulic lines from the surface for actuating the orienting device, various further orienting devices have been developed which are actuated by the fluid being conducted through the drill string, such as the drilling mud. For instance, U.S. Pat. No. 5,215,151 issued Jun. 1, 1993 to Smith et. al. and Sperry-Sun Drilling Services Technology Update, Winter 1995, entitled “Coiled Tubing BHA Orienter for Directional and Horizontal Drilling” each describe an orienting device or orienting sub which is actuated by the flow of the drilling mud through the device.
These orienting devices are located in the bottom hole assembly above the motor and are actuated by the pressure drop across, or the mud flow rate through, the bottom hole assembly including the orienting device. In particular, a flow path is provided through the orienting device for the circulation of the drilling fluid relatively unrestricted therethrough at all times. Further, the device is comprised of a drive piston which is exposed to the drilling fluid as it circulates through the device. When the drilling fluid pumps are on, the flow induced pressure drop acts across the drive piston of the device and drives it downwards against a helical cam, which results in the indexing of an output shaft of the device a predetermined increment of degrees. Upon cessation of the flow, the drive piston is biased by a spring to be driven upwards to reset the orienting device. Thus, the flow through the device may be cycled a desired number of times in order to achieve the desired indexing of the output shaft and the downhole tool connected thereto.
However, there is no positive indication provided to the operator at the surface that the orienting device has in fact cycled or indexed upon pumping the drilling fluid therethrough. Further, given the relatively unrestricted flow of the drilling fluid permitted through the orienting device, it has been found that a relatively high pressure of the drilling fluid is required within the device to act upon the drive piston and move it downwards to index the output shaft. To achieve this necessary actuating pressure, the flow of the drilling fluid through the bottom hole assembly, including the motor, may similarly be excessive resulting in unnecessary wear and potential damage to the bottom hole assembly and the motor.
As a result, the orienting device may be used with a companion device referred to as an equalizer sub. The equalizer sub is positioned in the bottom hole assembly between the orienting device and the motor. The equalizer sub includes a restrictor nozzle which is positioned in the flow path of the drilling fluid to provide a partial restriction to the flow therethrough. More particularly, the restrictor nozzle generates a differential pressure and creates a pressure drop with which to power the orienting device. The restrictor nozzle provides a sufficient back pressure in the orienting device to actuate the drive piston and drive it downwards without the associated increase in the mud flow rate through the motor. Further, the equalizer sub includes a vent p
Gillis Ian
Lupien Daniel P.
Bagnell David
Gay Jennifer H
Halliburton Energy Service,s Inc.
Kuharchuk Terrence N.
McCully Michael D.
LandOfFree
Piston actuator assembly for an orienting device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Piston actuator assembly for an orienting device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Piston actuator assembly for an orienting device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2903374