CA1312072C - Downhole drilling assembly orienting device - Google Patents
Downhole drilling assembly orienting deviceInfo
- Publication number
- CA1312072C CA1312072C CA000606273A CA606273A CA1312072C CA 1312072 C CA1312072 C CA 1312072C CA 000606273 A CA000606273 A CA 000606273A CA 606273 A CA606273 A CA 606273A CA 1312072 C CA1312072 C CA 1312072C
- Authority
- CA
- Canada
- Prior art keywords
- drill string
- valve seat
- flow passageway
- drilling
- steering assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/02—Determining slope or direction
- E21B47/024—Determining slope or direction of devices in the borehole
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/10—Valve arrangements in drilling-fluid circulation systems
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/09—Locating or determining the position of objects in boreholes or wells, e.g. the position of an extending arm; Identifying the free or blocked portions of pipes
- E21B47/095—Locating or determining the position of objects in boreholes or wells, e.g. the position of an extending arm; Identifying the free or blocked portions of pipes by detecting an acoustic anomalies, e.g. using mud-pressure pulses
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
- E21B7/06—Deflecting the direction of boreholes
Abstract
ABSTRACT
The orientation of a downhole steering assembly used in drilling a horizontal well is located with respect to the earth using a sub placed above the downhole assem-bly. The sub comprises a housing having a central bore defining an inlet flow passageway said housing further defining a toroidal chamber in communication with said passageway. The toroidal chamber has a pocket, a valve seat, and a spherical valve that is rotatable in said toroidal chamber from a normally seated position in the pocket. Upon rotation of the drill string the spherical valve plugs the valve seat and causes an increase in the resistance to flow in the drilling mud through the drill string that can be detected at the surface.
The orientation of a downhole steering assembly used in drilling a horizontal well is located with respect to the earth using a sub placed above the downhole assem-bly. The sub comprises a housing having a central bore defining an inlet flow passageway said housing further defining a toroidal chamber in communication with said passageway. The toroidal chamber has a pocket, a valve seat, and a spherical valve that is rotatable in said toroidal chamber from a normally seated position in the pocket. Upon rotation of the drill string the spherical valve plugs the valve seat and causes an increase in the resistance to flow in the drilling mud through the drill string that can be detected at the surface.
Description
DOWNHOLE DRILLIN~ ASSEMBLY ORIE~TING DEVICE
Field oE the Invention This invention relates to a method and apparatus for horizontal drilling. More specifically, the invention relates to orienting a downhole drilling assembly includ-ing a steering tool assembly.
Background of the Invention During the drilling of subterranean wellbores, the upper portion of the drill string is composed of drill pipe which is operated under tension, the lower portion of the drill string is generally composed of drill collars whose weight is applied to the drill bit thereby placing 20 the collars in compression, and torque is applied to the entire drill string in order to rotate the drill bit~
Accordingly, the weight of the drill collars in com-pression can be resolved into two component forces: a first acting parallel to the axis of the collars and a 25 second acting normal to the first, perpendicular to the wellbore. Similarly, the load applied by the drill bit to the rock can be resolved into axial and normal component forces. The loads transmitted to the drill bit by the lowermost collars and the drill string affect the magni-... ,,.. .. ;
r~ 2 tude and direction of the forces applied by the drill bitto the rock.
If during drilling the magnitude and direction of the normal forces in the vicinity of the drill bit can 5 be controlled, then theoretically the bit can be steered and caused to drill in any desired subsurface location.
Various processes and associated equipment have been developed to both enhance and minimize this normal force. In regard to minimizing the normal force, various 10 types of drill collars, stabilizers and the like, has been used to continuously restore the borehole to vertical.
For exa~ple, U.S. Patent No. 4,319,649, issued March 16, 19~2, invented by J. D. Jeter, discloses drill collar sta-bilizers to maintain the drill string in a vertical direc-15 tion. In U.S. Patent No. 4,220,213, issued September 2,1980, invented by J. E. Hamilton, there is described plac-ing an eccentric member having a thick-walled side and a lighter side concentrically about a drill collar to main-tain drilling in the vertical direction. In this method, 20 gravity will cause the thick-walled portion of the eccen-tric collar to rotate to the low side of the deviated drill string.
Various types of drill collar stabilizers have also been used to alter the direction of drilling. U.S.
25 Patent Nos. 4,305,474, issued December 15, 1981, invented by N. Farris, et al. and 4,465,147, issued August 14, 1984, invented by R. ~eenstra, disclose stabilizers that create a force perpendicular to the drill string in order to steer the drill bit along a desired direction.
,~
~ 7 r~
One type of drilling process that i5 partic-ularly difficult to control is called horizontal drilling.
Horizontal drilling involves creating a highly curved wellbore having a tight radius and curvatureO This type 5 of drilling can be characterized by a rate of change of angle on the order of .5-6/ft, resulting in radii of cur-vature of 10-120 ft and a final drift angle of about 90.
In U.S. Patent No. 4,699,224, issued October 13, 1987, invented by M. B. Burton, there is disclosed a 10 method of horizontal drilling using a flexible drill string connected by a flexible joint to a drill bit collar equipped with a stabilizer, and rotary drill bit. This method includes the use of an eccentric cylindrical collar having a sidewall engaging means that circumferentially 15 mounts to the downhole end of the flexible drill string directly over the flexible joint leading to the drill bit collar. This eccentric collar forces the drill string passing therethrough to one side of the wellbore, thus lever arming the drill bit to the other side of the well-20 bore by pivoting on a stabilizer mounted to the dxill bitcollar between the flexible joint and the drill bit.
Although with the aid of the borehole engaging means the cylindrical eccentric collar is designed not to rotate with the drill string~ friction between the collar 25 and drill string plus downhole vibrations occurring during drilling will tend to rotate the collar, thereby resulting in the need for the collar to be reoriented periodically while drilling the curve from vertical to horizontal.
~ 3 ~ ~ ~ r~7 ~
One alternative would be to mark the pipe as it is being introduced into the wellbore, and once in the wellbore, rotate the drill string counterclockwise, stop-ping at the correct orientation, the surface pipe mark.
5 Although this method can be used in shallow wells, an alternative method is needed to orient the collar in deeper wells due to the unpredictable twist of the drillstring.
One method of orienting the eccentric collar 10 would be to use a steering tool as disclosed in Marshall~
Survey Steerin~ Tool: The Ultimate for Savin~ Rig Time, SPE 5897 (1976), but this would be expensive because it would require a wireline truck and associated equipment.
Another method would be to use a single-shot 15 orientation survey, for example, the device described in U.S. Patent 4,171,578, issued October 23, 1979, invented by E. L. Meador. The disadvantage of this method is the time required to introduce the instrument into the well-bore for each survey.
The accuracy of both the steering tool and the single-shot survey methods would be limited by the tor-sional flexibility of the drill collars since the orien-tation sub would have to be located above the drill collars because the internal diameter of the collars is 25 not sufficient for the survey tool to pass through.
In U.S. Patent 3,983,948, issued October 5, 1976, invented by J. D. Jeter, there is disclosed a tool for indicating the orientation of a downhole drilling assembly. This tool is undesirable because it is compli--S ~
cated with many intricate parts susceptible to breakdown in the harsh borehole environment. Further, the tool is not amenable to compact packaging for use in small diam-eter wellbores, for example, of less than ~ in. in diam-5 eter. Therefore, the tool is not appropriate for highcurvature or horizontal holes. Moreover, this tool appears to be limited to drilling with a downhole motor.
There is a need for a simple device with minimal moving parts for orienting a downhole drilling assembly 10 used in building angle during horizontal drilling. There is a novel need for a compact device for use in orienting downhole drilling assemblies, including a steering tool assembly that anticipates use in boreholes that have high curvature.
Summary of_the Invention One aspect of this invention is a method for indicating at the earth's surface when a drilling assembly connected to a drill string located in a wellbore is in a preselected orientation with respect to the earth. The 20 method comprises pumping drilling fluid down the drill string while rotating the drill string in a first direc-tion, and changing resistance to flow of the drilling fluid in the drill string to create an increase in said resistance to indicate that a downhole assembly is in a 25 preselected orientation relative to the earth. The increase can be accomplished using a sub located in the drill string above the steering assembly. The sub is activated by rotation of the drill string in a second direction that is opposite to the first direction. The ~ ~3 ~ i 2 downhole ~rilling assembly can include a steering assembly including an eccentric cylindrical collar means having a cylindrical hole passing therethrough wherein the central axis of the cylindrical hole is colinear with and dis-5 placed radially to one side relative to the central axisof the eccentric cylindrical collar means. The eccentric collar means can be equipped with a radially extending borehole engaging means that operatively engages the bore-hole during rotary drilling.
Another aspect of this invention is a method for orienting a drill bit steering assembly. The method com-prises pumping drilling fluid down the drill string while drilling in a first direction, ceasing the rotation of the drill string in the first direction and rotating the drill 15 string in a second direction opposite the first direction until a rise in pump pressure is detected at the surface, surface, ceasing the flow of drilling fluid and rotating the drill string in the first direction, and pumping the drilling fluid down the drill string and continuing to 20 drill.
Another aspect of this invention is an apparatus for indicating at the earth's surface when a downhole drilling assembly connected to a drill string having a drilling fluid flowing therethrough is in a given orien-25 tation relative to the earth. The apparatus i5 a subplaced in the drill string above the downhole drilling assembly. The sub is capable of increasing the resistance to the flow of drilling fluid through the drill string in response to rotation of the drill string. The sub can ~6--3~2~2 comprise a housing having a central bore defining an inlet flow passayeway and a toroidal chamber in communication with said passageway. The toroidal chamber can have a pocket and a valve seat. The housing further defines a 5 bifurcated outlet flow passageway, said bifurcated outlet flow passageway including an elongated outlet flow pas-sageway in communication with the inlet flow passageway and including a valve seat outlet flow passageway in com-munication with said valve seat. The sub also contains a 10 spherical valve being rotatable in said toroidal chamber from a normally seated position in the pocket. The toroi-dal chamber can define a ball race or an arcuate edge that is coaxial with the central bore. The bottom surface of the toroidal chamber can have irregular projections on 15 either side of the valve seat to prevent the ball plugging the valve seat prematurely. The elongated outlet passage-way can be in substantial coaxial alignment with the inlet flow passageway. The downhole steering assembly can include an cyllndrical collar means defining a cylindrical 20 hole passing therethrough, said cylindrical hole having a central axis colinear with and displaced radially to one side relative to the central axis of said collar means, and wherein the outer surface of the collar is equipped with a borehole engaging means. The valve seat can be 25 located on the low side of the borehole. The ball moves out of its normally seated position in the pocket and rotates along the toroidal chamber in response to rotation of the drill string, thereby plugging the valve seat and ~ 3~'t~'~
-increasiny the resistance to the flow of drilling fluid through the drill string.
Brief_Descriptlon of the Drawin~s FIGURE 1 is an axial sectional view of a pre-5 ferred embodiment of the apparatus of this invention.
FIGURE 2 is a circumferential sectional view ofthe apparatus of Figure 1 taken along line A-A.
Descri~tion of the Preferred Embodiment Referring to Figures 1 and 2, the downhole 10 steering assembly orienting device comprises a dense ball 1 in a ball race 3 that can seal an off-centered port 5 through which drilling fluid flows. The ball race 3 is only one embodiment of the toroidal chamber. The invention encompasses any toroidal chamber, for example, 15 an arcuate edge. The race 3 can be spiraled so that two revolutions oE the drill string would be required to move the ball 1 from a pocket 9 to the off-centered port 5.
The drilling assembly orienting device, which can be incorporated into a sub placed directly above a 20 downhole steering assembly Inot shown), contains two ports for passage of drilling fluid. The center port 7 is designed for the primary flow of drilling fluid and the off-center port 5 is used to provide a detectable resist-ance in the flow of drilling fluid wh~n the off-center 25 port 5 is on the low side of the borehole and a selected part of the steering assembly is on the high side of the borehole. The high side of the borehole is defined as the region in a given cross section taken perpendicular to the axis of the wellbore nearest the surface of the earth, that i5, opposite to the direction o the earth's gravita-tional force. The two ports, S and 7, can be sized so that a detectable increase in the surface drilling fluid pump pressure is generated when the off-centered port 5 is 5 plugged while the total drilling fluid pumping pressure does not become excessive.
The off-center port 5 should be located on the low side of the borehole. Where the downhole drilling assembly includes a steering assembly including an eccen-10 tric collar having a borehole engaging means, for exampleas shown in U. S. Patent No. 4,699,224, the off-center port 5 can be located 180 opposite the angular position of the borehole engaging meansO
The ball 1 is normally located in a pocket 9 15 when the drill string is rotated clockwise during normal drilling operations and is therefore incapable of plugging the center flow port 7. However, if the drill string is rotated counterclockwise, the ball 1, due to gravity, will stay on the low side of the hole and will plug the offcen-20 ter port 5 when the port 5 also reaches the low side. As soon as the port 5 is plugged, the pump pressure will increase, thus indicating at the surface that the borehole engaging portion of the eccentric collar is properly ori-ented to the high side of the borehole.
Irregular projections 11 can be incorporated into the ball race 3 on either side of the port 5 to pre-vent premature plugging of the port 5 by the ball 1 due to forces caused by the flowing fluid. Proper design of the irregular projections 11 should result in the port 5 being _g_ :~ 3~ 2~
repeatably plugged within a tolerance of +5 of the true low side.
Another method for using the apparatus of this invention to reorient a downhole assembly, for example, 5 the eccentric collar described in U.S. Patent 4,699,224, by initially orienting the eccentric collar using a con-ventional single-shot instrument as described in U.S.
Patent 4,171,578, then drill approximately 5-10 ft with stops made each foot to reorient the eccentric collar such 10 that the borehole engaging means is on the high side of the wellbore. This reorientation is a~complished by rotating the drillstring slowly counterclockwise until a rise in pump pressure is detected at the surface. The rise in pump pressure indicates that the eccentric collar 15 is properly oriented with the borehole engaging means adjacent the high side of the wellbore i.e. 7 that the borehole engaging means is adjacent the high side of the deviated borehole. The pump is then shut down and the drill string rotated one revolution clockwise to remove 20 the ball 1 from the port 5. The pump is then restarted and drilling is resumed.
After drilling about 30~ of the curve) the sin-gle-shot instrument is run to determine that the well is headed in the proper direction. If the direction should 25 need to be corrected, the proper tool face is determined using known art and the eccentric collar is positioned at the proper orientation relative to the high side of the hole using the apparatus of the this invention. A second check of the hole direction is made after drilling an 2~7~
additional 5-lO ft. In this way, the number of trips for the survey tool into the well is minimi2ed while at the same time ~he correct direction is assured~
:
Field oE the Invention This invention relates to a method and apparatus for horizontal drilling. More specifically, the invention relates to orienting a downhole drilling assembly includ-ing a steering tool assembly.
Background of the Invention During the drilling of subterranean wellbores, the upper portion of the drill string is composed of drill pipe which is operated under tension, the lower portion of the drill string is generally composed of drill collars whose weight is applied to the drill bit thereby placing 20 the collars in compression, and torque is applied to the entire drill string in order to rotate the drill bit~
Accordingly, the weight of the drill collars in com-pression can be resolved into two component forces: a first acting parallel to the axis of the collars and a 25 second acting normal to the first, perpendicular to the wellbore. Similarly, the load applied by the drill bit to the rock can be resolved into axial and normal component forces. The loads transmitted to the drill bit by the lowermost collars and the drill string affect the magni-... ,,.. .. ;
r~ 2 tude and direction of the forces applied by the drill bitto the rock.
If during drilling the magnitude and direction of the normal forces in the vicinity of the drill bit can 5 be controlled, then theoretically the bit can be steered and caused to drill in any desired subsurface location.
Various processes and associated equipment have been developed to both enhance and minimize this normal force. In regard to minimizing the normal force, various 10 types of drill collars, stabilizers and the like, has been used to continuously restore the borehole to vertical.
For exa~ple, U.S. Patent No. 4,319,649, issued March 16, 19~2, invented by J. D. Jeter, discloses drill collar sta-bilizers to maintain the drill string in a vertical direc-15 tion. In U.S. Patent No. 4,220,213, issued September 2,1980, invented by J. E. Hamilton, there is described plac-ing an eccentric member having a thick-walled side and a lighter side concentrically about a drill collar to main-tain drilling in the vertical direction. In this method, 20 gravity will cause the thick-walled portion of the eccen-tric collar to rotate to the low side of the deviated drill string.
Various types of drill collar stabilizers have also been used to alter the direction of drilling. U.S.
25 Patent Nos. 4,305,474, issued December 15, 1981, invented by N. Farris, et al. and 4,465,147, issued August 14, 1984, invented by R. ~eenstra, disclose stabilizers that create a force perpendicular to the drill string in order to steer the drill bit along a desired direction.
,~
~ 7 r~
One type of drilling process that i5 partic-ularly difficult to control is called horizontal drilling.
Horizontal drilling involves creating a highly curved wellbore having a tight radius and curvatureO This type 5 of drilling can be characterized by a rate of change of angle on the order of .5-6/ft, resulting in radii of cur-vature of 10-120 ft and a final drift angle of about 90.
In U.S. Patent No. 4,699,224, issued October 13, 1987, invented by M. B. Burton, there is disclosed a 10 method of horizontal drilling using a flexible drill string connected by a flexible joint to a drill bit collar equipped with a stabilizer, and rotary drill bit. This method includes the use of an eccentric cylindrical collar having a sidewall engaging means that circumferentially 15 mounts to the downhole end of the flexible drill string directly over the flexible joint leading to the drill bit collar. This eccentric collar forces the drill string passing therethrough to one side of the wellbore, thus lever arming the drill bit to the other side of the well-20 bore by pivoting on a stabilizer mounted to the dxill bitcollar between the flexible joint and the drill bit.
Although with the aid of the borehole engaging means the cylindrical eccentric collar is designed not to rotate with the drill string~ friction between the collar 25 and drill string plus downhole vibrations occurring during drilling will tend to rotate the collar, thereby resulting in the need for the collar to be reoriented periodically while drilling the curve from vertical to horizontal.
~ 3 ~ ~ ~ r~7 ~
One alternative would be to mark the pipe as it is being introduced into the wellbore, and once in the wellbore, rotate the drill string counterclockwise, stop-ping at the correct orientation, the surface pipe mark.
5 Although this method can be used in shallow wells, an alternative method is needed to orient the collar in deeper wells due to the unpredictable twist of the drillstring.
One method of orienting the eccentric collar 10 would be to use a steering tool as disclosed in Marshall~
Survey Steerin~ Tool: The Ultimate for Savin~ Rig Time, SPE 5897 (1976), but this would be expensive because it would require a wireline truck and associated equipment.
Another method would be to use a single-shot 15 orientation survey, for example, the device described in U.S. Patent 4,171,578, issued October 23, 1979, invented by E. L. Meador. The disadvantage of this method is the time required to introduce the instrument into the well-bore for each survey.
The accuracy of both the steering tool and the single-shot survey methods would be limited by the tor-sional flexibility of the drill collars since the orien-tation sub would have to be located above the drill collars because the internal diameter of the collars is 25 not sufficient for the survey tool to pass through.
In U.S. Patent 3,983,948, issued October 5, 1976, invented by J. D. Jeter, there is disclosed a tool for indicating the orientation of a downhole drilling assembly. This tool is undesirable because it is compli--S ~
cated with many intricate parts susceptible to breakdown in the harsh borehole environment. Further, the tool is not amenable to compact packaging for use in small diam-eter wellbores, for example, of less than ~ in. in diam-5 eter. Therefore, the tool is not appropriate for highcurvature or horizontal holes. Moreover, this tool appears to be limited to drilling with a downhole motor.
There is a need for a simple device with minimal moving parts for orienting a downhole drilling assembly 10 used in building angle during horizontal drilling. There is a novel need for a compact device for use in orienting downhole drilling assemblies, including a steering tool assembly that anticipates use in boreholes that have high curvature.
Summary of_the Invention One aspect of this invention is a method for indicating at the earth's surface when a drilling assembly connected to a drill string located in a wellbore is in a preselected orientation with respect to the earth. The 20 method comprises pumping drilling fluid down the drill string while rotating the drill string in a first direc-tion, and changing resistance to flow of the drilling fluid in the drill string to create an increase in said resistance to indicate that a downhole assembly is in a 25 preselected orientation relative to the earth. The increase can be accomplished using a sub located in the drill string above the steering assembly. The sub is activated by rotation of the drill string in a second direction that is opposite to the first direction. The ~ ~3 ~ i 2 downhole ~rilling assembly can include a steering assembly including an eccentric cylindrical collar means having a cylindrical hole passing therethrough wherein the central axis of the cylindrical hole is colinear with and dis-5 placed radially to one side relative to the central axisof the eccentric cylindrical collar means. The eccentric collar means can be equipped with a radially extending borehole engaging means that operatively engages the bore-hole during rotary drilling.
Another aspect of this invention is a method for orienting a drill bit steering assembly. The method com-prises pumping drilling fluid down the drill string while drilling in a first direction, ceasing the rotation of the drill string in the first direction and rotating the drill 15 string in a second direction opposite the first direction until a rise in pump pressure is detected at the surface, surface, ceasing the flow of drilling fluid and rotating the drill string in the first direction, and pumping the drilling fluid down the drill string and continuing to 20 drill.
Another aspect of this invention is an apparatus for indicating at the earth's surface when a downhole drilling assembly connected to a drill string having a drilling fluid flowing therethrough is in a given orien-25 tation relative to the earth. The apparatus i5 a subplaced in the drill string above the downhole drilling assembly. The sub is capable of increasing the resistance to the flow of drilling fluid through the drill string in response to rotation of the drill string. The sub can ~6--3~2~2 comprise a housing having a central bore defining an inlet flow passayeway and a toroidal chamber in communication with said passageway. The toroidal chamber can have a pocket and a valve seat. The housing further defines a 5 bifurcated outlet flow passageway, said bifurcated outlet flow passageway including an elongated outlet flow pas-sageway in communication with the inlet flow passageway and including a valve seat outlet flow passageway in com-munication with said valve seat. The sub also contains a 10 spherical valve being rotatable in said toroidal chamber from a normally seated position in the pocket. The toroi-dal chamber can define a ball race or an arcuate edge that is coaxial with the central bore. The bottom surface of the toroidal chamber can have irregular projections on 15 either side of the valve seat to prevent the ball plugging the valve seat prematurely. The elongated outlet passage-way can be in substantial coaxial alignment with the inlet flow passageway. The downhole steering assembly can include an cyllndrical collar means defining a cylindrical 20 hole passing therethrough, said cylindrical hole having a central axis colinear with and displaced radially to one side relative to the central axis of said collar means, and wherein the outer surface of the collar is equipped with a borehole engaging means. The valve seat can be 25 located on the low side of the borehole. The ball moves out of its normally seated position in the pocket and rotates along the toroidal chamber in response to rotation of the drill string, thereby plugging the valve seat and ~ 3~'t~'~
-increasiny the resistance to the flow of drilling fluid through the drill string.
Brief_Descriptlon of the Drawin~s FIGURE 1 is an axial sectional view of a pre-5 ferred embodiment of the apparatus of this invention.
FIGURE 2 is a circumferential sectional view ofthe apparatus of Figure 1 taken along line A-A.
Descri~tion of the Preferred Embodiment Referring to Figures 1 and 2, the downhole 10 steering assembly orienting device comprises a dense ball 1 in a ball race 3 that can seal an off-centered port 5 through which drilling fluid flows. The ball race 3 is only one embodiment of the toroidal chamber. The invention encompasses any toroidal chamber, for example, 15 an arcuate edge. The race 3 can be spiraled so that two revolutions oE the drill string would be required to move the ball 1 from a pocket 9 to the off-centered port 5.
The drilling assembly orienting device, which can be incorporated into a sub placed directly above a 20 downhole steering assembly Inot shown), contains two ports for passage of drilling fluid. The center port 7 is designed for the primary flow of drilling fluid and the off-center port 5 is used to provide a detectable resist-ance in the flow of drilling fluid wh~n the off-center 25 port 5 is on the low side of the borehole and a selected part of the steering assembly is on the high side of the borehole. The high side of the borehole is defined as the region in a given cross section taken perpendicular to the axis of the wellbore nearest the surface of the earth, that i5, opposite to the direction o the earth's gravita-tional force. The two ports, S and 7, can be sized so that a detectable increase in the surface drilling fluid pump pressure is generated when the off-centered port 5 is 5 plugged while the total drilling fluid pumping pressure does not become excessive.
The off-center port 5 should be located on the low side of the borehole. Where the downhole drilling assembly includes a steering assembly including an eccen-10 tric collar having a borehole engaging means, for exampleas shown in U. S. Patent No. 4,699,224, the off-center port 5 can be located 180 opposite the angular position of the borehole engaging meansO
The ball 1 is normally located in a pocket 9 15 when the drill string is rotated clockwise during normal drilling operations and is therefore incapable of plugging the center flow port 7. However, if the drill string is rotated counterclockwise, the ball 1, due to gravity, will stay on the low side of the hole and will plug the offcen-20 ter port 5 when the port 5 also reaches the low side. As soon as the port 5 is plugged, the pump pressure will increase, thus indicating at the surface that the borehole engaging portion of the eccentric collar is properly ori-ented to the high side of the borehole.
Irregular projections 11 can be incorporated into the ball race 3 on either side of the port 5 to pre-vent premature plugging of the port 5 by the ball 1 due to forces caused by the flowing fluid. Proper design of the irregular projections 11 should result in the port 5 being _g_ :~ 3~ 2~
repeatably plugged within a tolerance of +5 of the true low side.
Another method for using the apparatus of this invention to reorient a downhole assembly, for example, 5 the eccentric collar described in U.S. Patent 4,699,224, by initially orienting the eccentric collar using a con-ventional single-shot instrument as described in U.S.
Patent 4,171,578, then drill approximately 5-10 ft with stops made each foot to reorient the eccentric collar such 10 that the borehole engaging means is on the high side of the wellbore. This reorientation is a~complished by rotating the drillstring slowly counterclockwise until a rise in pump pressure is detected at the surface. The rise in pump pressure indicates that the eccentric collar 15 is properly oriented with the borehole engaging means adjacent the high side of the wellbore i.e. 7 that the borehole engaging means is adjacent the high side of the deviated borehole. The pump is then shut down and the drill string rotated one revolution clockwise to remove 20 the ball 1 from the port 5. The pump is then restarted and drilling is resumed.
After drilling about 30~ of the curve) the sin-gle-shot instrument is run to determine that the well is headed in the proper direction. If the direction should 25 need to be corrected, the proper tool face is determined using known art and the eccentric collar is positioned at the proper orientation relative to the high side of the hole using the apparatus of the this invention. A second check of the hole direction is made after drilling an 2~7~
additional 5-lO ft. In this way, the number of trips for the survey tool into the well is minimi2ed while at the same time ~he correct direction is assured~
:
Claims (11)
1. A method for indicating at the earth's sur-face when a steering assembly connected to a drill string located in a wellbore is in a preselected orientation with respect to the earth, comprising:
(a) pumping drilling fluid down the drill string while rotating the drill string in a first direction; and (b) changing resistance to the flow of the drilling fluid in the drill string to create a con-stant increase in said resistance to indicate that the steering assembly is in a preselected orientation relative to the earth, wherein step (b) further comprises rotating the drill string in a second direction that is oppo-site to the first direction to activate a sub located in the drill string above the steering assembly, and wherein the steering assembly is an eccen-tric cylindrical collar having a hole passing ther-ethrough, and having a radially extending borehole engaging means for operatively engaging the borehole during rotary drilling.
(a) pumping drilling fluid down the drill string while rotating the drill string in a first direction; and (b) changing resistance to the flow of the drilling fluid in the drill string to create a con-stant increase in said resistance to indicate that the steering assembly is in a preselected orientation relative to the earth, wherein step (b) further comprises rotating the drill string in a second direction that is oppo-site to the first direction to activate a sub located in the drill string above the steering assembly, and wherein the steering assembly is an eccen-tric cylindrical collar having a hole passing ther-ethrough, and having a radially extending borehole engaging means for operatively engaging the borehole during rotary drilling.
2. An apparatus for indicating at the earth's surface when a downhole steering assembly connected to a drill string is in a given orientation relative to the earth, comprising:
a sub for placement in the drill string above the steering assembly for increasing the resistance to the flow of drilling fluid through the drill string in response to rotation of the drill string, the sub further comprising a housing having a central bore defining an inlet flow passageway, said housing further defining a toroidal chamber in communication with said passageway, said toroidal chamber having a pocket and a valve seat, said hous-ing further defining a bifurcated outlet flow pas-sageway, said bifurcated outlet flow passageway including an elongated outlet flow passageway in com-munication with said inlet flow passageway and including a valve seat outlet flow passageway in com-munication with said valve seat; and a spherical valve being rotatable in said toroi-dal chamber from a normally seated position in said pocket.
a sub for placement in the drill string above the steering assembly for increasing the resistance to the flow of drilling fluid through the drill string in response to rotation of the drill string, the sub further comprising a housing having a central bore defining an inlet flow passageway, said housing further defining a toroidal chamber in communication with said passageway, said toroidal chamber having a pocket and a valve seat, said hous-ing further defining a bifurcated outlet flow pas-sageway, said bifurcated outlet flow passageway including an elongated outlet flow passageway in com-munication with said inlet flow passageway and including a valve seat outlet flow passageway in com-munication with said valve seat; and a spherical valve being rotatable in said toroi-dal chamber from a normally seated position in said pocket.
3. An apparatus of Claim 2 wherein the toroi-dal chamber defines a ball race.
4. An apparatus of Claim 2 wherein the elon-gated outlet flow passageway is in substantial coaxial alignment with the inlet flow passageway.
5. An apparatus of Claim 2 wherein the toroi-dal chamber is coaxial with the central bore.
6. An apparatus of Claim 2 wherein a bottom surface of the toroidal chamber has irregular projections on either side of the valve seat to prevent the ball from plugging the valve seat prematurely.
7. An apparatus of Claim 2 wherein the down-hole drilling steering assembly includes an eccentric cylindrical collar means defining a cylindrical hole pass-ing therethrough, and wherein the outer surface of said collar is equipped with a borehole engaging means.
8. An apparatus of Claim 7 wherein the valve seat is located on a low side of the borehole.
9. An apparatus of Claim 7 wherein the valve seat is located 180° from the borehole engaging means.
10. An apparatus of Claim 9 wherein the spheri-cal valve moves out of its normally seated position in the pocket and rotates along the toroidal chamber in response to rotation of the drill string thereby plugging the valve seat and increasing the resistance to the flow of drilling fluid through the drill string.
11. A method for orienting a drilling steering assembly connected to a drill string, comprising:
(a) pumping drilling fluid through the drill string while rotating in a first direction;
(b) ceasing the rotation of the drill string in the first direction and rotating the drill string in a second direction until a rise in the drilling fluid pump pressure is detected at the sur-face created by a sub located in the drill string, said sub positioned in the drill string above the steering assembly, said sub comprising a housing having a cen-tral bore defining an inlet flow passageway, said housing defining a toroidal chamber in communication with said passageway, said toroidal chamber having a pocket and a valve seat, said housing further defin-ing a bifurcated outlet flow passageway, said bifur-cated outlet flow passageway including an elongated outlet flow passageway in communication with said inlet flow passageway and including a valve seat outlet flow passageway in communication with said valve seat, and a ball valve being rotatable in said toroidal chamber from a normally seated positon;
(c) ceasing the flow of drilling fluid and rotating the drill string in the first direction; and (d) pumping drilling fluid through the drill string and drilling ahead.
(a) pumping drilling fluid through the drill string while rotating in a first direction;
(b) ceasing the rotation of the drill string in the first direction and rotating the drill string in a second direction until a rise in the drilling fluid pump pressure is detected at the sur-face created by a sub located in the drill string, said sub positioned in the drill string above the steering assembly, said sub comprising a housing having a cen-tral bore defining an inlet flow passageway, said housing defining a toroidal chamber in communication with said passageway, said toroidal chamber having a pocket and a valve seat, said housing further defin-ing a bifurcated outlet flow passageway, said bifur-cated outlet flow passageway including an elongated outlet flow passageway in communication with said inlet flow passageway and including a valve seat outlet flow passageway in communication with said valve seat, and a ball valve being rotatable in said toroidal chamber from a normally seated positon;
(c) ceasing the flow of drilling fluid and rotating the drill string in the first direction; and (d) pumping drilling fluid through the drill string and drilling ahead.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/281,293 US4899833A (en) | 1988-12-07 | 1988-12-07 | Downhole drilling assembly orienting device |
| US281,293 | 1988-12-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1312072C true CA1312072C (en) | 1992-12-29 |
Family
ID=23076693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000606273A Expired - Lifetime CA1312072C (en) | 1988-12-07 | 1989-07-20 | Downhole drilling assembly orienting device |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4899833A (en) |
| CA (1) | CA1312072C (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2008417A1 (en) * | 1990-01-23 | 1991-07-23 | Kenneth H. Wenzel | Orientable adjustable bent sub |
| US5103919A (en) * | 1990-10-04 | 1992-04-14 | Amoco Corporation | Method of determining the rotational orientation of a downhole tool |
| CA2052691C (en) * | 1990-10-04 | 2004-12-07 | Tommy M. Warren | Method of dynamically monitoring the orientation of a curve drilling assembly |
| US5547031A (en) * | 1995-02-24 | 1996-08-20 | Amoco Corporation | Orientation control mechanism |
| GB9503827D0 (en) * | 1995-02-25 | 1995-04-19 | Camco Drilling Group Ltd | "Improvements in or relating to steerable rotary drilling systems |
| CA2271401C (en) | 1999-02-23 | 2008-07-29 | Tesco Corporation | Drilling with casing |
| US6378626B1 (en) | 2000-06-29 | 2002-04-30 | Donald W. Wallace | Balanced torque drilling system |
| WO2009132159A2 (en) | 2008-04-23 | 2009-10-29 | Amkin Technologies | Position indicator for drilling tool |
| US8157024B2 (en) * | 2008-12-04 | 2012-04-17 | Schlumberger Technology Corporation | Ball piston steering devices and methods of use |
| WO2017004691A1 (en) * | 2015-07-09 | 2017-01-12 | Halliburton Energy Services, Inc. | Drilling apparatus with fixed and variable angular offsets |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE911242C (en) * | 1952-05-04 | 1954-05-10 | Deilmann Bergbau G M B H C | Device for determining the direction of rock boreholes during operation |
| GB1205068A (en) * | 1968-10-16 | 1970-09-16 | Byron Jackson Inc | Indicator for signalling the angular orientation of a well drilling string in an inclined well |
| US4319649A (en) * | 1973-06-18 | 1982-03-16 | Jeter John D | Stabilizer |
| US3983948A (en) * | 1974-07-01 | 1976-10-05 | Texas Dynamatics, Inc. | Method and apparatus for indicating the orientation of a down hole drilling assembly |
| US4171578A (en) * | 1977-01-28 | 1979-10-23 | Sperry-Sun, Inc. | Borehole tool |
| US4220213A (en) * | 1978-12-07 | 1980-09-02 | Hamilton Jack E | Method and apparatus for self orienting a drill string while drilling a well bore |
| US4276943A (en) * | 1979-09-25 | 1981-07-07 | The United States Of America As Represented By The Secretary Of The Army | Fluidic pulser |
| US4305474A (en) * | 1980-02-04 | 1981-12-15 | Conoco Inc. | Thrust actuated drill guidance device |
| ATE15927T1 (en) * | 1982-02-02 | 1985-10-15 | Shell Int Research | METHOD AND DEVICE FOR CONTROLLING THE DIRECTION OF THE BOREHOLE. |
| US4699224A (en) * | 1986-05-12 | 1987-10-13 | Sidewinder Joint Venture | Method and apparatus for lateral drilling in oil and gas wells |
-
1988
- 1988-12-07 US US07/281,293 patent/US4899833A/en not_active Expired - Lifetime
-
1989
- 1989-07-20 CA CA000606273A patent/CA1312072C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4899833A (en) | 1990-02-13 |
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