CA2130736A1 - Drilling apparatus and method - Google Patents
Drilling apparatus and methodInfo
- Publication number
- CA2130736A1 CA2130736A1 CA 2130736 CA2130736A CA2130736A1 CA 2130736 A1 CA2130736 A1 CA 2130736A1 CA 2130736 CA2130736 CA 2130736 CA 2130736 A CA2130736 A CA 2130736A CA 2130736 A1 CA2130736 A1 CA 2130736A1
- Authority
- CA
- Canada
- Prior art keywords
- drilling
- motor
- coiled tubing
- drilling apparatus
- drill string
- 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.)
- Abandoned
Links
- 238000005553 drilling Methods 0.000 title claims abstract description 43
- 238000000034 method Methods 0.000 title claims abstract description 7
- 239000012530 fluid Substances 0.000 claims description 7
- 230000000694 effects Effects 0.000 claims description 6
- 230000000452 restraining effect Effects 0.000 claims description 5
- 230000007812 deficiency Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK 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
- E21B7/067—Deflecting the direction of boreholes with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
- Drilling And Boring (AREA)
Abstract
Abstract TITLE: DRILLING APPARATUS AND METHOD
Drilling apparatus comprises a drill string having coiled tubing (10) which extends down a bore being drilled and which is uncoiled as drilling progresses. A leading end of the drill string carries a drilling motor (28) having a body (26) and a bit (32) rotatably driven with respect to the body (26). The bit (32) and the body (26) are out of alignment by a bend angle (38). A multi-plate brake (42) activated by a piston (44) controls relative rotation between the motor body (26) and the coiled tubing (10) in order to control drilling course.
Drilling apparatus comprises a drill string having coiled tubing (10) which extends down a bore being drilled and which is uncoiled as drilling progresses. A leading end of the drill string carries a drilling motor (28) having a body (26) and a bit (32) rotatably driven with respect to the body (26). The bit (32) and the body (26) are out of alignment by a bend angle (38). A multi-plate brake (42) activated by a piston (44) controls relative rotation between the motor body (26) and the coiled tubing (10) in order to control drilling course.
Description
213~73&
,~
C667.2/C
TITLE: DRILLING APPAR~TUS AND METHOD
Field of the Invention :
This invention relates to apparatus for and a method of drilling using a drill string comprising coiled tubing.
Background to the Invention With regard to borehole course control, drilling using coiled tubing differs from normal drilling practice using a rotating drill string because, since the continuous drill string is being fed from a reel on the surface, it cannot be rotated.
Whilst drilling with a conventional rotating drill string and a down hole motor it is normal to have, integral with the motor, a fixed bend. This is shown in Figure 1 of theaccompanying drawings where the motor body is denoted 1, the rotating structure driven by the down hole motor is shown at 2, the fixed angle of the bend in the motor body îs denoted by 3 and the rotating bit is shown by 4. When a change of drilling course is required, the plane of the bend is adjusted from the surface by simply rotating the complete drill string until the new plane is achieved. When drilling then recommences with the drill string fixed, the course of the bore hole changes in the plane of the bend. Tha angular orientation of the plane of the bend is referred to as "toolface".
When the desired course has been achieved and drilling straight ahead is required, the drill string is continuously rotated, slowly, from the surface. The bend thus rotates and this results in a slightly oversize, but generally straight, bore hole.
`-` 213~73~) The present invention is concerned with course control where the drill string incorporates coiled tubing and therefore cannot be rotated.
Summary of the Invention According to one aspect of the invention drilling apparatus comprises a drill string having coiled tubing which extends down a bore being drilled and which is uncoiled as drilling progresses, a leading end of the drill string carrying a drilling motor having a body and a bit rotatably driven with respect to the body, tlhe bit and the body being out of alignment by a bend angle and adjustment means for effecting controlled rotation of the motor body with respect to the coiled tubing for control of drilling course.
The invention thus uses the torque reaction from the motor to achieve the required toolface or orientation and for providing a slow rotation for drilling straight ahead.
The adjustment means preferably comprise a brake for controlling relative rotation between the motor body and the coiled tubing. The brake is conveniently activated by pressure fluid, such as hydraulic fluid. In a preferred embodiment, the brake is a multi-plate brake actuated by a piston and cylinder driven by the hydraulic fluid from a hydraulic pump.
Preferably, the brake operates between the motor body, or an extension thereof, and a body of a control section which is attached, conveniently through the intermediary of an adaptor, to the downstream end of the coiled tubing. The Gontrol section conveniently accommodates control electronics, including a transducer for measuring the relative angular position of the motor body with respect to a body of the control section. The motor is preferably driven by pressurised mud conveyed through a central bore in the drill string.
In order to increase the torque available to rotate the motor body for course control, the motor drive shaft may be extended into the control section, where controllable restraining means are provided to lock rotationally the motor drive shaft with respect to the control section. The controllable restraining means may be a clutch or multi-plate brake which may be controlled hydraulically or electrically.
---` 213~73~
According to another aspect of the invention there is provided a method of drilling using a drill string including coiled tubing and a drilling motor, comprising using the reaction torque of the motor to effect controlled adjusting rotation of the motor body with respect to the coiled tubing to effect control of drilling direction.
Two embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Figure 2 is a diagrammatic view, partially in longitudinal section, of the first embodiment, Figure 3 is a diagrammatic view, partially in longitudinal section of the second embodiment,and Figure 4 shows, to an enlarged scale, part of the structure of Figure 3.
The drilling appartus of the first embodiment has a drill string using coiled tubing the downhole end of which is shown at 10 in Figure 2. The coiled tubing is about 50 millimeters in diameter and, as drilling progresses, the coiled tubing is unwound from a reel at the ground surface. Because the coiled tubing is unwould from a reel, it cannot be rotated in the manner of a conventional drill string.
Figure 2 shows the structure connected to the downhole end of the coiled tubing. An adaptor 12 connects the coiled tubing to the body 14 of control electronics, this body being rotationally fixed to a sleeve 16 which is in turn fixed to a ring 18 incorporating bearings 20.
The body 14 incorporates a further set of bearings 22, and the bearings 20 and 22 are positioned to support, for controlled rotation, a hollow shaft 24 which is an extension of a housing 26 of a downhole motor 28 shown in the lower part of Figure 2. The structure to the left of the arrow 30 in Figure 2 rotates with respect to the motor body 26. The extemity of this rotating structure is constituted by a bit 32 which provides the cutting action. Spaced seals 34, 36 seal the shaft 24 with respect to the ring 18 and body 14, respectively.
213~73~
The body 26 of the motor incorporates a bend, ie a change of direction which is illustrated at 38 in Figure 2 and which typically is an angular misalignment of 1 or 2 degrees between the rotational axis of the bit 32 and the longitudinal axis of the major part of the body 26.
It will be appreciated that controlled rotation of the tubular extension constituting the shaft 24, and therefore the motor body 26, with respect to the body 14 of the control electronics, adjusts the toolface for control of drilling direction. The motor 28 is driven by a flow of pressurised mud which is delivered to the motor through a central bore in the drill string, the mud flow being indicated by the line 40 in Figure 2.
Relative rotation between the shaft 24 and the body 14 of the control electronics is governed by means of a multi-plate brake 42 which is accommodated in the annular space between the sleeve 16 and the shaft 24 and which has alternating plates projecting from these respective components. The braking effect is altered by means of an annular piston 44 movable in an annular cylinder 46 pressurised by hydraulic fluid derived from a hydraulic pump 48, either driven electrically or mechanically from the motor body extension. A change in hydraulic pressure causes a change in the thrust applied to the plates of the brake 42 and hence a change in the level of braking torque.
A transducer accommodated in the control electronics measures the relative angular position of the shaft 24 and the body 14. Information from this transducer also allows the relative rotational speed of the shaft 24 and body 14 to be calculated. Reference number 49 shows an electrical wireline communicating with the control electronics.
When course changing is required, the toolface necessary to change drilling direction onto the new course is computed. To set this toolface the body 26 of the motor is allowed to rotate slowly with respect to the body 14 of the control electronics, the torque being derived from the reaction of the motor, until the required toolface is achieved, when the brake 42 is applied so as effectively to lock the shaft 24 with respect to the body 14 of the control electronics. Control of this process is through valves which supply oil to the piston and cylinder arrangement. The speed of rotation of the body 26 whilst setting the toolface is controlled by a closed loop control system, the actual speed being derived from the angular position transducer.
213~3~
When the desired drilling course has been achieved and drilling straight ahead is required, the motor body 26 is allowed to rotate continuously, resulting in a slightly oversize borehole being drilled in a straight ahead direction.
One possible deficiency with the embodiment of Figure 2 is that the torque available for rotating the motor body 26 may be insufficient to effect the required rotation of the motor body. For example, this can happen if the drill string becomes "keyseated" and insufficient weight on the bit can be applied in order to generate bit torque. The modification of Figures 3 and 4 is intended to overcome this possible deficiency.
In Figures 3 and 4 parts corresponding to those of Figure 2 have been given the same reference numerals. The embodiment of Figures 3 and 4 differs from that of Figure 2 in that in Figures 3 and 4 the rotatable shaft 50 of the mud motor 28 is extended through the hollow shaft 24 forming an extension of the motor body and into the control section. Restraining means 52 are then provided, either by a clutch or multi-plate brake, to lock the motor shaft 50 to the body 14 of the control section. Under these circumstances the maximum mud motor torque is available to rotate the body 26 of the motor, and hence maximum use is made of the reaction torque in this embodiment.
:~- ~... ...
,~
C667.2/C
TITLE: DRILLING APPAR~TUS AND METHOD
Field of the Invention :
This invention relates to apparatus for and a method of drilling using a drill string comprising coiled tubing.
Background to the Invention With regard to borehole course control, drilling using coiled tubing differs from normal drilling practice using a rotating drill string because, since the continuous drill string is being fed from a reel on the surface, it cannot be rotated.
Whilst drilling with a conventional rotating drill string and a down hole motor it is normal to have, integral with the motor, a fixed bend. This is shown in Figure 1 of theaccompanying drawings where the motor body is denoted 1, the rotating structure driven by the down hole motor is shown at 2, the fixed angle of the bend in the motor body îs denoted by 3 and the rotating bit is shown by 4. When a change of drilling course is required, the plane of the bend is adjusted from the surface by simply rotating the complete drill string until the new plane is achieved. When drilling then recommences with the drill string fixed, the course of the bore hole changes in the plane of the bend. Tha angular orientation of the plane of the bend is referred to as "toolface".
When the desired course has been achieved and drilling straight ahead is required, the drill string is continuously rotated, slowly, from the surface. The bend thus rotates and this results in a slightly oversize, but generally straight, bore hole.
`-` 213~73~) The present invention is concerned with course control where the drill string incorporates coiled tubing and therefore cannot be rotated.
Summary of the Invention According to one aspect of the invention drilling apparatus comprises a drill string having coiled tubing which extends down a bore being drilled and which is uncoiled as drilling progresses, a leading end of the drill string carrying a drilling motor having a body and a bit rotatably driven with respect to the body, tlhe bit and the body being out of alignment by a bend angle and adjustment means for effecting controlled rotation of the motor body with respect to the coiled tubing for control of drilling course.
The invention thus uses the torque reaction from the motor to achieve the required toolface or orientation and for providing a slow rotation for drilling straight ahead.
The adjustment means preferably comprise a brake for controlling relative rotation between the motor body and the coiled tubing. The brake is conveniently activated by pressure fluid, such as hydraulic fluid. In a preferred embodiment, the brake is a multi-plate brake actuated by a piston and cylinder driven by the hydraulic fluid from a hydraulic pump.
Preferably, the brake operates between the motor body, or an extension thereof, and a body of a control section which is attached, conveniently through the intermediary of an adaptor, to the downstream end of the coiled tubing. The Gontrol section conveniently accommodates control electronics, including a transducer for measuring the relative angular position of the motor body with respect to a body of the control section. The motor is preferably driven by pressurised mud conveyed through a central bore in the drill string.
In order to increase the torque available to rotate the motor body for course control, the motor drive shaft may be extended into the control section, where controllable restraining means are provided to lock rotationally the motor drive shaft with respect to the control section. The controllable restraining means may be a clutch or multi-plate brake which may be controlled hydraulically or electrically.
---` 213~73~
According to another aspect of the invention there is provided a method of drilling using a drill string including coiled tubing and a drilling motor, comprising using the reaction torque of the motor to effect controlled adjusting rotation of the motor body with respect to the coiled tubing to effect control of drilling direction.
Two embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-Figure 2 is a diagrammatic view, partially in longitudinal section, of the first embodiment, Figure 3 is a diagrammatic view, partially in longitudinal section of the second embodiment,and Figure 4 shows, to an enlarged scale, part of the structure of Figure 3.
The drilling appartus of the first embodiment has a drill string using coiled tubing the downhole end of which is shown at 10 in Figure 2. The coiled tubing is about 50 millimeters in diameter and, as drilling progresses, the coiled tubing is unwound from a reel at the ground surface. Because the coiled tubing is unwould from a reel, it cannot be rotated in the manner of a conventional drill string.
Figure 2 shows the structure connected to the downhole end of the coiled tubing. An adaptor 12 connects the coiled tubing to the body 14 of control electronics, this body being rotationally fixed to a sleeve 16 which is in turn fixed to a ring 18 incorporating bearings 20.
The body 14 incorporates a further set of bearings 22, and the bearings 20 and 22 are positioned to support, for controlled rotation, a hollow shaft 24 which is an extension of a housing 26 of a downhole motor 28 shown in the lower part of Figure 2. The structure to the left of the arrow 30 in Figure 2 rotates with respect to the motor body 26. The extemity of this rotating structure is constituted by a bit 32 which provides the cutting action. Spaced seals 34, 36 seal the shaft 24 with respect to the ring 18 and body 14, respectively.
213~73~
The body 26 of the motor incorporates a bend, ie a change of direction which is illustrated at 38 in Figure 2 and which typically is an angular misalignment of 1 or 2 degrees between the rotational axis of the bit 32 and the longitudinal axis of the major part of the body 26.
It will be appreciated that controlled rotation of the tubular extension constituting the shaft 24, and therefore the motor body 26, with respect to the body 14 of the control electronics, adjusts the toolface for control of drilling direction. The motor 28 is driven by a flow of pressurised mud which is delivered to the motor through a central bore in the drill string, the mud flow being indicated by the line 40 in Figure 2.
Relative rotation between the shaft 24 and the body 14 of the control electronics is governed by means of a multi-plate brake 42 which is accommodated in the annular space between the sleeve 16 and the shaft 24 and which has alternating plates projecting from these respective components. The braking effect is altered by means of an annular piston 44 movable in an annular cylinder 46 pressurised by hydraulic fluid derived from a hydraulic pump 48, either driven electrically or mechanically from the motor body extension. A change in hydraulic pressure causes a change in the thrust applied to the plates of the brake 42 and hence a change in the level of braking torque.
A transducer accommodated in the control electronics measures the relative angular position of the shaft 24 and the body 14. Information from this transducer also allows the relative rotational speed of the shaft 24 and body 14 to be calculated. Reference number 49 shows an electrical wireline communicating with the control electronics.
When course changing is required, the toolface necessary to change drilling direction onto the new course is computed. To set this toolface the body 26 of the motor is allowed to rotate slowly with respect to the body 14 of the control electronics, the torque being derived from the reaction of the motor, until the required toolface is achieved, when the brake 42 is applied so as effectively to lock the shaft 24 with respect to the body 14 of the control electronics. Control of this process is through valves which supply oil to the piston and cylinder arrangement. The speed of rotation of the body 26 whilst setting the toolface is controlled by a closed loop control system, the actual speed being derived from the angular position transducer.
213~3~
When the desired drilling course has been achieved and drilling straight ahead is required, the motor body 26 is allowed to rotate continuously, resulting in a slightly oversize borehole being drilled in a straight ahead direction.
One possible deficiency with the embodiment of Figure 2 is that the torque available for rotating the motor body 26 may be insufficient to effect the required rotation of the motor body. For example, this can happen if the drill string becomes "keyseated" and insufficient weight on the bit can be applied in order to generate bit torque. The modification of Figures 3 and 4 is intended to overcome this possible deficiency.
In Figures 3 and 4 parts corresponding to those of Figure 2 have been given the same reference numerals. The embodiment of Figures 3 and 4 differs from that of Figure 2 in that in Figures 3 and 4 the rotatable shaft 50 of the mud motor 28 is extended through the hollow shaft 24 forming an extension of the motor body and into the control section. Restraining means 52 are then provided, either by a clutch or multi-plate brake, to lock the motor shaft 50 to the body 14 of the control section. Under these circumstances the maximum mud motor torque is available to rotate the body 26 of the motor, and hence maximum use is made of the reaction torque in this embodiment.
:~- ~... ...
Claims (10)
1. Drilling apparatus comprising a drill string having coiled tubing which extends down a bore being drilled and which is uncoiled as drilling progresses, a leading end of the drill string carrying a drilling motor having a body and a bit rotatably driven with respect to the body, the bit and the body being out of alignment by a bend angle and adjustment means for effecting controlled rotation of the motor body with respect to the coiled tubing for control of drilling course.
2. Drilling apparatus according to claim 1, wherein the adjustment means comprise a brake for controlling relative rotation between the motor body and the coiled tubing.
3. Drilling apparatus according to claim 2, wherein the brake is activated by pressure fluid, such as hydraulic fluid.
4. Drilling apparatus according to claim 3, wherein the brake is a multi-plate brake actuated by a piston and cylinder driven by hydraulic fluid from a hydraulic pump.
5. Drilling apparatus according to claim 1, wherein the brake operates between the motor body, or an extension thereof, and a body of a control section which is attached to the downstream end of the coiled tubing.
6. Drilling apparatus according to claim 5, wherein the control section accommodates control electronics, including a transducer for measuring the relative angular position of the motor body with respect to a body of the control section.
7. Drilling apparatus according to claim 5, wherein in order to increase the torque available to rotate the motor body for course control, the motor drive shaft is extended into the control section, where controllable restraining means are provided to lack rotationally the motor drive shaft with respect to the control section.
8. Drilling apparatus according to claim 7, wherein the controllable restraining means are a clutch or multi-plate brake.
9. Drilling apparatus according to claim 1, wherein the motor is driven by pressurised mud conveyed through a central bore in the drill string.
10. A method of drilling using a drill string including coiled tubing and a drilling motor, comprising using the reaction torque of the motor to effect controlled adjusting rotation of the motor body with respect to the coiled tubing to effect control of drilling direction.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9318311A GB2282165A (en) | 1993-09-03 | 1993-09-03 | Directional drilling apparatus and method |
| GB9318311.9 | 1993-09-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2130736A1 true CA2130736A1 (en) | 1995-03-04 |
Family
ID=10741474
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2130736 Abandoned CA2130736A1 (en) | 1993-09-03 | 1994-08-23 | Drilling apparatus and method |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA2130736A1 (en) |
| DE (1) | DE4432408A1 (en) |
| GB (1) | GB2282165A (en) |
| NO (1) | NO943218L (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5738178A (en) * | 1995-11-17 | 1998-04-14 | Baker Hughes Incorporated | Method and apparatus for navigational drilling with a downhole motor employing independent drill string and bottomhole assembly rotary orientation and rotation |
| GB2406344B (en) | 2003-07-01 | 2007-01-03 | Pathfinder Energy Services Inc | Drill string rotation encoding |
| US7222681B2 (en) | 2005-02-18 | 2007-05-29 | Pathfinder Energy Services, Inc. | Programming method for controlling a downhole steering tool |
| US8408331B2 (en) | 2010-01-08 | 2013-04-02 | Schlumberger Technology Corporation | Downhole downlinking system employing a differential pressure transducer |
| US8570833B2 (en) | 2010-05-24 | 2013-10-29 | Schlumberger Technology Corporation | Downlinking communication system and method |
| US8792304B2 (en) | 2010-05-24 | 2014-07-29 | Schlumberger Technology Corporation | Downlinking communication system and method using signal transition detection |
| US9366087B2 (en) | 2013-01-29 | 2016-06-14 | Schlumberger Technology Corporation | High dogleg steerable tool |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1991011646A1 (en) * | 1990-01-24 | 1991-08-08 | Johnson Howard E | Utility tunneling method and apparatus |
| US5311952A (en) * | 1992-05-22 | 1994-05-17 | Schlumberger Technology Corporation | Apparatus and method for directional drilling with downhole motor on coiled tubing |
| US5316094A (en) * | 1992-10-20 | 1994-05-31 | Camco International Inc. | Well orienting tool and/or thruster |
| GB9222298D0 (en) * | 1992-10-23 | 1992-12-09 | Stirling Design Int | Directional drilling tool |
-
1993
- 1993-09-03 GB GB9318311A patent/GB2282165A/en not_active Withdrawn
-
1994
- 1994-08-23 CA CA 2130736 patent/CA2130736A1/en not_active Abandoned
- 1994-08-31 DE DE19944432408 patent/DE4432408A1/en not_active Withdrawn
- 1994-08-31 NO NO943218A patent/NO943218L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE4432408A1 (en) | 1995-03-09 |
| GB9318311D0 (en) | 1993-10-20 |
| NO943218L (en) | 1995-03-06 |
| NO943218D0 (en) | 1994-08-31 |
| GB2282165A (en) | 1995-03-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |