MXPA97004585A - Orientable drilling with motor located in the drilling fund or p - Google Patents

Abstract

The present invention relates to a method for creating a borehole in a land formation using a drill assembly comprising a bore column extending into the borehole, a motor located at the bottom of the borehole including a borehole. stator, and a driving shaft for rotating a drill, whose drive shaft has an inclined orientation relative to a longitudinal axis of the bottom of the drill string, the stator of the motor is connected to the bottom of the drill string In a manner such as to allow rotation of the motor stator about the longitudinal axis, the drilling assembly further comprises control means for controlling the rotation of the motor stator about the longitudinal axis and with respect to the drilling column, the method is characterized in that includes the drilling of a substantially straight section of the borehole by inducing means of control ol to rotate the motor stator continuously around the longitudinal axis and relative to the bore column, while the motor located at the bottom of the borehole is operated to rotate the drill bit, where the drilling step of the section of the substantially straight borehole is alternated with an additional step of drilling a curved section of the borehole by inducing the control means to prevent rotation of the motor stator about the longitudinal axis and relative to the borehole column , while the motor located at the bottom of the bore is operated to rotate the drill, characterized in that before the drilling step of the curved section the control means is induced to rotate the motor stator about an angle corresponding to a selected orientation of the bit in relation to the sond well

Description

ORIENTING DRILL WITH ENGINE LOCATED IN THE DRILL OR WELL FIELD OF THE INVENTION The present invention relates to a method and a system for creating a borehole in a ground formation. More specifically, the invention relates to the drilling of boreholes so that a drilling or drilling assembly is applied which allows to orient or maneuver a drill to a desired underground target area. A typical application in which there is a need for such guidance or maneuvering of the bit, is, for example, in subsea oil drilling whereby a plurality of diverted boreholes are drilled from a non-coastal platform in multiple locations. from an area that contains hydrocarbon in a soil formation. Other applications where there is a need for steerable or maneuverable drilling, includes the drilling of horizontal or very steep drilling wells in which one zone contains hydrocarbon.

BACKGROUND OF THE INVENTION ref: 24980 Patent application EP-571045-A1 discloses a method for creating a borehole in a soil formation using a drilling or boring assembly comprising a bore column extending into the borehole. sounding, a motor located at the bottom of the hole or bore that includes a stator and a driving shaft for rotating a drill bit, this driving shaft has an inclined orientation relative to a longitudinal axis of the bottom of the sounding column, the The motor stator is connected to the bottom of the bore column in a manner that allows rotation of the motor stator about the longitudinal axis, the bore assembly also comprises control means for controlling the rotation of the motor stator around the motor. longitudinal axis and relative to the sounding column. In the known method, a motor located at the bottom of the borehole or well having a stator with an adjustable bar or curved tube is applied, whereby during straight drilling the bar or curved tube is adjusted so that the angle of the curved bar or tube is zero, and during curve drilling the curved bar or tube is adjusted so that the angle of the curved bar or tube corresponds to the curvature of the suitable borehole.

Prior to drilling a section of the curved borehole, the motor stator is rotated relative to the bore column around a selected number of incremental angular steps so that the motor stator is oriented in the desired azimuthal direction .

DESCRIPTION OF THE INVENTION It is an object of the invention to provide a method for creating a borehole in a soil or ground formation whereby a motor located at the bottom of the borehole or borehole is -used, which allows for curved drilling as well as the straight or inline drilling, without the need for a motor stator that has an adjustable bar or elbow. It is a further object of the invention to provide an assembly for drilling or boring to create a borehole in a soil formation using a motor located at the bottom of the well which allows for curved drilling as well as straight or in-line drilling, without the need for a motor stator that has an adjustable bar or elbow. The method according to the invention, for this, comprises the step of drilling a substantially straight section of the borehole by inducing the control means for rotating the motor stator continuously about the longitudinal axis and with respect to the bore column while the Motor located at the bottom of the well is operated to rotate the bit. The stator of the continuously rotating motor ensures that the orientation of the inclined driver shaft of the motor changes continuously so that there is no preferential direction in which the drill will proceed in the formation. As a consequence of this, the drill will drill a section of the straight or in-line borehole during such continuous rotation of the stator. The assembly for drilling in accordance with the invention comprises a drilling column that extends into the borehole, a motor located at the bottom of the borehole that includes a housing or stator and a driving shaft for rotating a drill bit, this drive shaft is oriented inclined relative to a longitudinal axis of the bottom of the bore column, the stator of the motor that connects to the bottom of the bore column in a manner that allows rotation of the motor stator about the longitudinal axis, the mounting for drilling further comprises control means for controlling the rotation of the stator of the motor around of the longitudinal axis and relative to the drilling column, and means for drilling a substantially straight or in line section of the borehole inducing the control means to rotate the motor stator continuously around the longitudinal axis and relative to the column of sounding while the motor located at the bottom of the hole or well is operated to rotate the bit. The invention will be described in more detail below with reference to the accompanying drawing in which Figure 1 shows in schematic form a lower part of a drill assembly as used in the method according to the invention. The drill assembly shown in the Figure 1 extends into a borehole 1 formed in a floor formation 3. The assembly, of which only the lower part is shown in Figure 1, includes a bore column in the form of a pipe or pipeline 5 of relatively small diameter, for example a diameter of approximately 50 mm. Before being lowered into the borehole 1, the holding tube or pipe 5 is stored in the form of a spiral in a bobbin or spool (not shown) located on the surface. When the drilling progresses or advances, the holding pipe or pipe 5 is unwound from the bobbin or spool and gradually lowered into the borehole 1. The pipe or holding pipe 5, therefore, is also referred to as "coil" ", and drilling with such a coil is also referred to as" coil drilling ". A drilling motor located at the bottom of the well or bore 6 having a stator 7 is located at the lower end of the drill assembly, this motor 6 drives or drives a drive shaft 8 provided with a drill 9 which digs into the rock at the bottom of the borehole 11 during drilling. The motor located at the bottom of the borehole or well 6 forms a hydraulic motor of the Moineau type which is well known in the art of steerable or maneuverable drilling. The driving shaft 8 and the drill 9 are arranged inclined relative to the stator of the motor 7, so that a longitudinal axis 13 of the lower end portion of the coil 5 is oriented to the angle 15 relative to a longitudinal axis 17 of the driving shaft 8. The longitudinal axes 13 and 17 have an intersection point 19 located below the stator of the motor 7. The stator 7 of the motor located at the bottom of the bore 6 is provided with a number of stabilizing blades or blades 21 to stabilize and centralize the lower part of the drilling assembly in the borehole 1. The motor located at the bottom of the well or bore 6 is connected to the coil 5 via an electric motor 23 having a stator 25 and a motor shaft 27, the upper end of the stator 25 is fixedly connected to the lower end of the coil 5, and the lower end of the motor shaft 27 is fixedly connected to the upper end of the stator 7 of the motor located at the bottom of the perforation 6. The motor shaft 27 of the electric motor 23 is rotated about its longitudinal axis, relative to the stator 25 of the electric motor 23. When the electric motor 23 is operated, the motor shaft 27 rotates about its longitudinal, relative axis. to the stator 25. A borehole (not shown) extends through the interior of the electric motor 23, this bore provides a fluid flow path between the interior of the coil and the fluid inlet of the motor located at the bottom of the well or borehole 6. Thus, when the drilling fluid is pumped through the coil to drive the motor located at the bottom of the bore 6, the drilling fluid flows through the bore of the electric motor 23 to the motor inlet located in the bottom of the perforation 6. The electric power is provided to the electric motor 23 via a power supply line that extends through the interior of a protective steel sheath or sheath Ector 29 which is rigidly connected along the coil 5, to the surface. The power supply line is connected on the surface to a power supply (not shown) which is controlled by a suitable control system (not shown). The electric motor 23 is further provided with an orientation indicator (not shown) to provide an indication of the angular orientation of the motor shaft 27, and thus also of the angular orientation of the motor located at the bottom of the bore 6, relative to the serpentine 5. The orientation indicator provides a signal representing the orientation of the motor shaft 27 to an operator on the surface, via a suitable signal line that extends through the steel sheath or sheath 29. During normal assembly operation to drill, a section of the drill hole or drill hole, substantially straight, is drilled as follows. The drilling fluid is pumped through the coil 5 and through the bore of the electric motor 23 to the fluid inlet of the motor located at the bottom of the bore 6. Wherefore the motor located at the bottom of the bore 6 is operated to drive the drive shaft 8 and the drill 9. Simultaneously with the operation of the motor located at the bottom of the bore 23, the control system on the surface induces the power supply to provide electric power to the electric motor 23, so that the motor shaft 27 of the electric motor 23 is rotated continuously at a controlled speed and whereby the motor stator located at the bottom of the bore 6 is rotated at the same controlled speed. The drill 9 consequently rotates in the borehole 1 around both axes 13 and 17. Since the orientation of the drill 9 in the borehole 1 continuously changes due to the rotation of the drill 9 around the axis 13, there is no preferential direction for the drill 9 to deepen the borehole 1. Consequently, the drill bit 9 drills a straight section which substantially runs along the axis 13. It should be noted that the deviations of the straight or in line direction of the section of the well drilled in this way, can occur if the formation of soil or soil 3 is anisotropic or inhomogeneous.

However, such deviations can be corrected by measuring the direction of the borehole 1 at regular intervals, for example by well-known telemetric methods, and by drilling a short curve section as described below, if necessary. When a section of the borehole, curved or curved is about to be drilled following the drilling of the section of the borehole, straight or in line, the borehole proceeds as follows. First the surface control system induces the power supply to operate the electric motor 23 so that the motor shaft 27 is rotated about a selected angle corresponding to a selected orientation of the motor stator 7 located at the bottom of the motor. perforation 6 in borehole 1, this orientation of the motor stator .7 determines the direction in which the drilling of a section of the curved or curved borehole proceeds. To achieve the desired orientation of the motor stator 7, the orientation indicator is induced to provide an indication of the angular orientation of the motor shaft 27 to an operator on the surface. After the desired orientation is reached, the electric motor 23 is stopped, and the motor located at the bottom of the bore 6 is operated so as to rotate the drive shaft 8 and the drill bit 9 by pumping the drilling fluid through the coil 5 and through the bore of the electric motor 23 to the fluid inlet of the motor located at the bottom of the bore 6. Thus, the bore proceeds with the stator 7 of the motor located at the bottom of the drilling 6 stationary while the drill 9 turns. Since the drill 9 is inclined with respect to the longitudinal axis 13 of the lower part of the drilling assembly, the borehole 1 is intensified in the inclination direction of the drill 9 so that the section of the curved borehole in curve it is perforated. When the borehole 1 is found to be directed along the desired course, and the borehole should be continued in a straight line, the electric motor 23 is operated again so that the stator of the motor 7 is continuously rotated continuously and the motor located at the bottom of the bore 6 is operated so that the drill bit 9 rotates. To reach a target area in the formation of the floor 3, the drilling operator can repeat the above procedure to alternately drill sections of the borehole. probing in curve or straight. During drilling, the coil will coil due to the reaction moments acting on the coil, the degree of coiling is dependent on several factors, such as the diameter and thickness of the coil wall, the weight of the auger or trepan, the pressure of the fluid that drives the motor located at the bottom of the hole, or the magnitude of friction forces between the coil and the borehole wall. Instead of 'guiding the motor located at the bottom of the bore by operating the electric motor in the manner described above, the motor can be alternatively oriented by varying the coil torsion angle, for example by adjusting the weight of the bit or trepan or by adjusting the pressure of the drilling fluid which drives the motor located at the bottom of the borehole, or by a combined operation of the electric motor and a variation of the twist or kink angle. Instead of applying an electric motor to rotate the stator of the motor located at the bottom of the bore that drives or drives the drill, a hydraulic motor or any other suitable motor that can be operated in a controlled manner, can be applied. Preferably the control means does not include means for controlling the rotation of the motor stator about the longitudinal axis and with respect to the bore column, this rotation is caused by reactive torsional forces exerted on the stator of the motor due to the reactive torsion action of the rotating drill in the borehole. In conclusion, the method and system described above use a coil, a motor located at the bottom of the borehole and a secondary motor to control the rotation of the stator of the motor located at the bottom of the borehole, allow the drilling of sections of the borehole. probing in curve and straight lines without the need of a sounding column that is rotated on the surface.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is evident from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property

Claims (14)

1. A method for creating a borehole in a soil or ground formation using a drill assembly comprising a borehole extending into the borehole, a motor located at the bottom of the borehole including a stator and A driving shaft for rotating a drill bit, this driving shaft has an inclined orientation relative to a longitudinal axis of the bottom of the drill string, the motor stator is connected to the bottom of the drill string in a way that it allows rotation of the motor stator about the longitudinal axis, the drilling assembly further comprises control means for controlling the rotation of the motor stator about the longitudinal axis and with respect to the drilling column, the method is characterized in that it comprises drilling a substantially straight section of the borehole inducing the control means to rotate the motor stator continuously around the axis ngitudinal and in relation to the drilling column while the motor located at the bottom of the borehole is operated to rotate the bit.

2. The method according to claim 1, characterized in that the drilling step of the section of the substantially straight borehole is alternated with an additional step of drilling a curved section of the borehole inducing the control means to prevent rotation of the motor stator around the longitudinal axis and in relation to the bore column, while the motor located at the bottom of the borehole is operated to rotate the drill bit.

3. The method according to claim 2, characterized in that prior to the step of drilling the section in curve, the control means are induced to rotate the stator of the motor around an angle corresponding to a selected orientation of the bit relative to the well of sounding.

4. The method according to any of claims 1-3, characterized in that the control means does not include means for controlling the rotation of the motor stator about the longitudinal axis and with respect to the bore column, this rotation is caused by forces of Reactive torsion exerted on the stator of the motor due to the reactive torsional action of the rotating drill in the borehole.

5. The method according to any of claims 1-4, characterized in that the control means include one of the group of a hydraulic motor and an electric motor.

6. The method according to any of claims 1-5, characterized in that the sounding column * which forms a coil which is spun on a bobbin or spool, where the coil is unwound from the spool or reel and down to the well of sounding when the drilling of the borehole proceeds.

7. A drilling assembly for creating a borehole in a soil formation, characterized in that it comprises a bore column extending into the borehole, a motor located at the bottom of the borehole that includes a stator and a driving shaft for rotating a drill bit, this driving axis is tilted relative to a longitudinal axis of the bottom of the drill string, the motor stator is connected to the bottom of the drill string in a way that allows rotation of the motor stator about the longitudinal axis, the drilling assembly further comprises control means for controlling the rotation of the motor stator about the longitudinal axis and relative to the bore column, and means for drilling a substantially straight section of the borehole. probing by inducing the control means to rotate the motor stator continuously around the longitudinal axis and in relation to the column of sounding while the motor located at the bottom of the hole is operated to rotate the bit.

8. The drilling assembly according to claim 7, characterized in that means for alternating the step of drilling the section of the substantially straight borehole with a drilling passage of a curve section of the borehole inducing the control means to prevent the rotation of the motor stator around the longitudinal axis and in relation to the drilling column, while the motor located at the bottom of the drilling is operated to rotate the drill.

9. The drilling assembly according to claim 8, characterized in that it comprises stopping means prior to drilling the curved or curved section, inducing the control means for rotating the motor stator about an angle corresponding to a selected orientation of the bit in relation to the well of sounding.

10. The corking assembly according to any of claims 7-9, characterized in that the control means does not include means for controlling the rotation of the motor stator about the longitudinal axis and with respect to the sounding column, this rotation is caused by reactive torsional forces exerted on the stator of the motor due to the reactive torsional action of the rotary drill in the borehole.

11. The drilling assembly according to any of claims 7-10, characterized in that the control means include any of the group of a hydraulic motor and an electric motor.

12. The drilling assembly according to any of claims 7-11, characterized in that the drilling column forms a coil which is wound on a bobbin or spool, the assembly further comprising means for unwinding the bobbin coil or spool and lowering the coil to the borehole when drilling the borehole.

13. The method substantially as described above, with reference to the drawing.

14. The drill assembly is substantially as described above, with reference to the drawing.