Patent Application
20110139508
Controlled steering or directional drilling techniques are commonly used in the oil, water, and gas industry to reach resources that are not located directly below a wellhead. The advantages of directional drilling are well known and include the ability to reach reservoirs where vertical access is difficult or not possible (e.g. where an oilfield is located under a city, a body of water, or a difficult to drill formation) and the ability to group multiple wellheads on a single platform (e.g. for offshore drilling).
With the need for oil, water, and natural gas increasing, improved and more efficient apparatus and methodology for extracting natural resources from the earth are necessary.
The present invention is filed concurrently with Applicant docket number 92.1296, titled ACTUATORS, ACTUATABLE JOINTS, AND METHODS OF DIRECTIONAL DRILLING that is herein incorporated by reference.
The present invention generally recites a gauge pad for a rotary component received within a borehole, the gauge pad comprising an exterior surface dimensioned for rotation in close proximity to the borehole, a pocket extending through the exterior surface, the pocket in fluid communication with a pressurized fluid source and wherein the exterior surface is dimensioned such that when a pressurized fluid is discharged through the pocket, the velocity of the fluid through a gap between the exterior surface and borehole creates a pressure drop sufficient to pull the rotary component toward the gauge pad.
In accordance with one embodiment of the present invention, the pocket of the gauge pad may have a substantially circular profile. For example, this pocket may have a diameter of less than about 20 mm. Additionally, in accordance with the present invention, the exterior surface of the gauge pad may be substantially smooth and may have a substantially circular profile. Additionally, in accordance with one aspect of the present invention, the gap is less than about 0.5 mm. Furthermore, the pressurized fluid used in conjunction with the present invention may be drilling mud, as understood by one skilled in the art.
Additionally, in accordance with aspects of the present invention, the pocket and the exterior surface may be dimensioned to maximize the pressure drop for a particular pressurized fluid or alternatively may be dimensioned to maximize the pressure drop for a particular borehole. Furthermore, the pressurized fluid may be selectively discharged from the pocket or may be continuously discharged from the pocket.
In accordance with an alternative embodiment of the present invention, a gauge pad for a rotary component received within a borehole, the gauge pad comprising an exterior surface dimensioned for rotation in close proximity to the borehole, a pocket extending through the exterior surface, the pocket in fluid communication with a pressurized fluid source, wherein the exterior surface is dimensioned such that when a pressurized fluid is discharged through the pocket if the distance between the exterior surface is less than a distance d, the velocity of the fluid through a gap between the exterior surface and borehole creates a pressure drop sufficient to pull the rotary component toward the gauge pad and if the distance between the exterior surface is greater than distance d, the fluid pushes the rotary component away from the gauge pad is recited.
In accordance with an alternative embodiment of the present invention a rotary component comprising one or more gauge pads, each gauge pad including an exterior surface dimensioned for rotation in close proximity to the borehole, a pocket extending through the exterior surface, the pocket in fluid communication with a pressurized fluid source wherein the exterior surface is dimensioned such that when a pressurized fluid is discharged through the pocket, the velocity of the fluid through a gap between the exterior surface and borehole creates a pressure drop sufficient to pull the rotary component toward the gauge pad is recited herein.
The said rotary component may further comprise an actuator configured to control the discharge of the pressurized fluid through the pockets of the one or more gauge pads. In one embodiment the actuator may be a valve. Additionally, the rotary component may further comprise a control device configured to control the operation of the actuator.
The said control device of the present invention may include one or more sensors selected from the group consisting of: a rotational speed sensor, an accelerometer, and a three-dimensional accelerometer as understood by one skilled in the art. The rotary component may further comprise one or more cutters positioned on the rotary component to smooth the borehole surface. In accordance with the present invention, the one or more cutters are positioned in proximity to the one or more gauge pads. Additionally, the one or more cutters may be configured to cut a borehole having a diameter less than or equal to the diameter of the gauge pad, rotary component, and the gap. In accordance with the present embodiment, the aforementioned gap is between about 0.3 mm and about 0.5 mm.
In accordance with an alternative embodiment of the present invention, a method for directional drilling is recited, wherein the method comprises the steps of providing a rotary component including one or more additional gauge pads having an exterior surface dimensioned for rotation in close proximity to the borehole, an pocket extending through the exterior surface, the pocket in fluid communication with a pressurized fluid source wherein the exterior surface is dimensioned such that when a pressurized fluid is discharged through the pocket, the velocity of the fluid through a gap between the exterior surface and borehole creates a pressure drop sufficient to pull the rotary component toward the gauge pad and the step of rotating the rotary component and further selectively discharging the pressurized fluid through the pocket to pull the rotary component toward the gauge pad such that a curved borehole may be drilled. In accordance with the present embodiment, the rotary component may include an actuator configured to control the discharge of the pressurized fluid through the pocket.
Additionally, the rotary component may include a control device configured to control the operation of the actuator wherein the control device includes one or more sensors selected from the group consisting of: a rotational speed sensor, an accelerometer, and a three-dimensional accelerometer.
For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures wherein like reference characters denote corresponding parts throughout the several views and wherein:
Embodiments of the invention provide gauge pads, cutters, rotary components, and methods for directional drilling. Various embodiments of the invention can be used in wellsite systems.
A drill string 12 is suspended within the borehole 11 and has a bottom hole assembly (BHA) 100 which includes a drill bit 105 at its lower end. The surface system includes platform and derrick assembly 10 positioned over the borehole 11, the assembly 10 including a rotary table 16, kelly 17, hook 18 and rotary swivel 19. The drill string 12 is rotated by the rotary table 16, energized by means not shown, which engages the kelly 17 at the upper end of the drill string. The drill string 12 is suspended from a hook 18, attached to a traveling block (also not shown), through the kelly 17 and a rotary swivel 19 which permits rotation of the drill string relative to the hook. As is well known, a top drive system could alternatively be used.
In the example of this embodiment, the surface system further includes drilling fluid or mud 26 stored in a pit 27 formed at the well site. A pump 29 delivers the drilling fluid 26 to the interior of the drill string 12 via a port in the swivel 19, causing the drilling fluid to flow downwardly through the drill string 12 as indicated by the directional arrow 8. The drilling fluid exits the drill string 12 via ports in the drill bit 105, and then circulates upwardly through the annulus region between the outside of the drill string and the wall of the borehole, as indicated by the directional arrows 9. In this well known manner, the drilling fluid lubricates the drill bit 105 and carries formation cuttings up to the surface as it is returned to the pit 27 for recirculation.
The bottom hole assembly 100 of the illustrated embodiment includes a logging-while-drilling (LWD) module 120, a measuring-while-drilling (MWD) module 130, a roto-steerable system and motor, and drill bit 105.
The LWD module 120 is housed in a special type of drill collar, as is known in the art, and can contain one or a plurality of known types of logging tools. It will also be understood that more than one LWD and/or MWD module can be employed, e.g. as represented at 120A. (References, throughout, to a module at the position of 120 can alternatively mean a module at the position of 120A as well.) The LWD module includes capabilities for measuring, processing, and storing information, as well as for communicating with the surface equipment. In the present embodiment, the LWD module includes a pressure measuring device.
The MWD module 130 is also housed in a special type of drill collar, as is known in the art, and can contain one or more devices for measuring characteristics of the drill string and drill bit. The MWD tool further includes an apparatus (not shown) for generating electrical power to the downhole system. This may typically include a mud turbine generator (also known as a “mud motor”) powered by the flow of the drilling fluid, it being understood that other power and/or battery systems may be employed. In the present embodiment, the MWD module includes one or more of the following types of measuring devices: a weight-on-bit measuring device, a torque measuring device, a vibration measuring device, a shock measuring device, a stick slip measuring device, a direction measuring device, and an inclination measuring device.
A particularly advantageous use of the system hereof is in conjunction with controlled steering or “directional drilling.” In this embodiment, a roto-steerable subsystem 150 (
Directional drilling is, for example, advantageous in offshore drilling because it enables many wells to be drilled from a single platform. Directional drilling also enables horizontal drilling through a reservoir. Horizontal drilling enables a longer length of the wellbore to traverse the reservoir, which increases the production rate from the well.
A directional drilling system may also be used in vertical drilling operation as well. Often the drill bit will veer off of a planned drilling trajectory because of the unpredictable nature of the formations being penetrated or the varying forces that the drill bit experiences. When such a deviation occurs, a directional drilling system may be used to put the drill bit back on course.
A known method of directional drilling includes the use of a rotary steerable system (“RSS”). In an RSS, the drill string is rotated from the surface, and downhole devices cause the drill bit to drill in the desired direction. Rotating the drill string greatly reduces the occurrences of the drill string getting hung up or stuck during drilling. Rotary steerable drilling systems for drilling deviated boreholes into the earth may be generally classified as either “point-the-bit” systems or “push-the-bit” systems.
In the point-the-bit system, the axis of rotation of the drill bit is deviated from the local axis of the bottom hole assembly in the general direction of the new hole. The hole is propagated in accordance with the customary three-point geometry defined by upper and lower stabilizer touch points and the drill bit. The angle of deviation of the drill bit axis coupled with a finite distance between the drill bit and lower stabilizer results in the non-collinear condition required for a curve to be generated. There are many ways in which this may be achieved including a fixed bend at a point in the bottom hole assembly close to the lower stabilizer or a flexure of the drill bit drive shaft distributed between the upper and lower stabilizer. In its idealized form, the drill bit is not required to cut sideways because the bit axis is continually rotated in the direction of the curved hole. Examples of point-the-bit type rotary steerable systems, and how they operate are described in U.S. Patent Application Publication Nos. 2002/0011359; 2001/0052428 and U.S. Pat. Nos. 6,394,193; 6,364,034; 6,244,361; 6,158,529; 6,092,610; and 5,113,953.
In the push-the-bit rotary steerable system there is usually no specially identified mechanism to deviate the bit axis from the local bottom hole assembly axis; instead, the requisite non-collinear condition is achieved by causing either or both of the upper or lower stabilizers to apply an eccentric force or displacement in a direction that is preferentially orientated with respect to the direction of hole propagation. Again, there are many ways in which this may be achieved, including non-rotating (with respect to the hole) eccentric stabilizers (displacement based approaches) and eccentric actuators that apply force to the drill bit in the desired steering direction. Again, steering is achieved by creating non co-linearity between the drill bit and at least two other touch points. In its idealized form, the drill bit is required to cut side ways in order to generate a curved hole. Examples of push-the-bit type rotary steerable systems and how they operate are described in U.S. Pat. Nos. 5,265,682; 5,553,678; 5,803,185; 6,089,332; 5,695,015; 5,685,379; 5,706,905; 5,553,679; 5,673,763; 5,520,255; 5,603,385; 5,582,259; 5,778,992; and 5,971,085.
Referring now to
An embodiment of a Bernoulli gauge pad 200 having a cylindrical exterior surface 202 and pocket 204 is depicted in
Bernoulli gauge pad 200 utilizes Bernoulli's principle (which states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure of a decrease in the fluid's potential energy) to pull a rotary component coupled with the Bernoulli gauge pad 200 toward the Bernoulli gauge pad 200.
The net pressure for the Bernoulli gauge pad can be determined by integrating the pressure profile, which produces a net negative pressure of about 15 bar and net steering force of about 3 kN. Accordingly, the low pressure zone created by the exterior surface 202 is sufficient to overcome the positive pressure created by fluid exiting from the pocket 204. If the Bernoulli gauge pad 200 is pulled closer to the wall of the borehole, the pressure drop and resultant steering force increases. For example, if the gap is reduced to 0.4 mm, the pressure drop is about 20 bar and the net steering force is about 7 kN. Likewise, if the gap is reduced to 0.3 mm, the pressure drop is about 30 bars and the net steering force is about 11 kN.
As the gap increases, the “pull” force weakens and eventually a “push” force from the fluid ejected from pocket 204 dominates to produce a net push force.
The resultant forces for Bernoulli gauge pad can also be adjusted by altering the dimensions of exterior surface 202 and pocket 204. For example,
The pressure profile for push-type steering device 200b is depicted in
Referring now to
As clearly depicted in
Referring now to
Rotary component 400 includes a Bernoulli gauge pad 406. Bernoulli gauge pad 406 includes an exterior surface 408 and a pocket 410 extending through the exterior surface. Pocket 410 extends through the exterior surface 408 and is in fluid communication with a pressurized fluid source (e.g., the interior cavity of the rotary component 400).
In some embodiments, exterior surface 408 is fabricated from and/or coated with a wear-resistant material such as steel, “high speed steel,” carbon steel, brass, copper, iron, polycrystalline diamond compact (PDC), hardface, ceramics, carbides, ceramic carbides, cermets, and the like. Suitable coatings are described, for example, in U.S. Patent Publication No. 2007/0202350. Also, although exterior surface 408 is depicted as a separate material from rotary component 400, exterior surface can be an integral portion of rotary component 400. Additionally or alternatively, exterior surface 408 can have beveled or smooth edges to reduce frictions and/or damage to the gauge pad 406 as the rotary component 400 spins within the borehole 402.
When the Bernoulli gauge pad 406 is positioned in proximity to the borehole wall, the fluid velocity between the exterior surface 408 and the borehole wall exceeds fluid velocity within the pocket 410. This increase in velocity results in a drop in pressure between the exterior surface 408 and the borehole wall relative to the pocket pressure as described in Bernoulli's equation. This pressure drop pulls the rotary component 400 toward the exterior surface as depicted with arrows 412a, 412b.
In contrast, as depicted in
Referring now to
In embodiments in which the Bernoulli gauge pads 506 are selectively actuated, the control unit can maintain the proper angular position of the bottom hole assembly relative to the subsurface formation. In some embodiments, the control unit is mounted on a bearing that allows the control unit to rotate freely about the axis of the bottom hole assembly. The control unit, according to some embodiments, contains sensory equipment such as a three-axis accelerometer and/or magnetometer sensors to detect the inclination and azimuth of the bottom hole assembly. The control unit can further communicate with sensors disposed within elements of the bottom hole assembly such that said sensors can provide formation characteristics or drilling dynamics data to control unit. Formation characteristics can include information about adjacent geologic formation gather from ultrasound or nuclear imaging devices such as those discussed in U.S. Patent Publication No. 2007/0154341, the contents of which is hereby incorporated by reference herein. Drilling dynamics data may include measurements of the vibration, acceleration, velocity, and temperature of the bottom hole assembly.
In some embodiments, control unit is programmed above ground to following a desired inclination and direction. The progress of the bottom hole assembly can be measured using MWD systems and transmitted above-ground via a sequences of pulses in the drilling fluid, via an acoustic or wireless transmission method, or via a wired connection. If the desired path is changed, new instructions can be transmitted as required. Mud communication systems are described in U.S. Patent Publication No. 2006/0131030, herein incorporated by reference. Suitable systems are available under the POWERPULSE™ trademark from Schlumberger Technology Corporation of Sugar Land, Tex.
In order to urge the bottom hole assembly rotary component 500, one or more Bernoulli gauge pads 506 can be selectively actuated with respect to the rotational position of the Bernoulli gauge pad 506. For illustration,
In embodiments with multiple Bernoulli gauge pads 506, the actuation of Bernoulli gauge pads 506 can be coordinated to steer the rotary component 500 in a desired direction. For example, the actuation profile of Bernoulli gauge pad 506a can be repeated by Bernoulli gauge pads 506b, 506c, and 506d at 90°, 180°, and 270° offsets, respectively.
In some embodiments, a rotary valve (also referred to a spider valve) can be used to selectively actuate Bernoulli gauge pads 506. Suitable rotary valves are described in U.S. Pat. Nos. 4,630,244; 5,553,678; 7,188,685; and U.S. Patent Publication No. 2007/0242565.
In another embodiment, fluid flows continuously from Bernoulli gauge pads 506. Such an embodiment can be deployed to enhance the steering provided by other drill string components (e.g., pads and the like). As other steering components move the drill string, the Bernoulli gauge pad 506 closest to the target direction will be brought in proximity to the borehole wall to produce a pull force to enhance steering. It is estimated that such enhancements could increase steering angles about 0.5°. Such increases in steering angles significantly reduce drilling time and expense over curved well bores spanning several miles.
The Bernoulli gauge pads described herein also have a variety of other benefits. For example, the large exterior surface of Bernoulli gauge pads increases the mechanical robustness of the gauge pads relative to push-type devices with small exterior surfaces.
Additionally, if erosion of the borehole wall occurs when a Bernoulli gauge pad is used, the erosion will occur in the desired direction of steering. In contrast, erosion from a push-type steering device will occur opposite to the desired direction of steering.
Referring now to
Cutter bits 612 engage the borehole wall to enlarge and/or smooth the borehole while the flow of fluid over the exterior surface 608 creates a pressure drop that pulls the rotary component 600 toward the cutter bits 612 to enhance cutting. Cutter bits 612 can be positioned on the leading and/or trailing edges of exterior surface 608 and can be composed of a variety of materials such as polycrystalline diamond compact (PDC), ceramics, carbides, cermets, and the like. In some embodiments, exterior surface 608 includes a tapered region 614 to minimize friction and damage during rotation. Tapered regions 614 can be included in all embodiments of Bernoulli gauge pads and Bernoulli cutters described herein.
Referring now to
Each Bernoulli actuator 702 includes a first plate 704 and a second plate 706. A pocket 708 extends through the first plate 704 and is in fluid communication with a pressurized fluid source 710. The first plate 704, the second plate 706, and the pocket 708 are dimensioned such that when a pressurized fluid is discharged through the pocket 708, the velocity of the fluid through a gap 712 between the first plate 704 and the second plate 706 creates a pressure drop sufficient to pull the second plate 706 toward the first plate 704.
As discussed herein in the context of Bernoulli gauge pads, embodiments of the first plate 704, second plate 706, and/or pocket 708 can have a substantially circular profile and/or substantially smooth surfaces.
A variety of fluids can be used to actuate the Bernoulli actuators 702. In some embodiments, the fluid is a drilling fluid such as mud, aerated mud, stable foam, unstable foam, air, gases, and the like.
One or more Bernoulli actuators 702 can be mounted within a joint in drill string 700 to effect and/or assist in steering of the drill string 700. For example, first plate 704 can be mounted on a male joint member 714 and second plate 706 can be mounted on within a female joint member 716. Although plates 704, 706 in
In some embodiments depicted in
In other embodiments depicted in
In some embodiments, control unit 722 is programmed above ground to following a desired inclination and direction. The progress of the drill string can be measured using MWD systems and transmitted above-ground via a sequences of pulses in the drilling fluid, via an acoustic or wireless transmission method, or via a wired connection. If the desired path is changed, new instructions can be transmitted as required. Mud communication systems are described in U.S. Patent Publication No. 2006/0131030, herein incorporated by reference. Suitable systems are available under the POWERPULSE™ trademark from Schlumberger Technology Corporation of Sugar Land, Tex.
In some embodiments, a rotary valve (also referred to a spider valve) can be used to selectively actuate Bernoulli actuators 702. Suitable rotary valves are described in U.S. Pat. Nos. 4,630,244; 5,553,678; 7,188,685; and U.S. Patent Publication No. 2007/0242565.
In some embodiments, flexation of joint 700 can be regulated by various joint members such as pins 724 on the female member 716 with ridges 726 on male member 714.
One skilled in the art will readily recognize that the present invention may be utilized for a variety of additional applications in accordance with that which is claimed herein. In one embodiment, one or more cutters may be disposed in advance of the pad arrangement recited herein such that the borehole wall is cut to provide a smooth surface for the present invention to act upon. Additionally in an embodiment wherein a valve arrangement is disposed to actuation one or a plurality of gauge pads or actuators, the valve arrangement may serve as a suitable device to impart the required pressure drop for operation of the gauge pad or actuator. In an alternative embodiment, the aforementioned pressure drop may be achieved using a restrictor (not shown), wherein the restrictor may be manufactured using a variety of methods as understood by one skilled in the art. One suitable, but not exclusive, material is TSP. In accordance with one embodiment, this TSP arrangement may be infiltrated into the drill bit matrix during manufacture. Alternatively, the pocket arrangement of the present invention may serve as the suitable restrictor.
In accordance with further aspects of the present invention, the gap region of the present invention may be profiled such that the fluid passing through said gap is preferentially controlled. In one embodiment, the gap region may be profiled, as understood by one skilled in the art, to increase the diffusion effect of the fluid. In an alternative embodiment, the gap region may be profiled such that the tendency for the flow to separate in the region of the gap is decreased.
In accordance with alternative embodiments of the present invention, a standoff may be provided such that the gap region is sufficiently maintained. As understood by one skilled in the art, said standoff may be of a sufficiently had material, such as TSP.
All patents, published patent applications, and other references disclosed herein are hereby expressly incorporated by reference in their entireties by reference.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents of the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.
