Patent Application
20100139981
1. Field of the Disclosure
This disclosure relates generally to oilfield downhole tools and more particularly to modular drilling assemblies utilized for drilling wellbores having one or more enlarged diameter sections.
2. Description of the Related Art
To obtain hydrocarbons such as oil and gas, boreholes or wellbores are drilled by rotating a drill bit attached to the bottom of a drilling assembly (also referred to herein as a “Bottom Hole Assembly” or (“BHA”). The drilling assembly is attached to the bottom of a tubing or tubular string, which is usually either a jointed rigid pipe (or “drill pipe”) or a relatively flexible spoolable tubing commonly referred to in the art as “coiled tubing.” The string comprising the tubing and the drilling assembly is usually referred to as the “drill string.” When jointed pipe is utilized as the tubing, the drill bit is rotated by rotating the jointed pipe from the surface and/or by a motor contained in the drilling assembly. In the case of a coiled tubing, the drill bit is rotated by the motor. During drilling, a drilling fluid (also referred to as the “mud”) is supplied under pressure into the tubing. The drilling fluid passes through the drilling assembly and then discharges at the drill bit bottom. The drilling fluid provides lubrication to the drill bit and carries to the surface rock pieces disintegrated by the drill bit in drilling the wellbore via an annulus between the drill string and the wellbore wall. The motor, if used, may be rotated by the drilling fluid passing through the drilling assembly, by an electric motor, or other suitable driver. A drive shaft connected to the motor and the drill bit rotates the drill bit.
In certain instances, it may be desired to form a wellbore having a diameter larger than that formed by the drill bit. For instance, in some applications, constraints on wellbore geometry during drilling may result in a relatively small annular space in which cement may flow, reside and harden. In such instances, the annular space may need to be increased to suitably fix a casing or liner in the wellbore. In other instances, an unstable formation such as shale or salt may swell to reduce the diameter of the drilled wellbore and make it difficult to install a liner or casing. To compensate for this swelling, the wellbore may have to be drilled to a larger diameter while drilling through the unstable formation. In still other situations, such as in monobore drilling, it may be desired to increase a diameter of the wellbore to accept casing that is to be expanded. Furthermore, it may be desired to increase the diameter of only certain sections of a wellbore in real-time and in a single trip.
The present disclosure addresses the need for systems, devices and methods for selectively increasing the diameter of a drilled wellbore.
In aspects, the present disclosure relates to devices and methods for drilling wellbores with one or more pre-selected bore diameters. An exemplary BHA made in accordance with the present disclosure may be deployed via a conveyance device such as a tubular string, which may be jointed drill pipe or coiled tubing, into a wellbore. The BHA may include a hole enlargement device and tools for measuring selected parameters of interest. In one embodiment, a downhole and/or surface controller control the hole enlargement device. Bi-directional data communication between the BHA and the surface may be provided by a data conductor, such as a wire, formed along a drilling tubular such as jointed pipe or coiled tubing. Mud pulse telemetry, acoustic signals, optical signals, and EM signals may also be utilized. The hole enlargement device includes one or more extendable cutting elements that selectively enlarges the diameter of the wellbore formed by the drill bit. In an automated or closed-loop drilling mode, the controller is programmed with instructions for controlling the hole enlargement device in response to a measured parameter of interest. In further aspects, controllers at the surface and/or in the wellbore may be programmed to adjust one or more operating parameters to optimize the relationship between drilling performance and tool wear.
In one arrangement, the hole enlargement device includes an actuation unit that translates or moves the extendable cutting elements between a radially extended position and a radially retracted position. The cutting element may be configured to form a substantially circular wellbore having a diameter larger than the wellbore formed by the drill bit The actuation unit includes a piston-cylinder type arrangement that is energized using pressurized fluid such as clean hydraulic fluid or drilling mud. Valves and valve actuators control the flow of fluid between a fluid reservoir and the piston-cylinder assemblies. An electronics package positioned in the hole enlargement device operate the valves and valve actuators in response to a signal that is transmitted from a downhole and/or a surface location. In some embodiments, the actuation unit is energized using hydraulic fluid in a closed loop. The hole enlargement device may also include one or more position sensors that transmit a position signal indicative of a radial position of the cutting elements. Also, the hole enlargement device ma be configured to be operated substantially independently of the steering device.
In one operating mode, the drill string, together with the BHA described above, is conveyed into the wellbore. Drilling fluid pumped from the surface via the drill string energizes the drilling motor, which then rotates the drill bit to drill the wellbore. As needed, the hole enlargement device positioned adjacent the drill bit is activated to enlarge the diameter of the wellbore formed by the drill bit. For instance, surface personnel may transmit a signal to the electronics package for the hole enlargement device that causes the actuation unit to translate the cutting elements from a radially retracted position to a radially extended position. The position sensors upon detecting the extended position transmit a position signal indicative of an extended position to the surface. Thus, surface personnel have a positive indication of the position of the cutting elements. Advantageously, surface personnel may activate the hole enlargement device in real-time while drilling and/or during interruptions in drilling activity. For instance, prior to drilling into an unstable formation, the cutting elements may be extended to enlarge the drilled wellbore diameter. After traversing the unstable formation, surface personnel may retract the cutting element. In other situations, the cutting elements may be extended to enlarge the annular space available for cementing a casing or liner in place.
In one aspect, the present disclosure provides an apparatus for forming a wellbore in an earthen formation. The apparatus may include a drill string; a hole enlargement device positioned along the drill string; and a controller operably coupled to the hole enlargement device. The controller may be responsive to a first signal and a second signal such that the controller activates the hole enlargement device upon receiving the first signal and deactivates the hole enlargement device upon receiving the second signal. In some arrangements, the controller may activate and de-activate the hole enlargement device a plurality of times. Also, the controller may be responsive a signal that a pressure pulse, an electrical signal, an optical signal, an EM signal, and/or an acoustic signal. In aspects, the drill string may include at least one conductor configured to convey an electrical signal, and/or an optical signal. The apparatus may also include at least one sensor that measures a selected parameter of interest. In one arrangement, the hole enlargement device may include at least one cutting element and the sensor may measure a displacement of the at least one cutting element.
In another aspect, the present disclosure provides an apparatus for forming a wellbore in an earthen formation that includes a drill string; a hole enlargement device positioned along the drill string; and an actuator operably coupled to the hole enlargement device via a fluid circuit. The actuator may supply pressurized fluid via the fluid circuit to activate the hole enlargement device. The actuator may have a hydraulic pump. In some arrangements, the hydraulic pump may be energized by a pressurized fluid flowing in the drill string. The hydraulic pump may also be energized by electrical power. In aspects, the apparatus may include a downhole battery supplying the electrical power, and/or a downhole generator supplying the electrical power. Also, the apparatus may include a conductor coupling the hydraulic pump to a surface electrical power supply.
In still other aspects, the present disclosure provides a method for forming a wellbore in an earthen formation. The method may include enlarging a diameter of the wellbore with a hole enlargement device conveyed on a drill string; measuring a parameter of interest using a sensor positioned on the drill string; and controlling the hole enlargement device in response to the measured parameter of interest. In one aspect wherein the drill string includes a drill bit, the method includes drilling the wellbore with the drill bit; measuring a first parameter of interest using a sensor positioned proximate to the drill bit; and controlling the hole enlargement device in response to the measured parameter of interest and the second parameter of interest. In certain applications, the parameter of interest and the second parameter of interest relate to one of: (i) weight at a selected location on the drill string; (ii) weight at the drill bit; (iii) torque at a selected location on the drill string; and (iv) torque at the drill bit. Also, the method may further include estimating a difference between one of: (i) weight at a selected location on the drill string and weight at the drill bit; and (ii) torque at a selected location on the drill string and torque at the drill bit. In some aspects, the method includes adjusting an operating parameter of the hole enlargement device in response to the estimated difference. Moreover, when the parameter of interest relates to a formation intersected by the wellbore, the method may include adjusting an operating parameter of the hole enlargement device in response to the measured parameter of interest. In applications wherein the parameter of interest relates to a formation intersected by the wellbore and the drill string includes a bottomhole assembly, the method may include adjusting an operating parameter of the bottomhole assembly in response to the measured parameter of interest. Also, in variants, the operating parameter may be one of: (i) weight on the hole enlargement device, (ii) a rotational speed of the hole enlargement device; and (iii) flow rate. Further, the method may include displaying on a display device one of: (i) the measured parameter, and (ii) an value obtained by processing the measured parameter. In some applications, estimating downhole a difference between one of: (i) weight at a selected location on the drill string and weight at the drill bit; and (ii) torque at a selected location on the drill string and torque at the drill bit may be utilized. In applications, displaying on a display device a value of the difference estimated downhole may also be performed.
Illustrative examples of some features of the disclosure thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto.
For detailed understanding of the present disclosure, references should be made to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals and wherein:
The present disclosure is susceptible to embodiments of different forms. Shown in the drawings and described in detail are specific embodiments of the present disclosure. It should be understood that the present disclosure is an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein.
Referring initially to
During drilling operations, a suitable drilling fluid 34 from a mud pit (source) 36 is circulated under pressure through the drill string 22 by a mud pump 38. The drilling fluid 34 passes from the mud pump 38 into the drill string 22 via a desurger 40, fluid line 42 and the kelly joint 38. The drilling fluid 34 is discharged at the borehole bottom 44 through an opening in the drill bit 102. The drilling fluid 34 circulates uphole through the annular space 46 between the drill string 22 and the borehole 12 and returns carrying drill cuttings to the mud pit 36 via a return line 48. A sensor S1 preferably placed in the line 42 provides information about the fluid flow rate. A surface torque sensor S2 and a sensor S3 associated with the drill string 22 respectively provide information about the torque and the rotational speed of the drill string. Additionally, a sensor S4 associated with line 32 is used to provide the hook load of the drill string 22.
A surface controller 50 receives signals from the downhole sensors and devices via a sensor 52 placed in the fluid line 42 and signals from sensors S1, S2, S3, hook load sensor S4 and any other sensors used in the system and processes such signals according to programmed instructions provided to the surface controller 50. The surface controller 50 displays desired drilling parameters and other information on a display/monitor 54 and is utilized by an operator to control the drilling operations. The surface controller 50 contains a computer, memory for storing data, recorder for recording data and other peripherals. The surface controller 50 processes data according to programmed instructions and responds to user commands entered through a suitable device, such as a keyboard or a touch screen. The controller 50 is preferably adapted to activate alarms 56 when certain unsafe or undesirable operating conditions occur. As will be described in greater detail below, the controller 50 may be programmed for closed-loop drilling by adjusting one or more parameters (e.g., RPM, hook load, flow rate, etc.) as well as downhole parameters such as azimuth and inclination in order to follow a pre-defined well trajectory.
Referring now to
In one embodiment, the BHA 100 includes a drill bit 102, a hole enlargement device 110, a steering device 115, a drilling motor 120, a sensor sub 130, a bidirectional communication and power module (BCPM) 140, a stabilizer 150, and a formation evaluation (FE) sub 160. The steering device 115 is responsive to command signals. The command signals may be generated downhole and/or at the surface. Thus, the steering device 115 may be re-oriented or reconfigured in situ to change drilling direction without retrieving the BHA 100 from the wellbore. In an illustrative embodiment, the hole enlargement device 110 is integrated into a motor flex shaft 122 using a suitable electrical and mechanical connection 124. The hole enlargement device 110 may be a separate module that is mated to the motor flex shaft 122 using an appropriate mechanical joint and data and/or power connectors. In another embodiment, the hole enlargement device 110 is structurally incorporated in the flex shaft 122 itself. The steering device 115 and the hole enlargement device 110 may share a common power supply, e.g., hydraulic or electric, and a common communication system. In embodiments, drill bit 102, the steering device 115, and the hole enlargement device 110 are axially spaced apart. Additionally, the steering device 115 may be operated to steer the BHA 100 during drilling without operating the hole enlargement device 110 (i.e., without enlarging the wellbore diameter) and the hole enlargement device 110 may be operated without operating the steering device 115 (i.e., generating steering forces to steering the BHA 100).
To enable power and/or data transfer to the hole enlargement device 110 and among the other tools making up the BHA 100, the BHA 100 includes a power and/or data transmission line (not shown). The power and/or data transmission line (not shown) may extend along the entire length of the BHA 100 up to and including the hole enlargement device 110 and the drill bit 102. Exemplary uplinks, downlinks and data and/or power transmission arrangements are described in commonly owned and co-pending U.S. patent application Ser. No. 11/282,995, filed Nov. 18, 2005, which is hereby incorporated by reference for all purposes.
The hole enlargement device may include expandable cutting elements. In embodiments, the cutting elements may be actuated or extended simultaneously. For instance, at least two cutting elements may engage a wellbore wall surface at the same time. Surface personnel may use the power and/or data link between the hole enlargement device and BCPM and the surface to determine the position of the hole enlargement device cutting elements (i.e., expanded or retracted) and to issue instructions to cause the cutting elements to move between an expanded and retracted position. Thus, for example, the hole enlargement device cutting elements can be shifted to an expanded position as the BHA penetrates a swelling formation such as shale and later returned to a retracted position as the BHA penetrates into a more stable formation. One suitable hole enlargement device is referred to as an “underreamer” in the art.
Referring now to
In other embodiments, the actuation unit 220 may use devices such as an electric motor or employ shape-changing materials such as magnetostrictive or piezoelectric materials to translate the cutting elements 210 between the extended and retracted positions. In still other embodiments, the actuation unit 220 may be an “open” system that utilizes the circulating drilling fluid to displace the piston 222 within the cylinder 223. Thus, it should be appreciated that embodiments of the hole enlargement device 200 may utilize mechanical, electro-mechanical, electrical, pneumatic and hydraulic systems to move the cutting elements 210.
Additionally, while the hole enlargement device 200 is shown as integral with the motor shaft 122, in other embodiments the hole enlargement device 200 may be integral with the drill bit 102. For example, the hole enlargement device 200 may be adapted to connect to the drill bit 102. Alternatively, the drill bit 102 body may be modified to include radially expandable cutting elements (not shown). In still other embodiments, the hole enlargement device 200 may be positioned in a sub positioned between the steering device 130 and the drill bit 102 or elsewhere along the drill string. Moreover, the hole enlargement device 200 may be rotated by a separate motor (e.g., mud motor, electric motor, pneumatic motor) or by drill string rotation. It should be appreciated that the above-described embodiments are merely illustrative and not exhaustive. For example, other embodiments within the scope of the present disclosure may include cutting elements in one section of the BHA and the actuating elements in another section of the BHA. Still other variations will be apparent to one skilled in the art given the present teachings.
As previously discussed, embodiments of the present disclosure are utilized during “automated” drilling. In some application, the drilling is automated using downhole intelligence that control drilling direction in response to directional data (e.g., azimuth, inclination, north) measured by onboard sensors. The intelligence may be in the form of instructions programmed into a downhole controller that is operatively coupled to the steering device. Discussed in greater detail below are illustrative tools and components suitable for such applications.
Referring now to
The formation evaluation sub 160 may includes sensors for determining parameters of interest relating to the formation, borehole, geophysical characteristics, borehole fluids and boundary conditions. These sensor include formation evaluation sensors (e.g., resistivity, dielectric constant, water saturation, porosity, density and permeability), sensors for measuring borehole parameters (e.g., borehole size, and borehole roughness), sensors for measuring geophysical parameters (e.g., acoustic velocity and acoustic travel time), sensors for measuring borehole fluid parameters (e.g., viscosity, density, clarity, rheology, pH level, and gas, oil and water contents), and boundary condition sensors, sensors for measuring physical and chemical properties of the borehole fluid.
The subs 130 and 160 may include one or more memory modules and a battery pack module to store and provide back-up electric power may be placed at any suitable location in the BHA 100. Additional modules and sensors may be provided depending upon the specific drilling requirements. Such exemplary sensors may include an rpm sensor, sensor for measuring weight on the drill bit/hole enlargement device, sensors for measuring torque on the drill bit/hole enlargement device, sensors for measuring mud motor parameters (e.g., mud motor stator temperature, differential pressure across a mud motor, and fluid flow rate through a mud motor), and sensors for measuring vibration, whirl, radial displacement, stick-slip, torque, shock, vibration, strain, stress, bending moment, bit bounce, axial thrust, friction and radial thrust. The near bit inclination devices may include three (3) axis accelerometers, gyroscopic devices and signal processing circuitry as generally known in the art. These sensors may be positioned in the subs 130 and 160, distributed along the drill pipe, in the drill bit and along the BHA 100. Further, while subs 130 and 160 are described as separate modules, in certain embodiments, the sensors above described may be consolidated into a single sub or separated into three or more subs. The term “sub” refers merely to any supporting housing or structure and is not intended to mean a particular tool or configuration.
For automated drilling, a processor 132 processes the data collected by the sensor sub 130 and formation evaluation sub 160 and transmit appropriate control signals to the steering device 115. In response to the control signals, pads 117 of the steering device 115 extend to apply selected amounts of force to the wellbore wall (not shown). The applied forces create a force vector that urges the drill bit 102 in a selected drilling direction. The processor 132 may also be programmed to issue instructions to the hole enlargement device 110 and/or transmit data to the surface. The processor 132 may be configured to decimate data, digitize data, and include suitable PLC's. For example, the processor may include one or more microprocessors that uses a computer program implemented on a suitable machine readable medium that enables the processor to perform the control and processing. The machine readable medium may include ROMs, EPROMs, EAROMs, Flash Memories and Optical disks. Other equipment such as power and data buses, power supplies, and the like will be apparent to one skilled in the art. While the processor 132 is shown in the sensor sub 130, the processor 132 may be positioned elsewhere in the BHA 100. Moreover, other electronics, such as electronics that drive or operate actuators for valves and other devices may also be positioned along the BHA 100.
The bidirectional data communication and power module (“BCPM”) 140 transmits control signals between the BHA 100 and the surface as well as supplies electrical power to the BHA 100. For example, the BCPM 140 provides electrical power to devices such as the hole enlargement device 110 and steering device 115 and establishes two-way data communication between the processor 132 and surface devices such as the controller 50 (
The BHA 100 also includes the stabilizer 150, which has one or more stabilizing elements 152 and is disposed along the BHA 100 to provide lateral stability to the BHA 100. The stabilizing elements 152 may be fixed or adjustable.
Referring now to
At some point during the drilling activity, surface personnel may desire to enlarge the diameter of the well being drilled. Such an action may be due to encountering a formation susceptible to swelling, due to a need for providing a suitable annular space for cement or for some other drilling considerations such as swelling salt or unstable shale formations. Surface personnel may transmit a signal using the communication downlink (e.g., mud pulse telemetry) that causes the downhole electronics 230 to energize the actuation unit 220, which in turn extends the cutting elements 210 radially outward. When the cutting elements 210 reach their extended position, the position sensor 232 transmits a signal indicative of the extended position, which is displayed on display 54. Thus, surface personnel are affirmatively notified that the hole enlargement device 110 is extended and operational. With the hole enlargement device 110 activated, automated drilling may resume (assuming drilling was interrupted—which is not necessary). The drill bit 102 which now acts as a type of pilot bit drills the wellbore to a first diameter while the extended cutting elements 210 enlarge the wellbore to a second, larger diameter. Because the cutting elements 210 may be extended simultaneously, the cross-section of the resulting hole is substantially circular in shape. The BHA 100 under control of the processors 50 and/or 132 continue to automatically drill the formation by adjusting or controlling the steering device 115 as needed to maintain a desired wellbore path or trajectory. If at a later point personnel decide that an enlarged wellbore is not necessary, a signal transmitted from the surface to the downhole electronics 230 causes the cutting elements 210 to retract. The position sensor 232, upon sensing the retraction, generates a corresponding signal which is ultimately displayed on display 54. It should be understood, that the cutting elements 210 may be expanded and retracted a plurality of times during a single drilling trip into the wellbore. That is, as the BHA 100 traverses multiple layers of the formation during a single trip, the cutting elements 210 may be extended and retracted a plurality of times during that single trip; i.e., without being extracted out of the well.
It should be understood that the above drilling operation is merely illustrative. For example, in other operations, the surface and/or downhole processors may be programmed to automatically extend and retract the cutting elements as needed. As may be appreciated, the teachings of the present application may readily be applied to other drilling systems. Such other drillings systems include BHAs coupled to a rotating drilling string and BHA's wherein rotation of the drill string is superimposed on the mud motor rotation.
Referring now to
The sensors 264, 268 uphole and downhole of the cutting elements 210 may measure physical drilling characteristics that can be processed to determine the forces at or being applied to the cutting elements 210. For instance, the sensors 264, 268 may measure weight on bit above and below the cutting elements 210, respectively. Using known mathematical models, these measurements may be used to estimate the weight on the hole enlargement device (or WOR 284 as described below) at the cutting elements 210. Similarly, the sensors may measure torque on bit uphole and downhole of the cutting elements 210 to allow an estimation of the torque (or TOR 288 as described below) at the cutting elements 210. In like manner, estimation of bending forces and other drilling dynamics may be made for the hole enlargement device 200 and cutting elements 210.
The sensors 266 at the hole enlargement device 200 may include sensors for measuring RPM's, temperature, pressure, acceleration, vibration, whirl, radial displacement, stick-slip, torque, strain, stress, bending moment, bit bounce, axial thrust, friction, backward rotation, BHA buckling and radial thrust. For example, the sensors 270 at the actuation unit 220 may include sensors for measuring hydraulic pressure, temperature, and position of various components making up the actuation unit 220. In embodiments, one or more sensors may be utilized to measure the radial displacement of the cutting elements 210. One illustrative length measurement device for such a function includes a longitudinal variable displacement transducer. The length measurement device may be used to determine the radial extension of a cutting element 210, which then may be used to estimate a diameter of the drilled borehole. Thus, an indirect caliper-like measurement of the borehole may be obtained.
Also, as described previously, sensors distributed along the drill string can measure physical quantities such as drill string acceleration and strain, internal pressures in the drill string bore, external pressure in the annulus, vibration, temperature, electrical and magnetic field intensities inside the drill string, bore of the drill string, etc. Suitable systems for making dynamic downhole measurements include COPILOT, a downhole measurement system, manufactured by BAKER HUGHES INCORPORATED.
Referring still to
Referring now to
Referring now to
In embodiments, the actuation unit 220 uses pressurized fluid to extend and retract the cutting elements 210. As noted previously, biasing elements 238 may be used to bias or urge the cutting elements 210 into a retracted or closed position. Alternative or in addition to the use of biasing mechanisms, the flow control system 272 may apply pressurized fluid to the radial displacement system 270 such that hydraulic pressure drives the pistons in a radially outward and a radially inward position. For illustration, arrow 280 shows pressurized fluid entering one chamber of the cylinder 223 and arrow 282 shows pressurized fluid entering the opposing chamber of the cylinder 223. Thus, the piston 222, and attached cutting elements 210 (
The devices of the present disclosure may be advantageous utilized in a number of situations. One illustrative situation or application involves wellbores that have trajectories that intersect one or more unstable layers that may include shale or swelling salt. Referring now to
In one mode of operation, the operator continually processes and evaluates measurements obtained from the formation evaluation sub 160 and other downhole tools to characterize the nature of the formation being drilled (e.g., lithological or geophysical characteristics). Based on this information, the operator may conclude that the drill bit 102 is traversing a shale layer (e.g., layer 290), which often is an unstable formation that is susceptible to swelling. At the appropriate time, the operator transmits a downlink instructing the hole enlargement device 200 to expand and underream the wellbore 12. Thus, with continued drilling, the hole enlargement device 200 increases the diameter of the layer 290 relative to the diameter of the wellbore 12 in the stable layer 292. At some point, the operator may conclude that the drill bit 102 has penetrated into a relatively stable layer 292, e.g., a formation having sandstone. Prior to the hole enlargement device 200 entering the relatively stable layer 292, the operator transmits another downlink instructing the hole enlargement device 200 to retract and thereby discontinue underreaming. Drilling may continue without extracting the BHA 100 from the well. Advantageously, therefore, the hole enlargement device 200 is operated to underream only one or more selected formations. Moreover, the hole enlargement device 200 may be activated and deactivated as many times as needed while the drilling system 100 is in the wellbore.
In one mode of operation, the measurements of the sensors 264, 266, 268 and/or estimates of parameter based on such measurements may be presented to the operator on the display 54. Illustrative measurements or estimated parameters include switching status (e.g., position of cutting elements 210), hydraulic pressure, temperature, general health status of the tool, detailed blade extension information (e.g., amount of extension), estimated borehole diameter, etc. Furthermore, the operator may transmit signals via the communication device to operate the hole enlargement device 200. For instance, an operator may transmit an ‘open’ or ‘activate’ signal that causes the actuation unit 220 to radially extend the cutting elements 210. After some time, the operator may transmit a ‘close’ or ‘deactivate’ signal that causes the actuation 220 to cause the cutting elements 210 to radially retract. It should be appreciated that hydraulic power from clean hydraulic fluid or drilling mud may be used to actively extend and retract the cutting elements 210.
Referring now to
In one aspect, this information may be used for automated drilling. In certain applications, automated drilling involves adjusting drilling parameters to account for drilling conditions and dynamics. This automated control may be performed by a downhole controller, a surface controller or a combination thereof that are programmed to automatically adjust the operating set points or operating drilling parameters in response to measured and/or calculated drilling dynamics. For example, operating parameters may be automatically adjusted to reduce measured parameters such as vibration, bending moments, etc. Exemplary operating control parameters include, but are not limited to, weight-on-bit, RPM of the drill string, hook load, drilling fluid flow rate, and drilling fluid properties. During operation, the controller(s) may use one or more models for predicting drilling system behavior and the measured drilling dynamics parameters to determine values for one or more drilling parameters that may optimize drilling or maintain selected parameters within specified constraints or ranges.
In another aspect, the reamer and the drill bit may be viewed as an inter-related system wherein the behavior of the reamer influences the behavior of the drill bit and vice-versa. In this scenario, measurements of WOR 284, WOB 286, TOR 288, and TOB 290 may be used to automatically calculate the weight and torque difference between the drill bit and the reamer. The information may be inputted into an automated drilling system. Alternatively or additionally, this information may be presented to the operator. For instance, the display 54 may provide a numeric value of the differences in weight and torque of the reamer and the drill bit and/or utilize a coding scheme to help evaluate the differences in weight and torque values to recognize critical situations easier (e.g., green to represent an acceptable difference, yellow to represent a cautionary difference, red to represent an unacceptable difference, etc.).
In still other aspect, this information may be used to select drilling parameters that optimize drilling through a variety of formations. For instance, the formation evaluation data may be used to adjust or control the reamer while the reamer traverses a relatively hard formation. The drilling parameters (e.g., WOR, RPM, etc.) may be adjusted to prevent premature wear by limiting overload of the hole enlargement device in the hard formation. Real time or near-real time control and monitoring of the hole enlargement device may be useful in formations such as interbedded formations wherein changes in formation lithology can impose damaging wear if operation of the hole enlargement device is not appropriately varied. Thus, reamer and/or drill bit operations may be controlled in response to formation lithology.
Data representative of drilling dynamics may also be used to properly operate the reamer when encountering problematic formations. Referring now to
From the above, it should be appreciated that what has been described includes, in part, an apparatus that may include a hole enlargement device positioned along a drill string; and a controller operably coupled to the hole enlargement device. The hole enlargement device may include a plurality of cutting elements that may be actuated simultaneously to form a substantially circular wellbore. The controller may be responsive to a first signal and a second signal such that the controller activates the hole enlargement device upon receiving the first signal and deactivates the hole enlargement device upon receiving the second signal. In some arrangements, the controller may activate and de-activate the hole enlargement device several times during a single trip into the wellbore. The steering device and the hole enlargement device may be operated independently of one another. Also, the controller may be responsive to a pressure pulse, an electrical signal, an optical signal, an EM signal, and/or an acoustic signal. In aspects, the drill string may include wired pipe, e.g., drill pipe that has one or more conductors that convey an electrical signal, and/or an optical signal. The apparatus may also include one or more sensors that measure a selected parameter of interest. In one arrangement, the hole enlargement device may include one or more cutting elements and the sensor may measure a displacement the cutting elements.
From the above, it should be appreciated that what has been described also includes, in part, an apparatus that includes hole enlargement device positioned along a drill string; and an actuator operably coupled to the hole enlargement device via a fluid circuit. The actuator may supply pressurized fluid via the fluid circuit to activate the hole enlargement device. The actuator may have a hydraulic pump that may be energized by a pressurized fluid flowing in the drill string and/or energized by electrical power. In aspects, the electrical power may be supplied by a downhole battery, a downhole generator, and/or a conductor coupling the hydraulic pump to a surface electrical power supply.
From the above, it should be appreciated that what has been described further includes, in part, a method that includes enlarging a diameter of the wellbore with a hole enlargement device conveyed on a drill string; measuring a parameter of interest using a sensor positioned on the drill string; and controlling the hole enlargement device in response to the measured parameter of interest.
When the drill string includes a drill bit, the method may include drilling the wellbore with the drill bit; measuring a first parameter of interest using a sensor positioned proximate to the drill bit; and controlling the hole enlargement device in response to the measured parameter of interest and the second parameter of interest. In certain applications, the parameter of interest and the second parameter of interest may relate to weight at a selected location on the drill string; weight at the drill bit; torque at a selected location on the drill string; and torque at the drill bit. The method may further include estimating a difference between the weight at a selected location on the drill string and weight at the drill bit and/or the torque at a selected location on the drill string and torque at the drill bit. In some aspects, the method includes adjusting an operating parameter of the hole enlargement device in response to the estimated difference.
When the parameter of interest relates to a formation intersected by the wellbore, the method may include adjusting an operating parameter of the hole enlargement device in response to the measured parameter of interest. In applications wherein the parameter of interest relates to a formation intersected by the wellbore and the drill string includes a bottomhole assembly, the method may include adjusting an operating parameter of the bottomhole assembly in response to the measured parameter of interest. Also, in variants, the operating parameter may the weight on the hole enlargement device, a rotational speed of the hole enlargement device; and/or flow rate. Further, the method may include displaying on a display device the measured parameter, and/or a value obtained by processing the measured parameter. In some applications, the method may utilize estimating downhole a difference between the weight at a selected location on the drill string and weight at the drill bit and/or the torque at a selected location on the drill string and torque at the drill bit. In applications, displaying on a display device a value of the difference estimated downhole may also be performed.
The foregoing description is directed to particular embodiments of the present disclosure for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope of the disclosure. It is intended that the following claims be interpreted to embrace all such modifications and changes.
This application takes priority from U.S. Provisional Application Ser. No. 61/147,911 filed Jan. 28, 2009. This application is a continuation-in-part of U.S. application Ser. No. 11/681,370, filed Mar. 2, 2007 which in turns claims priority from U.S. Provisional Application Ser. No. 60/778,329, filed Mar. 2, 2006. Each application is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61147911 | Jan 2009 | US | |
| 60778329 | Mar 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11681370 | Mar 2007 | US |
| Child | 12689452 | US |
