CA2874639A1 - Axially amplified pulsing tool - Google Patents
Axially amplified pulsing tool Download PDFInfo
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- CA2874639A1 CA2874639A1 CA2874639A CA2874639A CA2874639A1 CA 2874639 A1 CA2874639 A1 CA 2874639A1 CA 2874639 A CA2874639 A CA 2874639A CA 2874639 A CA2874639 A CA 2874639A CA 2874639 A1 CA2874639 A1 CA 2874639A1
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Abstract
An amplification tool and method of drilling a borehole with same, particularly for laterally inclined and/or horizontal portions of a borehole. Pressure pulses in a drilling fluid in drill string act on one or more axially aligned pistons in the amplification tool, which is connected in the drill string to produce a force to drive a force responsive device in the drill string. Each piston has a piston face, a first fluid chamber on one side of the piston face, and a second fluid chamber on the other side of the piston face. The first fluid chamber is in fluid communication with the drilling fluid and the second fluid chamber is in fluid communication with a pressurized fluid held at a set pressure within the amplification tool. Pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with the force which is amplified by an amount proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons.
Description
AXIALLY AMPLIFIED PULSING TOOL
FIELD OF THE INVENTION
This invention relates to an amplification tool and a method of drilling for pressure pulse amplification during drilling.
BACKGROUND
Conventional vertical oil and gas wells are drilled by rotary drilling from a surface derrick. A drill string extends from the surface derrick to a drill bit located at the lower end of the drill string. The drill string is typically suspended from blocks at the derrick or from a top drive. In conventional drilling, the drill string itself is rotated from the surface.
Directional drilling is used when reservoirs are laterally distanced from the surface derrick. In directional drilling there may be a generally vertical section and/or an inclined section down to a depth, followed by sections which deviate laterally from the vertical plane. The drill bit for lateral directional drilling may be rotated by the drill string from the surface during the generally vertical and/or inclined sections, and/or it may be rotated by a mud motor located above the drill bit.
In the laterally inclined and/or horizontal stage of drilling, the drill bit is typically rotated by a downhole mud motor. Drilling fluid, often a drilling mud, is pumped from the surface, downwardly through the drill string, through the drill bit, and then upwardly in the annulus between the drill string and the borehole back to the surface. Drill cuttings and rock chips are carried from the drill bit back to the surface. The drill string typically includes drill pipe, sections of drill collars and drilling tools such as reamers, drilling jars, drilling shock tools, hammer tools, and measurement-while-drilling (MWD) tools.
During the lateral or horizontal phases of drilling, a portion of the drill string is in direct contact with the borehole, which causes significant frictional resistance, particularly if and when the drill string is sliding and not rotating. If the drill string stops, the friction between the drill string and the borehole makes it difficult to advance the drill string into the borehole when drilling is restarted.
Overcoming the friction between the borehole and the drill sting helps the driller to provide the optimal amount of weight on the drill bit for maximum penetration rate. If undue force is needed to overcome the friction, damage to the downhole drilling equipment can occur, and penetration rates are reduced.
Directional drilling uses a technology and devices known as measurement-while drilling (MWD) to communicate the azimuth and inclination of the borehole to the surface. The MWD devices are electromechanical devices located above the drill bit in the bottomhole assembly (BHA). The MWD device typically transmits data to the surface using mud-pulse telemetry. The MWD device produces pressure pulses in the drilling fluid such that a parameter of the pulses, for example the pulse frequency and/or the pulse amplitude, is dependent on a measured parameter, for example the inclination of the borehole. The MWD devices may use positive-pulse, negative-pulse or continuous-wave systems. When the fluid flow through the drill string is restricted by operation of a valve, or poppet, a pressure pulse is created, the leading edge of which is a rise in pressure. This method is generally termed positive mud pulse telemetry. The term negative mud pulse telemetry is typically used to describe systems in which a valve opens a passage to the lower pressure environment outside the drill string (i.e., the annulus between the drill string and the borehole), thus generating a negative pressure pulse having a falling leading edge.
At the surface, the pressure pulses from the MWD device are analysed or decoded to determine a relevant measured borehole parameter. Devices to generate pulses for mud pulse telemetry (i.e., MWD devices) are more fully described in, for example, US Patent Nos. 3,958,217, 4,905,778, 4,914,637 and 5,040,155.
As above, the weight on the drill bit (weight-on-bit, or WOB) is an important factor for drilling penetration rates at the rock face. In directional drilling, the WOB is high in a vertical stage of the drilling, but is considerably lessened in the laterally inclined or horizontal stages of the drilling. Specific downhole tools exist to increase
FIELD OF THE INVENTION
This invention relates to an amplification tool and a method of drilling for pressure pulse amplification during drilling.
BACKGROUND
Conventional vertical oil and gas wells are drilled by rotary drilling from a surface derrick. A drill string extends from the surface derrick to a drill bit located at the lower end of the drill string. The drill string is typically suspended from blocks at the derrick or from a top drive. In conventional drilling, the drill string itself is rotated from the surface.
Directional drilling is used when reservoirs are laterally distanced from the surface derrick. In directional drilling there may be a generally vertical section and/or an inclined section down to a depth, followed by sections which deviate laterally from the vertical plane. The drill bit for lateral directional drilling may be rotated by the drill string from the surface during the generally vertical and/or inclined sections, and/or it may be rotated by a mud motor located above the drill bit.
In the laterally inclined and/or horizontal stage of drilling, the drill bit is typically rotated by a downhole mud motor. Drilling fluid, often a drilling mud, is pumped from the surface, downwardly through the drill string, through the drill bit, and then upwardly in the annulus between the drill string and the borehole back to the surface. Drill cuttings and rock chips are carried from the drill bit back to the surface. The drill string typically includes drill pipe, sections of drill collars and drilling tools such as reamers, drilling jars, drilling shock tools, hammer tools, and measurement-while-drilling (MWD) tools.
During the lateral or horizontal phases of drilling, a portion of the drill string is in direct contact with the borehole, which causes significant frictional resistance, particularly if and when the drill string is sliding and not rotating. If the drill string stops, the friction between the drill string and the borehole makes it difficult to advance the drill string into the borehole when drilling is restarted.
Overcoming the friction between the borehole and the drill sting helps the driller to provide the optimal amount of weight on the drill bit for maximum penetration rate. If undue force is needed to overcome the friction, damage to the downhole drilling equipment can occur, and penetration rates are reduced.
Directional drilling uses a technology and devices known as measurement-while drilling (MWD) to communicate the azimuth and inclination of the borehole to the surface. The MWD devices are electromechanical devices located above the drill bit in the bottomhole assembly (BHA). The MWD device typically transmits data to the surface using mud-pulse telemetry. The MWD device produces pressure pulses in the drilling fluid such that a parameter of the pulses, for example the pulse frequency and/or the pulse amplitude, is dependent on a measured parameter, for example the inclination of the borehole. The MWD devices may use positive-pulse, negative-pulse or continuous-wave systems. When the fluid flow through the drill string is restricted by operation of a valve, or poppet, a pressure pulse is created, the leading edge of which is a rise in pressure. This method is generally termed positive mud pulse telemetry. The term negative mud pulse telemetry is typically used to describe systems in which a valve opens a passage to the lower pressure environment outside the drill string (i.e., the annulus between the drill string and the borehole), thus generating a negative pressure pulse having a falling leading edge.
At the surface, the pressure pulses from the MWD device are analysed or decoded to determine a relevant measured borehole parameter. Devices to generate pulses for mud pulse telemetry (i.e., MWD devices) are more fully described in, for example, US Patent Nos. 3,958,217, 4,905,778, 4,914,637 and 5,040,155.
As above, the weight on the drill bit (weight-on-bit, or WOB) is an important factor for drilling penetration rates at the rock face. In directional drilling, the WOB is high in a vertical stage of the drilling, but is considerably lessened in the laterally inclined or horizontal stages of the drilling. Specific downhole tools exist to increase
2 the penetration rates. One class of tools uses a water hammer effect to create pulsation of the flow of the drilling fluid through the drill bit to increase penetration rates. In these tools, the direction of the pulse is toward the drill bit. A
second class of tools, known as shock tools, use a pressure pulse to deliver a force on the drill string to agitate or vibrate the drill string to overcome the friction between the drill string and the borehole in the lateral section of the drilled borehole. Some shock tools use a pressure pulse to act on a piston, creating a force proportional to the area of the piston multiplied by the amplitude of the pressure pulse. Shock tools may create a pulse in either direction, i.e., toward or away from the drill bit. Shock tools are advantageously positioned proximate the bent section of the borehole, where the drill string moves away from a generally vertical inclination to a more lateral inclination. In this position, the shock tool is used to vibrate the drill string, where the friction between the BHA and the borehole is the greatest. Another type of tool creates a hammer effect on the drill bit, with the pulses acting on an anvil in the direction of the drill bit. A few exemplary tools are summarized below.
US Patent 6,279,670 to Eddison et al., describes a downhole flow pulsing tool for use with a pressure responsive device as a shock tool which expands and retracts in response to the pressure pulses created by the tool. The tool includes a housing with a throughbore for drilling fluid and a valve in the bore with a valve member which is moveable to vary the area of a passage in the bore. A fluid actuated positive displacement motor (mud motor) drives the valve member to vary the flow passage area. Expansion and retraction of the shock tool provides a percussive effect at the drill bit.
US Patent 6,053,261 to Walter describes a tool to provide a cyclical water hammer effect and water pulsating effect. A hollow housing defines a primary flow passage carrying a drilling fluid, and an elongated conduit with an upstream and a downstream end defining a main flow passage therethrough. The downstream end communicates with the primary flow passage and a by-pass flow passage extending lengthwise of the conduit from the upstream to the downstream ends. A nozzle located in the hollow housing adjacent to and spaced from the upstream end of the
second class of tools, known as shock tools, use a pressure pulse to deliver a force on the drill string to agitate or vibrate the drill string to overcome the friction between the drill string and the borehole in the lateral section of the drilled borehole. Some shock tools use a pressure pulse to act on a piston, creating a force proportional to the area of the piston multiplied by the amplitude of the pressure pulse. Shock tools may create a pulse in either direction, i.e., toward or away from the drill bit. Shock tools are advantageously positioned proximate the bent section of the borehole, where the drill string moves away from a generally vertical inclination to a more lateral inclination. In this position, the shock tool is used to vibrate the drill string, where the friction between the BHA and the borehole is the greatest. Another type of tool creates a hammer effect on the drill bit, with the pulses acting on an anvil in the direction of the drill bit. A few exemplary tools are summarized below.
US Patent 6,279,670 to Eddison et al., describes a downhole flow pulsing tool for use with a pressure responsive device as a shock tool which expands and retracts in response to the pressure pulses created by the tool. The tool includes a housing with a throughbore for drilling fluid and a valve in the bore with a valve member which is moveable to vary the area of a passage in the bore. A fluid actuated positive displacement motor (mud motor) drives the valve member to vary the flow passage area. Expansion and retraction of the shock tool provides a percussive effect at the drill bit.
US Patent 6,053,261 to Walter describes a tool to provide a cyclical water hammer effect and water pulsating effect. A hollow housing defines a primary flow passage carrying a drilling fluid, and an elongated conduit with an upstream and a downstream end defining a main flow passage therethrough. The downstream end communicates with the primary flow passage and a by-pass flow passage extending lengthwise of the conduit from the upstream to the downstream ends. A nozzle located in the hollow housing adjacent to and spaced from the upstream end of the
3 conduit discharges flow from the primary passage into the main flow passage.
The space between the nozzle and the upstream end provides communication between the main flow passage and the by-pass flow passage. An axially movable valve member is located in the downstream end of the conduit to co-operate with a valve seat downstream of the valve member to interrupt the flow through the conduit.
One or more passages downstream of the valve seat provide communications between the main flow passage and the by-pass passage in a region downstream of the valve seat. A spring urges the valve member toward an open position in the upstream direction. The valve member is adapted to close in response to flow along the valve member, thus interrupting the flow through the conduit and creating a water hammer pulse which travels upstream through the conduit and the nozzle and also through the space between the nozzle and the upstream end of the conduit. The pulse also travels downstream along the by-pass passage and through the further passages to the region downstream of the valve member, to momentarily equalize water hammer pressures on upstream and downstream sides of the valve member. The spring acts on the valve member under these equalized pressures such that flow in the conduit again commences and the valve member closes again. The above recited sequence of events is repeated to produce the cyclical water hammer and flow pulsating effect.
Unfortunately, the amplitude (or pressure) of the pressure pulses created by the MWD devices are typically too low to be useful in the water hammer and/or shock tools pulsing tools. Drilling operators are reluctant to increase the amplitude of the MWD pulse, since this can result in undue wear on the MWD and other downhole tools and/or interfere with the frequency or amplitude parameters of the MWD pulses that need to be read at the surface. US Patent 6,588,518 to Eddison indicates that the MWD pulse may be modified to above 500 psi, although there is no teaching provided for such modification. Furthermore, MWD devices are typically operated at pressures closer to 300 psi, or lower, not the greater than 500 psi pulse range suggested by Eddison.
The downhole mud motor, which is powered by the pressurized drilling mud
The space between the nozzle and the upstream end provides communication between the main flow passage and the by-pass flow passage. An axially movable valve member is located in the downstream end of the conduit to co-operate with a valve seat downstream of the valve member to interrupt the flow through the conduit.
One or more passages downstream of the valve seat provide communications between the main flow passage and the by-pass passage in a region downstream of the valve seat. A spring urges the valve member toward an open position in the upstream direction. The valve member is adapted to close in response to flow along the valve member, thus interrupting the flow through the conduit and creating a water hammer pulse which travels upstream through the conduit and the nozzle and also through the space between the nozzle and the upstream end of the conduit. The pulse also travels downstream along the by-pass passage and through the further passages to the region downstream of the valve member, to momentarily equalize water hammer pressures on upstream and downstream sides of the valve member. The spring acts on the valve member under these equalized pressures such that flow in the conduit again commences and the valve member closes again. The above recited sequence of events is repeated to produce the cyclical water hammer and flow pulsating effect.
Unfortunately, the amplitude (or pressure) of the pressure pulses created by the MWD devices are typically too low to be useful in the water hammer and/or shock tools pulsing tools. Drilling operators are reluctant to increase the amplitude of the MWD pulse, since this can result in undue wear on the MWD and other downhole tools and/or interfere with the frequency or amplitude parameters of the MWD pulses that need to be read at the surface. US Patent 6,588,518 to Eddison indicates that the MWD pulse may be modified to above 500 psi, although there is no teaching provided for such modification. Furthermore, MWD devices are typically operated at pressures closer to 300 psi, or lower, not the greater than 500 psi pulse range suggested by Eddison.
The downhole mud motor, which is powered by the pressurized drilling mud
4 injected into the drill string from the surface, is typically located downhole above the drill bit and rotates the bit to advance the borehole. The water hammer and pulsing shock tools create pressure pulses with one or more valves or flow throttling devices.
These tools are more effective when they generate a larger pressure pulse. The pressure pulses from downhole water hammer and/or pulsing shock tools are found to interfere with the frequency/amplitude parameters of the MWD device, making it more difficult for the drilling operator to analyse the MWD signals at the surface.
SUMMARY
Broadly stated, there is provided a method of drilling a borehole which includes:
a) generating pressure pulses in a drilling fluid in drill string;
b) allowing the pressure pulses to act on one or more axially aligned pistons in an amplification tool connected in the drill string to produce a force to drive a force responsive device in the drill string; and c) wherein each of the one or more pistons has a piston face, a first fluid chamber on one side of the piston face, and a second fluid chamber on the other side of the piston face, the first fluid chamber being in fluid communication with the drilling fluid and the second fluid chamber being in fluid communication with a pressurized fluid held at a set pressure within the amplification tool;
such that the pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with the force which is amplified by an amount proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons.
Also provided is an amplification tool adapted for mounting on a drill string containing a drilling fluid, the drill string having a drill bit, a pulse generating device adapted to create pressure pulses in the drilling fluid, and a force responsive device on the drill string adapted to impart a force on a portion of the drill string. The amplification tool includes a stationary, pressure-containing, tubular housing connected in the drill string and having a throughbore to permit passage of the
These tools are more effective when they generate a larger pressure pulse. The pressure pulses from downhole water hammer and/or pulsing shock tools are found to interfere with the frequency/amplitude parameters of the MWD device, making it more difficult for the drilling operator to analyse the MWD signals at the surface.
SUMMARY
Broadly stated, there is provided a method of drilling a borehole which includes:
a) generating pressure pulses in a drilling fluid in drill string;
b) allowing the pressure pulses to act on one or more axially aligned pistons in an amplification tool connected in the drill string to produce a force to drive a force responsive device in the drill string; and c) wherein each of the one or more pistons has a piston face, a first fluid chamber on one side of the piston face, and a second fluid chamber on the other side of the piston face, the first fluid chamber being in fluid communication with the drilling fluid and the second fluid chamber being in fluid communication with a pressurized fluid held at a set pressure within the amplification tool;
such that the pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with the force which is amplified by an amount proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons.
Also provided is an amplification tool adapted for mounting on a drill string containing a drilling fluid, the drill string having a drill bit, a pulse generating device adapted to create pressure pulses in the drilling fluid, and a force responsive device on the drill string adapted to impart a force on a portion of the drill string. The amplification tool includes a stationary, pressure-containing, tubular housing connected in the drill string and having a throughbore to permit passage of the
5 drilling fluid therethrough such that the pressure pulses from the pulse generating device may travel through the throughbore of the housing to the force responsive device. One or more axially aligned, tubular pistons are sealed for limited longitudinal movement within the housing. Each of the one or more pistons has a piston face, a piston throughbore co-extensive with the housing throughbore, a first fluid chamber on one side of the piston face and a second fluid chamber on the other side of the piston face. The first fluid chamber is adapted for fluid communication with the drilling fluid in the housing throughbore, and the second fluid chamber is adapted for fluid communication with a pressurized fluid held at a set pressure within the housing. Pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with an amplified force which is proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons, for delivery to the force responsive device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of one exemplary placement of the axially amplified pulsing tool (AAPT) in a drill string for directional drilling.
FIG. 2 is an enlarged view of portion A of FIG. 1, showing exemplary components at the drill bit end of the drill string.
FIG. 3 is an enlarged view of portion B of FIG. 1, showing one embodiment of the AAPT tool.
FIG. 4 is a cross sectional view of the AAPT tool along the longitudinal axis, showing a gas chamber component at the drill bit-facing end of the tool, a shock tool component at the surface-facing end of the tool, and an amplification portion of the tool between these ends. This placement of the AAPT tool on the drill string exemplifies one pulsing embodiment to reduce friction at the bent section of the drill string.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of one exemplary placement of the axially amplified pulsing tool (AAPT) in a drill string for directional drilling.
FIG. 2 is an enlarged view of portion A of FIG. 1, showing exemplary components at the drill bit end of the drill string.
FIG. 3 is an enlarged view of portion B of FIG. 1, showing one embodiment of the AAPT tool.
FIG. 4 is a cross sectional view of the AAPT tool along the longitudinal axis, showing a gas chamber component at the drill bit-facing end of the tool, a shock tool component at the surface-facing end of the tool, and an amplification portion of the tool between these ends. This placement of the AAPT tool on the drill string exemplifies one pulsing embodiment to reduce friction at the bent section of the drill string.
6 FIG. 5 is a sectional view along line A-A of FIG. 4 showing the spline mandrel details.
FIG. 6 is a perspective view of one of the pressure balanced sleeves for the pistons of FIG. 4.
FIG. 7 is the sectional view of the tool as shown in FIG. 4, but with shading to show the paths of the drilling mud, pressurized fluid and pressurized gas in the gas chamber and amplification portion of the tool. The path of the drilling mud is shown with dark grey shading in the housing throughbore bore and on one side of each piston. The path of the pressurized fluid is shown with broken lines extending from the gas chamber of the tool to the pressure balance sleeves and to the other side of each piston. The path of the pressurized gas is shown with light grey shading in the gas chamber. Oil in the shock tool component is shown in white (no shading).
DETAILED DESCRIPTION
Having reference to Figs. 1 - 7, one exemplary embodiment of an amplification tool is shown generally at 10. The tool 10 is shown and described herein in use with an integral shock tool component 12. A shock tool is but one example of a force responsive device which might be used with the amplification tool 10. However, it should be understood the amplification tool 10 may have other applications in a drill string, and need not include the shock tool component 12 as an integral component or at all.
In Figs. 1-3, the amplification tool 10 is shown to be positioned in the drill string 11 adjacent (i.e., proximate to) to the a bent section 11 b of the drill string, where the drill string deviates from a generally vertical orientation to a generally laterally inclined or horizontal orientation. The amplification tool 10 in this embodiment includes an integral shock tool component 12 as a force responsive device which can be used to deliver an amplified force to overcome frictional losses which are particularly high at the bent section llb of the drill string. The drill bit lla
FIG. 6 is a perspective view of one of the pressure balanced sleeves for the pistons of FIG. 4.
FIG. 7 is the sectional view of the tool as shown in FIG. 4, but with shading to show the paths of the drilling mud, pressurized fluid and pressurized gas in the gas chamber and amplification portion of the tool. The path of the drilling mud is shown with dark grey shading in the housing throughbore bore and on one side of each piston. The path of the pressurized fluid is shown with broken lines extending from the gas chamber of the tool to the pressure balance sleeves and to the other side of each piston. The path of the pressurized gas is shown with light grey shading in the gas chamber. Oil in the shock tool component is shown in white (no shading).
DETAILED DESCRIPTION
Having reference to Figs. 1 - 7, one exemplary embodiment of an amplification tool is shown generally at 10. The tool 10 is shown and described herein in use with an integral shock tool component 12. A shock tool is but one example of a force responsive device which might be used with the amplification tool 10. However, it should be understood the amplification tool 10 may have other applications in a drill string, and need not include the shock tool component 12 as an integral component or at all.
In Figs. 1-3, the amplification tool 10 is shown to be positioned in the drill string 11 adjacent (i.e., proximate to) to the a bent section 11 b of the drill string, where the drill string deviates from a generally vertical orientation to a generally laterally inclined or horizontal orientation. The amplification tool 10 in this embodiment includes an integral shock tool component 12 as a force responsive device which can be used to deliver an amplified force to overcome frictional losses which are particularly high at the bent section llb of the drill string. The drill bit lla
7 is located at the rock face end of the drill string 11. A downhole power section, typically a mud motor 11c, is located above the drill bit 11a. Drilling fluid, typically a drilling mud, in the drill string 11 rotates the mud motor 11c to rotate the drill bit lla below the mud motor 11c. The mud motor 11 c is connected through an adjustable bent housing lld and a bearing assembly lle to the drill bit 11a. Above the mud motor 11c is a rotor keeper sub/adapter 11f and a drill collar llg for housing the measurement-while-drilling (MWD) device 11h. In Figs. 1-3, the amplification tool 10 is shown to be located in the drill string 11 above the MWD device 11h and below the bent section llb of the drill string, separated by additional sections of the drill string 11.
Other placements and applications for the amplification tool 10 are possible, as will be evident to those skilled in the art. The tool may be integrated with, or used separately with, other downhole tools, for example other spring bias devices, shock tools, hammer devices, and water hammer devices. While the tool 10 is shown and described herein as being responsive to pressure pulses in the drilling fluid from an MWD device, it will be evident to those skilled in the art that other pulse generating devices, for example valves or throttling devices, might be used to generate pressure pulses in the drilling fluid.
Turning to Fig. 4, the amplification tool 10 is shown to include a pressure-containing housing 13 in several sections and a continuous internal throughbore 15, also in sections, for passage of the drilling fluid through the tool 10. Each of the sections of the housing 13 and the components forming the continuous throughbore 15 are sealed together, for example with 0-ring seals 38 at threaded or other connections, as is well known to those skilled in the art. A shock tool component 12 is shown at a mandrel end portion 10a of the tool 10 (which is surface-facing in Fig.
4). A pressure balance end portion 10b of the tool 10 is shown in Fig. 4 to be drill bit-facing. An amplification portion 10c is located between the end portions 10a and 10b. As noted above, this is only one exemplary application for the tool 10, and it will be evident that the tool 10 may be located differently, and may, for example, be flipped end for end, in other applications. The mandrel end portion 10a is shown to
Other placements and applications for the amplification tool 10 are possible, as will be evident to those skilled in the art. The tool may be integrated with, or used separately with, other downhole tools, for example other spring bias devices, shock tools, hammer devices, and water hammer devices. While the tool 10 is shown and described herein as being responsive to pressure pulses in the drilling fluid from an MWD device, it will be evident to those skilled in the art that other pulse generating devices, for example valves or throttling devices, might be used to generate pressure pulses in the drilling fluid.
Turning to Fig. 4, the amplification tool 10 is shown to include a pressure-containing housing 13 in several sections and a continuous internal throughbore 15, also in sections, for passage of the drilling fluid through the tool 10. Each of the sections of the housing 13 and the components forming the continuous throughbore 15 are sealed together, for example with 0-ring seals 38 at threaded or other connections, as is well known to those skilled in the art. A shock tool component 12 is shown at a mandrel end portion 10a of the tool 10 (which is surface-facing in Fig.
4). A pressure balance end portion 10b of the tool 10 is shown in Fig. 4 to be drill bit-facing. An amplification portion 10c is located between the end portions 10a and 10b. As noted above, this is only one exemplary application for the tool 10, and it will be evident that the tool 10 may be located differently, and may, for example, be flipped end for end, in other applications. The mandrel end portion 10a is shown to
8 include a box end component 10d, for threaded connection into the drill string, while the pressure balance end portion 10b is shown to include a pin end component 10e, for threaded connection into the drill string, as is conventional.
The shock tool component 12 includes components commonly included in a spring-biassed shock tool, in which springs are mounted between axially aligned telescoping parts (mandrel and spline) such that a force acting on a piston connected to the mandrel separates the telescoping parts to axially extend the telescoping parts and to impart axial movement in the drill string. As shown in the exemplary embodiment of Fig. 4, the shock tool component 12 is adapted to use a plurality of BelleviIleTM spring washers 14 to move a spring mandrel 16 within a spring housing 18 through a limited longitudinal distance "L", in response to pressure pulses moving in the drilling fluid in the internal throughbore 15 of the tool. The spring mandrel 16 is threaded at one end 16a to a spline mandrel 22. The spline mandrel 22 is housed within a mandrel housing 24 and a spline housing 26. The spline mandrel 22 is sealed within the housings 24, 26 for movement with the spring mandrel 16. A plurality of spline keys 28, as better shown in the cross sectional Fig.
5, prevent rotation of the spline mandrel 22 within the mandrel and spline housings 24, 26. The opposite end 16b of the spring mandrel 16 is threaded to a shock tool piston 32, held within a shock tool piston housing 34. Each of the spline mandrel, spring mandrel and shock tool piston 22, 16, 32 are threadedly connected together and are hollow to provide the continuous throughbore 15 for a continuous fluid passage for the drilling fluid pumped being from the surface. Each of the mandrel housing, spline housing, spring housing and shock tool piston housing 24, 26, 18, 34 are pressure-containing housings with seals (see piston seals 36, rod seals 37, 0-ring seals 38 and wiper seal 40) between the housings and the mandrels/shock piston. Guide or wear rings 42 may be included between the housings and the mandrels/shock pistons for smooth longitudinal movement of the mandrels 22, 16 and shock piston 32 within the housings 24, 26, 18, 34.
The shock tool annular spaces 43 between the mandrels/shock piston 22, 16, 32 and the housings 24, 26, 18, 34 are oil-filled through ports 44, and closed off with
The shock tool component 12 includes components commonly included in a spring-biassed shock tool, in which springs are mounted between axially aligned telescoping parts (mandrel and spline) such that a force acting on a piston connected to the mandrel separates the telescoping parts to axially extend the telescoping parts and to impart axial movement in the drill string. As shown in the exemplary embodiment of Fig. 4, the shock tool component 12 is adapted to use a plurality of BelleviIleTM spring washers 14 to move a spring mandrel 16 within a spring housing 18 through a limited longitudinal distance "L", in response to pressure pulses moving in the drilling fluid in the internal throughbore 15 of the tool. The spring mandrel 16 is threaded at one end 16a to a spline mandrel 22. The spline mandrel 22 is housed within a mandrel housing 24 and a spline housing 26. The spline mandrel 22 is sealed within the housings 24, 26 for movement with the spring mandrel 16. A plurality of spline keys 28, as better shown in the cross sectional Fig.
5, prevent rotation of the spline mandrel 22 within the mandrel and spline housings 24, 26. The opposite end 16b of the spring mandrel 16 is threaded to a shock tool piston 32, held within a shock tool piston housing 34. Each of the spline mandrel, spring mandrel and shock tool piston 22, 16, 32 are threadedly connected together and are hollow to provide the continuous throughbore 15 for a continuous fluid passage for the drilling fluid pumped being from the surface. Each of the mandrel housing, spline housing, spring housing and shock tool piston housing 24, 26, 18, 34 are pressure-containing housings with seals (see piston seals 36, rod seals 37, 0-ring seals 38 and wiper seal 40) between the housings and the mandrels/shock piston. Guide or wear rings 42 may be included between the housings and the mandrels/shock pistons for smooth longitudinal movement of the mandrels 22, 16 and shock piston 32 within the housings 24, 26, 18, 34.
The shock tool annular spaces 43 between the mandrels/shock piston 22, 16, 32 and the housings 24, 26, 18, 34 are oil-filled through ports 44, and closed off with
9 oribital oil plugs 45. The path of the oil-filled annular spaces 43, ports 44, and channels 44a communicating between the components of the shock tool 12 are best seen in Fig. 7, wherein the oil-filled annular spaces 43 are shown in white (no shading, marked 142). The spring washers 14 are spaced apart and held within the spring annulus 46 between the spring mandrel 16 and the spring housing 18 by a spring sleeve 48 at one end 50, a spacer 52 at the other end 54 and a guide washer 56 and guide ring 42 intermediate the ends 50, 54. The shock tool piston 32 includes a piston face 60. A shock tool piston chamber 62 is located on one side of the piston face 60 (downhole-facing in Fig. 4). The shock tool piston chamber 62 is in fluid communication with the drilling fluid through ports 64 opening into the throughbore 15 of the shock tool piston 32. In this manner, the shock tool piston 32 is able to transmit pressure pulses within the drilling fluid to the spring mandrel 16 and thus to the spline mandrel 22 for limited longitudinal axial movement (distance 12).
The longitudinal travel of the mandrels/spring piston "L" is set by the spacing of of shoulders S1, S2 formed in the inner wall of the spline housing 26, and shoulders S3, S4 formed in the spring sleeve 48. The shoulders S1, S2 determine the weight-on-bit (WOB) travel of the spline mandrel in the downhole direction of travel, while the shoulders S3, S4 determine the limited longitudinal movement of the amplification tool 10 in the opposite direction. This distance "L", for example 1.125 inches, is the amount of oscillating movement that the shock tool components can make as the mandrels/shock tool piston 22, 16, 32 expand and retract within the housings 24, 26, 18, 34 to impart an axially amplified force on the drill string 11. A
small preload on the spring washers 14 is typically set. This preload ensures the spring washers 14 are held tight in the spring housing 18, without rattling.
The amplification tool 10 is shown in Fig. 4 to include one or more, axially aligned and threadedly connected pistons. In Fig. 4, three pistons 66, 68, 70 are shown. In other embodiments, the tool may include at least one piston, for example two or more pistons, or for example from two to seven pistons. The number of pistons may be varied according to the application for the tool, and the desired amount of amplification for the particular application. Since each of the pistons may be generally similar (except for the outermost pistons and their connections to components located above and below), for ease of description, like parts of each piston are labelled with the same reference numerals in the Figures. The pistons 66, 68 and 70 are hollow to provide the continuous throughbore 15 for passage of the drilling fluid through the tool 10. The pistons 66, 68, 70 are generally tubular shaped with a sealing end 72, a mid-section 74 and a connecting end 76. For a first stage piston 66 and a second stage piston 68, the connecting ends 76 are threaded so that the pistons 66, 68 and 70 may be connected together for simultaneous longitudinal movement. For third stage (last stage) piston 70, the connected end 76 is not threaded, but is adapted for a sliding connection to components at the pressure balance end 10b of the tool 10, as more fully described below.
The pistons 66, 68, 70 are held within a piston housing section 78, with each piston housing section 78 being threaded together with each other, or with the components of the housing 13 located above or below, to form the pressure-containing housing 13 of the tool 10. The pistons 66, 68, 70 are each mounted for sealed movement within a pressure balance sleeve 80 for limited axial movement through the longitudinal distance "L". The pressure balance sleeve 80 is stationary and is sealed within the housing section 78 (stepped shoulders 81 in the inner bore of the housing section 78 hold the pressure balance sleeve in place). The pistons 66, 68, 70 include a piston face 82 (downhole-facing) at the sealing end 72 of the pistons. The piston face 82 is sealed within a pressure balance sleeve 80 such that a first fluid chamber 86 is formed on one side of the piston face 82 (i.e., the downhole- or drill bit-facing side of the piston face 82 in Fig. 4) and a second fluid chamber 88 is formed on the other side of the piston face 82 (i.e, the mandrel-or surface-facing side of the piston face 82 in Fig. 4). The various seals for the pistons 66, 68, 70, pressure balance sleeves 80 and housing sections 78 components are shown as 0-rings 38, piston seals 36, along with guide rings 42, although other known seals and/or guides may be used.
The threaded end 96 of the piston housing section 78 for the third (last stage) piston 70 is shown in Fig. 4 to be threaded to a pressure balance housing section 100 of the pressure-containing housing 13, and the connected end 76 of the third piston 70 allows for telescoping, sliding movement within a stationary hollow pressure balance tube 102 in a manner to provide the continuous throughbore 15 for passage of the drilling fluid through the tool 10. The pressure balance housing section 100 and pressure balance tube 102 are part of a gas chamber component 104 provided at the pressure balance end 10b of the tool 10. The gas chamber component 104 has the function of providing a pressurized fluid supply within the tool 10, separate from the drilling fluid. The pressurized fluid is generally a non-compressible fluid such as oil, which may thus be held at a set pressure within the housing 13 and thus within the tool 10. The gas chamber component 104 is more fully described hereinbelow.
The first fluid chamber 86 for each piston face 82 communicates through drilling fluid ports 105 formed in the wall of the mid-section 74 of the pistons 66, 68, 70 through to the continuous throughbore 15 such that the first fluid chamber 86 is in fluid communication with the drilling fluid. The second fluid chamber 88 on the other side of the each piston face 82 is in fluid communication with the pressurized fluid held at a set pressure set by the gas in the gas chamber component 104. The set pressure may be set at the surface by the drilling operator, before the tool
The longitudinal travel of the mandrels/spring piston "L" is set by the spacing of of shoulders S1, S2 formed in the inner wall of the spline housing 26, and shoulders S3, S4 formed in the spring sleeve 48. The shoulders S1, S2 determine the weight-on-bit (WOB) travel of the spline mandrel in the downhole direction of travel, while the shoulders S3, S4 determine the limited longitudinal movement of the amplification tool 10 in the opposite direction. This distance "L", for example 1.125 inches, is the amount of oscillating movement that the shock tool components can make as the mandrels/shock tool piston 22, 16, 32 expand and retract within the housings 24, 26, 18, 34 to impart an axially amplified force on the drill string 11. A
small preload on the spring washers 14 is typically set. This preload ensures the spring washers 14 are held tight in the spring housing 18, without rattling.
The amplification tool 10 is shown in Fig. 4 to include one or more, axially aligned and threadedly connected pistons. In Fig. 4, three pistons 66, 68, 70 are shown. In other embodiments, the tool may include at least one piston, for example two or more pistons, or for example from two to seven pistons. The number of pistons may be varied according to the application for the tool, and the desired amount of amplification for the particular application. Since each of the pistons may be generally similar (except for the outermost pistons and their connections to components located above and below), for ease of description, like parts of each piston are labelled with the same reference numerals in the Figures. The pistons 66, 68 and 70 are hollow to provide the continuous throughbore 15 for passage of the drilling fluid through the tool 10. The pistons 66, 68, 70 are generally tubular shaped with a sealing end 72, a mid-section 74 and a connecting end 76. For a first stage piston 66 and a second stage piston 68, the connecting ends 76 are threaded so that the pistons 66, 68 and 70 may be connected together for simultaneous longitudinal movement. For third stage (last stage) piston 70, the connected end 76 is not threaded, but is adapted for a sliding connection to components at the pressure balance end 10b of the tool 10, as more fully described below.
The pistons 66, 68, 70 are held within a piston housing section 78, with each piston housing section 78 being threaded together with each other, or with the components of the housing 13 located above or below, to form the pressure-containing housing 13 of the tool 10. The pistons 66, 68, 70 are each mounted for sealed movement within a pressure balance sleeve 80 for limited axial movement through the longitudinal distance "L". The pressure balance sleeve 80 is stationary and is sealed within the housing section 78 (stepped shoulders 81 in the inner bore of the housing section 78 hold the pressure balance sleeve in place). The pistons 66, 68, 70 include a piston face 82 (downhole-facing) at the sealing end 72 of the pistons. The piston face 82 is sealed within a pressure balance sleeve 80 such that a first fluid chamber 86 is formed on one side of the piston face 82 (i.e., the downhole- or drill bit-facing side of the piston face 82 in Fig. 4) and a second fluid chamber 88 is formed on the other side of the piston face 82 (i.e, the mandrel-or surface-facing side of the piston face 82 in Fig. 4). The various seals for the pistons 66, 68, 70, pressure balance sleeves 80 and housing sections 78 components are shown as 0-rings 38, piston seals 36, along with guide rings 42, although other known seals and/or guides may be used.
The threaded end 96 of the piston housing section 78 for the third (last stage) piston 70 is shown in Fig. 4 to be threaded to a pressure balance housing section 100 of the pressure-containing housing 13, and the connected end 76 of the third piston 70 allows for telescoping, sliding movement within a stationary hollow pressure balance tube 102 in a manner to provide the continuous throughbore 15 for passage of the drilling fluid through the tool 10. The pressure balance housing section 100 and pressure balance tube 102 are part of a gas chamber component 104 provided at the pressure balance end 10b of the tool 10. The gas chamber component 104 has the function of providing a pressurized fluid supply within the tool 10, separate from the drilling fluid. The pressurized fluid is generally a non-compressible fluid such as oil, which may thus be held at a set pressure within the housing 13 and thus within the tool 10. The gas chamber component 104 is more fully described hereinbelow.
The first fluid chamber 86 for each piston face 82 communicates through drilling fluid ports 105 formed in the wall of the mid-section 74 of the pistons 66, 68, 70 through to the continuous throughbore 15 such that the first fluid chamber 86 is in fluid communication with the drilling fluid. The second fluid chamber 88 on the other side of the each piston face 82 is in fluid communication with the pressurized fluid held at a set pressure set by the gas in the gas chamber component 104. The set pressure may be set at the surface by the drilling operator, before the tool
10 is run in the drill string 11, to approximate a downhole pressure of the drilling fluid at an expected downhole location of the amplification tool 10, for example at the location as shown in Fig. 1. This set pressure is generally the pressure within the piston housing sections 78, and thus within the tool 10. As shown in Figs. 4 and 6, the pressure balance sleeves 80 include circumferentially spaced pressure balance ports 106 and pressure balance channels 108 which allow the pressurized fluid from the gas chamber component 104 to travel through circumferentially spaced piston housing conduits 109 formed in the wall of each piston housing section 78 to the annular space 79 between the pressure balance sleeve 80 and the piston housing section 78 and to fill the second fluid chamber 88 on the other side of each piston face 82. In this way, the pressures on either side of the piston face 82 can be generally balanced in a manner to allow the pistons 66, 68, 70 to amplify pressure pulses in the drilling fluid, for example from the MWD device, and thus create an amplified force for the force responsive device (such as the shock tool component 12). It should be understood that, the term "generally balanced", as used herein and in the claims to refer to the pressures on either side of the piston face 82, does not imply equal. Rather, a pressure difference across the piston faces will still allow the tool to work to generate an amplified force. For example, a pressure imbalance of about 500 psi may still generate an amplified force, depending on the size of the initial pressure pulse and the number of pistons. Thus, the term "generally balanced" refers to a set pressure in the pressurized fluid which will approximate the downhole pressure of the drilling fluid at the tool location, but includes a pressure balance range sufficient to still generate an amplified force for the pressure pulse being received by the tool 10 with the number of pistons in the tool.
It will be understood that the porting, channels and conduits as described above for the shock tool component 12 and for the amplification portion 10c of the tool 10, are provided and sized to reduce any dampening effect of fluid travel within the tool 10.
The piston face 82 of each piston 66, 68, 70 is shown in Fig. 4 to be stepped such that the surface areas of piston face portion 82a and 82b (shown in Fig.
4 for piston 66) are combined to form the total surface area of the piston face 82 that is acted on by the drilling fluid, and thus the pressure pulses in the drilling fluid.
The gas chamber component 104 of the tool 10 includes a pressure balance housing 100 threaded at one end 110 to the housing section 78 of the third (last stage) piston 70 and threaded at the other end 112 to a charge sub 114. The housing 100 and charge sub 114 form sections of the pressure-containing housing 13 of the tool 10. The hollow pressure balance tube 102 extends through, and seals on, the pressure balance housing 100. The charge sub 114 is formed with a central bore 116 which communicates with the pressure balance tube 102, such that the pressure balance tube 102 and the central bore 116 form the continuous throughbore 15 for passage of the drilling fluid through the tool 10. A
pressure balanced annular piston 118 is sealed with piston seals 120 and guide rings 42 in the annulus 124 formed between the pressure balance housing 100 and the pressure balance tube 102. The pressurized fluid, such as pressurized oil, is filled on the side of the piston 118 facing the pistons 66, 68, 70 and a pressurized gas such as nitrogen is filled on the side of the piston 118 facing the charge sub 114. 0-ring seals 38 are included between the housing section 78 for the third piston 70 and the pressure balance housing 100 and the pressure balance tube 102, as well as between the pressure balance housing 100 and the charge sub 114 and between the pressure balance tube 102 and the charge sub 114.
To set the pressure within the gas chamber tool, a charging conduit 128 is formed in the outer wall of the charge sub 114, to communicate through a high pressure check valve 130 to the annulus 124 on the side of the piston 118 facing the charge sub 114. The conduit 128 is sealed with an orbital plug 132. The pressurized fluid, such as oil, is filled through level plug 134 on the piston-facing side of the annular piston 118, to provide pressurized fluid in the pressurized fluid path through to orbital plug 135. In the initial set-up, the pressure balance piston 118 is moved longitudinally within the annulus 124 to set the volume of the pressurized fluid needed to fill the path of the pressurized fluid through to the second fluid chamber for each piston 66, 68, 70. This volume will vary with the number of pistons 66, 68, 70.
In Fig. 7, only the paths of the fluids/gases are marked. The path of the drilling fluid is marked 136. The path of the pressurized fluid such as oil is marked 138. The path of the pressurized gas is marked 140. The separate path of the oil in the shock tool 12 is marked 142 (no shading).
Other Exemplary Embodiments/Applications As set out above, while the amplification tool 10 and method of drilling have been described herein with an integral shock tool component 12 as a force responsive device, and adapted to allow pressure pulses from an MWD device to act on the piston faces 82 of pistons 66, 68, 70, the tool 10 is not limited to applications with shock tools, or to using MWD pulses.
In other embodiments, the method and/or amplification tool 10 may be modified to be used with other drilling tools, for example to provide an amplified force to drive a hammer or water hammer at the drill bit. In such applications, the tool 10 may be reversed in the direction of the piston movement to apply force toward the drill bit. The tool 10 may be located proximate the drill bit in such applications.
In other embodiments, the method and/or tool 10 might be modified such that the shock tool component or a spring bias device is provided separately from the tool to provide an amplified force in either direction in a drill string, for example to reduce frictional losses in the drill string.
In other embodiments, the method and/or tool 10 might be modified to include a spring instead of a gas chamber to provide the set pressure on the pressurized fluid.
In other embodiments, the method and/or tool 10 might be modified to use more than one amplification tool 10 in the drill string.
In still other embodiments, the method and/or tool 10 might include the components of the pressure balance end portion 10b and the amplification portion 10c, for producing an amplified force to a simple spring device in the drill string for producing amplified pressure pulses in the drilling fluid. When coupled with an MWD device, this embodiment of the tool 10 can produce an amplified MWD
pressure pulse in the drilling fluid for detection at the surface. It will be appreciated that a major advantage of the amplification tool 10 is that the amplified pressure pulse derived from the MWD pulse is generally of the same frequency as the MWD
pulse, so does not interfere with analysing the MWD pulse at the surface.
Example It will now be apparent that the amplification tool 10 as described above (AAPT tool) does not work using the annulus pressure from the borehole (external the drill string). A simple, non-limiting comparative example is provided to highlight the problem with using the annulus pressure and an internal tool pressure to create a pressure differential across piston faces, such as is shown in the prior art devices of US Patent 8,322,463 to Walter.
US Patent 8,322,463 - Prior Art Patent In Walter's tool, one side of the pistons feels the internal bore pressure of the drilling mud (for example, 2000 psi) and the other side of the pistons feels the annulus borehole pressure external of the drill string, which is much lower than the pressure of the drilling mud (for example 1000 psi). Assuming a pulse pressure of 300 psi is applied to a piston with a piston face area of 5.6in2, in one stage of the tool (i.e., one piston) the output force is (2000-1000)x5.6in2 = 5,600 lbs (push force).
When the tool feels a pulse of 300 psi the output force is (2300-1000)x5.6in2=
7,280 lbs (push force). While there is no teaching in the patent, it is evident to the inventor of this application that, without a preload on the spring, some of the available travel in the shock tool will be used up or sacrificed in the initial push force.
Thus, for the purposes of this comparative example calculation, the springs are assumed to be preloaded, for example by 5,600 lbs to isolate the pulse force and maintain full theoretical range of travel for the tool. With this preload, the tool generates 7,280-5,600 = 1,680 lbs force output. Now, if a second piston is added to get more force, with 2 stages the output force is double, for example 11,200 and 14,560 lbs push force. In that case, the springs would require an initial set preload of
It will be understood that the porting, channels and conduits as described above for the shock tool component 12 and for the amplification portion 10c of the tool 10, are provided and sized to reduce any dampening effect of fluid travel within the tool 10.
The piston face 82 of each piston 66, 68, 70 is shown in Fig. 4 to be stepped such that the surface areas of piston face portion 82a and 82b (shown in Fig.
4 for piston 66) are combined to form the total surface area of the piston face 82 that is acted on by the drilling fluid, and thus the pressure pulses in the drilling fluid.
The gas chamber component 104 of the tool 10 includes a pressure balance housing 100 threaded at one end 110 to the housing section 78 of the third (last stage) piston 70 and threaded at the other end 112 to a charge sub 114. The housing 100 and charge sub 114 form sections of the pressure-containing housing 13 of the tool 10. The hollow pressure balance tube 102 extends through, and seals on, the pressure balance housing 100. The charge sub 114 is formed with a central bore 116 which communicates with the pressure balance tube 102, such that the pressure balance tube 102 and the central bore 116 form the continuous throughbore 15 for passage of the drilling fluid through the tool 10. A
pressure balanced annular piston 118 is sealed with piston seals 120 and guide rings 42 in the annulus 124 formed between the pressure balance housing 100 and the pressure balance tube 102. The pressurized fluid, such as pressurized oil, is filled on the side of the piston 118 facing the pistons 66, 68, 70 and a pressurized gas such as nitrogen is filled on the side of the piston 118 facing the charge sub 114. 0-ring seals 38 are included between the housing section 78 for the third piston 70 and the pressure balance housing 100 and the pressure balance tube 102, as well as between the pressure balance housing 100 and the charge sub 114 and between the pressure balance tube 102 and the charge sub 114.
To set the pressure within the gas chamber tool, a charging conduit 128 is formed in the outer wall of the charge sub 114, to communicate through a high pressure check valve 130 to the annulus 124 on the side of the piston 118 facing the charge sub 114. The conduit 128 is sealed with an orbital plug 132. The pressurized fluid, such as oil, is filled through level plug 134 on the piston-facing side of the annular piston 118, to provide pressurized fluid in the pressurized fluid path through to orbital plug 135. In the initial set-up, the pressure balance piston 118 is moved longitudinally within the annulus 124 to set the volume of the pressurized fluid needed to fill the path of the pressurized fluid through to the second fluid chamber for each piston 66, 68, 70. This volume will vary with the number of pistons 66, 68, 70.
In Fig. 7, only the paths of the fluids/gases are marked. The path of the drilling fluid is marked 136. The path of the pressurized fluid such as oil is marked 138. The path of the pressurized gas is marked 140. The separate path of the oil in the shock tool 12 is marked 142 (no shading).
Other Exemplary Embodiments/Applications As set out above, while the amplification tool 10 and method of drilling have been described herein with an integral shock tool component 12 as a force responsive device, and adapted to allow pressure pulses from an MWD device to act on the piston faces 82 of pistons 66, 68, 70, the tool 10 is not limited to applications with shock tools, or to using MWD pulses.
In other embodiments, the method and/or amplification tool 10 may be modified to be used with other drilling tools, for example to provide an amplified force to drive a hammer or water hammer at the drill bit. In such applications, the tool 10 may be reversed in the direction of the piston movement to apply force toward the drill bit. The tool 10 may be located proximate the drill bit in such applications.
In other embodiments, the method and/or tool 10 might be modified such that the shock tool component or a spring bias device is provided separately from the tool to provide an amplified force in either direction in a drill string, for example to reduce frictional losses in the drill string.
In other embodiments, the method and/or tool 10 might be modified to include a spring instead of a gas chamber to provide the set pressure on the pressurized fluid.
In other embodiments, the method and/or tool 10 might be modified to use more than one amplification tool 10 in the drill string.
In still other embodiments, the method and/or tool 10 might include the components of the pressure balance end portion 10b and the amplification portion 10c, for producing an amplified force to a simple spring device in the drill string for producing amplified pressure pulses in the drilling fluid. When coupled with an MWD device, this embodiment of the tool 10 can produce an amplified MWD
pressure pulse in the drilling fluid for detection at the surface. It will be appreciated that a major advantage of the amplification tool 10 is that the amplified pressure pulse derived from the MWD pulse is generally of the same frequency as the MWD
pulse, so does not interfere with analysing the MWD pulse at the surface.
Example It will now be apparent that the amplification tool 10 as described above (AAPT tool) does not work using the annulus pressure from the borehole (external the drill string). A simple, non-limiting comparative example is provided to highlight the problem with using the annulus pressure and an internal tool pressure to create a pressure differential across piston faces, such as is shown in the prior art devices of US Patent 8,322,463 to Walter.
US Patent 8,322,463 - Prior Art Patent In Walter's tool, one side of the pistons feels the internal bore pressure of the drilling mud (for example, 2000 psi) and the other side of the pistons feels the annulus borehole pressure external of the drill string, which is much lower than the pressure of the drilling mud (for example 1000 psi). Assuming a pulse pressure of 300 psi is applied to a piston with a piston face area of 5.6in2, in one stage of the tool (i.e., one piston) the output force is (2000-1000)x5.6in2 = 5,600 lbs (push force).
When the tool feels a pulse of 300 psi the output force is (2300-1000)x5.6in2=
7,280 lbs (push force). While there is no teaching in the patent, it is evident to the inventor of this application that, without a preload on the spring, some of the available travel in the shock tool will be used up or sacrificed in the initial push force.
Thus, for the purposes of this comparative example calculation, the springs are assumed to be preloaded, for example by 5,600 lbs to isolate the pulse force and maintain full theoretical range of travel for the tool. With this preload, the tool generates 7,280-5,600 = 1,680 lbs force output. Now, if a second piston is added to get more force, with 2 stages the output force is double, for example 11,200 and 14,560 lbs push force. In that case, the springs would require an initial set preload of
11,200 lbs. The tool now generates 14,560-11,200 = 3,360 lbs force. With such a high preload on the springs, this 3,360 lbs push translates into a very small movement, less than about 1/8". With three stages of a third piston, the preload on the springs is so high that the pulse force is not strong enough to move the springs, and the tool is not moving. Instead, the tool is dead in the borehole. This scenario becomes worse as the spread increases between the internal tool and annulus pressures, which is likely to be the case.
ii) AAPT Tool Example In contrast, the AAPT tool works using a charged gas pressure chamber at a set pressure within the tool. One side of the piston feels the internal bore pressure of the drilling fluid (say 2000 psi) and the other side of the piston feels the set charge pressure, which is pre-set to approximate the downhole pressure of the drilling fluid at a downhole location of the AAPT tool, for example an estimated internal bore pressure might be 2000 psi. In one stage of the AAPT tool (one piston, with a piston surface area of 5.6in2) the output force is (2000-2000)x5.6in2= 0 lbs (at rest, without the pressure pulse). However, when the tool feels a pulse of about 300 psi, for example from the MWD device, the output force is (2300-2000)x5.6in2= 1,680 lbs.
The spring in the AAPT tool may be preloaded a little, as described above, to hold the spring washers tightly in the housing to avoid rattling. However, unlike the situation in the above-noted Walter tool, because the piston(s) of the AAPT
tool are generally balanced with the pressurized fluid opposing the internal pressure of the drilling fluid, the springs of the AAPT tool do not need to be preloaded to offset a large pressure imbalance across the pistons. The AAPT tool generates 1,680 lbs force minus the small spring preload. Adding subsequent stages (pistons) multiplies the pulse by the number of additional pistons, since the internal bore pressure is balanced on either side of the pistons. Thus, adding a second piston (two stages), produces a force of 3,360 lbs, and a third piston (three stages) produces a force of 5,040 lbs. Setting the charge pressure for the pressurized fluid to approximate the actual bore pressure where the tool is located downhole provides the strongest output force. The output force diminishes as the span increases between the set charge pressure and bore pressure. The AAPT tool is charged at the surface by the drilling operator, prior to use, with the predicted downhole pressure. The internal bore pressure during testing at the surface is substantially less than what the internal bore pressure is when the AAPT tool is downhole.
As used herein and in the claims, the word "comprising" is used in its non-limiting sense to mean that items following the word in the sentence are included and that items not specifically mentioned are not excluded. The use of the indefinite article "a" in the claims before an element means that one of the elements is specified, but does not specifically exclude others of the elements being present, unless the context clearly requires that there be one and only one of the elements.
All references mentioned in this specification are indicative of the level of skill in the art of this invention. All references are herein incorporated by reference in their entirety to the same extent as if each reference was specifically and individually indicated to be incorporated by reference. However, if any inconsistency arises between a cited reference and the present disclosure, the present disclosure takes precedence. Some references provided herein are incorporated by reference herein to provide details concerning the state of the art prior to the filing of this application, other references may be cited to provide additional or alternative device elements, additional or alternative materials, additional or alternative methods of analysis or application of the invention.
The terms and expressions used are, unless otherwise defined herein, used as terms of description and not limitation. There is no intention, in using such terms and expressions, of excluding equivalents of the features illustrated and described, it being recognized that the scope of the invention is defined and limited only by the claims which follow. Although the description herein contains many specifics, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the embodiments of the invention.
One of ordinary skill in the art will appreciate that elements and materials other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such elements and materials are intended to be included in this invention. The invention illustratively described herein suitably may be practised in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein.
ii) AAPT Tool Example In contrast, the AAPT tool works using a charged gas pressure chamber at a set pressure within the tool. One side of the piston feels the internal bore pressure of the drilling fluid (say 2000 psi) and the other side of the piston feels the set charge pressure, which is pre-set to approximate the downhole pressure of the drilling fluid at a downhole location of the AAPT tool, for example an estimated internal bore pressure might be 2000 psi. In one stage of the AAPT tool (one piston, with a piston surface area of 5.6in2) the output force is (2000-2000)x5.6in2= 0 lbs (at rest, without the pressure pulse). However, when the tool feels a pulse of about 300 psi, for example from the MWD device, the output force is (2300-2000)x5.6in2= 1,680 lbs.
The spring in the AAPT tool may be preloaded a little, as described above, to hold the spring washers tightly in the housing to avoid rattling. However, unlike the situation in the above-noted Walter tool, because the piston(s) of the AAPT
tool are generally balanced with the pressurized fluid opposing the internal pressure of the drilling fluid, the springs of the AAPT tool do not need to be preloaded to offset a large pressure imbalance across the pistons. The AAPT tool generates 1,680 lbs force minus the small spring preload. Adding subsequent stages (pistons) multiplies the pulse by the number of additional pistons, since the internal bore pressure is balanced on either side of the pistons. Thus, adding a second piston (two stages), produces a force of 3,360 lbs, and a third piston (three stages) produces a force of 5,040 lbs. Setting the charge pressure for the pressurized fluid to approximate the actual bore pressure where the tool is located downhole provides the strongest output force. The output force diminishes as the span increases between the set charge pressure and bore pressure. The AAPT tool is charged at the surface by the drilling operator, prior to use, with the predicted downhole pressure. The internal bore pressure during testing at the surface is substantially less than what the internal bore pressure is when the AAPT tool is downhole.
As used herein and in the claims, the word "comprising" is used in its non-limiting sense to mean that items following the word in the sentence are included and that items not specifically mentioned are not excluded. The use of the indefinite article "a" in the claims before an element means that one of the elements is specified, but does not specifically exclude others of the elements being present, unless the context clearly requires that there be one and only one of the elements.
All references mentioned in this specification are indicative of the level of skill in the art of this invention. All references are herein incorporated by reference in their entirety to the same extent as if each reference was specifically and individually indicated to be incorporated by reference. However, if any inconsistency arises between a cited reference and the present disclosure, the present disclosure takes precedence. Some references provided herein are incorporated by reference herein to provide details concerning the state of the art prior to the filing of this application, other references may be cited to provide additional or alternative device elements, additional or alternative materials, additional or alternative methods of analysis or application of the invention.
The terms and expressions used are, unless otherwise defined herein, used as terms of description and not limitation. There is no intention, in using such terms and expressions, of excluding equivalents of the features illustrated and described, it being recognized that the scope of the invention is defined and limited only by the claims which follow. Although the description herein contains many specifics, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the embodiments of the invention.
One of ordinary skill in the art will appreciate that elements and materials other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such elements and materials are intended to be included in this invention. The invention illustratively described herein suitably may be practised in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein.
Claims (25)
1. A method of drilling a borehole, comprising:
generating pressure pulses in a drilling fluid in drill string;
allowing the pressure pulses to act on one or more axially aligned pistons in an amplification tool connected in the drill string to produce a force to drive a force responsive device in the drill string; and wherein each of the one or more pistons has a piston face, a first fluid chamber on one side of the piston face, and a second fluid chamber on the other side of the piston face, the first fluid chamber being in fluid communication with the drilling fluid and the second fluid chamber being in fluid communication with a pressurized fluid held at a set pressure within the amplification tool;
such that the pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with the force which is amplified by an amount proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons.
generating pressure pulses in a drilling fluid in drill string;
allowing the pressure pulses to act on one or more axially aligned pistons in an amplification tool connected in the drill string to produce a force to drive a force responsive device in the drill string; and wherein each of the one or more pistons has a piston face, a first fluid chamber on one side of the piston face, and a second fluid chamber on the other side of the piston face, the first fluid chamber being in fluid communication with the drilling fluid and the second fluid chamber being in fluid communication with a pressurized fluid held at a set pressure within the amplification tool;
such that the pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with the force which is amplified by an amount proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons.
2. The method of claim 1, wherein the set pressure of the pressurized fluid is set to approximate a downhole pressure of the drilling fluid at a downhole location of the amplification tool.
3. The method of claim 2, wherein the set pressure of the pressurized fluid is set by a supply of pressurized gas in a gas chamber within the amplification tool.
4. The method of claim 3, wherein the amplification tool includes two or more pistons.
5. The method of claim 4, wherein the pressurized fluid is oil.
6. The method of claim 5, wherein the force responsive device is a spring bias device.
7. The method of claim 6, wherein the pressure pulses are generated by a measurement-while-drilling (MWD) device and the amplified force acting on the spring bias device produces an amplified MWD pressure pulse in the drilling mud.
8. The method of claim 5, wherein the force responsive device includes axially aligned telescoping parts with one or more springs mounted between the telescoping parts, and wherein the amplified force separates the telescoping parts to cause axial movement in the drill string.
9. The method of claim 8, wherein the axial movement in the drill string is to reduce friction between the drill string and the borehole in a laterally inclined or horizontal section of the borehole.
10. The method of claim 9, wherein the pressure pulses are generated by a measurement-while-drilling device.
11. The method of claim 10, wherein the force responsive device is integral with the amplification tool.
12. The method of claim 11, wherein the amplification tool includes 2-7 pistons.
13. An amplification tool adapted for mounting on a drill string containing a drilling fluid, the drill string having a drill bit, a pulse generating device adapted to create pressure pulses in the drilling fluid, and a force responsive device on the drill string adapted to impart a force on a portion of the drill string, the amplification tool comprising:
a stationary, pressure-containing, tubular housing connected in the drill string and having a throughbore to permit passage of the drilling fluid therethrough such that the pressure pulses from the pulse generating device may travel through the throughbore of the housing to the force responsive device; and one or more axially aligned, tubular pistons sealed for limited longitudinal movement within the housing, each of the one or more pistons having a piston face, a piston throughbore co-extensive with the housing throughbore, a first fluid chamber on one side of the piston face and a second fluid chamber on the other side of the piston face, the first fluid chamber being adapted for fluid communication with the drilling fluid in the housing throughbore, and the second fluid chamber being adapted for fluid communication with a pressurized fluid held at a set pressure within the housing;
such that the pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with an amplified force which is proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons, for delivery to the force responsive device.
a stationary, pressure-containing, tubular housing connected in the drill string and having a throughbore to permit passage of the drilling fluid therethrough such that the pressure pulses from the pulse generating device may travel through the throughbore of the housing to the force responsive device; and one or more axially aligned, tubular pistons sealed for limited longitudinal movement within the housing, each of the one or more pistons having a piston face, a piston throughbore co-extensive with the housing throughbore, a first fluid chamber on one side of the piston face and a second fluid chamber on the other side of the piston face, the first fluid chamber being adapted for fluid communication with the drilling fluid in the housing throughbore, and the second fluid chamber being adapted for fluid communication with a pressurized fluid held at a set pressure within the housing;
such that the pressure pulses acting in the drilling fluid in the first fluid chamber of the one or more pistons moves the one or more pistons with an amplified force which is proportional to the surface area of the piston faces and a multiple of the number of the one or more pistons, for delivery to the force responsive device.
14. The amplification tool of claim 13, wherein the housing includes a sealed gas chamber at a first end portion of the housing, the gas chamber being adapted to hold a pressurized gas for applying the set pressure on the pressurized fluid.
15. The amplification tool of claim 14, wherein the gas chamber is adapted to set the set pressure of the pressurized fluid to approximate a downhole pressure of the drilling fluid at a downhole location of the amplification tool.
16. The amplification tool of claim 15, wherein:
the piston face of each of the one or more pistons is sealed within a stationary, concentric, tubular pressure balance sleeve which is sealed in the housing and which forms the first fluid chamber and the second fluid chamber on opposite sides of the piston face;
each of the pressure balance sleeves is formed with one or more sleeve ports to provide fluid communication to the second fluid chamber for the pressurized fluid;
and each of the one or more pistons is formed with one or more piston ports in the piston throughbore to provide fluid communication to the first fluid chamber for the drilling mud.
the piston face of each of the one or more pistons is sealed within a stationary, concentric, tubular pressure balance sleeve which is sealed in the housing and which forms the first fluid chamber and the second fluid chamber on opposite sides of the piston face;
each of the pressure balance sleeves is formed with one or more sleeve ports to provide fluid communication to the second fluid chamber for the pressurized fluid;
and each of the one or more pistons is formed with one or more piston ports in the piston throughbore to provide fluid communication to the first fluid chamber for the drilling mud.
17. The amplification tool of claim 16, wherein the one or more pistons is two or more pistons.
18. The amplification tool of claim 17, wherein the gas chamber includes a tubular pressure balance tube adapted for connecting with one of the two or more pistons so as to be co-extensive with the piston throughbore of the connected piston in a manner that allows the connected piston to slide within the pressure balance tube during piston movement.
19. The amplification tool of claim 18, wherein the gas chamber includes an annular piston sealed in an annulus formed between the housing and the pressure balance tube, such that the pressurized fluid may be held in the annulus on a piston-facing side of the annular piston and the pressurized gas may be held in the annulus on the other side of the annular piston.
20. The amplification tool of claim 18, wherein the housing includes a side wall formed with one or more circumferentially spaced conduits to provide fluid communication of the pressurized fluid through to an annular space formed between the housing and each of the pressure balance sleeves.
21. The amplification tool of claim 20, wherein each of the pressure balance tubes has an outer wall formed with one or more longitudinal channels to provide fluid communication of the pressurized fluid in the annular space through to the one or more sleeve ports.
22. The amplification tool of claim 21, wherein the housing is closed at the first end portion with a charge sub and wherein the charge sub includes a valved charge conduit through to the annulus for charging the gas chamber with the pressurized gas.
23. The amplification tool of claim 22, wherein the housing includes a second end portion which includes a spring bias device.
24. The amplification tool of claim 22, wherein the housing includes a second end portion which includes the force responsive device, the force responsive device comprising axially aligned telescoping parts and one or more springs mounted between the telescoping parts, and wherein one of the telescoping parts is connected to one of the two or more pistons such that the amplified force from the two or more pistons separates the telescoping parts to impart the force to the portion of the drill string.
25. The amplification tool of claim 24, wherein the number of the two or more pistons is 2-7.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201361914771P | 2013-12-11 | 2013-12-11 | |
| US61/914,771 | 2013-12-11 |
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| Publication Number | Publication Date |
|---|---|
| CA2874639A1 true CA2874639A1 (en) | 2015-06-11 |
| CA2874639C CA2874639C (en) | 2022-05-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2874639A Active CA2874639C (en) | 2013-12-11 | 2014-12-11 | Axially amplified pulsing tool |
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| Country | Link |
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| CA (1) | CA2874639C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018119007A1 (en) * | 2016-12-20 | 2018-06-28 | National Oilwell Varco, L.P. | Drilling oscillation systems and optimized shock tools for same |
| CN110374509A (en) * | 2019-08-26 | 2019-10-25 | 山东陆海石油技术股份有限公司 | The double pressure chamber helicoid hydraulic motors of drag reduction jar |
| CN114278245A (en) * | 2021-07-20 | 2022-04-05 | 中石化石油工程技术服务有限公司 | Hydraulic oscillator |
-
2014
- 2014-12-11 CA CA2874639A patent/CA2874639C/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018119007A1 (en) * | 2016-12-20 | 2018-06-28 | National Oilwell Varco, L.P. | Drilling oscillation systems and optimized shock tools for same |
| US10718168B2 (en) | 2016-12-20 | 2020-07-21 | National Oilwell Varco, L.P. | Drilling oscillation systems and optimized shock tools for same |
| CN110374509A (en) * | 2019-08-26 | 2019-10-25 | 山东陆海石油技术股份有限公司 | The double pressure chamber helicoid hydraulic motors of drag reduction jar |
| CN114278245A (en) * | 2021-07-20 | 2022-04-05 | 中石化石油工程技术服务有限公司 | Hydraulic oscillator |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2874639C (en) | 2022-05-24 |
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