Downhole vibration enhancing apparatus and method of using and tuning the same

The present disclosure is directed to an apparatus for use with a vibratory tool in a bottom hole assembly to enhance the vibration of the bottom hole assembly. The apparatus includes at least one spring mechanism and a fluid passageway disposed within a housing. The apparatus can be tuned and/or parts of the bottom hole assembly can be manipulated to match the frequency of the vibratory tool and/or the frequency of the vibratory tool can be tuned to match the vibrational frequency of the bottom hole assembly and the apparatus.

The present disclosure is directed toward a vibration enhancing apparatus that includes a first end and a second end. The apparatus also includes a passageway disposed at least partially within a housing to permit fluid to flow through the apparatus. Furthermore, the apparatus includes at least one spring designed having a spring constant that is responsive to a vibratory tool and other tools used in a bottom hole assembly with the apparatus.

The present disclosure is also directed toward a vibration enhancing apparatus that includes a housing and at least one spring disposed within the housing and around a mandrel slidably disposed in the housing. The apparatus also includes a first piston element disposed on one end of the mandrel and slidably disposed in the housing. Additionally, the apparatus includes an internal port radially disposed in the mandrel in fluid communication with a first annulus area disposed between the mandrel and the housing and in fluid communication with the first piston element. The apparatus further includes an external port radially disposed in the housing in fluid communication with a second annulus area disposed between a portion of the first piston element.

This disclosure is also directed towards a method of determining a vibrational frequency at which a vibratory tool useable in a downhole assembly operates, the downhole assembly separated into an upper bottom hole assembly and a lower bottom hole assembly having a mass and designing a vibration enhancing apparatus that cooperates with the lower bottom hole assembly to have a resonant frequency that is substantially equal to the vibrational frequency of the vibratory tool.

This disclosure is further directed toward a method of determining a resonant frequency of a vibration enhancing apparatus cooperating with a lower bottom hole assembly of a bottom hole assembly and designing a vibratory tool to be used in the bottom hole assembly having a vibrational frequency that is responsive to the resonant frequency of the vibration enhancing apparatus and the lower bottom hole assembly.

The disclosure is also directed toward a method of deploying a bottom hole assembly, the bottom hole assembly comprising a vibration enhancing apparatus and a vibratory tool; operating the vibratory tool at a vibrational frequency; and operating the vibration enhancing apparatus and a lower portion of the bottom hole assembly at a resonant frequency that is responsive to the predetermined frequency of the vibratory tool to maximize vibration amplitude of the bottom hole assembly.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure relates to a vibration enhancing apparatus10that can be configured to be used with any type of vibratory tool12(or agitation tool) known in the art, such as the XRV produced by Thru Tubing Solutions, the NOV Agitator, or the Tempress produced by Oil States, to amplify the vibration or agitation provided by the vibratory tool12. The present disclosure is also directed toward a method of using the apparatus10and a method of tuning the apparatus10to maximize the amplification of the vibratory tool12. As shown inFIG. 1, the apparatus10described herein can be incorporated into a bottom hole assembly (BHA)14with a vibratory tool12and other types of downhole tools known in the art, such as, motors16and drill bits18. The amplification of the vibration of the vibratory tool12provides additional vibration to the BHA14to assist in advancing the BHA14into the wellbore. The vibration enhancing apparatus10can be disposed above or below the vibratory tool12in the BHA14.

The apparatus10, shown in more detail inFIGS. 2 and 3, includes a housing20, a first end22, a second end24, a fluid passageway26, and at least one spring28disposed within the housing20. The at least one spring28can be a mechanical spring, oil-spring, gas-spring, and the like. In one embodiment, the at least one spring28can be disposed between the fluid passageway26and the housing20. In another embodiment, the fluid passageway26can be disposed between a spring housing (not shown) and the housing20, which could cause the fluid passageway26to be disposed around the at least one spring28or outside of the at least one spring28. In this embodiment, the fluid passageway26could be an annulus area disposed between the at least one spring28and the housing20.

In one embodiment, the apparatus10can be disposed downhole from the vibratory tool12in the BHA14. In this embodiment, the first end22of the apparatus10is in fluid communication with the vibratory tool12and the fluid passageway26. The second end24would be adapted to be connectable to other downhole tools to be disposed downhole of the apparatus10. In another embodiment, the apparatus10can be disposed uphole from the vibratory tool12in the BHA14. In this embodiment, the first end22of the apparatus10would be adapted to be connectable to other downhole tools to be disposed uphole of the apparatus10. The second end24of the apparatus10is in fluid communication with the fluid passageway26and the vibratory tool12disposed below.

The end22or24in fluid communication with the vibratory tool12can extend from inside of the housing20. This end22or24can also be provided with a splined section30disposed thereon to prevent the fluid passageway26and the at least one spring28from rotating independently of the housing20, vibratory tool12or the BHA14. The apparatus10further includes a spline receiving area32to cooperate with the splined section30to allow the housing20, the end22or24opposite of the vibratory tool12and the tools disposed below the apparatus10to have axial motion represented by reference numeral27with respect to the vibratory tool12, yet still prevent the fluid passageway26and the at least one spring28from rotating independently of the housing20, vibratory tool12or the BHA14.

As previously stated, this disclosure is also directed to a method of using the apparatus10. The apparatus10and vibratory tool12are run into a wellbore. Fluid can then be pumped into and through the vibratory tool and the apparatus10to advance the BHA14further into the wellbore.

In another aspect of the present disclosure, a method of tuning or optimizing the effectiveness of the apparatus10is disclosed herein. Any tools in the BHA14disposed uphole (upper BHA34and tubing35) from the apparatus10provides the driving force for the BHA14into the wellbore and all tools in the BHA14disposed below the apparatus10is considered the lower BHA36. The at least one spring28in the apparatus10allows free axial movement between the upper BHA34and the lower BHA36while the splined section30and the spline receiving area32cooperate to restrict rotational motion between the upper BHA34and the lower BHA36.

FIG. 4shows a diagram depicting a typical spring-mass system38. The spring-mass system38includes a spring40, a mass42and a point44from which the spring40and mass42oscillate. The apparatus10represents the spring40in a typical spring-mass system38. The lower BHA36represents the mass in the typical spring-mass system38. The upper BHA34represents the point44from which the mass42(lower BHA36) and the spring40(apparatus10) oscillate. The typical spring-mass system38has a resonant frequency at which it oscillates, known as its natural frequency.

In one embodiment, the vibratory tool12used in the BHA14will have a unique vibrational frequency. The apparatus10can be set up to cooperate with the lower BHA36to have a resonant frequency that is equivalent to the unique vibrational frequency of the vibratory tool12. The resonant frequency (f) is a function of the spring constant (K) and the mass (M) (i.e., the mass of the tools disposed below the apparatus10or the mass of the tools present in the lower BHA36) present within the system, and can be determined using the following equation:

The vibrational frequency of the vibratory tool12used in the BHA14can be calculated or measured. Once the vibrational frequency of the vibratory tool12has been determined, the following equation can be used to determine the spring constant (K) which will cause the natural frequency of the spring mass system represented by the apparatus10and the lower BHA36to match the input frequency of the vibratory tool12:
K=M(2πf)2

The at least one spring28of the apparatus10can be designed such that it has the required spring constant (K) to maximize the vibration amplitude of the BHA14from the vibratory tool12and the apparatus10. In one embodiment, the at least one spring28and/or the mass of the lower BHA36can be adjusted to achieve the maximum vibration amplitude of the BHA14.

In another embodiment, the vibratory tool12can be designed to have a specific frequency to match the resonant frequency of a specific apparatus10having a predetermined spring constant (K) and the mass of a specific lower BHA36.

In yet another aspect of the present disclosure, a method for designing the apparatus10, adjusting the mass of the lower BHA36and/or designing the vibratory tool12to make the unique frequency of the vibratory tool substantially equal to the resonant frequency of the apparatus10and the lower BHA36is disclosed. In one aspect of this embodiment, the unique vibrational frequency of the vibratory tool12is determined. The vibrational frequency of the vibratory tool12is used to design the at least one spring28of the apparatus10to maximize the vibration amplitude of the BHA14. The method can also include the step manipulating the mass of the lower BHA36and/or the at least one spring28to have a resonant frequency that matches the frequency of the vibratory tool12to maximize the vibration amplitude of the BHA14. In another embodiment, the resonant frequency of the apparatus10and the lower BHA36is determined. Once the resonant frequency of the apparatus10and the lower BHA36is determined, the vibratory tool12can be designed to have a vibrational frequency substantially equal to the resonant frequency of the apparatus10and the lower BHA36.

The apparatus10can be designed with a “pump-open” or “pump-closed” area. When the apparatus10is of the “pump-open” type, a method is provided wherein the apparatus10is caused to extend the apparatus10when the pressure of the fluid flowing through the apparatus10is greater than the pressure of the fluid outside of the apparatus10, and contract the apparatus10when the pressure of the fluid is greater outside of the apparatus10than the pressure of the fluid is inside the apparatus10. Conversely, when the apparatus10is of the “pump-closed” type, a method is provided wherein the apparatus10is caused to contract the apparatus10when the pressure of the fluid flowing through the apparatus10is greater than the pressure of the fluid outside of the apparatus10, and extend the apparatus10when the pressure of the fluid is greater outside of the apparatus10than the pressure of the fluid is inside the apparatus10.

When the vibratory tool12operates, there is fluid pulsation through the apparatus10which occurs at the same frequency as the vibratory force generated by the vibratory tool12. This fluid pulsation causes pressure fluctuations above and below the vibratory tool12. If the apparatus10is designed with a pump-open or pump-closed area and is positioned such that it is exposed to the fluid pressure fluctuations produced by the vibratory tool12, a hydraulic force will be generated within the apparatus10which will cause the apparatus10to experience a cyclic contraction/extension force. If the spring28/mass of the BHA14is “tuned” to this cyclic loading frequency, maximum vibration of the BHA14and tubing will result. So, another novel concept is to “tune” the natural frequency of the BHA14to match the cyclic hydraulic loading produced by the vibratory tool12acting on a spring tool with a “pump-open/closed” area.

In real systems, there is often significant damping in addition to the spring and mass.FIG. 5depicts this real system where damping can be incorporated into the spring-mass system. There is a “damped” natural frequency which is different than the undamped natural frequency. Similar calculations can be used to calculate the damped natural frequency as the undamped frequency described previously. All methods, etc., described for the undamped system can be equally applied to the damped system. The following equations are used to evaluate the damped natural frequency:
α=R/(2 m) is a decay constant and ωd=√{square root over (ω02−α2)} is the characteristic (or natural) angular frequency of the system

FIGS. 6 and 7depict a specific embodiment of the present disclosure wherein the vibration enhancing apparatus10is used with a vibratory tool12having an inlet46, an outlet48and a vortex chamber50. In addition, the vibratory tool12in this embodiment can include a first fluid port52and a second fluid port54, which are both in fluid communication with the inlet46and the vortex chamber50. Furthermore, the vibratory tool12in this embodiment can include a first fluid return port56and a second fluid return port58. The first and second fluid return ports56and58allow for a portion of the fluid entering the vortex chamber50to be returned to a fluid loop port60. The fluid loop port60directs fluid from the first and second fluid return ports56and58to an interchange area62where the fluid flowing in from the inlet46is directed back and forth from the first fluid port52to the second fluid port54.

In another embodiment of the present disclosure,FIG. 8shows the apparatus10in a “pump-closed” embodiment. The apparatus10includes a top sub70for connection to other downhole tools disposed above the apparatus10in the BHA14and a bottom sub72for connection to other downhole tools disposed below the apparatus10in the BHA14. The apparatus10further includes a mandrel74supported by or connected to the top sub70on an upper end76of the mandrel74. The other end of the mandrel74, or lower end78, is supported by or connected to a piston element80.

The apparatus10of the embodiment shown inFIG. 8further includes an upper housing82, a lower housing84and a connector element86disposed between the upper housing82and the lower housing84. The connector element86can be threaded on each end to attach to the upper housing82and the lower housing84. A lower end88of the lower housing84is connected to the bottom sub72. A portion of top sub70, the mandrel74, and the piston element80are slidably disposed within and move independently of the upper housing82, the lower housing84, the connector element86and the bottom sub72.

The apparatus10includes at least one spring90disposed around the mandrel74and between the mandrel74and the upper housing82. In one embodiment, the spring90is disposed between an upper shoulder92disposed on the inside of the upper housing82and a lower shoulder94disposed on the inside of the upper housing82. In another embodiment, the apparatus10includes two springs90where the springs are separated by a lip element96disposed on the inside of the upper housing82. It should be understood and appreciated that the lip element96is disposed on the inside of the upper housing82between the upper shoulder92and the lower shoulder94. Furthermore, the apparatus10can be designed to incorporate any desired number of springs90.

The top sub70has a passageway98disposed therein to permit fluid to flow through the top sub70and into the mandrel74. The top sub70includes a splined section100on a lower end102of the top sub70where splines104extend radially therefrom. The splines104engage a spline receiving area106disposed on the inside of the upper housing82. The splines104engagement with the spline receiving area106prevent the top sub70, and thus the mandrel74and the piston element80, from rotating independently of the upper housing82, the lower housing84, the connector element86and the bottom sub72.

The mandrel74includes a passageway108axially disposed therein to permit fluid to flow from the top sub70and through the mandrel74. The mandrel74also includes an internal port110radially disposed in the lower end78of the mandrel74to permit fluid to flow into an annulus area112and engage with a portion of the piston element80. The annulus area112is disposed between the connector element86and the piston element80that is attached to the lower end78of the mandrel74. As fluid, which is at a higher pressure than fluid outside of the apparatus10, flows into the annulus area112, the bottom sub72, the lower housing84and the upper housing82are forced to move in the uphole direction with respect to the top sub70, the mandrel74and the piston element80. This uphole movement of the bottom sub72, the lower housing84and the upper housing82causes the apparatus10to contract and compress the spring(s)90.

Further, the lower housing84includes an external port114in fluid communication with a second annulus area116disposed between the piston element80and the lower housing84. The second annulus area116is disposed on the downhole side of a piston head118of the piston element80. When the pressure of the fluid outside of the apparatus10becomes higher than the pressure of the fluid flowing through the apparatus10, the bottom sub72, the lower housing84and the upper housing82are forced to move in the downhole direction with respect to the top sub70, the mandrel74and the piston element80. This downhole movement of the bottom sub72, the lower housing84and the upper housing82causes the apparatus10to extract and thus, reduce the compression of the spring(s)90. In this embodiment, the piston element80can further include a tubular extension120that extends into the lower sub72and is slidably disposed therein.

In a further embodiment of the present disclosure shown inFIG. 9, the apparatus10can include a second piston element122disposed between the piston element80and the mandrel74. The second piston element122includes a piston head124and a tubular extension126extending therefrom. The piston head124of the second piston element122is connected to the lower end78of the mandrel74and the tubular extension126of the second piston element122is connected to the piston head118If the piston element80. The lower end of the tubular extension126of the piston element122further includes an internal port128radially disposed therein in fluid communication with a third annulus area130and the piston head118of the piston element80. The piston elements80and122both have passageways disposed therein to permit fluid to flow from the mandrel74into and out of the lower sub72.

Similar to the operation of the apparatus10previously described herein, the second piston element122increases the contraction of the apparatus10and the compression of the spring90. The third annulus area130is disposed between a shoulder section132disposed on the inside of the lower housing84and the piston element80that is attached to the lower end of the second piston element122. As fluid, which is at a higher pressure than fluid outside of the apparatus10, flows into the third annulus area130, the bottom sub72, the lower housing84and the upper housing82are forced to move in the uphole direction with respect to the top sub70, the mandrel74, the piston element80, and the second piston element122. This uphole movement of the bottom sub72, the lower housing84and the upper housing82causes the apparatus10to contract and compress the spring(s)90.

Further, the lower housing84includes a second external port134in fluid communication with a fourth annulus area136disposed between the piston element80and the lower housing84. The fourth annulus area136is disposed on the downhole side of the piston head124of the piston element122and uphole of the shoulder section132of the lower housing84. When the pressure of the fluid outside of the apparatus10becomes higher than the pressure of the fluid flowing through the apparatus10, the bottom sub72, the lower housing84and the upper housing82are forced to move in the downhole direction with respect to the top sub70, the mandrel74, the piston element80, and the second piston element122. This downhole movement of the bottom sub72, the lower housing84and the upper housing82causes the apparatus10to extract and thus, reduce the compression of the spring(s)90. While only two piston elements80and122are shown inFIG. 9, it should be understood and appreciated that any number of piston elements can be included in the apparatus10, as well as the corresponding internal and external ports, as desirable by an operator of the apparatus10.

From the above description, it is clear that the present disclosure is well adapted to carry out the objectives and to attain the advantages mentioned herein as well as those inherent in the disclosure. While presently disclosed embodiments have been described for purposes of this disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are accomplished within the spirit of the disclosure.