In the resource recovery industry, mud motors are common devices used to generate torque for uses including drilling among other things. Mud motors utilize the energy of a flowing fluid therethrough to generate rotational torque that is applied in one example to a drill bit. Occasionally the torque created in the mud motor is insufficient to drive the connected tool (e.g. drill bit) through whatever is the target surface. This results in a stall of the mud motor. Fluid flowing through the mud motor without the mud motor rotating changes from a positive operational action to a detrimental one. Specifically, the same flowing fluid that provided the energy for the generation of torque in the rotating mud motor will cause damage to the motor in the form of flow cutting and erosion of sealing surfaces within the mud motor when the motor is not able to rotate due to insufficient torque to overcome the surface against which the connected tool is turning. Such flow cutting and erosion results in delays and increased costs and hence is undesirable to the operator. The art would well receive solutions that avoid such damage.
A mud motor stall protector including a housing, a piston translationally disposed in the housing, the piston defining a flow passage therein, and a pin positioned relative to the housing to occupy a portion of the flow passage of the piston or leave the flow passage of the piston open depending upon position of the piston relative to the pin.
A mud motor protector including a housing, and a piston disposed within the housing and defining a fluid flow channel therein, the piston being first responsive to a pressure differential across a set of piston seals resulting in piston movement that causes a reduction in flow area in the fluid flow channel of the piston and then responsive primarily to the restriction of the flow area of the fluid flow channel through the piston.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
As will be appreciated by one of ordinary skill in the art, and referring to
Referring to
Protector 20 comprises a housing 22 that includes a housing port 24 (two are shown, more or fewer are contemplated) extending between an outer surface 26 of the housing and an inside dimension surface 28. In an embodiment, the housing also defines two additional inside surfaces 30 and 32. Inside surface 30 is of a diameter smaller than the diameter of the inside surface 28. A piston 34 is shaped to communicate with the surfaces 30 and 28 through seals 36 and 38. The piston is also shaped to communicate with surface 32 through seal 40. The communications and their effects are discussed hereunder. The piston 34 defines a flow passage 42 and an opening 44 (three visible but more or fewer contemplated) that is alignable or misalignable with the port 24 depending upon the position of the piston 34. The piston 34 further includes a nozzle 46 that may be formed within the piston or may be a separate component that is disposed in sealed relationship with the piston 34. The nozzle defines a fluid conduit 47 that supplies fluid to flow passage 42 during use. In an embodiment, a biasing member 48 such as a spring is disposed between a piston shoulder 50 and a housing shoulder 52. The spring 48 is a compression spring that will urge the piston back to a closed position (shown in
Having described all of the parts of the protector 20 above, its operation is here addressed. Due to the surfaces 30 and 28 being of differing diameter, a differential piston area is created between the seals 36 and 38. Accordingly, when pressure is applied to the seals 36 and 38 through opening 44 and from a volume 60, the differential piston areas will cause the piston 34 to move. The pressure increase that piston 34 is designed to respond to is related to a motor stall. Specifically, when the motor 10 stalls and the flow therethrough becomes labored, the pressure of the fluid being supplied thereto through protector sub 54 increases (since it is being pumped from a remote location and now suddenly cannot flow as easily through the mud motor 10). That pressure exists through the fluid in volume 60 and through openings 44 and in the piston flow passage 42 for example. This pressure thus acts on the seals 36 and 38 as described. The piston 34 will then move as described, that movement being toward the right side of
Referring to
The protector 20 disclosed herein ensures reduced erosional damage to a mud motor 10 because the protector automatically continues to keep the motor free of fluid flow until the pumps 12 are shut down. Hence the delay of which those of skill in the art are painfully aware between the onset of a stall and the recognition of that fact resulting in the shutting down of pumps 12 has no additional deleterious effect on the mud motor since the protector 20 maintains the motor 10 in the safe condition until the pumps are actually shut down due to the fact that the protector piston 34 cannot reset until the pumps 12 are shut down and pressure and flow upstream of the protector 20 have ceased.
Set forth below are some embodiments of the foregoing disclosure:
Embodiment 1: A mud motor stall protector including a housing, a piston translationally disposed in the housing, the piston defining a flow passage therein, and a pin positioned relative to the housing to occupy a portion of the flow passage of the piston or leave the flow passage of the piston open depending upon position of the piston relative to the pin.
Embodiment 2: The protector as in any prior embodiment wherein the housing further includes a port extending from an inside surface of the housing to an outside surface of the housing.
Embodiment 3: The protector as in any prior embodiment wherein the piston includes an opening alignable or misalignable with the housing port depending upon position of the piston within the housing.
Embodiment 4: The protector as in any prior embodiment wherein the housing further defines at least two inside dimension areas.
Embodiment 5: The protector as in any prior embodiment wherein the at least two areas are on opposing sides of a port extending from an inside surface of the housing to an outside surface of the housing.
Embodiment 6: The protector as in any prior embodiment wherein the at least two areas create, with the piston, a differential piston area that causes the piston to translate during use of the protector based upon exposure to a threshold pressure.
Embodiment 7: The protector as in any prior embodiment wherein the threshold pressure is associated with a stall of a mud motor operably attached to the protector.
Embodiment 8: The protector as in any prior embodiment wherein the housing defines three inside dimension areas.
Embodiment 9: The protector as in any prior embodiment wherein the piston further includes a nozzle.
Embodiment 10: The protector as in any prior embodiment wherein the pin and the piston, when the pin occupies a portion of a fluid conduit of a nozzle of the piston, create a pressure drop in flowing fluid.
Embodiment 11: The protector as in any prior embodiment wherein the pressure drop urges the piston to a position where a piston opening is aligned with a housing port.
Embodiment 12: The protector as in any prior embodiment wherein pressure drop urges the piston against a reset spring.
Embodiment 13: The protector as in any prior embodiment further comprising a protector sub attached to the housing and supporting the pin.
Embodiment 14: The protector as in any prior embodiment wherein the protector sub includes supply channels that supply fluid to a mud motor.
Embodiment 15: A mud motor protector including a housing, and a piston disposed within the housing and defining a fluid flow channel therein, the piston being first responsive to a pressure differential across a set of piston seals resulting in piston movement that causes a reduction in flow area in the fluid flow channel of the piston and then responsive primarily to the restriction of the flow area of the fluid flow channel through the piston.
Embodiment 16: The protector as in any prior embodiment wherein a pin fixed relative to the housing, when occupying a portion of the fluid flow channel of the piston causes the reduction in flow area.
Embodiment 17: A mud motor system including a mud motor, and a mud motor protector as in any prior embodiment fluidly connected to the mud motor.
Embodiment 18: A mud motor system including a mud motor, and a mud motor protector as in any prior embodiment fluidly connected to the mud motor.
Embodiment 19: A well system including a borehole in a subsurface formation, a string disposed in the borehole, a mud motor protector as in any prior embodiment connected to the string, and a mud motor fluidly connected to the mud motor protector.
Embodiment 20: A well system including a borehole in a subsurface formation, a string disposed in the borehole, a mud motor protector as in any prior embodiment connected to the string; and a mud motor fluidly connected to the mud motor protector.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.
Number | Name | Date | Kind |
---|---|---|---|
6263969 | Stoesz et al. | Jul 2001 | B1 |
7757781 | Hay et al. | Jul 2010 | B2 |
20040129423 | Eddison | Jul 2004 | A1 |
20180163509 | Churchill | Jun 2018 | A1 |
Number | Date | Country | |
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20200095836 A1 | Mar 2020 | US |