Pump for Inflating a Downhole Element, Method, and System

In the resource recovery and fluid sequestration industries the setting of seals in the downhole environment is ubiquitous. Such seals include inflatable seals, which naturally require inflation. Reliable inflation apparatus is difficult to achieve. The art will well receive inflation apparatus that reliably and efficiently inflates seals as needed.

An embodiment of a pump for inflating a downhole element, including a housing having an inlet and an outlet, a piston disposed within the housing, a reversing lead screw in the housing, and a drive operably connected to the reversing lead screw.

An embodiment of a method for setting a downhole element, including rotating a reversing lead screw, reciprocating a piston in a piston chamber with the reversing lead screw, drawing fluid into the piston chamber with movement of the piston in a first direction and expelling fluid from the chamber with movement of the piston in an opposite direction, and directing the expelled fluid to the downhole element.

An embodiment of a borehole system, including a borehole in a subsurface formation, a string in the borehole, and a pump for inflating a downhole element, disposed within or as a part of the string.

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.

Referring to, a pump for inflating a downhole elementis illustrated in cross section in a position where fluid has been drawn into the tool () and a position where the drawn in fluid has been expelled from the pump. The pumpis configured to reciprocate between the positions illustrated into draw fluid into a piston chamberand expel fluid from the piston chamber. The fluid when expelled is conveyed to a downhole element(schematically illustrated) that may be a bridge plug or other inflatable. Fluid may be so conveyed with reciprocal movement of the pumpuntil the downhole elementis inflated to a threshold pressure. In embodiments, that pressure that is preselected and can be verified through an amperage draw that indicates the threshold pressure or through a pressure sensor device.

Pumpincludes a housinghaving an inlet. The inletoptionally may include a filterand may include a one-way valvesuch as a check valve to allow fluid flow in a direction into the piston chamberand prevent flow of fluid out of the chamberthrough the inlet. Housingalso includes an outletthat may include a one-way valve, such as a check valve, to prevent fluid expelled from the chamberfrom moving back into chamber. The housing will further include a portthat allows fluid communication between an inside area of the housingand an annulusoutside of the housing.

Disposed with the housingis a reversing lead screwsupported by a thrust bearingand a centralizer. The centralizerincludes openingsto allow free fluid movement therethrough to avoid the creation of a hydraulic head. The lead screwis connected to a driveto rotate the lead screw in a consistent direction. In some embodiments, the drivemay include a gear trainto modify produced torque to suit the particular application. A pistonis disposed telescopically with the lead screwand is driven by the lead screwthrough a blade or nutdisposed in the pistonand in operable contact with a grooveof the lead screw. Pistonincludes a sealso that hydraulic pressure may be generated in the chamberwith movement of the pistonto reduce the volume of the chamber. Pistonalso, in some embodiments, will include an alignment groovethat interacts with a keyfixedly disposed in the housing. It will be understood that the groove could also be on the housingand the keyon the piston with the same effect of preventing rotation of the pistonwhile permitting axial movement of the piston.

During use, the drive, which may be an electric motor, a hydraulic motor, etc., rotates the screw, which causes the pistonto cycle to the right or left in the figures (the left position being depicted inand the right position being depicted in). The movement is self-reversing and the piston will continuously draw fluid through inletinto chamberwhen moving to the position ofand then expel that fluid through outletto the downhole elementwhen moving to the position of. Various elementsmay take more or fewer cycles of pistonto reach a selected threshold pressure. Once the selected threshold pressure is reached however, the downhole elementmay be released and the pumpmay be withdrawn to surface or other destination. An indication that the threshold pressure has been reached may be obtained simply through a pressure gauge or may be obtained through drive amperage draw. As will be appreciated, amperage draw in an electric motor will rise as the motor works harder against some impediment. In this case, the driveis urging the pistonagainst the rising hydraulic pressure in the element. Amperage will naturally increase as the pressure in elementincreases. The specific pressure threshold for a particular elementcan be mapped to a particular amperage or range of amperage to give a signal at surface that the elementis inflated. At this point, the elementshould be released. An additional data point that can be obtained is that the amperage of drivewill immediately fall once the elementhas been released because the pumpis merely circulating fluid in the annulus and not building pressure. This will confirm that the elementhas been successfully released.

Referring to, a borehole systemis illustrated. The systemcomprises a boreholein a subsurface formation. A stringis disposed within the borehole. A pumpas disclosed herein is disposed within or as a part of the string.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1: A pump for inflating a downhole element, including a housing having an inlet and an outlet, a piston disposed within the housing, a reversing lead screw in the housing, and a drive operably connected to the reversing lead screw.

Embodiment 2: The pump as in any prior embodiment, wherein the piston includes a reversing lead screw follower.

Embodiment 3: The pump as in any prior embodiment, wherein the follower is a nut.

Embodiment 4: The pump as in any prior embodiment, wherein the follower is a blade.

Embodiment 5: The pump as in any prior embodiment, wherein the drive is a motor.

Embodiment 6: The pump as in any prior embodiment, further including an antirotation key disposed between the piston and the housing.

Embodiment 7: The pump as in any prior embodiment, wherein the inlet includes a filter.

Embodiment 8: The pump as in any prior embodiment, wherein the inlet includes a one-way valve.

Embodiment 9: The pump as in any prior embodiment, wherein the outlet includes a one-way valve.

Embodiment 10: A method for setting a downhole element, including rotating a reversing lead screw, reciprocating a piston in a piston chamber with the reversing lead screw, drawing fluid into the piston chamber with movement of the piston in a first direction and expelling fluid from the chamber with movement of the piston in an opposite direction, and directing the expelled fluid to the downhole element.

Embodiment 11: The method as in any prior embodiment, further including filtering fluid being drawn into the piston chamber.

Embodiment 12: The method as in any prior embodiment, further including driving the reversing lead screw with a motor.

Embodiment 13: The method as in any prior embodiment, wherein the drawing and expelling is continued until a threshold pressure is achieved in the downhole element.

Embodiment 14: The method as in any prior embodiment, wherein the threshold pressure is determined by amperage draw in a motor rotating the reversing lead screw.

Embodiment 15: The method as in any prior embodiment, further including releasing the downhole element.

Embodiment 16: The method as in any prior embodiment, further including verifying release by a experiencing reduction in amperage draw in a motor rotating the reversing lead screw subsequent to occurrence of an amperage draw consistent with the downhole element being inflated to a threshold pressure.

Embodiment 17: A borehole system, including a borehole in a subsurface formation, a string in the borehole, and a pump for inflating a downhole element as in any prior embodiment, disposed within or as a part of the string.

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 terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” and/or “generally” can include a range of ±8% of a given value.

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a borehole, and/or equipment in the borehole, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

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.