The embodiments described herein relate to an annular packer that includes a solid mandrel and may be set using annular pressure.
Improving the safety and integrity of oilfield operations and design is a top priority in the oil and gas industry. It is important to provide an effective barrier between the downhole formation and the rig floor in order to prevent uncontrolled flow of fluids up to the wellhead. The main barrier between the formation and the rig floor is typically a cemented casing string. The cement creates a barrier in the annular space between the casing string and the formation directing the formation fluids and/or pressure into the production string where multiple devices and methods may be used to control the wellbore pressure.
In some instances, it may be necessary to provide another barrier in the annulus. Annulus packing devices are previously known to be used to create an annular seal Annular packing devices are typically set by the application of pressure from within the bore of the device to set a packing element against the casing string. However, the flow paths required for setting the packing elements may provide additional leak paths whereby formation fluid may travel into the wellbore through the device. It may be desirable to have an annular packing device that does not include any flow paths from the bore that may be potential leak paths. Other annular packing devices may require complex setting mechanisms such as using an electronic or acoustic signal transmitted to the tool to set the packing elements. The complexity of such systems increases the costs of such annular packers. Further, such systems require an application of providing the requisite signals to the downhole location of the annular packer. It would be desirable to provide an annular packer that may be simply actuated by the application of annulus pressure.
The present disclosure is directed to an annular packing device and method that overcomes some of the problems and disadvantages discussed above.
One embodiment is an annular packer comprising a solid mandrel having a first end, a second end, a central bore, and an exterior. The annular packer comprises a first sealing element connected to the exterior of the mandrel and a second sealing element connected to the exterior of the mandrel, wherein the second sealing element is expanded radially by axial movement of at least a portion of the second sealing element. The annular packer comprises a first piston movable from a first position to a second position within a first chamber on the exterior of the mandrel, the first piston and first chamber being positioned between the first sealing element and the second sealing element. A pressure differential exterior of the mandrel moves the first piston from the first position to the second position and the movement of the first piston to the second position axially moves at least a portion of the second sealing element.
An application of pressure around the exterior of the mandrel may move a portion of the first sealing element away from the exterior of the mandrel to create a first seal against a casing and the radial expansion by axial movement of at least a portion of the second sealing element creates a second seal against the casing. The first seal may cause a pressure differential. The annular packer may include a cone connected to the exterior of the mandrel adjacent to the second sealing element, the cone may be positioned between the first piston and the second sealing element and the movement of the first piston to the second position may move at least a portion of the cone between a portion of the second sealing element and the exterior of the mandrel.
The annular packer may include an equalization port. The equalization port may be closed when the first piston is in its first position and may be open when the first piston is in its second position. The first seal may be released when the equalization port is open. The annular packer may include a spring that biases the first sealing element to move away from the casing towards the exterior of the mandrel. The second seal may remain set against the casing during and after when the equalization port is opened. The annular packer may include a shearable device that selectively retains the first piston in its first position, wherein the shearable device is configured to shear and release the first piston at a predetermined pressure differential. The annular packer may include a second piston movable from a first position to a second position within a second chamber on the exterior of the mandrel. The second piston may be connected to the first piston and a pressure differential may move the second piston from its first position to its second position. The solid mandrel may comprise a single opening, the single opening being the central bore, the central bore may extend from the first end to the second end along a longitudinal axis of the solid mandrel.
One embodiment is an annular packer comprising a solid mandrel having a first end, a second end, a central bore, and an exterior. The annular packer comprises a first sealing element connected to the exterior of the mandrel and a second sealing element connected to the exterior of the mandrel, wherein the second sealing element is radially expanded by axial movement of at least a portion of the second sealing element. The annular packer includes at least one piston moveable from a first position to a second position within a chamber on the exterior of the mandrel. The at least one piston and chamber being positioned between the first sealing element and the second sealing element and the chamber including a rupture disc. A predetermined pressure differential exterior of the mandrel burst the rupture disc and moves the at least one piston from the first piston to the second position and wherein the movement of the at least one piston to the second position axially moves at least a portion of the second sealing element.
An application of pressure around the exterior of the mandrel may move a portion of the first sealing element away from the exterior of the mandrel to create an initial seal against a casing and the radial expansion of the second sealing element creates a second seal against the casing. The first seal may cause a pressure differential. The annular packer may include a cone connected to the exterior of the mandrel with the second sealing element being positioned between the first sealing element and the cone.
The annular packer may include an equalization port. The equalization port may be closed when the first piston is in its first position and may be open when the first piston is in its second position. The initial seal may be released when the equalization port is open. The annular packer may include a spring that biases the first sealing element to move away from the casing towards the exterior of the mandrel. The second seal may remain set against the casing when the equalization port is opened. The annular packer may include a plurality of pistons positioned between the second sealing element and the first sealing element. A predetermined pressure differential exterior of the mandrel bursts the rupture disc and moves the plurality of pistons to move at least a portion of the second sealing element onto at least a portion of the cone.
One embodiment is a method of sealing an annulus comprising applying pressure to an annulus between a mandrel and a casing, the mandrel being a solid mandrel having a central bore extending from a first end to a second end. The method comprises moving a portion of a first sealing element against the casing to create an initial seal, a portion of the first sealing element being connected to an exterior of the mandrel. The method comprises moving at least one piston with the pressure being applied to the annulus, the piston being slidably connected to the exterior of the mandrel. The movement of the at least one piston moves a portion of a second sealing element against the casing to create a second seal. A portion of the second sealing element being connected to the exterior of the mandrel.
The method may include opening a port to equalize the pressure and release the initial seal, wherein the second seal remains set against the casing. The movement of the at least one piston may move a cone underneath the second sealing element to move a portion of the second sealing element against the casing. The movement of the at least one piston may move a portion of the second sealing element onto a portion of a cone to move a portion of the second sealing element against the casing. The method may include increasing the pressure in the annuls after creating the initial seal and bursting a rupture disc that permits the pressure being applied to the annulus to move at least one piston. Releasing the initial seal may include moving a portion of the first sealing element away from the casing towards the exterior of the mandrel. A spring may move a portion of the first sealing element away from the casing. The method may include shearing a device prior to moving the at least one piston with pressure, wherein shearing the device releases the at least one piston.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the invention as defined by the appended claims.
The annular packer 100 includes at least one first sealing element 130 and at least one second sealing element 170 on the exterior of the mandrel 110. The first sealing element 130 may be various sealing elements that may be actuated by annular pressure to move away from the mandrel 110 to engage the casing 1 to create an initial seal. One example of such a first sealing element is a packer cup. The first sealing element 130 will hereinafter be referred to as a packer cup, but may be various sealing elements as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. The second sealing element 170 may be various sealing elements. For example, the mechanically actuated sealing element may be radially expanded against the casing due to axial movement of a portion and/or components of the sealing element. The second sealing element 170 may be a sealing element that may be expanded radially due to movement along a cone 160 as described herein.
The packer cup 130 will create a first or an initial seal with the casing 1 (shown in
The annulus packer 100 may include a sleeve 120 connected to the exterior of the mandrel 110 that provides a flow path to the piston chambers 145 and 155 when the packer cup 130 engages the casing 1 preventing the flow of fluid down the annulus 2 past the packer cup 130. Ports 121 permit the flow of fluid behind the sleeve 120 to actuate the pistons 140 and 150. Ports 122 and 123 in the sleeve 120 permit the flow of fluid into the piston chambers 145 and 155 to actuate the pistons 140 and 150 via annulus pressure. An equalization port 180 permits the equalization of pressure across the packer cup 130 after the setting of the sealing element 170 as discussed herein.
The movement of the pistons 140 and 150 also uncover equalization port 180 after setting the primary seal 170 in the annulus. Equalization port 180 permits the equalization of pressure above and below the packer cup 130, which releases the initial seal set by the packer cup 130 against the casing 1. The primary annular seal between the tool 100 and the casing 1 that is created by the sealing element 170 and cone 160 remains set even upon equalization of pressure above and below the packer cup 130. The tool 100 shown in
The exterior of the mandrel 210 includes a plurality of pistons 240 that may be actuated to move a sealing element 270 along a cone 260 to sealingly engage with the casing 1 as described herein. A rupture disc 201 on the exterior of the mandrel 210 selectively permits pressure from actuating the pistons 240 to create the annular seal until a predetermined pressure is reached in the annulus 2 between the casing 1 and the annular packer 200. A flow path 202 fluidly connects the rupture disc 201 with the plurality of pistons 240 on the exterior of the mandrel 210. A shear pin 203 prevents the premature movement of the pistons 240 along the exterior of the mandrel 210 until acted upon by annular pressure through the burst ruptured disc and flow path 202.
The pumping of fluid down the annulus 2 will continue to increase annular pressure until rupture disc 201 bursts as shown in
After the annular seal is set, the spring 232 will push the spring piston 234 away from the end of the spring housing 231. As the spring piston 234 travels within the housing 231, c-ring 233 captures a portion of the spring piston 234 moving the seal 235 off sealing surface 236 as shown in
Although this invention has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments that do not provide all of the features and advantages set forth herein, are also within the scope of this invention. Accordingly, the scope of the present invention is defined only by reference to the appended claims and equivalents thereof.