Frac plug and methods of use
View Patent ↗A frac plug for use in a plug and perf arrangement to within a wellbore. The frac plug includes a central mandrel and locking portion which can be set within the wellbore. A bypass port is disposed through the central mandrel and is unblocked to fluid flow during setting of the plug assembly. Thereafter, the central mandrel is axially shifted within the set locking portion to block fluid communication across the frac plug.
1. A frac plug for use in closing off a portion of a wellbore tubular to fluid flow, the frac plug comprising:
a central mandrel defining a central flowbore along its length;
a locking portion radially surrounding the central mandrel, the locking portion having a locking device that is moveable between unset and set positions by axial compression of the locking device upon the central mandrel;
a bypass port disposed through the central mandrel to allow fluid communication with the central flowbore, the bypass port being open to fluid flow when the locking portion is in the set position; and
wherein the central mandrel is axially shiftable within the locking portion once it is in the set position to close the bypass port to fluid flow and preclude fluid communication across the frac plug.
2. The frac plug of claim 1 wherein the locking device of the locking portion comprises an elastomeric packer element.
3. The frac plug of claim 1 wherein the locking device of the locking portion comprises a slip assembly.
4. The frac plug of claim 1 wherein the locking portion is compression set by a setting tool.
5. The frac plug of claim 1 wherein the flowbore of the central mandrel further includes a flow blockage within.
6. A plug and perf arrangement for injection of fracturing fluid within a portion of a wellbore, the plug and perf arrangement comprising:
a running string that is disposed within the wellbore from a surface location;
a setting tool for compression-setting a frac plug within the tubing string;
a frac plug releasably secured to the setting tool, the frac plug having:
a) a central mandrel defining a central flowbore along its length;
b) a locking portion radially surrounding the central mandrel, the locking portion having a locking device that is moveable between unset and set positions by axial compression of the locking device upon the central mandrel;
c) a bypass port disposed through the central mandrel to allow fluid communication with the central flowbore, the bypass port being open to fluid flow when the locking portion is in the set position; and
d) wherein the central mandrel is axially shiftable within the locking portion once it is in the set position to close the bypass port to fluid flow and preclude fluid communication across the frac plug.
7. The plug and perf arrangement of claim 6 wherein the locking device of the locking portion comprises an elastomeric packer element.
8. The fluid injection arrangement of claim 6 wherein the locking device of the locking portion comprises a slip assembly.
9. The fluid injection arrangement of claim 6 further comprising a perforating gun to form perforations within a formation radially surrounding the portion of wellbore.
10. A method of setting a frac plug within a wellbore, the method comprising the steps of:
disposing a frac plug within a wellbore to a location wherein it is desired to close off fluid flow, the frac plug having a central mandrel and a locking portion which radially surrounds the central mandrel;
setting the locking portion of the frac plug within the wellbore to lock the frac plug in place;
as the locking portion of the frac plug is being set, opening a bypass port in the central mandrel to permit fluid communication across the frac plug;
pressurizing the wellbore above the frac plug to create fluid pressure upon the central mandrel; and
shifting the central mandrel within the locking portion to close the bypass port and preclude fluid communication across the frac plug.
11. The method of claim 10 wherein the step of setting the locking portion further comprises setting an elastomeric packer.
12. The method of claim 10 wherein the step of setting the locking portion further comprises setting a slip assembly.
13. The method of claim 10 wherein the step of setting the locking portion further comprises axially compressing the locking portion upon the central mandrel.
14. The method of claim 10 wherein the step of opening the bypass port in the central mandrel is performed as the locking portion is set by unblocking the bypass port.
15. The method of claim 10 wherein the step of shifting the central mandrel within the locking portion to close the bypass port further comprises blocking the bypass port with the locking portion.
16. The method of claim 10 wherein the step of disposing the frac plug within a wellbore further comprises running the frac plug in on a wireline running string.