RELATED APPLICATIONS

This application is a non-provisional application that claims the benefit of U.S. Applications No. 62/293,543 filed February 10, 2016 and No. 62/270,745 filed on Dec. 22, 2015, which are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention generally relates to oil and gas extraction. Specifically, the invention provides an expandable anchor sleeve system which can be used as a packer, a flow restriction barrier for fracturing operations or a bridge plug.

2. Background of the invention

Downhole tools referred to as packers, frac plugs and bridge plugs are well known in the art of producing oil and gas. However, most of conventional downhole tools are set against well casing by anchoring elements such as slips which include sliding wages which may cause premature set conditions and questionable reliability. Thus, what is needed and provided by the present disclosure is a reliable anchoring system and a simple reliable tool setting system capable of preventing premature set conditions and improved reliability which is achieved by utilizing metal plasticity resulting in eliminating moving parts and providing significantly larger passage through compared to conventional tools.

SUMMARY OF THE INVENTION

An expandable anchor sleeve system comprises an expandable anchor sleeve and an expansion device. The sleeve has three major components: a sealing element at the back-end portion, a gripping device at the front-end portion, and an anchoring element in the middle portion. In a preferred embodiment, the anchoring element has the difference between front-end radial thickness and back end radial thickness to be not less than the difference between corresponding radii of maximum and minimum diameters of the base casing. The expansion device comprises a shaft and a connecting device coupled to the shaft at the front-end. The expansion device also includes an expansion swage slidably attached to the shaft, and a thruster. The thruster is connected to the expansion swage and propels the expansion swage towards the connecting device. The connecting device adapted to be engaged with gripping device of the sleeve, providing that it can be disengaged from the gripping device at a certain release force.

Upon expansion of the sleeve, anchoring element comes in contact with base casing and the force for swage propagation increases due to interference force between anchoring element and the base casing. Due to the conical shape of the anchoring element with thickness increasing in front direction the interference force increases with swage propagation in the front direction. Thus, the total cladding force, defined as a sum of free expansion force and interference force, increases upon swage propagation in the front direction. When cladding force reaches the value of the release force the expansion device disconnects from the sleeve. Thus, providing the release force being greater than the free expansion force, the expansion device expands the sleeve bringing anchoring element in interference contact with base casing and then disconnects connecting device from the gripping element in one stroke of the thruster. The sleeve may be configured as a frac plug, a caged ball frac plug, a bridge plug or a packer.

BRIF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a section view of an expandable sleeve.

Fig. 2 is a section view of a sleeve of Fig. 1 comprising an anchoring element with a C-ring from hardened material.

Fig. 3 is a section view of the expandable sleeve of Fig. 1 attached to the expansion device.

Fig. 4 is a section view of the expandable sleeve in the set position with the expansion device disconnected from the sleeve.

Fig. 5 is a section view of the sleeve of Fig. 4 with expansion device being removed and a frac ball landed in the sleeve.

Fig. 6 is a section view of the sleeve with a caged ball.

Fig. 7 is a section view of the sleeve with a plug.

DESCRIPTION OF THE PREFERED EMBODIMENT

Fig. 1 schematically shows a cross-section of the expandable anchor sleeve 20 before expansion. The sleeve 20 has a front-end and a back-end. The sleeve 20 has three major components: a sealing element 21 at the back-end portion, a gripping device 23 at the front-end portion, and an anchoring element 22 in the middle portion.

Sealing element 21 may comprise metal wickers or elastomeric components, or combination thereof providing sealing engagement with inside surface 51 of base casing 1 1 , see Fig. 5, upon radial expansion of the sleeve.

The anchoring element 22 may be adapted to come in interference contact with inside surface 51 of base casing 1 1 , see Fig. 4, upon radial expansion of the sleeve 20. The external surface of the anchoring element 22 may comprise wickers or hardened coating with hard particles. In embodiments, anchoring element 22 may comprise a C-ring 44 made from hardened material, see Fig. 2. In an embodiment, the anchoring element 22 may have a conical shape of the internal or external or both surfaces providing that the front-end radial thickness 26 being greater than the back-end radial thickness 25 to accommodate for variations in the base casing internal diameter 50, see Fig. 5. In a preferred embodiment, the anchoring element 22 further may have the difference between front-end radial thickness 26 and back end radial thickness 25 to be not less than the difference between corresponding radii of maximum and minimum diameters of the base casing defined for example by API, 5CT Specification for Casing and Tubing. The gripping element 23 may comprise shear pins and/or protrusions, or combination thereof providing that it is adapted to receive a connecting device 34 of the expansion device 30, see Fig. 3.

The expansion device comprises a shaft 32 with a connecting device 34 coupled to the shaft 32 at the front-end. The expansion device also includes an expansion swage 35 slidably attached to the shaft 32 and a thruster 31. The thruster 31 may be connected to the expansion swage 35 and propels the expansion swage 35 towards the connecting device 34.

The connecting device 34 may be any device adapted to be engaged with gripping device 23 of the sleeve 20, for example it may comprise shear pins or protrusions, or combination thereof providing that it may be disengaged from the gripping device 23 at a certain release force, applied in the rear-end direction. In embodiments, connecting device 34 and gripping device 23 comprise mateable threads adapted to secure expansion device to the sleeve 20 and to permit release of connecting device 34 from the gripping device of the sleeve 20 upon application of the release force.

The swage diameter 36 may be selected such that upon expansion the anchoring element comes in interference contact with internal surface of the base casing having the maximum internal diameter. The swage diameter 36, geometry and material properties of the sleeve 20 define a free expansion force, necessary for radial expansion of the sleeve 20 in free conditions, i.e. without interference with the base casing. Upon expansion, the sleeve 20 anchoring element 22 comes in contact with base casing and the force for swage propagation increases due to interference force between anchoring element and the base casing. Due to the conical shape of the anchoring element with increasing thickness in front direction the interference force increases with swage propagation in the front direction. Thus, the total cladding force, defined as a sum of free expansion force and interference force, increases upon swage propagation in the front direction. When cladding force reaches the value of the release force the expansion device disconnects from the sleeve 20. Thus, providing the release force being greater than the free expansion force, the expansion device expands the sleeve bringing anchoring element 22, see Fig. 4, in interference contact with base casing 11 and then disconnects connecting device 34 from the gripping element 23 in one stroke of the thruster 31.

In operation, the expandable sleeve system shown in Fig. 3 is deployed in the well to a desired location. Then, the thruster 31 is actuated setting the sleeve 20 in the well casing and disconnecting from the sleeve 20. After that the expansion device can be retrieved from the well and a frac ball 15, see Fig. 5, can be dropped to land on partially expanded portion 16 of the sleeve 20 or on a ball seat, not shown. The frac ball 15 can be metallic or non-metallic having a spherical, elliptical, conical or a cylindrical shape providing that it may close off the passage through the sleeve 20. Pressure is elevated from the surface and a zone thereabove may be fractured. By repeating this operation the desired number of zones may be fractured.

In another embodiment, it may be seen in more detail as generally illustrated in Fig. 6, wherein the frac ball 15 is positioned (caged) in front-end of the sleeve 20C between the ball seat 45 and the connecting device 34 of the expansion device 30 before deployment in the well. The sleeve 20C is identical in all respects to that described with respect to Fig. 1 except it has an elongated front-end with the ball seat 45 positioned in front of the gripping element 23. The ball seat 45 is defined as a step reduction in the internal diameter of the sleeve 20C having the internal diameter less than the frac ball diameter. Also, the expansion device 30 may be identical in all respects to that described with respect to Fig. 3. In operation, the expandable sleeve system shown in Fig. 6 may be deployed in the well to a desired location. Then, the thruster 31 may be actuated setting the sleeve 20 in the well casing and disconnecting from the sleeve 20. After the expansion device is retrieved, increased fluid pressure in the well will cause the ball 15 to engage seat 45 to prevent flow downwardly through the sleeve 20 and a zone thereabove may be fractured. Repeating this operation desired number of zones can be fractured.

Fig. 7 generally illustrates another embodiment, which may be identical in all respects to that described with respect to Fig. 3 except that it comprises a pug 55 attached to the sleeve 20P in the front of the gripping element 23. The plug 55 may be metallic or non-metallic or made from material dissolvable in well fluids. Once set in the well, sleeve 20P may prevent flow downwardly and upwardly acting as a bridge plug.

In another embodiment, the expandable sleeve 20 as illustrated in Fig. 3 may comprise a threaded portion at the front-end, not shown, to provide a threaded connection to a tubular, a nipple, a sandscreen, a velocity string or the like. Once set in the well it will provide the hanging and sealing capacity acting as a packer. Alternatively, a nipple may be positioned inside the sleeve.

An expandable sleeve system for use in a wellbore comprising a base casing, comprising: n expandable sleeve comprising a front-end and a back-end, comprising: a sealing element disposed at the back-end portion capable of providing a hydraulic seal between the expandable sleeve and base casing upon radial expansion of the sleeve; an anchoring element positioned in the middle portion of the sleeve, the Anchoring element having a conical shape with the difference between front- end radial thickness and back-end radial thickness being not less than the difference between corresponding radii of maximum and minimum internal diameters of the base casing; a gripping element positioned at the front-end portion of the sleeve; an expansion device comprising: a shaft and an expansion swage slidably attached to the shaft and having a diameter such that upon expansion said anchoring element comes in interference contact with internal surface of the base casing having maximum internal diameter; a connecting device coupled to the front-end of the shaft and adapted to be engaged with the gripping element of the sleeve before expansion and to be disengaged from the sleeve after expansion upon application of a release force and a thruster capable of providing said release force. The anchoring element comprises a C-ring made from hardened material. The expandable sleeve comprises a ball seat. The expandable sleeve comprises a ball seat in the front-end portion. A frac ball is disposed between the ball seat and the connecting device before deployment in the well. Fluid pressure applied in the well above the sleeve will engage the frac ball with the ball seat preventing downward flow therethrough. The expandable sleeve comprises a plug attached to the sleeve in the front of the gripping element. The expandable sleeve comprises a threaded portion at the front-end.

A method for installation of an expandable anchor sleeve in a well comprising a base casing, comprising: Connecting the expandable anchor sleeve to an expansion device wherein the expandable anchor sleeve comprising: a front-end and a back-end comprises: a sealing element disposed at the back-end portion capable of providing a hydraulic seal between the expandable sleeve and base casing upon radial expansion of the sleeve, an anchoring element positioned in the middle portion of the sleeve, the anchoring element having a conical shape with the difference between front-end radial thickness and back-end radial thickness being not less than the difference between corresponding radii of maximum and minimum internal diameters of the base casing, and a gripping element positioned at the front-end portion of the sleeve; and the expansion device comprising: a shaft and an expansion swage slidably attached to the shaft and having a diameter such that upon expansion said anchoring element comes in interference contact with internal surface of the base casing having maximum internal diameter, a connecting device coupled to the shaft and adapted to be engaged with the gripping element of the sleeve before expansion and to be disengaged from the sleeve after expansion upon application of a release force and a thruster capable of providing said release force; deploying the expandable anchor sleeve connected to the expansion device to the desired location in the well; activating the expansion device so that the anchor sleeve is expanded and comes in interference contact with the base casing and disengages from the expansion device; removing the expansion device from the well. The expandable sleeve comprises a ball seat in the front-end portion. A frac ball disposed between the ball seat and the connecting device before deployment in the well. The expandable sleeve comprises a plug attached to the sleeve in the front of the gripping element. The expandable sleeve comprises a threaded portion at the front-end.

A fracturing method for plurality of zone comprising: connecting an expandable frac sleeve to an expansion device wherein the expandable frac sleeve comprising a front-end and a back-end comprises: a sealing element disposed at the back-end portion capable of providing a hydraulic seal between the expandable sleeve and base casing upon radial expansion of the sleeve, an anchoring element positioned in the middle portion of the sleeve, the anchoring element having a conical shape with the difference between front-end radial thickness and back-end radial thickness being not less than the difference between corresponding radii of maximum and minimum internal diameters of the base casing, and a gripping element positioned at the front-end portion of the sleeve; and the expansion device comprising: a shaft and an expansion swage slidably attached to the shaft and having a diameter such that upon expansion said anchoring element comes in interference contact with internal surface of the base casing having maximum internal diameter, a connecting device coupled to the shaft and adapted to be engaged with the gripping element of the sleeve before expansion and to be disengaged from the sleeve after expansion upon application of a release force and a thruster capable of providing said release force; deploying the expandable anchor sleeve attached to the expansion device to the desired location in the well; activating the expansion device so that the anchor sleeve is expanded and comes in interference contact with the base casing and disengages from the anchor sleeve; retrieving the expansion device from the well; deploying a frac ball to land in the frac sleeve; fracturing new perforated zone up-hole of the sleeve; repeating steps (a)-(e) for fracturing desired number of zones.

A fracturing method for plurality of zone comprising: connecting an expandable frac sleeve to an expansion device wherein the expandable frac sleeve comprising a front-end and a back-end comprises: a sealing element disposed at the back-end portion capable of providing a hydraulic seal between the expandable sleeve and base casing upon radial expansion of the sleeve, an anchoring element positioned in the middle portion of the sleeve, the anchoring element having a conical shape with the difference between front-end radial thickness and back-end radial thickness being not less than the difference between corresponding radii of maximum and minimum internal diameters of the base casing, a gripping element positioned at the front-end portion of the sleeve, a ball seat positioned in front of the gripping element and a frac ball positioned between the ball seat and the gripping element; and the expansion device comprising: a shaft and an expansion swage slidably attached to the shaft and having a diameter such that upon expansion said anchoring element comes in interference contact with internal surface of the base casing having maximum internal diameter, a connecting device coupled to the shaft and adapted to be engaged with the gripping element of the sleeve before expansion and to be disengaged from the sleeve after expansion upon application of a release force and a thruster capable of providing said release force; deploying the expandable anchor sleeve attached to the expansion device to the desired location in the well; activating the expansion device so that the anchor sleeve is expanded and comes in interference contact with the base casing and disengages from the anchor sleeve; retrieving the expansion device from the well; fracturing new perforated zone up-hole of the sleeve; repeating steps (a)-(e) for fracturing desired number of zones. An expandable anchor sleeve comprising a front-end and a back-end for use in a wellbore comprising a base casing, comprising an anchoring element having a conical shape with the front-end radial thickness being larger than the back-end radial thickness, providing that anchoring element comes in interference contact with the base casing upon radial expansion of the sleeve by an expansion swage propagating in the front-end direction. A sealing element capable of providing a hydraulic seal between the expandable sleeve and base casing upon radial expansion of the sleeve. A sealing element disposed at the back-end portion. A gripping element positioned at the front-end portion of the sleeve. The anchoring element comprises a C-ring made from hardened material. The expandable sleeve comprises a ball seat in the front-end portion. The expandable anchor sleeve comprises a plug attached to the sleeve in the front of the gripping element. Expandable anchor sleeve comprises a threaded portion at the front-end. The anchoring element having the difference between front-end radial thickness and back-end radial thickness being not less than the difference between corresponding radii of maximum and minimum internal diameters of the base casing.

The expandable sleeve described herein may thus be configurable as a standard frac plug, a caged ball frac plug, a bridge plug or a packer. Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.