Magnetic impulse applied sleeve method of forming a wellbore casing

A method of forming a wellbore casing within a borehole that traverses a subterranean formation includes the steps of assembling a tubular liner by coupling a threaded portion of a first tubular member to a threaded portion of a second tubular member and coupling a tubular sleeve to the threaded portions of the first and second tubular members. The method further includes positioning the wellbore casing within the borehole and radially expanding and plastically deforming the wellbore casing assembly within the borehole. The step of coupling the tubular sleeve through the threaded portions of the and second tubular members includes applying impulsive magnetic energy to the tubular sleeve.

BACKGROUND OF THE INVENTION

This invention relates generally to oil and gas exploration, and in particular to forming and repairing wellbore casings to facilitate oil and gas exploration.

Conventionally, when a wellbore is created, a number of casings are installed in the borehole to prevent collapse of the borehole wall and to prevent undesired outflow of drilling fluid into the formation or inflow of fluid from the formation into the borehole. The borehole is drilled in intervals whereby a casing which is to be installed in a lower borehole interval is lowered through a previously installed casing of an upper borehole interval. As a consequence of this procedure the casing of the lower interval is of smaller diameter than the casing of the upper interval. Thus, the casings are in a nested arrangement with casing diameters decreasing in downward direction. Cement annuli are provided between the outer surfaces of the casings and the borehole wall to seal the casings from the borehole wall. As a consequence of this nested arrangement a relatively large borehole diameter is required at the upper part of the wellbore. Such a large borehole diameter involves increased costs due to heavy casing handling equipment, large drill bits and increased volumes of drilling fluid and drill cuttings. Moreover, increased drilling rig time is involved due to required cement pumping, cement hardening, required equipment changes due to large variations in hole diameters drilled in the course of the well, and the large volume of cuttings drilled and removed.

During oil exploration, a wellbore typically traverses a number of zones within a subterranean formation. Wellbore casings are then formed in the wellbore by radially expanding and plastically deforming tubular members that are coupled to one another by threaded connections. Existing methods for radially expanding and plastically deforming tubular members coupled to one another by threaded connections are not always reliable, and do not always produce satisfactory results. In particular, the threaded connections can be damaged during the radial expansion process. Furthermore, the threaded connections between adjacent tubular members, whether radially expanded or not, are typically not sufficiently coupled to permit the transmission of energy through the tubular members from the surface to the downhole location.

The present invention is directed to overcoming one or more of the limitations of the existing procedures for forming new sections of casing in a wellbore.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a method of forming a wellbore casing within a borehole that traverses a subterranean formation is provided that includes externally applied tubular sleeve for improved sealing a wellbore casing joints.

According to another aspect of the present invention, a method of forming a wellbore casing within a borehole that traverses a subterranean formation is provided that includes magnetic impulse method for externally applying a tubular sleeve for improved sealing of wellbore casing joints.

According to another aspect of the present invention, a method of forming a wellbore casing within a borehole that traverses a subterranean formation is provided that includes expanding joined tubular members such as joined wellbore casings with a tubular sleeve externally applied to the surfaces of the joined wellbore casing and overlapping the joint thereby maintaining an improved seal of the wellbore casing joints after expansion.

According to another aspect of the present invention, a method of improving the seal of tubular members that are connected and then expanded is provided, that includes using a magnetic impulse method for externally applying a tubular sleeve to the joint between the tubular members prior to expanding the connected tubular members.

According to another aspect of the present invention, an improved method of connecting wellbore casing tubular member is provided that includes forming raised ring portions to enhance surface contact stress in the coupling connection and subsequently applying inward radial force with a tubular sleeve imposed by magnetic impulse method for improved sealing of the joints between the tubular members.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

Upon coupling the first and second tubular members, such as upon coupling the first and second wellbore casings14and16, as depicted inFIG. 2, a first surface portion26and a second surface portion28are adjacently positionally in the axial direction and may or may not have the same or nearly the same outside diameters32and34. It would understood that according to the foregoing methods and apparatus for expanding the wellbore casing, the depiction inFIG. 2andFIG. 3may or may not demonstrate an overlapping portion that has been previously expanded. In either instance, it is desirable for the present invention that the exterior first outside diameter32and the outside diameter34have the same or nearly the same dimensions. For further be seen that a joint30is formed there between that may include a small gap such as a bevel or partial channel on either member as is conventional for accommodating nicks or dents so that they will not interfere with complete coupling between the first and second wellbore casings.

Referring toFIG. 3, it will again be understood that the first wellbore casing14and the second wellbore casing16may or may not have been radially expanded in the depiction ofFIG. 4. A tubular sleeve40is positioned overlapping the first surface portion26of the first wellbore casings14and also overlapping the second surface portion28of the second wellbore casing16, thereby overlapping the joint30and axially extending in either direction there from at least partially over the overlapping coupling as well as partially over a portion of casing16that does not overlap first wellbore casing14.

The tubular sleeve40is preferably composed of electrically conductive material that are suitably malleable or flowable to be shaped mechanically, as for example copper, aluminum, light metal, and metal alloys. Steel alloys and other metal alloys with suitable electrically conductivity and with suitable malleability or suitable flow behavior may also be used. The inside diameter42, of the tubular sleeve40is only slightly larger than the outside diameter of at the joint30the first tubular member14or the second tubular member16. This means a cylindrical gap44between the inside surface46of sleeve40and the first and outside surfaces26and28of wellbore casings14and16respectively. The outside diameter48of tubular sleeve40is slightly larger than the inside diameter42defining a thickness49that is relatively thin compared the thickness of the wellbore casings14and16.

FIG. 5is a schematic illustration of the overlapping wellbore casings14and16and the overlapping tubular sleeve40, as inFIG. 4, and further schematically depicts a magnetic impulse energy applicator50. The impulse energy applicator50, according to one aspect of the present invention, is aligned with the tubular sleeve at a position overlapping the joint30and extending a distance over the surfaces26and28on either side of the joint30. The magnetic impulse apparatus50may comprise an impulse conductor ring52having an inside diameter54slightly larger than the outside diameter of the ring40, thereby leaving a small cylindrical gap56there between. Conductor ring52is interrupted with a radially extending gap (not shown) and is operatively connected to an impulse generator58such that the magnetic impulse power flows circumferentially around conductor ring52when applied from the impulse generator58. This method applied to joints of wellbore casing has not heretofore been known, although there are conventional devices and it is a conventional concept for providing a magnetic impulse for shaping of cylindrical metal parts. Thus, the adaptation of one of more of the methods and apparatus according to one or more of the following may be used in connection with this aspect of the present invention: (1) U.S. Pat. No. 5,444,963 issued to Steingroever, et al., Aug. 29, 1995; (2) U.S. Pat. No. 5,586,460 issued to Steingroever Dec. 24, 1996; (3). U.S. Pat. No. 5,953,805 issued to Steingroever Sep. 21, 1999, as well as the techniques an apparatus is described on the web page of Magnetic-Physics, Inc., with reference to the shaping technique under the trademark Magnetopuls, the disclosures of which are incorporated by reference.

With reference toFIG. 6, the method of applying the tubular sleeve to the joint of wellbore casing14and16may be more fully understood. The magnetic impulse generator58provides a magnetic in pulse to the conductor ring52. The magnetic impulse causes a powerful magnetic field60to be produced and simultaneously causes a counter current magnetic pulse62to be produced within tubular sleeve40. An extremely high concentration of magnetic flux at64results in the gap56between tubular sleeve40and impulse ring52. This high flux concentration due to the magnetic impulse generates a large force66inward from the ring52thereby collapsing tubular sleeve40onto the surfaces26and28at the joint. This effectively forms a first sealing interface70between the first surface26and the inside surface44of the tubular sleeve, and also forms a sealing interface72between the inside surface44of the tubular sleeve and the surface28of the second wellbore casing. With sufficiently high force, the malleable or flowable material from which tubular sleeve40is made, flows at74into the joint gap30. This method produces a surface to surface air tight metallic seal entirely over the coupling between the first wellbore casing14and the second wellbore casing16. The strength of the tubular sleeve40also holds the joint together during the process of mechanical expansion of the wellbore casing at the joint.

In an exemplary embodiment, as illustrated inFIGS. 7 and 8, the first and second tubular members,14and16, and the tubular sleeve40may then be positioned within another structure10such as, for example, a wellbore10, and radially expanded and plastically deformed, for example, by moving an expansion cone80through the interiors of the first and second tubular members14and16. The tapered portions,76and78, of the tubular sleeve40as may result from material flow due to large magnetic force of the type of material of sleeve40and facilitate the insertion and movement of the first and second tubular members14and16within and through the structure10, and the movement of the expansion cone80through the interiors of the first and second tubular members,14and16, may be from top to bottom or from bottom to top.

In an exemplary embodiment, during the radial expansion and plastic deformation of the first and second tubular members,14and16, the tubular sleeve40is also radially expanded and plastically deformed. In an exemplary embodiment, as a result, the tubular sleeve40may be maintained in circumferential tension and the overlapping end coupling portions,18and20, of the first and second tubular members,14and16, may be maintained in circumferential compression.

InFIG. 9, a fragmentary cross-sectional schematic illustration shows an exemplary embodiment of method and apparatus in which first and second tubular members114and116are overlapping coupled together, as with a first coupling portion118and a second coupling portion120pressed together in surface-to-surface engagement, and with an overlapping tubular sleeve40applied to the exterior thereof and providing a substantially continuous tubular assembly that may be expanded and plastically deformed. The first coupling portion118and the second coupling portion120may be overlappingly coupled together, as with a first female coupling portion and a second male coupling portion pushed, slid or pressed together in surface-to-surface engagement, and An overlapping tubular sleeve40is applied to the coupling to provide sealing and to stress the tubular coupling portions toward each other. In an exemplary embodiment, one or more raised ridge rings84(a-c) and corresponding troughs rings86(a-c) are formed interposed between the first and second couplings to increase the surface to surface contact stress for maintaining sealing contact upon expanding and plastically deforming the coupling and tubular sleeve at the overlapping portions of the first and second tubular members. In this method and apparatus the peaks88(a-c) of the ridges84(a-c) have a small area of surface contact with the opposed coupling portion, compared to the entire overlapping coupling area, such that the stress or force per area of contact is significantly increased thereby facilitating the surface to surface seal at the coupling joint. Although the ridge rings84are shown formed in the second male coupling portion with the peaks toward the first female male coupling portion, it will be understood based upon this disclosure that the ridge rings84might alternatively be formed on the female coupling portion118with the peaks toward the female coupling portion120. The tubular sleeve40as applied to the exterior of the overlapping tubular members increases the sealing stress. In a further exemplary embodiment, the tubular sleeve40acting together with the raised ridge rings84work together to maintain the seal when the tubular members114and116are expanded and plastically deformed as disclosed herein.

FIG. 10depicts another exemplary embodiment of the invention in which an interior tubular sleeve41is aligned with coupling joint between tubular members14and16. Before or after expanding the tubular members the interior tubular sleeve41is forced outward by magnetic impulse device51in a conventional manner or the adaptation of one of more of the methods and apparatus according to one or more of the following may be used in connection with this aspect of the present invention: (1) U.S. Pat. No. 5,444,963 issued to Steingroever, et al., Aug. 29, 1995; (2) U.S. Pat. No. 5,586,460 issued to Steingroever Dec. 24, 1996; (3). U.S. Pat. No. 5,953,805 issued to Steingroever Sep. 21, 1999, as well as the techniques an apparatus is described on the web page of Magnetic-Physics, Inc., with reference to the shaping technique under the trademark Magnetopuls, the disclosures of which are incorporated by reference. The interior sleeve41is applied to the interior surfaces of the tubular members overlapping the coupling joint and thereby facilitates sealing and connection between the tubular members.

As more fully disclosed in U.S. provisional patent application No. 60/405,394, filed on Aug. 23, 2002, the disclosure of which is incorporated herein by reference, one or more layers or coatings of softer material, preferably metallic material having a modulus of elasticity lower than the modulus of elasticity of the tubular members at the coupling joint, may be interposed between the joints, to facilitate sealing before and after expanding and plastically deforming joined tubular members such as wellbore casings. The interposed material may also be a material of the type having a lower melting point before deformation than after deformation. For example the material may be an exothermic material that initially releases energy upon stress or heat input thereby melting or plastically flowing at one temperature and subsequently without the further release of such heat energy having a higher melting point or plastic flow temperature.

In several alternative embodiments, the first and second tubular members,14and16, are radially expanded and plastically deformed using other conventional methods for radially expanding and plastically deforming tubular members such as, for example, internal pressurization and/or roller expansion devices such as, for example, that disclosed in U.S. patent application publication no. US 2001/0045284 A1, the disclosure of which is incorporated herein by reference.

The use of the tubular sleeve40during (a) the coupling of the first tubular member19to the second tubular member16, (b) the placement of the first and second tubular members in the structure10, (c) the radial expansion and plastic deformation of the first and second tubular members, and (d) magnetic impulse applying tubular sleeve to the overlapping coupling ends between the first and second tubular members provides a number of significant benefits. For example, the tubular sleeve40protects the exterior surfaces of the end portions,18and20, of the first and second tubular members,14and16, during handling and insertion of the tubular members within the structure10. In this manner, damage to the exterior surfaces of the end portions,18and20, of the first and second tubular member,14and16, are prevented that could result in stress concentrations that could result in a catastrophic failure during subsequent radial expansion operations. Furthermore, the tubular sleeve40provides an alignment guide that facilitates the insertion and threaded coupling of the second tubular member16to the first tubular member14. In this manner, misalignment that could result in damage to the threaded connections,22and24, of the first and second tubular members,14and16, may be avoided. In addition, during the relative rotation of the second tubular member with respect to the first tubular member, required during the threaded coupling of the first and second tubular members, the tubular sleeve40provides an indication of to what degree the first and second tubular members are threadably coupled. For example, if the tubular sleeve40can be easily rotated, that would indicate that the first and second tubular members,14and16, are not fully threadably coupled and in intimate contact with the internal flange36of the tubular sleeve. Furthermore, the tubular sleeve16may prevent crack propagation during the radial expansion and plastic deformation of the first and second tubular members,14and16. In this manner, failure modes such as, for example, longitudinal cracks in the end portions,18and20, of the first and second tubular members may be limited in severity or eliminated all together. In addition, after completing the radial expansion and plastic deformation of the first and second tubular members,14and16, the tubular sleeve40may provide a fluid tight metal-to-metal seal between interior surface of the tubular sleeve and the exterior surfaces of the end portions,18and20, of the first and second tubular members. In this manner, fluidic materials are prevented from passing through the threaded connections,22and24, of the first and second tubular members,14and16, into the annulus between the first and second tubular members and the structure10. Furthermore, because, following the radial expansion and plastic deformation of the first and second tubular members,14and16, the tubular sleeve40may be maintained in circumferential tension and the end portions,18and20, of the first and second tubular members,14and16, may be maintained in circumferential compression, axial loads and/or torque loads may be transmitted through the tubular sleeve. In addition, the tubular sleeve40may also increase the collapse strength of the end portions,18and20, of the first and second tubular members,14and16.

A useful method of forming a wellbore casing within a borehole that traverses a subterranean formation has been described that includes a first wellbore casing for positioning within the borehole and coupling the first wellbore casing to the borehole, positioning a second wellbore casing within the borehole such that the second wellbore casing overlaps with and is coupled to a portion of the first wellbore casing thereby forming a joint, positioning a tubular sleeve so that it overlaps with and is coupled to at least a portion of the first wellbore casing and to a portion of the second wellbore casing, the tubular sleeve extending a length in either axial direction from the joint between the first and second wellbore casings, causing the tubular sleeve to collapse inwardly onto the respective end portions of the first and second wellbore casings and to sealingly engage the exterior surfaces of the end portions of the first and second wellbore casings respectively on either side of the joint there between, thereby facilitating sealing the joint.

In an exemplary embodiment, the method further includes regularly expanding and plastically deforming the overlapping portions of the first and second wellbore casing and regularly expanding and plastically deforming the tubular sleeve that was sealingly collapsed onto the overlapping portions of the first and second wellbore casings. In an exemplary embodiment, the exterior diameters of the first and second wellbore casings axially adjacent to the joint there between are substantially equal. In an exemplary embodiment, the inside diameters of the first wellbore casings and the inside diameter of the second wellbore casing are substantially equal. In an exemplary embodiment, the inside diameters of the first wellbore casing and the second wellbore casing are substantially constant.

It will further understood by those skilled in the art upon reading the foregoing disclosure and the claims that follow, and upon review of the drawings that the method may further include forming a wellbore casing within a borehole that traverses a subterranean formation including positioning first wellbore casing, second wellbore casing and additional wellbore casings within the borehole that overlaps one with the other and that are coupled to one another at a joint between each successive wellbore casing. In the method with additional wellbore casings would further includes additional tubular sleeves positioned to overlap each successive joint of the successive wellbore casings in causing each sleeve to collapse inwardly on the respective end portions of the first, second, and additional wellbore casings to sealingly engage the exterior surfaces of the respective end portions. The method further includes the use of magnetic impulse energy to collapse the tubular sleeves onto the surfaces of the wellbore casings at the joints thereof, thereby facilitating sealing of the joints.

It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, the teachings of the present illustrative embodiments may be used to provide a wellbore casing, a pipeline, or a structural support. Furthermore, the elements and teachings of the various illustrative embodiments may be combined in whole or in part in some or all of the illustrative embodiments.

Although illustrative embodiments of the invention have been shown and described, a wide range of modification, changes and substitution is contemplated in the foregoing disclosure. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.