Patent Application
20140374121
1. Field of Invention
The invention is directed to entry guides for aligning one downhole component relative to another downhole component within a wellbore and, in particular, to entry guides formed at least in part by a dissolvable material.
2. Description of Art
Entry guides such as mule shoes are generally known in the art. In typical arrangement, the mule shoe is attached to the bottom of a downhole casing or tubing string that is run-in a wellbore. The purpose of the mule shoe is to guide the tubing string into the bore of another downhole component already in place within the wellbore. Because the bore of the downhole component already in place in the wellbore is smaller than the diameter of the wellbore, there is a transition from the inner wall surface or inside diameter of the wellbore to the inner wall surface or inside diameter of the downhole component already disposed in the wellbore. The function of the mule shoe is to provide a tapered surface to guide the tubing string attached to the mule shoe into the bore of the existing component disposed downhole. After insertion into the downhole component already in place within the wellbore, the bores of the two downhole components are in alignment such that remedial or other downhole operations can be performed through the bore of the tubing string and through the bore of the downhole component already in place within the wellbore.
Broadly, the entry guides disclosed herein are formed at least in part by a material capable of disappearing. In certain embodiments, the entry guides include a profile disposed on a lower end of the guides that facilitates insertion of the guide into a bore of a downhole component already disposed within the wellbore. All or part of the guide is formed out of the dissolvable material such that, in one specific embodiment, after the tubing string is inserted into the bore of the downhole component already disposed in the wellbore, all or part of the guide dissolves.
While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
Referring now to
Lower end 23 includes a shape or profile 29 to facilitate insertion of guide 20 into a receptacle such as a bore of another component. As discussed in greater detail below, in one specific embodiment, profile 29 guides tubing string 70 into the desired opening of a downhole component disposed in the wellbore into which guide 20 is ultimately inserted by centralizing tubing string 70 and providing a low friction means of entry. As illustrated in
In addition, all or part, e.g., upper end 22, lower end 23, inner wall surface 25, of guide 20 is formed of dissolvable material 30 (
As used herein “dissolvable material” means that the material is capable of being corroded, dissolved, degraded, disintegrated or otherwise compromised by a stimulus such that it no longer retains its initial shape. Thus, dissolvable material 30 is initially designed to have a first or initial shape (
In addition, the dissolvable materials 30 described herein can be formed out of any material that is capable of being removed from the entry guide 20 such that all or part of entry guide 20 dissolves after entry guide 20 has performed its intended function, such as insertion of entry guide 20 into a downhole component already disposed within a wellbore. Thus, “dissolvable material” as used herein comprises any material capable of disappearing or being removed such as through application of temperature, pressure, contact with a fluid, being combusted, being exploded, or being broken up. “Dissolvable” is understood to encompass the terms, but not be limited to the terms, dissolvable, degradable, combustible, and disintegrable as well as materials that are capable of being “removed,” “degraded,” “combusted,” “fractured,” “detonated,” “deflagrated,” “disintegrated,” “degradation,” “combustion,” “explosion,” and “disintegration.”
Suitable dissolvable materials 30 for forming all or part of guide 20 include, but are not limited to materials such as those disclosed and described in U.S. Patent Publication No. 2010/0252273 filed in the name of Duphorne, U.S. Patent Publication No. 2011/0132620 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0132619 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0132621 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0136707 filed in the name of Xu, et al., U.S. Patent Publication No. 2011/0132612 filed in the name of Agrawal, et al., U.S. Patent Publication No. 2011/0135953 filed in the name of Xu, et al., U.S. Patent Publication No. 2011/0135530 filed in the name of Xu, et al., U.S. Patent Publication No. 2012/0024109 filed in the name of Xu, et al., and U.S. Patent Publication No. 2012/0255743 filed in the name of Oxford, each of which is hereby incorporated by reference in its entirety.
Other dissolvable materials 30 comprise composite energetic materials that can be deflagrated or detonated upon proper initiation. These energetic materials typically include an energetic resin and a reinforcement filler. Suitable energetic materials are described in greater detail, including methods of activation of these energetic materials, in U.S. Published Patent Application No. 2005/0281968 which is hereby incorporated by reference herein in its entirety.
Still other suitable dissolvable materials 30 are frangible materials such as non-metallic filamentary or fiber reinforced composite materials that are reducible to a fine particulate matter when subjected to an explosive force. Examples include, but are not limited to graphite reinforced epoxy or glass reinforced epoxy. Breaking or reducing the frangible materials into a fine particulate matter can be accomplished through any method or device known in the art, such as the use of an explosive charge and detonator operatively associated with the sacrificial material and a firing mechanism operatively associated with the detonator and explosive charge in a manner similarly described in U.S. Pat. No. 4,537,255 which is hereby incorporated by reference herein in its entirety or as described in U.S. Published Patent Application No. 2003/0168214 A1, which is also hereby incorporated by reference herein in its entirety.
Yet other suitable dissolvable materials 30 include “fusible materials” such as those that burn or combust due to a chemical reaction between fluid in the wellbore being exposed to the fusible material, such as water in the wellbore contacting the fusible material comprising one or more of potassium, magnesium, or sodium, or as a result of a temperature increase caused by the wellbore itself, or by friction being applied to the fusible material. One specific fusible material is PYROFUZE® available from Sigmund Cohn Corp. of Mount Vernon, N.Y. The PYROFUZE® fusible material consists of two metallic elements in intimate contact with each other. When the two elements are brought to the initiating temperature, or selected temperature increase, they alloy rapidly resulting in instant deflagration without support of oxygen. The reaction end products consist normally of tiny discreet particles of the alloy of the two metallic elements. Therefore, after the fusible material combusts, the area and volume in which fusible material was previous disposed becomes void thereby causing all or a portion of entry guide or profile of the entry guide to sufficiently disappear.
As mentioned above, guide 20 is not required to be formed completely out of dissolvable material 30. To the contrary, one or more portions of guide 20 can be formed out of non-dissolvable materials. For example, guide 20 may include one or more portions or pieces of one or more non-dissolvable materials that are held together by one or more dissolvable material 30. In these examples, the portions of dissolvable material 30 are dissolved, corroded, etc. or otherwise become compromised causing the guide 20 to break apart. Thus, while not all of guide 20 is “dissolved” or otherwise “disappears,” it is sufficiently compromised such that guide 20 will not hinder subsequent operations. For example, in certain embodiments, guide 20 may become sufficiently compromised to permit access through bore 72 of tubing string 70 and bore 52 of downhole component 50 as discussed in greater detail below with respect to
Referring now to
Profile 29 of guide 20 contacts an upper end of downhole component 50 and guides tubing string 70 into bore 52 of downhole component 50 (
Although not required to be, dissolution of all or part of guide 20 can be accomplished by contacting guide 20 with a stimulus such as a corrosive fluid either already disposed in the wellbore, or pumped down the wellbore, or pumped down bore 72 of tubing string 70, which acts on dissolvable material 30 causing it to be compromised such as through dissolution, degradation, or other known mechanism due to the corrosive fluid contacting guide 20. Upon guide 20 being compromised, all or part of the inner diameter of bore 72 becomes unblocked. As illustrated in
As noted above, not all of guide 20 is required to dissolve or “disappear” as those terms are used herein. For example, in certain embodiments, upper end 22 is the only portion of guide 20 formed of a dissolvable material 30. In these embodiments, upper end 22 dissolves thereby compromising the connection between guide 20 and tubing string 70, i.e., compromising threads 28. After being compromised, the remaining portion of guide 20 falls off tubing string 70.
In other embodiments, a central portion of body 21 around bore 26 is formed out of dissolvable material 30, however, outer wall surface 24 is formed out of a non-dissolvable materials. As a result, the diameter of bore 26 increases as the central portion dissolves. In certain of these embodiments, the diameter of bore 26 increases to the same diameter of bore 72 of tubing string 70.
It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the dissolvable material can comprise combinations of one or more different dissolvable materials such as one that dissolves at a first rate and a second that dissolves at a second rate. In addition, the profile of the entry guide is not required to be uniformly shaped as shown in the embodiments of
