Technique for expanding tubular structures

#The present invention relates generally to a technique for expanding tubing, such as tubing utilized within wellbores, and particularly to a technique utilizing an expansion device moved through the tubing.

#A variety of devices are used to expand certain types of tubing from a smaller diameter to a larger diameter. Tubulars, such as those used within wellbores drilled for the production of desired fluids, are sometimes deformed within the wellbore. Typically, the tubing is moved to a desired wellbore location and then forced to a radially expanded condition with an expansion tool.

#An exemplary existing expansion tool is a solid conical mandrel designed to be forced through the tubing to obtain the desired expansion. One problem occurs, however, when such devices must be moved through constrictions in the wellbore. The constriction potentially can impede or prohibit passage of the tool. Another problem can occur in attempting to expand the tubing to conform to “washouts” or other expanded regions in the wellbore. Existing tools are unable to conform to distorted tubular cross-sections. It would be advantageous to have a technique adapted to expand desired tubulars while allowing conformity to such perturbations within the wellbore.

#The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

#FIG. 1 is a front elevational view of an exemplary expansion system disposed within a wellbore;

#FIG. 2 is a schematic cross-sectional view of an exemplary mandrel utilized with the expansion system illustrated in FIG. 1;

#The present technique utilizes an expansion device with a generally tubular section of material. The expansion device is moved through the tubular component to expand the diameter of the component. The technique may be beneficial in expanding numerous types of tubular components in a variety of environments, but for purposes of explanation the technique will be described in conjunction with the expansion of tubular components in wellbore environments. This explanation should not be construed as limiting, but the wellbore environment is one environment in which the present technique is of particular benefit. Also, the use of the term tubular should not be construed as limiting and generally applies to closed, elongate structures having a longitudinal opening therethrough. The cross-sectional configuration of a given tubular may have a variety of forms, such as circular, ovular, undulating, and other configurations.

#Referring generally to FIG. 1, an exemplary expansion system 15 is illustrated according to one embodiment of the present invention. Expansion system 15 is disposed within a wellbore 16 formed in a subterranean, geological formation 17. In this particular application, wellbore 16 extends into geological formation 17 from a wellhead 18 disposed generally at a formation surface 19, such as the surface of the earth. Furthermore, wellbore 16 is defined by a wellbore surface 20 that may be lined with a liner 22. The wellbore 16 is illustrated as having a desired location 24 for receiving a tubular to be expanded on location.

#Expansion system 15 generally comprises a tubular component 26 that may be deployed at desired location 24. The system further comprises an expansion device 28 capable of being moved through a generally central longitudinal opening 30 extending through tubular component 26. Expansion device 28 is pulled or pushed through longitudinal opening 30 by an appropriate mechanism 32, such as a tubing, cable or other mechanism.