| abstract |
A first tubular member 370 of smaller diameter is coupled to a second tubular member 100 of larger diameter by placing the smaller tubular inside the larger tubular and displacing an expansion cone 375 through the smaller tubular. The interface between cone and tubular is lubricated and the cone is moved by pumping fluids 320 into the first member, the fluids being drawn from nearby rather than pumped down a borehole from the surface. The inside of the first tubular may be coated in lubricant, or the lubricant may be injected into the interface. The lubricant may comprise two components, whereby the first is coated onto the tubular and the second is circulated along with the pressurising fluids. Expansion of the first tubular can be used to repair a breach in a wellbore casing and it may carry a sealing element 380 to enhance the seal (figure 3c). |