BACKGROUND

Field

The disclosure relates to methods of coating an inner surface of a coiled tubing string, methods of conducting tubing operations using a coated tubing string, and associated apparatus thereof.

Description of the Related Art

Operational problems can arise when pumping fluids through coiled tubing. For example, frictional forces between the pumped fluids and the coiled tubing can require excess pumping power to pump the fluids, excess pressure to pump the fluids, and/or a different fluid composition. Frictional forces can also hinder fluid flow rates. Such problems can result in large operational costs, delayed operations, and/or operational failures. Such problems can also reduce the useful life of the coiled tubing.

Therefore, there is a need for coiled tubing as a conduit for operations where frictional forces between pumped fluids and coiled tubing are reduced.

SUMMARY

Implementations of the present disclosure relate to methods of conducting a coiled tubing operation.

In one implementation, a method of conducting a coiled tubing operation, includes forming a tubing string. The tubing string has a central annulus, an inner surface, and an outer surface, and the tubing string is formed from a metallic material. The method also includes coiling the tubing string onto a spool, and moving a coating into the central annulus. The method also includes curing the coating onto the inner surface of the tubing string to form a layer of the coating on the inner surface of the tubing string.

In one implementation, a method of conducting a coiled tubing operation includes applying a coating onto a surface of a metal substrate, and curing the coating onto the surface of the metal substrate to form a layer of the coating in contact with the surface of the metal substrate. The method also includes forming a tubing string from the metal substrate such that the surface of the metal substrate forms an inner surface of the tubing string. The tubing string has a central annulus, the inner surface, and an outer surface. The method also includes coiling the tubing string onto a spool.

In one implementation, a method of conducting a coiled tubing operation, includes forming a tubing string. The tubing string has a central annulus, an inner surface, and an outer surface. The method also includes applying a coating onto the inner surface of the tubing string, and curing the coating onto the inner surface of the tubing string to form a layer of the coating in contact with the inner surface of the tubing string. The method also includes coiling the tubing string onto a spool.

