Directional casing and liner drilling with mud motor

Abstract

A directional casing drilling system includes a casing string, a mud motor operatively coupled to the casing string, a rotary steerable system operatively coupled to the mud motor, and a drill bit operatively coupled to the rotary steerable system.

Description

BACKGROUND OF INVENTION [0001] Wells are generally drilled into the ground to recover natural deposits of hydrocarbons and other desirable materials trapped in geological formations in the Earth's crust. A well is typically drilled using a drill bit attached to the lower end of a “drill string.” The drill string is a long string of sections of drill pipe that are connected together end-to-end. Drilling fluid, called “mud,” is typically pumped down through the drill string to the drill bit. The drilling fluid lubricates and cools the drill bit, and it carries drill cuttings back to the surface in the annulus between the drill string and the borehole wall. [0002] In conventional drilling, a well is drilled to a selected depth, and then the wellbore is typically lined with a larger-diameter pipe, usually called “casing.” Casing typically consists of casing sections connected end-to-end, similar to the way drill pipe is connected. To accomplish this, the drill string and the drill bit a...

AI Technical Summary

Benefits of technology

[0029] In one or more embodiment, the invention relates to a directional drilling system that includes a casing string, a mud motor operatively coupled to the casing string, a rotary steerable system operatively coupled to the mud motor, and

Problems solved by technology

This process is very time consuming and costly.

Additionally, other problems are often encountered when tripping the drill string.

For example, the drill string may get stuck in the borehole while it is being removed.

These problems require additional time and expense to correct.

Often the drill bit will veer off of a planned drilling trajectory because of the unpredictable nature of the formations being penetrated or the varying forces that the drill bit experiences.

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