Detachable Reamer for Wellbore Drilling Direction Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing drilling methods for wellbores often require the reamer to be placed meters above the pilot drill bit, making it difficult to steer the drilling direction effectively and complicating the retrieval of the drill string without removing the reamer or liner.

Innovation Solution

A drilling assembly with a first drill bit and a second reamer bit positioned uphole, connected via a selective connection device that allows the reamer to be engaged and disengaged from the drill string, enabling the drill string to be retrieved without removing the reamer or liner, using expandable members and power units to control the connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the reamer is placed meters above the pilot drill bit, then the drill string can be retrieved without removing the reamer, but the drilling direction cannot be steered effectively

Engineering Contradiction:

Improvedrilling direction controlVSAvoidreamer positioning system

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The reamer is designed with expandable members that allow it to transition between a compact state for transport and an expanded state for effective steering. The reamer can be collapsed to a small diameter for retrieval with the drill string, then expanded at the target location to provide adequate steering capability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The reamer is positioned inside or adjacent to the drill string during retrieval operations, allowing it to be nested within the drill string diameter. This nesting arrangement enables the reamer to be transported without removal while maintaining the ability to expand for steering when needed.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of operation

If the reamer is placed close to the pilot drill bit for effective steering, then drilling direction can be controlled, but the drill string cannot be retrieved without removing the reamer

Engineering Contradiction:

Improvedrilling direction controlVSAvoidreamer removal time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The reamer's expandable design allows it to be compact during retrieval and expand only when needed for steering, eliminating the need for removal. The dynamic size change enables both close positioning for steering and easy retrieval without removal.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Instead of removing the reamer from the wellbore, the system recovers the drill string while leaving the reamer in place. The reamer remains positioned close to the pilot bit for continued steering capability, and can be reused in subsequent operations without removal or reinstallation.

Inventive Principle:

Principle #34Discarding and recovering

3Ease of operation

If the reamer is permanently attached to the drill string, then it can be easily retrieved, but it cannot be left in the wellbore for subsequent operations

Engineering Contradiction:

Improvedrill string retrievalVSAvoidreamer reuse capability

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The drilling system is segmented into separable components: the drill string with pilot bit that can be retrieved, and the reamer that remains in the wellbore. The selective connection device allows these segments to be connected during drilling operations and disconnected for drill string retrieval, enabling both easy retrieval and reamer reuse.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system discards the drill string from the wellbore while recovering and retaining the reamer in place. The reamer is left positioned in the wellbore for subsequent operations, eliminating the need for reinstallation and enabling continuous drilling operations without removing the reamer.

Inventive Principle:

Principle #34Discarding and recovering

4Loss of time

If a selective connection device is used to engage and disengage the reamer, then the drill string can be retrieved without removing the reamer, but the device complexity increases

Engineering Contradiction:

Improvedrill string retrieval timeVSAvoidconnection device structure

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The selective connection device is designed to be actuated by the drilling system itself, using existing drilling operations to engage or disengage the reamer. The connection mechanism can be activated by rotational motion or axial forces already present during normal drilling operations, eliminating the need for separate actuation systems and reducing overall complexity.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8056649B2Apparatus and methods for drilling wellbores that utilize a detachable reamer

Publication Date: 2011.11.15 BAKER HUGHES CO

AI summary

An apparatus for use in a wellbore is provided that in one aspect includes: a drilling assembly configured to carry a first drill bit at an end thereof, a second drill bit disposed uphole of the first drill bit, and a connection device that is configured to selectively connect the second drill bit to the drilling assembly and disconnect the second drill bit from the drilling assembly.