Single Trip Sidetracking via Casing Weakening and Milling

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Solution Overview

Problem

The process of sidetracking a well is time-consuming and inefficient due to the need for multiple tool assemblies and steps, particularly when drilling through strong casing strings, which requires weakening the casing prior to creating a window exit.

Innovation Solution

A system and method that utilize a milling assembly in conjunction with a whipstock to create a single trip window exit, where the downhole subassembly weakens the casing string before the milling assembly drills through, allowing for a long, straight window exit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional multi-step procedures are used to create a window exit through casing strings, then the milling assembly can successfully drill through the casing, but the operation becomes time-consuming and complex requiring multiple tool assemblies

Engineering Contradiction:

Improvesuccessful window exit creationVSAvoidoperation completion time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The downhole subassembly performs preliminary weakening of the casing string at the target location before the milling assembly arrives. This pre-conditioning of the casing allows the milling assembly to create the window exit more efficiently during a single trip operation, eliminating the need for multiple tool assemblies and steps.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent combines the casing weakening function and the window milling function into a single integrated bottom hole assembly that can be deployed in one trip. The downhole subassembly and milling assembly work together as a unified system, merging previously separate operations into a single coordinated process.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If multiple tool assemblies are deployed to weaken casing and create window exit, then the operation can be completed successfully, but the device complexity and number of steps increase

Engineering Contradiction:

Improveoperation successVSAvoidnumber of tool assemblies

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bottom hole assembly is designed as a universal system that performs multiple functions: the downhole subassembly weakens the casing while the milling assembly creates the window exit. This multi-functional design eliminates the need for separate specialized tool assemblies for each operation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces the time and complexity of sidetracking by enabling a single trip operation, efficiently creating a window exit within the casing string, thereby enhancing drilling efficiency and reducing the need for multiple tool assemblies.

Implementation Method 1

Additional tools and equipment may be used to weaken the inside portion of the casing string prior to the milling assembly coming into contact with the casing string

Methodology Applied

Scientific EffectMaterial weakening:

Data Source

PatentUS10989006B2Creation of a window opening/exit utilizing a single trip process

Publication Date: 2021.04.27 HALLIBURTON ENERGY SERVICES INC

AI summary

This disclosure may generally relate to drilling operations and, more particularly, to systems and methods for sidetracking an existing well. A bottom hole assembly may comprise a milling assembly, a whipstock coupled to the milling assembly, wherein the whipstock comprises an inclined ramp configured for diverting the milling assembly toward a casing string, and a downhole subassembly coupled to the whipstock, wherein the downhole subassembly comprises a body portion and one or more components on the body portion operable to weaken and/or remove material from the casing string.