Composite Casing Window Covering for Lateral Wellbore Integrity

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Solution Overview

Problem

Traditional methods for creating lateral wellbores through pre-milled windows in casing sections face issues with debris generation and the cost and time required to replace mill bits with drill bits, while previous sealing attempts fail to maintain structural and pressure integrity, leading to fluid leakage.

Innovation Solution

A composite material covering for the casing section, comprising a pressure-bearing layer and a structural layer, applied externally to cover the pre-milled window and extend beyond its perimeter, providing enhanced pressure and structural integrity, and capable of undergoing a phase transformation to reduce debris during drilling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pre-milled window is covered with traditional sealing material, then fluid seal is created, but structural integrity is compromised and fluid leakage occurs

Engineering Contradiction:
Improvefluid sealVSAvoidstructural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies a composite material comprising a metal layer and a polymer layer to cover the pre-milled window. The metal layer provides structural integrity and pressure containment, while the polymer layer provides fluid sealing properties. This composite structure resolves the contradiction by combining materials with complementary properties to simultaneously achieve both structural strength and fluid seal.

Inventive Principle:
Principle #40Composite materials

2Productivity

If mill bit is replaced with drill bit to form lateral wellbore, then lateral wellbore can be formed, but time and cost increase

Engineering Contradiction:
Improvelateral wellbore formationVSAvoidbit replacement time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent changes the physical parameters of the covering material by using a composite with specific mechanical properties that allow it to be drilled with a mill bit rather than requiring replacement with a drill bit. The composite material's composition and thickness are optimized to enable continuous drilling operation without bit changes, maintaining productivity while reducing time loss.

Inventive Principle:
Principle #35Parameter changes

3Strength

If composite material covering is used to maintain pressure integrity, then pressure and structural integrity are improved, but debris generation during drilling increases

Engineering Contradiction:
Improvepressure integrityVSAvoiddebris generation
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The composite material is segmented into distinct layers with different functions: the metal layer provides structural integrity and generates minimal debris, while the polymer layer provides sealing and can be designed to fragment or dissolve in a controlled manner during drilling, reducing overall debris generation. This segmentation allows each layer to address specific concerns independently.

Inventive Principle:
Principle #1Segmentation

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

The composite material effectively maintains pressure and structural integrity, reducing debris and fluid leakage, and allows for efficient formation of lateral wellbores without the need for extensive window enlargement, thus improving the wellbore creation process.

Implementation Method 1

one or more of the layers of the composite material undergo a phase transformation from a solid to a liquid or semi-liquid after introduction into the wellbore and wherein the one or more layers melt at the bottomhole temperature of the wellbore

Methodology Applied
Scientific EffectPhase transformation: Phase Change

Implementation Method 2

a first layer, wherein the first layer is a pressure-bearing layer that is capable of withstanding a specific pressure differential

Methodology Applied
Scientific EffectPressure resistance:

Data Source

PatentEP3033474B1Method of creating a lateral wellbore, using a casing string with pre-milled windows having a composite material covering
Publication Date: 2018.12.05 HALLIBURTON ENERGY SERVICES INC
  • EP3033474B1 patent drawingFigure 1A~1B
  • EP3033474B1 patent drawingFigure 2
  • EP3033474B1 patent drawingFigure 3

AI summary

A casing section comprising: a body comprising a wall; a window, wherein the window is an opening in the wall of the body; and a covering, wherein the covering: (A) is composed of a composite material; (B) is located on the outer surface of the body; (C) covers the window; and (D) spans at least a sufficient distance beyond the perimeter of the window such that the casing section has a desired pressure rating at the location of the window. A method of creating a lateral wellbore in a subterranean formation comprising: introducing a casing string into a wellbore, wherein the casing string comprises at least one casing section; drilling through at least a portion of the covering from the inside of the casing string to expose the window; and forming the lateral wellbore adjacent to the exposed window.