Hydraulic Near-Bit Reamer Activation via Drop Ball Flow Restriction

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Solution Overview

Problem

In well drilling operations, existing systems face challenges in efficiently enlarging the borehole diameter to accommodate larger casing strings and ensure adequate annulus space for cement sheath, particularly when drilling through existing casing strings, as conventional methods may degrade performance of downhole tools and fail to effectively activate borehole openers.

Innovation Solution

The implementation of a near-bit reamer (NBR) activated by adjusting hydraulic pressure within the bottom hole assembly, using techniques such as deformable drop balls, filter actuation assemblies, and high-viscous pill fluids to create temporary flow restrictions and increase hydraulic pressure, allowing cutter elements to deploy and expand the borehole diameter without impairing the functionality of adjacent tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional drilling methods are used to drill through existing casing strings, then the drilling operation can proceed, but the borehole diameter is insufficient to accommodate larger casing strings and adequate annulus space for cement sheath

Engineering Contradiction:

Improveborehole diameterVSAvoiddrilling system complexity

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The bottom hole assembly is segmented into distinct functional zones: a protected zone containing MWD/LWD tools isolated from high pressure, and an activation zone where hydraulic pressure is increased to deploy the near-bit reamer. This segmentation allows the reamer to be activated without exposing the entire BHA to high pressures that would degrade tool performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A flow restriction device is introduced as an intermediary element to create temporary pressure buildup. This device is positioned upstream of the reamer and, when activated (e.g., by a drop ball), restricts flow to generate the hydraulic pressure needed to deploy the reamer's cutter elements, while the pressure is contained to a specific zone rather than affecting the entire system.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If hydraulic pressure is increased to activate the near-bit reamer, then the borehole can be enlarged, but the performance of downhole tools like MWD and LWD may be degraded

Engineering Contradiction:

Improveborehole enlargement efficiencyVSAvoiddownhole tool performance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flow restriction device is activated before the reamer deployment to pre-build hydraulic pressure in the annulus. This preliminary pressure buildup ensures that when the reamer's cutter elements are deployed, they have sufficient force to effectively enlarge the borehole, improving productivity while the pressure is contained to a specific zone rather than affecting the entire system.

Inventive Principle:

Principle #10Preliminary action

3Volume of moving object

If a larger diameter borehole is drilled to accommodate larger casing strings, then more annulus space is available for cement sheath, but conventional drilling methods cannot achieve the desired diameter when drilling through existing casing

Engineering Contradiction:

Improveborehole diameterVSAvoiddrilling operation simplicity

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The near-bit reamer is designed to be self-deploying through hydraulic pressure built up in the annulus. The cutter elements automatically extend when the hydraulic pressure exceeds a threshold, eliminating the need for complex external activation mechanisms or manual intervention, thus maintaining ease of operation while achieving larger borehole diameter.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Hydraulic pressure in the annulus is utilized to activate the near-bit reamer. By introducing a flow restriction that temporarily increases annular pressure, the cutter elements are deployed without requiring complex mechanical activation systems, maintaining operational simplicity while achieving the desired borehole enlargement.

Inventive Principle:

Principle #29Pneumatics and hydraulics

4Productivity

If flow restriction is created to increase hydraulic pressure for reamer activation, then the near-bit reamer can be effectively deployed, but the drilling fluid flow is temporarily impeded

Engineering Contradiction:

Improvereamer activation effectivenessVSAvoiddrilling fluid flow

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The flow restriction is applied temporarily and periodically rather than continuously. The restriction device (e.g., drop ball) is activated to build pressure for reamer deployment, then removed or bypassed to restore normal drilling fluid flow. This periodic application achieves effective reamer activation while minimizing the duration and impact of flow restriction.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The flow restriction is applied briefly just long enough to build sufficient hydraulic pressure for reamer cutter deployment, then the restriction is removed and normal flow resumes. The critical pressure buildup phase is rushed through quickly, minimizing the time during which drilling fluid flow is impeded while still achieving effective reamer activation.

Inventive Principle:

Principle #21Skipping (Rushing through)

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 enables efficient enlargement of the borehole diameter while maintaining the performance of downhole tools like MWD and LWD, ensuring proper functioning of directional drilling systems and allowing for larger casing strings by effectively activating the near-bit reamer with controlled hydraulic pressure increases.

Implementation Method 1

adjusting the hydraulic pressure of the drilling fluid within a bottom hole assembly

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

techniques such as deformable drop balls, filter actuation assemblies, and high-viscous pill fluids to create temporary flow restrictions and increase hydraulic pressure

Methodology Applied

Scientific EffectFlow restriction:

Implementation Method 3

techniques such as deformable drop balls, filter actuation assemblies, and high-viscous pill fluids to create temporary flow restrictions and increase hydraulic pressure

Methodology Applied

Scientific EffectViscosity:

Data Source

PatentUS9810025B2Hydraulic activation of mechanically operated bottom hole assembly tool

Publication Date: 2017.11.07 HALLIBURTON ENERGY SERVICES INC

AI summary

A method of hydraulically activating a mechanically operated wellbore tool in a bottom hole assembly includes: holding moveable elements of the wellbore tool in an unactivated position using a shear pin; inserting one or more drop balls into a drilling fluid; and flowing the drilling fluid with the drop balls to a flow orifice located in or below the wellbore tool. The flow orifice is at least partially plugged with the drop balls to restrict fluid flow and correspondingly increases the hydraulic pressure of the drilling fluid. The hydraulic pressure is increased to a point beyond the rating of the shear pin, thereby causing the shear pin to shear and allowing the moveable elements of the tool to move to an activated position.