Downhole Isolation Tool Sliding Sleeve for Well Sealing

Solution Overview

Problem

Current downhole tools require killing the well to remove or replace pumps and gas separators, leading to costly and time-consuming processes, and can result in permanent well damage due to the release of pressurized fluids and gases, especially in heavy oil formations with abrasive sand.

Innovation Solution

A downhole isolation tool with a sliding sleeve and seal sub configuration that allows direct seating and sealing engagement with downhole assemblies, enabling fluid flow control to prevent pressurized fluids and gases from reaching the surface during pump removal or gas separator cleaning, and allowing for reverse flushing without removing the assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the well is killed to remove or replace downhole pumps, then pressurized fluids and gases are prevented from reaching the surface, but the process becomes costly and time-consuming

Engineering Contradiction:

Improvewell sealingVSAvoidmaintenance time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The isolation tool is deployed and activated before pump removal to establish a sealed environment. The sliding sleeve is initially positioned to allow fluid flow, then moved to the sealed position to isolate the wellbore from the surface before the pump is extracted, enabling maintenance without killing the well

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The isolation tool acts as an intermediary device between the wellbore and the surface equipment. It provides a mechanical seal through the sliding sleeve mechanism that isolates the pressurized wellbore environment from the surface, allowing pump removal while maintaining well pressure containment

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the well is killed to remove or replace downhole pumps, then pressurized fluids and gases are prevented from reaching the surface, but operational costs increase

Engineering Contradiction:

Improvewell sealingVSAvoidoperational cost

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The isolation tool is deployed and activated before pump removal to establish a sealed environment. The sliding sleeve is initially positioned to allow fluid flow, then moved to the sealed position to isolate the wellbore from the surface before the pump is extracted, enabling maintenance without killing the well

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The isolation tool acts as an intermediary device between the wellbore and the surface equipment. It provides a mechanical seal through the sliding sleeve mechanism that isolates the pressurized wellbore environment from the surface, allowing pump removal while maintaining well pressure containment

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the well is killed to remove or replace downhole pumps, then pressurized fluids and gases are prevented from reaching the surface, but well damage may occur due to release of pressurized fluids

Engineering Contradiction:

Improvewell sealingVSAvoidwell damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The isolation tool is deployed and activated before pump removal to establish a sealed environment. The sliding sleeve is initially positioned to allow fluid flow, then moved to the sealed position to isolate the wellbore from the surface before the pump is extracted, enabling maintenance without killing the well

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The isolation tool acts as an intermediary device between the wellbore and the surface equipment. It provides a mechanical seal through the sliding sleeve mechanism that isolates the pressurized wellbore environment from the surface, allowing pump removal while maintaining well pressure containment

Inventive Principle:

Principle #24Intermediary (Mediator)

4Productivity

If a ported sliding sleeve is used to allow fluid flow, then fluid can be drawn from the wellbore through the sleeve, but the well cannot be sealed when pump removal is required

Engineering Contradiction:

Improvefluid flowVSAvoidwell sealing

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The sliding sleeve is designed to be movable between two positions: an open position where it allows fluid flow from the wellbore through the apertures in the production tubing, and a sealed position where it blocks the apertures to prevent fluid flow. This dynamic reconfiguration enables the system to switch between production and maintenance modes

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The sliding sleeve incorporates seal members at specific locations that can engage with the bore surface to create localized sealing zones. When the sleeve is moved to the sealed position, these seal members contact the bore wall to block fluid flow paths, providing selective sealing while maintaining the overall structure's integrity

Inventive Principle:

Principle #3Local quality

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 solution reduces the need to kill the well during maintenance, saves rig time, prevents well damage, and allows for efficient cleaning of gas separators without removing them, thereby enhancing operational efficiency and reducing costs.

Implementation Method 1

In an open first position, the sliding sleeve is positioned within the bore so that second and third aperture means, and the seal member, are aligned with the bypass channel to allow communication of fluids from the lower cavity to the upper cavity

Methodology Applied

Scientific EffectFluid flow control through aperture alignment:

Implementation Method 2

an elongate sliding sleeve having an upper and lower end and an elongate cavity therewithin separated into an upper cavity and a lower cavity by a seal member that prevents fluid communication between the upper and lower cavity

Methodology Applied

Scientific EffectMechanical sealing:

Implementation Method 3

a bypass channel, situated along the bore at a bore surface distal to the upper and lower ends of the seal sub, and bounded by the sidewall of the seal sub, thereby preventing fluid communication exterior to the seal sub from the bypass channel

Methodology Applied

Scientific EffectFluid bypass through channel:

Data Source

PatentUS10590740B2Modified downhole isolation tool having a seating means and ported sliding sleeve

Publication Date: 2020.03.17 OIL REBEL INNOVATIONS

AI summary

A downhole isolation tool for insertion in a wellbore and seated engagement to a downhole assembly, for allowing, when a sliding sleeve thereof is slidably positioned in a first position and when coupled to a lower end of said pump apparatus, fluids within a hydrocarbon formation to be drawn through such tool and allowed to pass to the pump apparatus for pumping uphole, and when such sliding sleeve is positioned in a second position and decoupled from said lower end of the pump assembly, for preventing said fluids from passing therethrough and uphole.