Downhole Tool Fluid Flow Path Closure for Reverse Cementing Pressure Testing

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Solution Overview

Problem

In reverse cementing operations, the inability to perform pressure testing of the casing string during or shortly after cementing leads to increased costs and downtime due to the need for the cement slurry to fully set, potentially forming micro-annuli that allow fluid to flow through the casing string.

Innovation Solution

A downhole tool with a fluid flow path that can be closed before, during, or after the cementing operation, allowing pressure testing while the cement is in a fluid state, using mechanisms such as a flapper valve, sleeve shifting, or a ball and ball seat to prevent fluid flow and reduce the likelihood of micro-annulus formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure testing is performed after cement slurry fully sets, then the casing string integrity can be verified, but the operation time is extended and costs increase

Engineering Contradiction:

Improvecasing string integrity verificationVSAvoidoperation time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by closing the fluid flow path through the downhole tool before the cement slurry fully sets. This allows pressure testing to be performed during or shortly after the cementing operation, rather than waiting for complete setting. The fluid flow path is closed using mechanisms such as a flapper valve, sleeve shifting, or ball and ball seat, enabling early verification of casing integrity and reducing operational downtime.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If pressure testing is delayed until cement sets, then accurate integrity assessment is possible, but micro-annuli may form allowing fluid leakage

Engineering Contradiction:

Improveintegrity assessment accuracyVSAvoidmicro-annulus formation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent performs pressure testing as a preliminary action before the cement slurry fully sets and potentially forms micro-annuli. By closing the fluid flow path early and conducting pressure testing during or shortly after cementing, the system verifies casing integrity while the cement is still in a plastic state, preventing micro-annulus formation that would occur with delayed testing.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If the fluid flow path remains open during cementing, then cement can be properly placed, but pressure testing cannot be performed

Engineering Contradiction:

Improvecement placementVSAvoidpressure testing capability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies dynamics by using a downhole tool with a fluid flow path that can transition from open to closed state. During cementing, the fluid flow path is open to allow proper cement placement. After cementing, the path is closed using mechanisms such as a flapper valve, sleeve shifting, or ball and ball seat, enabling pressure testing. This dynamic state change resolves the contradiction between maintaining open flow for cementing and closing for pressure testing.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The downhole tool is designed with multi-functionality, serving dual purposes: allowing fluid flow during cementing operations and preventing fluid flow during pressure testing. The tool integrates cement placement capability with pressure testing capability through its ability to transition the fluid flow path between open and closed states, eliminating the need for separate operations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Productivity

If early pressure testing is attempted, then downtime is reduced, but the cement may not have set properly affecting test accuracy

Engineering Contradiction:

Improveoperational efficiencyVSAvoidpressure test accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs pressure testing as a preliminary action during or shortly after cementing while the cement is still in a plastic state. This preliminary testing approach maintains measurement accuracy because the cement has sufficient strength to support the test, while simultaneously reducing downtime by eliminating the wait for complete setting. The fluid flow path closure mechanism enables this early testing without compromising test validity.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11519258B2Pressure testing casing string during reverse cementing operations

Publication Date: 2022.12.06 HALLIBURTON ENERGY SERVICES INC

AI summary

A method of pressure testing a casing string in a reverse cementing operation in a wellbore can include: introducing the casing string and a downhole tool installed within the casing string into the wellbore, wherein the downhole tool comprises a fluid flow path defined by an inner diameter of the downhole tool; introducing a cement composition into an annulus located between a wall of the wellbore and an outside of the casing string; causing the fluid flow path of the downhole tool to close against fluid flow from the annulus into at least a portion of the casing string; and increasing pressure within the portion of the casing string that is closed against fluid flow from the annulus. The fluid flow path can be closed by shifting an inner sleeve to close a flapper valve or flow ports, a bridge plug, a packer, or a ball and a ball seat.