Downhole Sand Fallback Prevention Tool With Deviated Flow Path

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Solution Overview

Problem

Conventional methods fail to effectively prevent sand fallback into electrical submersible pumps (ESPs) in oil and gas wells, leading to inoperability and damage due to the accumulation of formation sand and proppant, which can cause check valves to fail.

Innovation Solution

A downhole tool with a poppet valve mechanism that moves between open and closed positions to prevent sand fallback, using a deviated flow path to redirect sand away from the ESP during shutdown, and incorporating a wiper seal and weep hole to maintain fluid flow while inhibiting sand passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a check valve is used to prevent fluid backflow, then fluid flow back through the pump is prevented, but sand particles can still accumulate and cause valve failure

Engineering Contradiction:

Improvecheck valve reliabilityVSAvoidsand accumulation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The check valve is segmented into multiple functional components: a poppet body with a poppet valve for fluid flow control, a separate sand cup for sand accumulation, and a sand discharge mechanism. This segmentation allows the valve to handle both fluid flow and sand separation independently, preventing sand from interfering with the valve's sealing function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A sand cup is introduced as an intermediary component between the fluid flow path and the check valve seating surface. The sand cup captures sand particles that enter with the fluid, preventing them from reaching and damaging the valve seating surface. This intermediary structure protects the critical sealing interface from sand-related failures.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If sand fallback prevention is implemented, then ESP damage is reduced, but device complexity increases

Engineering Contradiction:

ImproveESP protectionVSAvoidvalve structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sand fallback prevention functionality is merged into the existing check valve structure. The poppet body incorporates both the fluid flow control function and the sand separation function in a single integrated component. The sand cup is positioned within the valve body, combining sand accumulation and fluid flow control in one assembly, thereby reducing overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The check valve is designed with multi-functionality: it simultaneously performs fluid flow control (check valve function), sand particle separation (sand cup function), and sand discharge (discharge port function). This universal design eliminates the need for separate sand removal devices, reducing device complexity while maintaining comprehensive ESP protection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If a poppet valve mechanism is used to prevent sand fallback, then sand accumulation in ESP is reduced, but mechanical wear on the valve increases

Engineering Contradiction:

Improvesand fallback preventionVSAvoidvalve service life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The harmful sand particles are extracted from the fluid stream by the sand cup before they can reach the poppet valve seating surface. By removing sand from the system at an early stage, the frequency and intensity of sand-related mechanical wear on the valve components is significantly reduced, extending valve service life.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The sand cup performs preliminary sand capture action before the fluid reaches the poppet valve. This preliminary separation reduces the sand load on the valve mechanism, minimizing mechanical wear and extending the operational life of the valve components.

Inventive Principle:

Principle #10Preliminary action

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 solution effectively reduces sand fallback, enhancing the reliability and longevity of ESPs by preventing sand accumulation and maintaining fluid flow, even during shutdown conditions, thus improving the operational efficiency and reducing mechanical wear on valves.

Implementation Method 1

incorporating a wiper seal and weep hole to maintain fluid flow while inhibiting sand passage

Methodology Applied

Scientific EffectPhysical barrier filtration: Filter (physical)

Implementation Method 2

using a deviated flow path to redirect sand away from the ESP during shutdown

Methodology Applied

Scientific EffectHydrodynamic separation: Cyclone Separation

Implementation Method 3

A downhole tool with a poppet valve mechanism that moves between open and closed positions to prevent sand fallback

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS11572760B2Modified sand fallback prevention tool

Publication Date: 2023.02.07 HALLIBURTON ENERGY SERVICES INC

AI summary

A downhole tool and method therefor use a deviated flow path to prevent/mitigate fallback of solids during shutdown of an ESP. The deviated flow path leverages the direction of fallback downhole and the relative inertias of the solid particulates and the fluid to minimize fallback into the ESP. The particulates change flow direction more slowly than fluid, and thus largely avoid the deviated flow path to instead fall through a bypass path during fallback. This obviates the need for mechanical valves that may be subject to excessive mechanical wear or other issues associated with solid particulates.