Converging-Diverging Nozzle for Steam Choking in SAGD Wells

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Solution Overview

Problem

In subterranean hydrocarbon production, especially in SAGD operations, steam preferentially enters production tubing over desired hydrocarbons due to its lower density, leading to inefficient hydrocarbon production.

Innovation Solution

A nozzle with a converging-diverging passage design, featuring a sharp transition corner, is positioned on the exterior of production tubing to choke steam flow while allowing hydrocarbons to pass through, utilizing the Venturi effect and Prandtl-Meyer expansion to enhance pressure drop and separate steam from hydrocarbon mixtures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If steam is injected into the reservoir to reduce hydrocarbon viscosity, then hydrocarbon mobility is improved, but steam preferentially enters production tubing due to lower density, reducing production efficiency

Engineering Contradiction:

Improvehydrocarbon production rateVSAvoidsteam loss in production tubing

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The nozzle is installed at specific locations (ports) along the production tubing to create localized flow control zones. Each nozzle provides targeted steam choking at its specific position, allowing differential control of steam vs. hydrocarbon flow at different depths in the reservoir, thereby preventing preferential steam entry while maintaining hydrocarbon production

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The nozzle geometry (converging-diverging passage with specific angle ranges: 5-15° for converging section, 5-20° for diverging section) is designed to change flow parameters (pressure, velocity, density) differently for steam and hydrocarbon mixtures. This parameter change exploits the density difference between steam and hydrocarbons to achieve selective flow control

Inventive Principle:

Principle #35Parameter changes

2Loss of substance

If a flow control device is installed to choke steam flow, then steam production is reduced, but the device complexity increases

Engineering Contradiction:

Improvesteam loss reductionVSAvoidnozzle structure complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The nozzle serves multiple functions simultaneously: it acts as a flow restrictor, a density-based separator, and a flow direction controller. This multi-functionality is achieved through its converging-diverging geometry which naturally creates different flow behaviors for steam and hydrocarbon mixtures without requiring additional components or complex mechanisms

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The nozzle is designed to be installed within the existing production tubing structure at port locations. The nozzle body is positioned such that its outlet aligns with the port opening, nesting the flow control function within the existing tubing architecture rather than requiring separate external equipment

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If a longer nozzle is used to improve flow control, then steam choking effectiveness increases, but the nozzle length and device size increase

Engineering Contradiction:

Improvesteam flow control effectivenessVSAvoidnozzle length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The nozzle achieves sufficient steam choking effectiveness with moderate length by using optimized angle ranges (5-15° for converging, 5-20° for diverging sections) that create efficient flow separation. The design applies partial action principle by not extending the nozzle length excessively beyond what is needed to achieve the desired flow control, balancing effectiveness with compact dimensions

Inventive Principle:

Principle #16Partial or excessive 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 nozzle effectively limits steam flow into production tubing, increasing the production rate of hydrocarbons by maintaining a high-quality, hydrocarbon-rich flow with a shorter nozzle length and avoiding shockwaves, thereby improving hydrocarbon extraction efficiency.

Implementation Method 1

utilizing the Venturi effect and Prandtl-Meyer expansion to enhance pressure drop and separate steam from hydrocarbon mixtures

Methodology Applied

Scientific EffectVenturi effect: Venturi Effect

Implementation Method 2

utilizing the Venturi effect and Prandtl-Meyer expansion to enhance pressure drop and separate steam from hydrocarbon mixtures

Methodology Applied

Scientific EffectPrandtl-Meyer expansion:

Data Source

PatentUS11536115B2Flow control nozzle and system

Publication Date: 2022.12.27 VARIPERM ENERGY SERVICES INC

AI summary

A flow control system includes a nozzle for controlling the flow of fluids into production tubing from a hydrocarbon containing reservoir. The nozzle comprises a passage extending between an inlet and an outlet, wherein the passage comprises converging and diverging sections separated by a corner. The nozzle serves to effectively choke the flow of steam and thereby allows preferential production of hydrocarbons.