Downhole Gas-Liquid Separator for Slug Control

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Solution Overview

Problem

In long horizontal liquid wells with a gas cap, gas slugging occurs, leading to segregated gas forming high-pressure bubbles that can kill the well and disrupt surface facilities, as existing separation technologies are inadequate in addressing this issue.

Innovation Solution

A system and method that passively separates gas from the fluid mix downhole and redirects the gas into a holding annulus, where it is re-injected into the liquid column in a controlled manner to improve homogeneity and flow characteristics, using a passive downhole gas/liquid separation device with a spiral baffle or tortuous apertures to break up gas slugs into finer bubbles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If gas is allowed to segregate and migrate upwardly in the wellbore, then gas slugs form providing lift to the liquid production, but this causes imbalance in fluid lift that can kill the well and upset surface facilities

Engineering Contradiction:
Improveliquid production flow rateVSAvoidwell flow stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the gas phase from the liquid phase by introducing a gas separator that divides the wellbore flow into separate gas and liquid pathways. The gas separator creates distinct zones where gas can be collected and managed separately from the liquid production stream, preventing the formation of disruptive gas slugs while maintaining continuous liquid flow.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a gas separator as an intermediary device between the producing formation and the surface facilities. This separator acts as a mediator that captures and manages gas phase separately, allowing liquid production to continue uninterrupted while preventing gas slugs from reaching the surface and disrupting operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If gas slugs are allowed to pass through surface equipment, then gas is produced along with liquid, but this upsets surface facilities and makes it difficult to efficiently process the produced liquid hydrocarbons

Engineering Contradiction:
Improvegas and liquid productionVSAvoidsurface facility operation
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent extracts the gas phase from the combined gas-liquid flow before it reaches surface equipment. The gas separator removes gas slugs from the production stream, directing gas to a separate pathway while allowing liquid hydrocarbons to flow continuously to surface facilities for efficient processing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The gas separator serves as an intermediary device that intercepts and separates gas from liquid downhole, preventing gas slugs from reaching surface facilities. This intermediary action protects surface equipment from disruption while maintaining production of both gas and liquid.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If existing downhole gas-liquid separator systems are used, then gas separation is attempted, but gas slugging continues to hamper production in such gaseous slug-laden wells

Engineering Contradiction:
Improvegas separation effectivenessVSAvoidproduction flow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by separating gas from liquid at the earliest possible point downhole, before gas slugs can form and disrupt production. The gas separator is positioned to intercept gas phase immediately upon entry into the wellbore, preventing slug formation upstream and maintaining continuous liquid flow to the surface.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs a downhole gas separator as an intermediary device that actively manages the gas-liquid separation process. This separator prevents gas slugs from forming in the first place by continuously separating gas phase from liquid phase, thereby maintaining stable production flow rates without the disruptions caused by gas slugging.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances the flow rate and reduces the risk of well failure by uniformly distributing gas bubbles within the liquid, improving the flow characteristics and preventing surface facility disruptions.

Implementation Method 1

using a passive downhole gas/liquid separation device with a spiral baffle or tortuous apertures to break up gas slugs into finer bubbles

Methodology Applied
Scientific EffectTortuous flow separation:

Implementation Method 2

The injection of gas bubbles provides added lift to the liquid production, while improving the flow characteristics

Methodology Applied
Scientific EffectGas lift: Gas Lift

Data Source

PatentEP3114311B1Fluid homogenizer system for gas segregated liquid hydrocarbon wells and method of homogenizing liquids produced by such wells
Publication Date: 2018.12.26 SAUDI ARABIAN OIL CO
  • EP3114311B1 patent drawingFigure 1~1A
  • EP3114311B1 patent drawingFigure 2~3
  • EP3114311B1 patent drawingFigure 4

AI summary

A system and method for improving the flow characteristics of gaseous slug-laden liquid hydrocarbon wells, particularly from horizontal, of similar boreholes. The invention provides a system and method which essentially homogenizes the liquid and the gas, utilizing a unique flow tube arrangement and a sequence of steps by first breaking up and separating the slugged gas from the liquid at a first location, and then gathering it into holding location - - i.e., an annulus section - - where it is re-introduced in controlled amounts into the liquid downstream of the first location. The gas is re-introduced into the liquid flow in such pre- determined and controlled quantities as to promote better pressure and flow characteristics of the hydrocarbon liquid product. Various alternative gas/liquid separation devices are incorporated into the system of the invention, which devices may be located either in a vertical wellbore or a horizontal wellbore, depending upon the particular well characteristics. Optionally, an electric submersible pump may be incorporated where needed to assist the mixed production flow toward surface. A compressor may optionally be provided in the gaseous holding location, where needed. An apparatus for homogenizing production fluid from an oil well having one or more horizontal bores is also disclosed.