Zonal Isolation Integrity Assessment via Pressure Differential Monitoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wellbore zonal isolation methods face challenges in maintaining integrity due to pressure and temperature differentials, leading to potential fluid mixing between zones, which complicates production and requires continuous monitoring for effective isolation.

Innovation Solution

A zonal isolation assessment system comprising a receiver, production tubing, and an assessment assembly with pressure sensors to determine the integrity of zonal isolation by comparing pressure values within the isolation tubing and the annulus, using energy harvesting from production fluid to power the sensors and transmit real-time data for continuous monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If zonal isolation assembly is deployed to isolate zones in wellbore, then fluid mixing between zones is prevented, but pressure and temperature differentials can compromise isolation integrity over time

Engineering Contradiction:
Improvezonal isolation integrityVSAvoidisolation durability under pressure differentials
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system performs preliminary assessment of zonal isolation integrity by deploying pressure sensors before production begins. The sensors establish baseline pressure values in both the isolated annulus and production tubing, enabling early detection of any pressure communication that would indicate compromised isolation. This preliminary monitoring capability allows for proactive identification of isolation issues before they lead to fluid mixing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements continuous feedback monitoring by comparing real-time pressure values from the annulus with pressure values from the production tubing. When pressure differentials exceed predetermined thresholds or when pressure equalization is detected, the system generates alerts indicating potential isolation failures. This feedback mechanism enables continuous verification of isolation integrity throughout the production lifecycle.

Inventive Principle:
Principle #23Feedback

2Reliability

If continuous monitoring of zonal isolation is implemented, then isolation integrity can be maintained, but system complexity and cost increase

Engineering Contradiction:
Improveisolation monitoring accuracyVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The assessment assembly is designed to perform multiple functions: it monitors pressure in both the isolated annulus and production tubing simultaneously, provides real-time communication of pressure values, and generates alerts for isolation failures. By consolidating these monitoring and assessment functions into a single integrated system rather than separate devices, the solution reduces overall system complexity while maintaining comprehensive monitoring capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system automatically compares pressure values from the annulus and production tubing against predetermined thresholds and generates alerts without requiring continuous human intervention. The autonomous assessment capability reduces the need for complex external monitoring infrastructure and manual analysis, simplifying the overall system while maintaining reliable isolation monitoring.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If pressure sensors are deployed to monitor both annulus and production tubing, then real-time detection of pressure communication is enabled, but energy requirements and device complexity increase

Engineering Contradiction:
Improvepressure detection accuracyVSAvoidsensor energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system combines multiple pressure sensing functions into a single assessment assembly that simultaneously measures pressure in both the isolated annulus and production tubing. By integrating these sensing capabilities into one device rather than using separate sensor systems, the solution reduces total energy consumption while maintaining the ability to detect pressure communication between zones through comparative analysis.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables real-time monitoring of zonal isolation integrity, detects early signs of pressure communication, and aids in production strategy planning by determining leakage percentages, thereby ensuring effective zonal isolation and preventing fluid mixing.

Implementation Method 1

a first pressure sensor residing at the internal volume of the isolation tubing and configured to sense a first pressure value representing a fluidic pressure of the internal volume

Methodology Applied
Scientific EffectPressure sensing: Pressure Gradient

Implementation Method 2

a second pressure sensor residing at the annulus and configured to sense a second pressure value representing a fluidic pressure of the annulus

Methodology Applied
Scientific EffectPressure sensing: Pressure Gradient

Implementation Method 3

the first and second pressure values are usable to determine, based comparing the first pressure value with the second pressure value, a zonal isolation integrity of the zonal isolation assembly

Methodology Applied
Scientific EffectPressure differential detection: Pressure Gradient

Data Source

PatentEP4146906B1Determining the integrity of an isolated zone in a wellbore
Publication Date: 2025.01.08 SAUDI ARABIAN OIL CO
  • EP4146906B1 patent drawingFigure 1
  • EP4146906B1 patent drawingFigure 2~3
  • EP4146906B1 patent drawingFigure 4~5

AI summary

A zonal isolation assessment system includes a receiver (106), a production tubing (112) disposed in a wellbore, a zonal isolation assembly (104), and an assessment assembly (102). The zonal isolation assembly includes an isolation tubing (103), a first sealing element (118), and a second sealing element (119) to fluidically isolate an internal volume of the isolation tubing (103) from an isolated annulus (101) defined between the isolation tubing and the wall of the wellbore. The assessment assembly includes a first pressure sensor (200) at the internal volume of the isolation tubing configured to sense a first pressure value and a second pressure sensor (202) at the annulus and configured to sense a second pressure value. The assessment assembly transmits to the receiver the first pressure value and the second pressure value to determine the integrity of the zonal isolation assembly.