Injection Well Crossflow Rate Determination via IPR Modeling

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Solution Overview

Problem

Existing methods for determining crossflow rates in injection wells are often operationally and economically inefficient, particularly when leaks occur, as they require deploying spinners or flow meters, which can cause mechanical damage and are not always viable.

Innovation Solution

The method involves using surface data during normal operation to model the injection well's performance and determine crossflow rates by converting surface injection pressures into bottomhole pressures, generating an Inflow Performance Relationship (IPR), and modeling the shut-in injection well as a producing well to calculate the crossflow rate at the leak location without the need for spinners or flow meters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If spinners or flow meters are deployed to determine crossflow rates, then measurement accuracy is improved, but device complexity and risk of mechanical damage increase

Engineering Contradiction:

Improvecrossflow rate measurement accuracyVSAvoiddownhole intervention complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual model (copy) of the injection well that replicates its flow characteristics. By modeling the well as a producing well and using surface pressure data to calculate bottomhole pressures, the system determines crossflow rates without physically deploying measurement devices into the wellbore, thereby avoiding mechanical damage risks while maintaining measurement capability

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical measurement system (spinners or flow meters) with a computational modeling system. Instead of using physical devices to measure crossflow rates downhole, the system uses surface pressure measurements combined with well performance modeling and nodal analysis to calculate the crossflow rates, eliminating the need for downhole mechanical measurement devices

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If downhole measurement devices are used, then crossflow rate determination is improved, but operational efficiency and cost increase

Engineering Contradiction:

Improvecrossflow rate determinationVSAvoidoperational efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The system uses existing surface pressure measurement data that is already being collected during normal well operation to determine crossflow rates. By leveraging data that is already available at the surface and combining it with computational modeling, the system eliminates the need for separate downhole measurement operations, thereby improving operational efficiency while maintaining measurement capability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent creates a virtual model of the injection well that replicates its flow characteristics. By modeling the well as a producing well and using surface pressure data to calculate bottomhole pressures, the system determines crossflow rates without physically deploying measurement devices into the wellbore, thereby avoiding mechanical damage risks while maintaining measurement capability

Inventive Principle:

Principle #26Copying

3Productivity

If surface data modeling is used to determine crossflow rates, then operational efficiency is improved, but measurement precision may be compromised

Engineering Contradiction:

Improveoperational efficiencyVSAvoidcrossflow rate accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces computational modeling and nodal analysis as an intermediary between surface pressure measurements and crossflow rate determination. This intermediary process transforms readily available surface data into accurate crossflow rate calculations by accounting for wellbore hydraulics, formation properties, and pressure gradients, thereby maintaining measurement precision while improving operational efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10215002B2Determining wellbore leak crossflow rate between formations in an injection well

Publication Date: 2019.02.26 SAUDI ARABIAN OIL CO

AI summary

Some examples of determining wellbore leak crossflow rate between formations in an injection well are described. During normal operation of an injection well, multiple bottomhole pressures are determined based on multiple surface injection pressures. An Inflow Performance Relationship (IPR) for the injection well is determined based on the multiple bottomhole pressures and the multiple injection flow rates. After shut-in responsive to a subsurface leak, the shut-in injection well is modeled as a producing well having the IPR determined during normal operation of the injection well. A crossflow rate in the injection well at a location of the subsurface leak in the injection well is determined based on the IPR of the modeled producing well.