Downhole Gravity Monitoring for CO2 Flooding Front Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The difficulty in predicting and monitoring non-uniform flooding fronts of gas injected into subterranean oil reservoirs, particularly due to the complex and unpredictable nature of fingering instability, which affects the efficiency of oil recovery processes.
Innovation Solution
A system utilizing a downhole gravity measurement tool to monitor parameters such as distance, inclination, and shape characteristics of the gas flooding front, leveraging the high density contrast between CO2 and brine or oil to track the movement and behavior of the flooding front, and adjust injection strategies accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas injection is performed to recover oil in reservoirs, then oil recovery efficiency is improved, but fingering instability occurs resulting in poor flood performance
Solution Approach 1:
The patent applies preliminary action by deploying monitoring tools and establishing measurement systems before gas injection begins. The system pre-positiones gravity measurement tools in observation wells and sets up the monitoring infrastructure to detect fingering phenomena as they develop, enabling early intervention before the instability severely degrades flood performance
Solution Approach 2:
The patent implements feedback by continuously monitoring gravity measurements and comparing them against baseline values to detect changes indicative of fingering. The system provides real-time feedback on flooding front position and stability, allowing operators to adjust injection parameters to maintain uniform flood performance while preserving oil recovery efficiency
2Device complexity
If conventional monitoring methods are used, then equipment complexity is reduced, but the ability to detect and measure flooding front parameters deteriorates
Solution Approach 1:
The patent replaces complex mechanical or chemical tracing methods with gravity measurement technology. By utilizing the density contrast between injected gas and formation fluids, the system detects flooding front position and characteristics through gravitational effects, achieving high measurement precision with relatively simple downhole sensor deployment
Solution Approach 2:
The patent exploits parameter changes in density between the injected gas phase and formation fluids to enable detection. By measuring gravitational effects that result from these density differences, the system achieves precise flooding front tracking without requiring complex instrumentation, as the physical parameter change itself provides the detection signal
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 accurate tracking and prediction of fingering phenomena, improving the sweep efficiency of CO2 in oil reservoirs by providing early warnings and optimizing injection patterns to mitigate poor flood performance.
Implementation Method 1
a downhole gravity measurement tool adapted to be deployed in a borehole and to make gravity measurements at a downhole location
Implementation Method 2
leveraging the high density contrast between CO2 and brine or oil to track the movement and behavior of the flooding front
Data Source
AI summary
Downhole gravity measurements are used to monitor the volumetric sweep of CO2 and estimate the fingering phenomenon if any. The gravity measurements have been found to be effective due to the high density contrast between CO2 and brine or oil which provides better and higher sensitivity. An analytical forward model is used to determine the location and shape characteristics of the flooding front. A strategy to monitor the movement of the CO2 flooding front and to predict the fingering phenomenon is used to provide a warning tool to improve the sweep efficiency, according to some embodiments.