Permanent Electromagnetic Wellbore Sensing for Cement Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for monitoring wellbore cement quality during and after cement placement in well completion operations are inefficient and inaccurate, with significant signal attenuation and inability to provide real-time data, leading to potential contamination and integrity issues.
Innovation Solution
A multi-purpose permanent electromagnetic sensing system is deployed along the casing, comprising an array of magnetic field transmitters and receivers that perform time-lapse measurements to monitor cement resistivity and fluid composition, allowing for real-time monitoring of cement curing and fluid flows, and can integrate with other sensing systems like fiber optics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If wireline-deployed through-casing resistivity (TCR) methods are used to monitor cement, then cement quality can be assessed after emplacement, but signal attenuation through casing is significant and real-time monitoring is not possible
Solution Approach 1:
The electromagnetic sensors are installed on the casing before cement emplacement, and the system is configured to monitor cement properties in real-time as the cement is being pumped into the annulus, enabling preliminary detection of cement quality issues during the placement process rather than after completion
Solution Approach 2:
The patent replaces wireline-deployed mechanical resistivity measurement systems with an electromagnetic sensing system that uses electromagnetic fields to measure cement resistivity and fluid properties through the casing wall, eliminating the need for physical wireline access and enabling continuous real-time monitoring
2Loss of time
If distributed fiber optic sensing methods are used for cement slurry monitoring, then real-time data can be obtained, but measurement accuracy is often unsatisfactory
Solution Approach 1:
The patent substitutes fiber optic sensing methods with electromagnetic sensors that directly measure electromagnetic field changes caused by cement resistivity variations, providing more accurate measurements of cement properties while maintaining real-time monitoring capability
Solution Approach 2:
The system monitors changes in electromagnetic field parameters (resistivity, conductivity) as the cement cures and transforms from liquid to solid state, detecting subtle parameter changes that indicate cement quality and curing progression with higher precision than fiber optic methods
3Measurement precision
If electromagnetic sensors are installed on each collar to enable real-time monitoring, then cement and fluid monitoring accuracy improves, but device complexity increases
Solution Approach 1:
The electromagnetic sensor system is designed to perform multiple functions including cement resistivity monitoring, fluid composition analysis, and curing detection using the same sensor array and processing electronics, reducing overall system complexity while maintaining high measurement precision
Solution Approach 2:
The monitoring system is divided into discrete sensor modules that can be independently installed on individual collars, allowing flexible configuration where sensors are placed only at critical locations rather than requiring complete coverage, thereby reducing complexity while maintaining monitoring effectiveness
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 system provides accurate and efficient monitoring of cement quality and fluid composition, enabling real-time data acquisition and improving wellbore integrity by detecting contamination and fluid flows, thus enhancing the reliability of well completion operations.
Implementation Method 1
significant signal attenuation through casing
Implementation Method 2
array of electromagnetic sensors configured to detect changes in electromagnetic fields
Implementation Method 3
As the cement slurry is pumped through the casing and into the annulus between the casing and the formation, the cement slurry displaces the spacer fluid, which in turn, displaces the drilling mud
Data Source
AI summary
Methods and systems of electromagnetic sensing in a wellbore are presented in this disclosure for monitoring annulus fluids and water floods. An array of transmitters and one or more receivers are located along a casing in the wellbore. A transmitter in the array and one of the receivers can be mounted on a same collar on the casing forming a transmitter-receiver pair. The receiver can receive a signal originating from the transmitter and at least one other signal originating from at least one other transmitter in the array, wherein the signal is indicative of a fluid in the wellbore in a vicinity of the transmitter-receiver pair and the at least one other signal is indicative of another fluid in a formation around the wellbore. The receiver can further communicate, via a waveguide, the signal and the at least one other signal to a processor for signal interpretation.