Rod String Mounted Low-Profile Wellbore Sensors
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Solution Overview
Problem
Current methods for monitoring wellbore conditions in artificial lift wells are inefficient, particularly when downhole pumps are not used, as sensors require the production tubing to be pulled for installation, powering, and replacement, leading to costly maintenance and temporary deployment challenges.
Innovation Solution
Low-profile sensors are installed on downhole equipment, such as rod strings, allowing them to take readings and transmit data to the surface while the rod string is in operation, with options for attachment via cable or directly to the rod string, enabling easier installation and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are placed on production tubing to monitor wellbore conditions, then measurement capability is provided, but replacement and maintenance require pulling the production tubing string which is costly and time-consuming
Solution Approach 1:
The sensor system is extracted from the production tubing and relocated to the rod string. This allows the sensor to be removed and replaced by simply pulling the rod string, which is a standard maintenance procedure, rather than requiring the expensive and time-consuming operation of pulling the production tubing string.
Solution Approach 2:
The rod string serves as an intermediary carrier for the sensor. By mounting the sensor on the rod string rather than the production tubing, the system uses the rod string as a mediator that provides both sensor support and an easy removal path, decoupling sensor maintenance from production tubing intervention.
2Adaptability or versatility
If sensors are mounted on downhole pumps with power conductors, then sensor functionality is enabled, but the system requires ESP configuration which limits applicability to specific pump types
Solution Approach 1:
The rod string-mounted sensor system is designed to be universally applicable to multiple artificial lift configurations including rod pumps, progressive cavity pumps, and reciprocating pumps. The sensor can operate in various power and signal transmission modes (battery-powered acoustic transmission, wired connection via power conductor, or wireless telemetry) making it adaptable to different pump types and well conditions.
3Ease of operation
If low-profile sensors are installed on rod strings, then ease of installation and retrieval is improved, but the sensor must withstand rod string rotation and reciprocating motion
Solution Approach 1:
The sensor mounting system is designed to accommodate the dynamic motion of the rod string. The sensor can be mounted to allow for rotation in progressive cavity pumps or reciprocating motion in rod pumps, with mounting mechanisms that maintain secure attachment while permitting the necessary mechanical movement without compromising sensor integrity or data quality.
Data Source
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AI summary
Methods and apparatus for sensing wellbore conditions in artificial lift wells using low profile sensors that are installed on down hole production equipment that makes them easier to install and retrieve. In one embodiment, low profile sensors are installed on a rod string making their insertion and removal much easier than it would be if they were mounted on production tubing. The sensors can be attached directly to the rod string or can be attached to a cable that is attached to the rod string. The sensors can transmit their data electrically through the cable or through the rod string. Alternatively, the sensors can transmit their data acoustically through the rod string.