Non-invasive Production Logging via Marker Transit Time
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Solution Overview
Problem
Conventional production logging systems require direct access to the well bore for measuring flow rates, which is difficult and expensive, especially in deviated or horizontal wells, leading to incomplete data collection as they often disturb flow regimes and are not feasible for most deviated wells.
Innovation Solution
The process involves conveying markers into the produced fluid at spaced apart locations along the well and detecting them at a common location to calculate fluid velocity and flow rate, using markers such as signal devices or distinct fluids that do not dissolve, allowing for non-invasive determination of production rates without interrupting normal production operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional production logging systems are used to measure flow rates, then direct measurement data can be obtained, but well intervention is required which is difficult and expensive in deviated or horizontal wells
Solution Approach 1:
The patent introduces markers as intermediary substances that are injected into the produced fluid at known locations and detected at the surface. These markers serve as mediators between the downhole flow and surface detection equipment, enabling flow rate measurement without requiring physical access to the well bore. The markers carry information about their injection location and timing, allowing calculation of fluid velocity and flow rate through mathematical relationships.
Solution Approach 2:
The patent replaces the mechanical system of conveying measurement tools through the well bore (wireline or pipe) with a chemical/biological system using detectable markers in the fluid stream. Instead of mechanically moving sensors downhole, the system uses fluid-dynamic transport of markers combined with surface detection, substituting mechanical intervention with a marker-based detection approach.
2Measurement precision
If conventional production logging equipment is conveyed into the well bore, then flow rates can be measured directly, but flow regimes are significantly disturbed
Solution Approach 1:
The markers act as minimally intrusive intermediaries that move with the fluid flow without significantly altering it. Unlike physical measurement tools that occupy space and can block or redirect flow, the markers are substances or particles that are transported by the flow itself, allowing measurement while maintaining natural flow conditions.
Solution Approach 2:
The patent changes the measurement approach from direct physical measurement (requiring tool presence in the well) to indirect measurement through marker transport characteristics. By measuring parameters such as marker arrival time and position at the surface, and using mathematical relationships involving known injection locations and well geometry, the system determines flow rates without physical intervention that would disturb the flow regime.
3Loss of information
If production logs are run in deviated wells to measure flow rates, then productivity data can be obtained, but the process is difficult and expensive requiring production shutdown
Solution Approach 1:
The system enables continuous production logging by injecting markers into the produced fluid stream during normal production operations. There is no need to shut in the well or stop production, as the markers are carried along with the producing fluid to the surface where they are detected. This maintains continuous production while simultaneously collecting productivity data from multiple locations along the well bore.
Solution Approach 2:
The markers serve as intermediaries that enable data collection during continuous production. By injecting detectable substances into the fluid stream and detecting them at the surface, the system obtains productivity information without requiring well intervention or production shutdown, thus maintaining continuous useful action (production) while gathering measurement data.
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 method enables accurate determination of production rates at multiple locations along a well without well intervention, providing valuable data for optimizing well performance and completion strategies, while maintaining consistent fluid production rates and minimizing operational disruptions.
Implementation Method 1
the elapsed time between release of each marker into the fluid and detection within the produced fluids at the common location, the velocity and fluid flow rate can be calculated
Data Source
AI summary
Processes and systems for logging production of fluid produced into a well bore without intervention of the well are disclosed. Two or more markers may be introduced into produced fluid at spaced apart locations along a well. The time for each marker to reach a common point may be measured and production rates for produced fluids at each spaced apart location may be calculated.