Nuclear Measurement Tool with Multi-Depth Sensors for Borehole Invasion Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current drilling technologies face challenges in accurately measuring hydrocarbon content in formations due to borehole fluid penetration, which distorts measurements and leads to inaccurate characterization of formation properties, especially with nuclear measurements being sensitive to shallow invasion.
Innovation Solution
A nuclear measurement tool equipped with a nuclear source and multiple sensors operating at different depths of investigation, along with processing means to determine properties like sigma, hydrogen index, density, and invasion profile, allowing for simultaneous correction of borehole fluid invasion and providing accurate estimates of formation properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If nuclear sensors are used to measure formation properties, then measurement capability is improved, but measurement precision deteriorates due to borehole fluid invasion
Solution Approach 1:
The tool divides the measurement function into multiple nuclear sensors, each with a different depth of investigation (DOI). This segmentation allows the system to measure properties at multiple depths simultaneously, enabling differentiation between invaded and uninvaded zones, and thus correcting for borehole fluid invasion effects to improve measurement precision.
Solution Approach 2:
The processing means acts as an intermediary that receives data from multiple sensors with different DOIs and applies computational algorithms to separate the effects of borehole fluid invasion from the true formation properties. This intermediary processing step transforms the raw multi-depth measurements into corrected formation property estimates.
2Measurement precision
If multiple sensors with different depths of investigation are used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The nuclear tool is designed with multi-functionality, where a single tool assembly houses multiple nuclear sensors that serve different measurement purposes (different depths of investigation). This universal design allows one tool to perform multiple measurement functions simultaneously, improving precision without requiring separate tools for each depth measurement.
Solution Approach 2:
The patent combines multiple nuclear sensors with different depths of investigation into a single integrated tool assembly. By merging these sensors and their associated electronics into one unit, the system achieves improved measurement precision while minimizing the increase in device complexity through consolidated design.
3Quantity of substance
If borehole fluid penetration occurs, then fluid mixing happens, but this leads to loss of information about original formation properties
Solution Approach 1:
The system performs preliminary measurements at multiple depths before the invasion zone completely obscures the original formation properties. By measuring at different depths of investigation, the system captures data from both invaded and uninvaded zones while the formation state is still accessible, allowing subsequent reconstruction of original formation properties through processing algorithms.
Solution Approach 2:
The processing means uses feedback from multiple sensor measurements to iteratively determine the invasion profile and correct for its effects. By continuously comparing measurements from sensors with different DOIs and adjusting the inversion algorithm, the system recovers accurate estimates of original formation properties despite the presence of borehole fluid invasion.
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
The tool enables accurate determination of formation properties by accounting for borehole fluid invasion, improving the accuracy of hydrocarbon content estimation and allowing for correction of other logging measurements sensitive to invasion, thereby enhancing the characterization of hydrocarbon reservoirs.
Implementation Method 1
a nuclear source for irradiating the formation
Data Source
AI summary
A nuclear measurement tool for determining properties of a formation penetrated by a borehole fluid. The tool comprising: a nuclear source for irradiating the formation and a a plurality of nuclear sensors each operating with a different depth of investigation into the formation. The tool further comprising processing means for receiving the data from the nuclear sensors and based thereon determining the properties of the formation by taking into account the penetration of the borehole fluid.