Drill String Notcher and Packer for Real-Time Formation Stress Testing
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Solution Overview
Problem
Current methods for determining formation stresses in boreholes are inefficient, requiring the removal of the bottom hole assembly, which increases drilling time and hinders the optimization of borehole trajectory for stability and production maximization.
Innovation Solution
A method and apparatus that utilize a drill string with a notcher and a test tool equipped with a packer to perform local induced break-out tests and fracturing operations, allowing for the derivation of formation stress-state data without removing the drill string, enabling the drilling of subsequent sections based on the obtained stress parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the bottom hole assembly is removed from the borehole to conduct stress tests, then formation stress data can be obtained, but drilling time increases considerably
Solution Approach 1:
The patent performs stress tests and fracturing operations while the drill string is still in place, before the bottom hole assembly would need to be removed. The notcher creates notches in the borehole wall during drilling, and stress tests are conducted on these notched sections while the drill string remains positioned, eliminating the need for subsequent removal operations
Solution Approach 2:
The patent combines multiple operations—drilling, notching, stress testing, and fracturing—into a single continuous process while the drill string remains in the borehole. The test tool with packer is deployed on the existing drill string, merging the testing function with the drilling operation rather than requiring separate operations
2Measurement precision
If the drill string is removed to perform stress tests, then formation stresses can be measured, but borehole stability decreases due to repeated entry and removal
Solution Approach 1:
Stress tests and fracturing operations are performed while the drill string remains in position, eliminating the repeated removal and re-entry operations that cause borehole instability. The notches are created and tests are conducted during a single continuous operation
Solution Approach 2:
The packer serves as an intermediary device that can be deployed on the drill string to isolate annulus sections for testing without requiring removal of the drill string. This intermediary tool enables stress measurement while maintaining the stabilizing presence of the drill string
3Measurement precision
If traditional stress testing methods are used requiring assembly removal, then comprehensive stress data is obtained, but drilling productivity decreases
Solution Approach 1:
Stress tests and fracturing operations are performed during the drilling process itself, before the drilling operation would normally conclude. This preliminary action eliminates the need for separate post-drilling testing operations, maintaining continuous productivity
Solution Approach 2:
The drill string remains continuously in position throughout the drilling, notching, and testing operations. The useful action of drilling is not interrupted by removal operations, and stress testing is performed as a continuous part of the drilling process rather than a separate operation
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 approach allows for the efficient estimation of formation stresses and fracturing parameters in real-time, optimizing borehole trajectories to minimize damage and enhance hydrocarbon or geothermal production by enabling precise notching and fracturing operations during the drilling process.
Implementation Method 1
performing a local induced break-out test (LIBOT) and/or local fracturing operation on an annulus section of the first section of the borehole between the drill string and a wall of the borehole using a test tool having a packer
Implementation Method 2
notching a wall of the borehole in one or more selected locations with a selected type of notch using a notcher disposed on the drill string for defined local weakening of the formation
Data Source
AI summary
A method for drilling a borehole penetrating an earth formation includes: drilling a first section of the borehole; notching a wall of the borehole in one or more selected locations with a selected type of notch using a notcher for defined local weakening of the formation; performing a local induced break-out test and/or local fracturing operation on an annulus section of the first section of the borehole between the drill string and a wall of the borehole using a test tool comprising a packer to provide formation stress-state data. The one or more locations is based on the formation stress-state data. The method further includes deriving stress-state of the formation and a fracturing parameter of the formation using the formation stress-state data and drilling a second section of the borehole using the derived stress-state and the fracturing parameter.