Azimuthal Electromagnetic Geosteering Vector for Non-Planar Formations
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Solution Overview
Problem
Current well placement techniques using MWD and LWD tools are inadequate for accurately determining the position of a borehole relative to formation layer boundaries, particularly in non-planar formations, leading to poor well placement and inefficient hydrocarbon extraction.
Innovation Solution
A method utilizing a geosteering vector calculated from electromagnetic measurements to direct the drilling tool towards the most conductive formation area, allowing for real-time evaluation of non-planar formations without requiring two- or three-dimensional modeling, and a superposition method to calculate electromagnetic couplings in complex formations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If propagation resistivity MWD tools are used for well placement, then deep imaging capability (up to 15 feet) is achieved, but directional information (azimuthal orientation) is lost because the tools are non-azimuthal
Solution Approach 1:
The patent transitions from non-azimuthal (2D) propagation resistivity measurements to azimuthal (3D) electromagnetic measurements by incorporating directional antenna arrays. This adds the azimuthal dimension to the measurements, enabling determination of both distance and orientation to formation boundaries while maintaining deep imaging capability.
2Length of stationary object
If propagation resistivity measurements are used, then deep formation imaging is possible, but the measurement range does not extend far enough to provide timely warning before drilling out of the intended reservoir layer
Solution Approach 1:
The azimuthal electromagnetic measurements provide earlier detection of formation boundaries by measuring in multiple directions simultaneously. This allows the drilling operation to take preliminary action (adjust well trajectory) before the drill bit actually reaches the boundary, preventing loss of time and avoiding drilling into unwanted formations.
3Ease of operation
If well placement techniques assume offset borehole formation geometry applies to the current borehole, then drilling operations can proceed without real-time directional data, but the results are inadequate due to formation variability
Solution Approach 1:
The patent implements real-time feedback by continuously measuring azimuthal electromagnetic responses during drilling and using this data to update well placement decisions. This closed-loop system provides accurate formation boundary location information specific to the current borehole, eliminating reliance on offset borehole assumptions and enabling precise well placement.
4Measurement precision
If non-planar formation geometry is evaluated using traditional methods, then comprehensive modeling can be performed, but the process is too time-consuming for real-time interpretation and MWD applications
Solution Approach 1:
The patent replaces complex mechanical/computational multi-dimensional modeling with an electromagnetic-based measurement and interpretation system. By using azimuthal electromagnetic measurements and horn analysis, the system directly determines formation geometry and boundary locations without requiring time-consuming numerical modeling, enabling real-time processing.
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
Enables accurate and efficient well placement by determining the direction of conductive layers and avoiding resistive formations, improving hydrocarbon extraction by optimizing borehole positioning in real-time drilling operations.
Implementation Method 1
transmitting an electromagnetic field from the transmitter along a tool plane normal to the tool axis and inducing a voltage at the receiver as a result of the electromagnetic field
Data Source
AI summary
An orientation vector, referred to hereinafter as the “geosteering vector,” is directed to the more conductive formation area within the DOI of the tool and away from the more resistive formation areas. Accordingly, drilling in a direction opposite the geosteering vector leads to more resistive formation. Also, the disclosed geosteering vectors obtained from the real and imaginary components will not align with each other for non-planar formations and therefore the misalignment of the geosteering obtained from real and imaginary components is indicative of a non-planar formation. A superposition method is disclosed which can be used to calculate electromagnetic (EM) couplings in a non-planar geometry formation (as well as in a planar geometry formation) in real time, without requiring two or three dimensional modeling calculations.