Combining Multiple Energy X-Ray Imaging And Well Data To Obtain High-Resolution Rock, Mechanical, And Elastic Property Profiles

Abstract

A method is provided for evaluating a geological formation which integrates well data and high resolution computed tomography of rock samples thereof. Relationships are determined for a formation between a formation property, such as an elastic property, and at least one of photoelectric effect index (PEF), effective atomic number (Zeff), and bulk density (RHOB), using well data, and tomographic imaging is used to determine at least one of the latter mentioned properties (PEF, Zeff, RHOB) at higher resolution, which can be used in the relationship to determine a corresponding formation property. This affords an opportunity to develop formation property data for more challenging formations to evaluate, such as thinly laminated formations or others. Computerized systems, computer program products on non-transitory computer usable storage media, and programs for performing the methods are also provided.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates generally to the field of geological formation evaluation and, more particularly, to a method for evaluating a geological formation which integrates well data and high resolution computed tomography of rock samples thereof. A system for performing the method also is provided.[0002]Well log measurements can provide a number of rock properties needed to plan well completion and lateral placement. These properties include mineralogy, bulk density, porosity, electrical resistivity and elastic-wave velocities. Elastic-wave velocities and bulk density can be used to compute the elastic moduli needed to estimate the mechanical properties and strength of the formation. These mechanical properties are important for planning deviated and lateral wells and for fracture treatment. However, conventional well data resolution typically is only about 1.5 to 1.0 feet (about 46 cm to about 30 cm). This well data resolution typically is not high e...

AI Technical Summary

Benefits of technology

The present invention is a method for evaluating geological formations using a combination of well data, laboratory data, and computed tomography (CT) data. The method allows for the determination of high-resolution properties of the formation, such as elastic modulus, using a mathematical function equation or cross-plot based on the relationship between different parameters, such as photoelectric effect index, effective atomic number, or bulk density. The method also involves performing a CT scan of a rock sample from the formation and using the resulting data to determine the photoelectric effect index, effective atomic number, or bulk density. The invention provides a more accurate and reliable means for evaluating geological formations and their properties.

Problems solved by technology

However, conventional well data resolution typically is only about 1.5 to 1.0 feet (about 46 cm to about 30 cm).

This well data resolution typically is not high enough for evaluating some formations, such as thinly laminated formations which have thicknesses below the indicated level of resolution feasible with conventional well data.

Well data resolution alone typically is not high enough for evaluating thinly laminated formations of shale.

Using only two-dimensional images, however, one is only able to estimate porosity and organic content.

However, this digital rock physics technology, e.g., 3D CT imaging and / or FIB-SEM technology, does not directly provide the elastic properties needed for computing the elastic moduli and other mechanical properties of the formation.

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