Downhole NMR Fluid Identification in Shale
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current logging technologies face challenges in accurately understanding the fluid and gas distribution within source shale formations, particularly in relating Nuclear Magnetic Resonance (NMR) data to the physical properties of shale, including pore size and wettability, which are crucial for evaluating shale production potential.
Innovation Solution
An apparatus and method utilizing a downhole NMR tool that performs measurements of transverse relaxation times to identify fluids and their locations within shale formations containing porous kerogen material and inorganic matrices, incorporating capillary condensation principles to differentiate between hydrocarbon and water-wet pores, allowing for precise fluid state determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional logging technologies are used, then basic formation evaluation can be performed, but accurate identification of fluid types and locations in shale formations is insufficient
Solution Approach 1:
The NMR tool segments the complex shale formation into distinct pore types (kerogen pores, inorganic matrix pores, micro-fractures) based on transverse relaxation time characteristics, allowing separate identification and analysis of each pore type and its associated fluids
Solution Approach 2:
The invention utilizes changes in NMR transverse relaxation time parameters to differentiate between various pore types and fluid states. By analyzing the distribution of T2 times, the system can identify hydrocarbon-wet versus water-wet pores and determine fluid saturation in different pore spaces
2Loss of information
If NMR measurements are performed on shale formations, then porosity and fluid information can be obtained, but the relationship between NMR data and physical properties (pore size, wettability) is not clearly established
Solution Approach 1:
The system establishes a feedback relationship between NMR measurements and formation properties by using the measured transverse relaxation time spectrum to infer pore size distribution and wettability characteristics, which then guides further interpretation of fluid saturation and type
Solution Approach 2:
The invention uses transverse relaxation time as an intermediary parameter that connects the NMR measurement to the physical properties of the formation. The T2 spectrum serves as a mediator that translates the complex NMR signal into meaningful information about pore size, wettability, and fluid type
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 identification and localization of fluids in shale formations, improving the interpretation of NMR data and enhancing the understanding of fluid distribution, thereby improving the evaluation of shale production potential.
Implementation Method 1
Nuclear Magnetic Resonance (NMR) provides an accurate porosity estimation along with information related to the fluids and gases within the rock
Implementation Method 2
incorporating capillary condensation principles to differentiate between hydrocarbon and water-wet pores
Data Source
AI summary
An apparatus is disclosed for identifying a fluid and locations of the fluid in a formation of shale having porous kerogen material and an inorganic matrix defining pores and micro-fractures. The apparatus includes: a carrier configured to be conveyed through a borehole penetrating the shale; a nuclear magnetic resonance (NMR) tool disposed at the carrier and configured to perform NMR measurements on the shale, the NMR measurements include a spectrum of transverse relaxation times; and a processor configured to receive NMR measurements on the shale performed by the NMR tool and to identify the fluid and locations of the fluid in the shale using the spectrum of transverse relaxation times.