Skip to main content
padlock icon - secure page this page is secure

A Precise Porosity Measurement Method for Oil-Bearing Micro/Nano Porous Shales Using Low-Field Nuclear Magnetic Resonance (LF-NMR)

Buy Article:

$106.51 + tax (Refund Policy)

Low-field nuclear magnetic resonance (LF-NMR) is a non-invasive and effective method for quantitatively characterizing rocks, and has been used to characterize nanopore structure of shales. However, water (or brine) has commonly been used to saturate samples in the previous LF-NMR tests of shale, resulting in hydration swelling. In this study, LF-NMR analyses of kerosene-saturated shales were performed under a variety of test conditions (i.e., various waiting times and echo times) to establish a precise measurement method for characterizing oil-bearing micro/nano porous shale porosity. Furthermore, helium (He) porosity measurements were used to verify the porosity determined by LF-NMR. Comparing the T 2 spectra pertaining to various waiting times, the optimal waiting time was determined. Subsequently, using He-porosity as a benchmark, the relative errors associated with NMR-determined porosities and He-determined porosities were estimated such that the optimal echo time could be determined. The primary findings of this study include followings: (1) The longer the waiting time, the more completely polarized the protons becomes; the protons in the kerosene within shales evaluated in the present study were approximately completely polarized as the waiting time is 1500 ms. (2) Echo time is a parameter that is critical to improving the accuracy of shale porosity determined by LF-NMR; at longer echo time, nanopores within the shales may not be detected resulting in a smaller NMR porosity, while at much shorter echo time (0.075 ms), the relaxometry data of kerogen can be detected resulting in a higher NMR porosity. An echo time of 0.2 ms is required to minimize relative errors. (3) For the shales in the Dongying depression, the most reasonable waiting time and echo time for LF-NMR porosity tests were 1500 ms and 0.2 ms, respectively.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Keywords: Echo Time; Hydration Swelling; Low-Field Nuclear Magnetic Resonance; Oil-Bearing Micro/Nano Porous Shale; Waiting Time

Document Type: Research Article

Affiliations: Research Institute of Unconventional Oil and Gas and Renewable Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China

Publication date: September 1, 2017

More about this publication?
  • Journal for Nanoscience and Nanotechnology (JNN) is an international and multidisciplinary peer-reviewed journal with a wide-ranging coverage, consolidating research activities in all areas of nanoscience and nanotechnology into a single and unique reference source. JNN is the first cross-disciplinary journal to publish original full research articles, rapid communications of important new scientific and technological findings, timely state-of-the-art reviews with author's photo and short biography, and current research news encompassing the fundamental and applied research in all disciplines of science, engineering and medicine.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Terms & Conditions
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more