The use of nuclear magnetic resonance, permeability, and diffusion to characterize the porous microstructure of sandstones

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5683472

Bowers, M C

The porous microstructure of rocks, pores and pore-throats control how fluid and gas migrate through a sedimentary rock and are the interface through which fluids interact with the rock matrix. Measurements like capillary pressure, permeability, formation factor and diffusivity are made to understand the nature of the porous microstructure. Current understanding of these measurements allows determination of which rocks allow more flow, which contain hydrocarbons, and which allow gases to easily diffuse through. These measurements are not understood well enough to quantitatively characterize the size, geometry and three dimensional arrangement of the porous microstructure. A three part study was undertaken to illustrate the validity of using pore types and throat size information to understand the variation in physical measurements of sedimentary rocks. Part I illustrates a method of determining porosity types from Nuclear Magnetic Resonance (NMR) longitudinal relaxation (T[sub 1]) data. If porosity types derived from NMR data correspond to the porosity types derived from thin sections, the idea of objectively classifying porosity types is validated. Part II is a case study to illustrate the applicability of using objectively classified porosity types and capillary tube models in a hydrocarbon producing field. It is shown that porosity types and their associated throats can be used to develop an understanding of the variation in permeability and which pathways are associated with flow. The sandstones used in this study are the Miocene sandstones of the Satun Field, Pattani Basin, Gulf of Thailand. The third and final part was undertaken to determine how diffusivity measurements are related to the porous microstructure. The diffusion of a gas through a rock is more sensitive to the relatively small features of the porous microstructure. Pore types and mercury injection are combined to quantify the porous microstructure and to create capillary tube models of diffusion.

• Research Organization: Dartmouth Coll., Hanover, NH (United States)
• OSTI ID: 5683472
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
040200 -- Oil Shales & Tar Sands-- Reserves
Geology
& Exploration
36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
58 GEOSCIENCES
580000 -- Geosciences
ASIA
DEVELOPING COUNTRIES
DIFFUSION
GEOLOGY
HYDROCARBONS
MAGNETIC RESONANCE
MICROSTRUCTURE
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
PERMEABILITY
POROSITY
RESONANCE
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
THAILAND