About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
AAPG Special Volumes
Abstract
Chapter from:
(Publication Subject:
Chapter 3
Seal Capacity of Nonsmectite Shale
by
James T. Krushin1
Amoco Exploration and Production Company, U.S.A.
1Currently
consultant, 13102 Fallsview Lane, #4904-F, Houston, Texas
ABSTRACT
phase
(i.e.,
mercury in the laboratory tests) begins to displace the wetting
phase
from the largest
interconnected pore throats. The 12 well-indurated nonsmectite shales studied range in age
from Precambrian to Jurassic and vary in mineralogy, porosity, permeability, cation
exchange capacity, organic content, and stratification. The shales are treated as two
distinct groups with respect to interpreting displacement pore throat size: nonorganic
shales and organic shales. Estimation of mineral percentages by X-ray diffraction
analysis, and classifying the shales according to silt/clay ratios, laminations, and major
nonclay/nonsilt mineralogy, permit petrographic prediction of seal capacity for nonorganic
shales. Quartz content of the matrix is the best predictor of the displacement pore throat
size for nonorganic shales. Sandy mudstones have the largest measured tabular displacement
pore throats for nonorganic shales and are in the 30-40 nm range. This pore throat size
range can limit the size of very large gas columns. Clay-rich and calcareous shales have
such small displacement pore throats (<15 nm) that they are excellent capillary seals.
The organic shales studied have large displacement pore throats relative to their low
porosity when compared to nonorganic shales. Volume reduction of the matrix associated
with hydrocarbon generation contributes to the largest pore throats in organic shales.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |