Petrophysical characteristics of carbonate reservoirs: The Red River Formation (Upper Ordovician), Williston Basin, Montana and North Dakota.
Item
-
Title
-
Petrophysical characteristics of carbonate reservoirs: The Red River Formation (Upper Ordovician), Williston Basin, Montana and North Dakota.
-
Identifier
-
AAI9325154
-
identifier
-
9325154
-
Creator
-
Tanguay, Lillian Hess.
-
Contributor
-
Adviser: Gerald M. Friedman
-
Date
-
1993
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Geology | Engineering, Petroleum
-
Abstract
-
Capillary-pressure and image analysis data from the Ordovician upper Red River formation is used to calculate or infer petrophysical characteristics such as apparent porosity, pore-throat size distribution, maximum-threshold injection radius, and recovery efficiency.;A classification of capillary-pressure curves based on sorting, the maximum threshold injection radius, and percent withdrawal efficiency delineates a petrophysical facies. Well sorted capillary-pressure curves are characterized by a maximum threshold injection radius occurring at less than 20% mercury intrusion and by a horizontal to subhorizontal plateaued intrusion curve resulting from an unimodal pore-throat size distribution. Medium sorted capillary-pressure curves are generally sinoidal in shape, and have a maximum threshold injection radius between 10% and 40% cumulative pore volume intrusion. Poorly sorted capillary-pressure curves as generally oblique or diagonal, with no plateau and a poorly defined maximum threshold injection radius.;Capillary-pressure curve types are used to determined the spatial distribution of petrophysical characteristics within a formation. Curve types are spatially clustered and subdivide a formation into petrophysical facies which are continuous laterally and vertically. The increase in size of the maximum threshold injection radius from the bottom to the top of a sequence reveals a coarsening upward sequence in which the top of a sequence is capped by a poorly sorted facies.;Maximum recovery efficiency is correlated to a minimum range in porosity and throat size distribution (1 um to 2 um). Porosity between 10% and 22% generate the greatest extrusion.;The maximum threshold extrusion radius indicates the capillary-pressure that must be maintained for maximum recovery. As the maximum threshold extrusion radius increases greater than 2 um, the withdrawal efficiency decreases. Well sorted pore-systems with low aspect ratios have the highest withdrawal efficiencies, whereas poorly sorted pore-systems generally have no recovery.;There is an inverse relationship between apparent porosity and aspect ratio. Lowest aspect ratios occur in intercrystalline porosity in planar euhedral-subhedral dolomites and the largest aspect ratios occur in anhydrite moldic intercrystalline porosity in subhedral to anhedral dolomite.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
