Effects of Porosity Type, Pore Geometry, and Diagenetic History on Tertiary Recovery of Petroleum from Carbonate Reservoirs. Final Report

摘要

The objective of this study is to determine the mechanisms controlling porosity in Red River formation (Upper Ordovician) carbonate reservoirs, and to determine what types of pore systems result from a given set of depositional and diagenetic conditions. The Red River Formation of Montana is a major oil-producing reservoir in the area and Cabin Creek Field is a good candidate to undergo tertiary recovery in the future. The first sections of this paper discuss the stratigraphy, distribution of lithofacies, depositional environments, and diagenesis of the study area.The section on distribution of porosity discusses the various types of porosity present, their origin, how they are distributed throughout the upper Red River reservoirs, and how they relate to depositional environment. Size and shape of pores and pore throats are discussed in the sections on pore geometry, first in terms of statistical measures from capillary-pressure curves, then by interpretation of scanning-electron micrographs of resin-pore casts. The last two sections discuss petrophysical relationships, diagenetic controls on the development and geometry of pore systems, and the role of pore geometry in the determination of carbonate reservoir characteristics. (ERA citation 07:003237)