Synergy of core petrophysical measurements, log data, and rock examination in carbonate reservoir studies
The pore system characteristics of a wide range of limestone rock types have been reviewed including: reef skeletal framework, chalks, calcareous sands, and mudstones with and without the presence of grains. The emphasis of the present discussion is on carbonate reservoirs that originated as calcareous sands. A synergistic study of the geological, petrophysical, and logging data of these rocks provided insight into their reservoir characteristics. For example, the geological analysis of porosity/permeability crossplots on semi-logarithmic paper produced linear, or at least discrete, trends for each different depositional rock types. Furthermore, the attempts to understand the underlying relationships between the porosity and permeability of these depositional rock types also permitted a better understanding of the affects of diagenesis, dolomitization, and fracturing in more quantitative terms. The diagenetic, or secondary, creation of porosity in carbonates, including grainstones, is quite common. In cases of moldic porosity and intragranular microporosity in grainstones this secondarily created porosity can be relatively isolated from the intergranular pore system. The secondary fraction of the pore volume was recognized and quantified through the analysis of porosity/permeability plots and SEM examination of the core and pore casts. Since this pore system data is relatable to the geological rock types and facies mapped and modeled by geologists, it is then possible to better understand the large-scale distribution of pore types and permeability. Furthermore, when the more thorough understanding of carbonate pore systems is related to the well-log data there is an improvement both in interpretation of logs and in the ability to map reservoir and depositional units.
- Research Organization:
- Schlumberger-Doll Research, Ridgefield, Connecticut
- OSTI ID:
- 5363084
- Report Number(s):
- CONF-8310121-
- Journal Information:
- Soc. Pet. Eng. AIME, Pap.; (United States), Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Vol. SPE11969; ISSN SEAPA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
CARBONATE ROCKS
CRYSTAL STRUCTURE
DATA ANALYSIS
DIAGENESIS
DRILL CORES
ENGINEERING
LIMESTONE
MAPPING
MICROSTRUCTURE
NATURAL GAS WELLS
OIL WELLS
PERMEABILITY
POROSITY
RESERVOIR ENGINEERING
RESERVOIR ROCK
ROCKS
SEDIMENTARY ROCKS
SYNERGISM
WELL LOGGING
WELLS