Page 73 - Fundamentals of Gas Shale Reservoirs

Principal products Oil, gas Oil, gas Gas, oil Gas, oil Oil, gas Gas Dry gas

Internal structures Finely laminated Laminated; well bedded Poorly bedded Poorly bedded; bioturbated Massive; bioturbated

Depositional environment Anoxic (saline); usu. lacustrine; rare marine Anoxic usu. marine Variable; often deltaic Mildly oxic; shelf/ slope; coals Highly oxic

10–40 20–60 40–80 50–150 20–200
OI

HI >700 350–700 200–350 50–200 <50
O/C ~0.1 ~0.1 ~0.2 ~0.4 ~0.3

H/C >1.4 1.2–1.4 1.0–1.2 0.7–1.0 0.4–0.7

Kerogen‐type assignment Types I, II Types I, II Type II Type III Types III, IV

Maceral description Alginite Amorphous Sporinite Cutinite Resinite Teleinite Collinite Fusinite Micronite Sclerotinite

Coal petrography Liptinite (exinite) Vitrinite Inertinite

Kerogen‐type descriptions a Kerogen description Algal amorphous Amorphous algal Hebaceous Woody Coaly a Adapted and modified from Jones (1984) and Hunt (1995).

TABLE 3.1 Organic matter classification Sapropelic Sapropelic Sapropelic Humic Humic