Prediction of diagenetic reactions and reservoir properties of North Sea reservoir sandstones

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5790764

Bjoerlykke, K ^[1]

---

1. Univ. of Oslo (Norway)

The shallowest Jurassic reservoirs at 1.5 km down to 2.5-3 km burial depth have very little quartz cement (<3%). Between 3.0 and 4.5 km there is a rather sharp increase in the amount of quartz cement, and stylolites are very common indicating important internal sources of silica. In the shallow marine and fluvial Jurassic sandstones kaolinite is the most abundant diagenetic clay mineral and secondary porosity owing to leaching of feldspars is well developed. In sandstones representing deeper water facies, also those closely associated with the source rocks, diagenetic kaolinite is often absent and there is less evidence of feldspar leaching. This suggests that release of acids from the source rocks had little effect on the development of secondary porosity and precipitation of kaolinite. In the Permian and Triassic reservoirs smectite and illite are usually more abundant than kaolinite suggesting that in the dry climate prevailing when these sandstones were deposited, meteoric water flushing was not very effective. From 3.5 to 4 km burial there is often a sharp increase in the content of diagenetic illite, probably owing to illitization of kaolinite and dissolution of K-feldspar causing a rapid deterioration of reservoir properties. Pore water analyses show increasing salinities and more positive {delta}{sup 18}O values with depth suggesting that large-scale convective flow or compactional flow has not taken place, thus limiting the potential for mass transfer by advection.

• OSTI ID: 5790764
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
NORTH SEA
PETROLEUM DEPOSITS
RESERVOIR ROCK
DIAGENESIS
MINERALOGY
CEMENTS
GEOCHEMISTRY
GEOLOGIC HISTORY
ILLITE
INTERSTITIAL WATER
JURASSIC PERIOD
KAOLINITE
OXYGEN ISOTOPES
PERMIAN PERIOD
POROSITY
SANDSTONES
SMECTITE
TRIASSIC PERIOD
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
ATLANTIC OCEAN
BUILDING MATERIALS
CHEMISTRY
CLAYS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GROUND WATER
HYDROGEN COMPOUNDS
ISOTOPES
MATERIALS
MESOZOIC ERA
MINERAL RESOURCES
MINERALS
OXYGEN COMPOUNDS
PALEOZOIC ERA
RESOURCES
ROCKS
SEAS
SEDIMENTARY ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SURFACE WATERS
WATER
020200* - Petroleum- Reserves
Geology
&amp; Exploration
580000 - Geosciences