ABSTRACT: Geological Study of the Triassic Reservoirs of the Hassi R'mel Gas Condensate Field, Algeria

A. Hamel

The gas condensate Hassi R'mel field, Algeria, was produced from three Triassic sandstone layers (A, B, C), separated by clay intervals.

The extent of the three layers is variable. The lowermost layer, C, characterized by the presence of quartz pebbles, is missing eastward and southward, with the exception of the Djebel Bissa and Hassi-R'mel Sud structures. The intermediate layer, B, has rapid lateral facies changes and disappears eastward and southward. The upper layer A, the most

extended, is present everywhere except on the Djebel Bissa and Hassi R'mel Sud structures.

Sedimentological and petrographic studies show that these sandstones, arranged in sand bodies stretched in a submeridian direction with increasing thickness northward, are very fine to medium, polycyclic, and come from the south. Quartz thermoluminescence reveals that the sandstones are from the same provenance, probably Ordovician sandstones.

The typical sequence was identified as a fluvial meandering sequence with low to moderate energy. Each sandstone layer corresponds to a period of fluvial deposition, at the end of which lagoons formed allowing the deposition of carbonate and sulfate clays. The whole Triassic is the beginning of a sedimentary cycle that evolves from a continental sedimentation (Triassic) to an evaporatic basin deposit.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990