New Gas Discoveries in the Ordovician Sandstone, Risha Area, Northeast Jordan

Ahed A. Sabbah and Hazem M. Ramini

Over thirty wells for exploration and production purposes were drilled in the Risha Area, northeast Jordan by the Natural Resources Authority since 1986. Commercial gas was discovered in the sandstones of Dubeidib Formation (Late Ordovician age). These sandstones are believed to have been deposited in the form of marine sand bars trending NNE-SSW.

During the Early Paleozoic time, Jordan has undergone periods of epirogenic movements ending in Late Ordovician. Two major lineament trends are dominant, one oriented northwest-southeast and the other ENE-WSW. A third trend oriented north-south to NNW-SSE also appears but more discontinuous.

Four source rock horizons were developed within the Early Paleozoic times. Oil generation of Lower Paleozoic source horizons took place in the Late Paleozoic. The upper Mudawwara hot shales of Silurian age is believed to have generated liquid hydrocarbons in the Late Cretaceous times, in a second phase of hydrocarbon generation. Dry gas was originated through organic maturation of the Lower Paleozoic source horizons.

The Risha Gas Field is producing 30 MMcfgd since it was first discovered in 1987.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California