HYDROCARBON GENERATION IN THE ESSAOUIRA BASIN OF WESTERN MOROCCO

The Essaouira basin is an important onshore hydrocarbon-generating bas in in western Morocco. There are seven producing or shut-in oil and ga s fields. Six produce from Jurassic and one from Triassic reservoirs. Basin modeling and geochemical evidence suggest that hydrocarbon gener ation occurred from at least two source rocks: (1) Jurassic (Oxfordian ) shale accumulated within the Neknafa syncline, and (2) deeply buried Carboniferous coals underlying the eastern basin area. The Oxfordian shale was sufficiently buried in western Essaouira to generate volumin ous gas and condensate liquids, and to expel them into structurally cl osed Jurassic reservoirs (Toukimt field) or offset horst-block Triassi c reservoirs (Meskala field). Geochemical evidence suggests that the J urassic-age reservoirs across the eastern Essaouira basin host comming led gases sourced from Jurassic and Carboniferous strata. Coal methane , generated from a deeply buried Carboniferous interval, may have been the main source for the eastern Essaouira basin. Traps developed as s tructures draping salt domes at junctions of offset transtensive fault s.