ABSTRACT

There has been a resurgence of salt dome exploration in the Mesozoic basins of the Gulf Coast in the last five years. The renewed interest in salt dome prospecting is driven by a reinterpretation of salt dome morphology and advancements in reflection seismology.

Salt domes were originally drilled on their crests at shallow depths, and the flanks were largely ignored. The domes were thought to have grown during Tertiary time, breeching the deeper traps. It was also thought that the salt stock was large and limited the extent of upturned beds beneath the dome overhang.

However, recent drilling has confirmed that the domes have episodic growth, complex faulting, and multiple unconformities. If porous and permeable beds surround the dome, oil and gas may accumulate in unconformity traps, in down-to-the-dome fault traps, and in upturned beds sealed against the salt stock or overhang base. Since the salt stock is small in comparison to the overhang, many of these traps exist beneath the salt cover, and remain undiscovered.

Several oil and gas operators currently have plans to drill salt dome prospects in East Texas, North Louisiana, and Mississippi. Some prospects are based solely on well control, while others rely on sophisticated seismic imaging. All of the prospects require drilling through an extensive thickness of salt to explore for reserves that remain beneath the salt cover.