The Bayou Blue field is on an intermediate-depth salt dome, where shallow oil in Pliocene and Miocene sands was discovered in September, 1929. The initial productive area, located on the apex of the dome, was considered depleted in 1932. First significant production from Miocene sands on the west flank was established in February, 1940. This led to active development of the northwest, west, and southwest flanks of the dome and re-establishment of shallow production on the crest. East-flank production from lower Miocene sands was first obtained in 1941. Deep Oligocene sand oil was discovered in 1954 on the northeast flank, but appears to be non-commercial. Through December, 1955, 13,108,421 barrels of oil had been produced.
The dome is elliptical in outline and is characterized by peripheral faulting, which generally parallels the elongate axis of the dome. These faults, which are downthrown away from the salt plug, change direction, producing an arcuate or sinuous trace on any particular datum. They may join the salt face with depth or along strike of the salt mass. The dominant peripheral fault of Bayou Blue offsets lowermost Miocene beds, which are present on the apex of the dome, to a position 4,600 feet structurally lower on the northwest flank of the dome. The major producing area of the structure is located southwest of the dome’s crest on the downthrown side of this peripheral fault zone in beds of Miocene age which terminate abruptly against the steep salt face. A system of complex radial and complementary faulting is present in the shallow beds above the apex of the plug.
Contoured fault maps are included of all important radial and peripheral faults. The over-all structural aspects of the dome are illustrated by an upper Miocene (Bigenerina 3) map and a lower Miocene (Siphonina davisi) map and six electric-log structural cross sections. Nineteen typical reservoirs encountered in the Bayou Blue field are included, to illustrate the local structural conditions and productive areas.