Abstract: Improved Efficiency and Cost Savings: Horizontal Drilling, South Florence Field, Vermilion Parish, Louisiana

Jeffrey A. Spencer, Travis H. Gillham, Allen T. Kutch, Art D. Lombard

Significant cost savings and improved recovery efficiency was demonstrated by the successful completion of a horizontal well in the South Louisiana middle Miocene trend of Vermilion Parish. This completion also represents the first gravel-packed horizontal well completion in the Gulf Coast.

The Amoco No. 104 Watkins well was drilled in South Florence Field to a total depth of 6878^prime MD (5686^prime TVD) as a horizontal well to minimize coning. The well was completed in November, 1994 from an open hole completion over a 600^prime horizontal section (6278-6878^prime MD). The well tested as high as 1079 BOPD, 769 MCFG, and 27 BW. The completed well cost of $1.1MM represents $600M savings over the cost of two vertical wells that would have been necessary to effectively drain the reservoir.

The horizontal target interval was the upper 8^prime of a 148^prime sand with a 30' hydrocarbon column. A well was drilled before the No. 104 to serve as both a pilot hole and to test deeper objectives. The No. 104 was then drilled and encountered the top of the objective reservoir within 150 ft of the pilot hole. The trap is an upthrown fault closure on a down-to-the-east fault associated with the South Florence graben system, the result of deep-seated salt movement. Structural control is provided by numerous wells and a 3-D seismic data set. An oil-water contact defines the downdip limit of this 63 acre reservoir. The completed reservoir, the "5400^prime Sand-lower lobe" is a very fine-grained, silty deltaic sand with sidewall core porosities of 28.9-32.3% and permeabilities of 1100 1050 md.

AAPG Search and Discovery Article #90955©1995 GCAGS 45th Annual Meeting and Gulf Section SEPM, Baton Rouge, Louisiana