Abstract

The Serbin Taylor sand field was discovered by Noble Producing Company on the Peters lease in November, 1985. As of this date, there are 251 wells that can be identified in some phase of drilling or production.

The Serbin field produces oil and gas from low permeability sandstones of upper Cretaceous Taylor age. The sandstones pinch out updip to the west and northwest forming the trapping mechanism. The field is now 23 miles long and 4 miles wide at the widest point.

Structure is not important to production in the field. Regional southeastward dip is faulted by rather insignificant up-to-the-coast faulting which affect production only when the sand is cut out of the well bore. This has happened in only one well in the field to date.

The Serbin sands are high in clay content, including kaolinite, chlorite and mixed layer expanding clays like illite. The effect of the mineralogy requires the sands to be fractured to produce at commercial rates. Present practices include gelled oil with 100,000 to 130,000 pounds of sand, oil being used to prevent damage to the formation.

No water drive is present and only small amounts of water have been seen in the main part of the field. There is a well on the eastern edge of the field that is reported to be making about 100 barrels of water a month, but there is no hard proven oil-water contact in the field to date.

The gas that is being produced is being sold rather than reinjected at the present time. Since this is primarily a gas expansion drive reservoir, much of the otherwise producible oil will be left in the ground as this practice continues.

Of the 112 wells that have been completed to date, the majority have been completed as flowing wells averaging between 29 and 192 barrels of oil per day. It is anticipated that these wells will level off at approximately 25–35 B0PD and 25–35 MCFPD and maintain a relatively stable production decline. All of the wells ultimately make a little water, but it is not an operational problem.

The updip wells to the west and northwest will be expected to have a higher gas-oil ratio than the wells in the main part of the field to the east.

Note: This paper was given at the STGS Luncheon in September 1987. All data in this paper reflects that date.