Discovery and Development of Person Field, Karnes County, Texas: ABSTRACT

Abstract

The Person field is significant principally because it has proved the presence of oil accumulation in commercial quantities in the downdip part of the Edwards trend. The field is similar to other well known Edwards limestone fields of South Texas, in that it produces on the upthrown side of a north-dipping fault which faults the upper Edwards against the impervious Georgetown limestone. The productive section in the Person field consists of the upper 200-350 feet of the Edwards. This section is characterized by streaks of porous limestone with considerable fracturing and vuggy to intergranular porosity separated by sections of hard dense limestone with no measurable porosity or permeability. Three productive sections tested in the discovery well had average porosities of 11-13 per cent and average permeabilities of 11-12 millidarcys. A definite gas cap approximately 200 feet thick has been established. The oil column appears to have a thickness of 100 to 150 feet. With the existence of the thick gas cap, high ratio problems have been fairly common and thus have complicated completions. The field is still in the process of development and the limits have not been defined; however, as this paper is written, the field extends 4 miles northeast-southwest and approximately 1-1½ miles northwest-southeast. Sixteen wells have been completed, five wells are drilling, and one is testing. End_of_Article - Last_Page 1603------------