Geology of North Part of Corsicana Shallow Oil Field, Ellis and Navarro Counties, Texas: ABSTRACT

Abstract

Oil was discovered at Corsicana, Texas, in 1894 during the drilling of a city water well. The boom which followed led to the development of the first commercial rotary method of drilling, the use of gas engines to pump wells, and the first regulatory efforts of oil and gas by the state of Texas. Two other booms occurred in the early 1950s and late 1970s because of waterflooding and an increase in the price of oil. Corsicana Shallow field consists of four producing horizons: Durango Sand, Wolfe City Sand, Pecan Gap Chalk, and Nacatoch Sand. The northern part of the field produces from the Wolfe City Sand of Campanian age within the Taylor Group. The sand can be divided into separate sand zones with independent oil-water contracts. As the sand zones are traced north and west, each thins and grades into shale. Corsicana field is located on the western edge of the East Texas embayment between the Balcones and Mexia-Talco fault zones. In the north part of the field, two fault trends are present, a N5°W up-to-the-coast fault zone and a N55°E trend of both up-to-the-coast and down-to-the-coast faults. Displacement along major faults ranges from 50 to 140 ft at the Wolfe City horizon. Product on techniques varied in Corsicana field with most wells being completed open hole with 2-in. tubing used for casing during the early 1950s. After 1959, most wells were completed by perforating through casing and mechanically fracturing the pay sand. New production techniques employed in the early 1980s involved the use of salt-water mud systems, selective perforating and treating of individual sand zones, and cement bond logs and radioactive tracer surveys. A polymer injection project in progress southeast of the city of Corsicana may provide additional means of oil recovery if the pilot project proves successful. End_of_Article - Last_Page 145------------