An Engineering Study of the Lafitte Oil Field

Abstract

The Lafitte field, the largest oil reserve in South Louisiana is inJefferson Parish, some 25 miles due south of the City of New Orleans. The discovery well, The Texas Company's No. I., Louisiana Land and ExplorationCo., in the southeast corner of sec. 19, T. 17 S., R. 24 E., was completed onMay IS, 1935. The initial production of this well was 960 bbl. of 34.9 A.P.I.gravity oil per day, through choke, with a tubing pressure of 1600 lb. per sq.in. Producing depth was 9558 to 9572 ft., the total depth being 9572feet. The development of the field has been at the rate of three to eight newproducing wells per year. Up to Jan. I., 1944, 60 producing wells and three dryholes had been drilled, while two of the original producing wells had beenabandoned. Although the field is not unitized, The Texas Company was the sole operator inthe field until the Lafitte Oil Co. completed its No. I Jefferson Parish, nearthe center of the west line of the NW /4 sec. 20, T. 17 S., R. 24 E., on July27, 1941. No additional wells have been drilled by the Lafitte OilCompany. Drilling and Well-Completion Practices All drilling operations have been conducted with the steam-driven rotaryequipment mounted on submersible barges. A canal is dug to the well location and the drilling unit is floated intoposition. The seacocks are then opened and the barge settles to the bottom.After the well is completed, seacocks are closed and water is pumped out of thebarge. This procedure permits the barge, with drilling equipment still inplace, to be floated and moved? off the location. The conventional open-hole and the gun perforation method of completing wellshas been used in this field. Where possible, the initial completion is from thedeepest sand and recompletions are made progressively up the hole, by pluggingback with cement to the upper sand and gun perforating opposite the newsand. The oil string usually is 7% in., 26 to 34-lb. casing. Three wells have beencompleted using 9%-in. 44-lb.casing set below 10,000'Feet. Fig. I shows the completion and recompletion practices on one well in thefield. This figure also shows the relative locations of the different producingsands as shown on the electric well log. Structure The structure is an elongated dome, cut by two north-south faults, whichdivides the field into three segments. The west segment is the higheststructurally and contains most of the recoverable oil and gas. The centersegment is less important and the east segment is of little value. Figs. 2,4,6,8 and 10 are depth contour maps on top of the five main producingsands in the field. T.P. 1869