Washburn-Lightning Prospect
La Salle County
The Washburn-Lightning prospect is made up of two 320 acre leases, one to the northeast (North Washburn) and one southwest (Lightning) of the North Washburn oil field, located in La Salle County, Texas.
The North Washburn prospect is an eastward extension of the North Washburn oil field which to date has produced 796,107 Bbls of oil from 25 wells. The field was discovered in 1958 by the No. 1 Pfluger well drilled by Sutton Producing Co. Production is from the Wilcox M Sand found at about 4,700 feet. The trap is an up-dip pinch-out of the sand. Where the sand is productive the maximum thickness is 12 feet.
The eastern limit of the field has yet to be defined; the North Washburn Prospect is to be drilled on the potentially productive east end of the field. The test well will be drilled to offset by one location two wells which produced on a cumulative production of 61,822 barrels of oil (BO). Gulf Oil drilled the #1 TCU well in early December, 1959 and the initial production of the well was 95 BO/day (BO/D) with a 17% water cut. In late December, 1959 Gulf drilled the #2 TCU well up dip to the #1 well and its initial production was 111 BO/D. The two wells combined to produce 61,822 BO. A third well was drilled by Gulf in October 1, 1960, the #3 TCU. This well encountered a thick remnant of the Wilcox M sand that side wall cored oil and Gulf, after perforating the sand, had no recovery. Gulf then acidized and water fracd the well with 10,000# of sand. The well flowed salt water after being swabbed. It is surmised that they frac'ed into the water sand above the Wilcox M sand; therefore, it is concluded this well did not condemn the area. Hence, a well drilled on strike with the Gulf #2 well and one location to the east could make a productive oil well. Furthermore, a well drilled by Cunningham et al in 1962 had a remnant of the Wilcox M sand that side wall cored oil, evidence the reserve could potentially extend much farther to the east. The Washburn test well will be drilled to 4850 to extend the North Washburn Field on strike to the east to tap into a possible reserve potential of 242,670Bbls of oil. Additional wells may be needed to drain all the potential of the Wilcox M reserve.
The Lightning prospect will test a possible new field discovery to the west of and on strike with the North Washburn oil field. The target sand for the Lighting Prospect is the same Wilcox sand found productive in the North Washburn field. In December, 1958, a well was drilled by the Lightning Oil Co. (Logan Ware No. 3-A) to a depth of 5,434 to test the Wilcox M Sand producing in the North Washburn Field to the east. The well encountered 6 of net sand at a measured depth of 4708. The well had oil shows from cores taken from 4704.5 to 4708.5, 4708.5 to 47010.5 and 4710.5 to 4713.5. A drill stem test taken at 4709 to 4715.5 showed on a Ό x Ό chokes 0# WP and recovered 120 mud, 420 SW with a BHP 30-25/1975#. The well was abandoned March 30th, 1959. The well was 4 high to the Lightning Oil Co. No. 1 Ware, H. Logan well which had an IPF of 95 BO/D from the Wilcox M Sand. The structural position of the 3-A well could indicate the well was drilled on the edge of a new feature. Lightning Oil Co. then proceeded to drill the Logan Ware No. 1-A well spudded in July, 1959. The well had only a remnant of sand, but the interval cored 10 of sandy shale with florescence (4699 to 4709). Lighting at that time abandoned the local area.
The Lightning test well will be drilled to 4850 to potentially discover a new field on strike with the North Washburn Field possibly bounded by the Lighting 3-A well. The new well is positioned to gain approximately 10 of structure to the Lighting 3-A, but still remain close to the abandoned well. Subsurface analysis of the prospect shows a distinct flattening very similar to the North Washburn Field; wells drilled in the heart of the new feature may have sands similar to those in the old field, up to 12 thick. Possible reserves are estimated to be 610,297 BO and, if found, will require additional wells to fully recover.
