The Smackover Formation is an Upper Jurassic carbonate limestone sequence that occurs in an arc along the northern paleo-shoreline of the Gulf Coast, from South Texas to northwestern Florida. Generally, the Smackover overlies the Norphlet Formation and is capped by the Buckner evaporative bed, which typically serves as the petroleum system seal. The Smackover has been a prolific oil and gas producer since the 1922 discovery well, Richardson No. 1, in Union County, Arkansas. The majority of Smackover production in the Wood County, Texas, part of the East Texas Basin occurs downdip of the Mexia-Talco Fault Zone and is associated with salt anticlines basinward of the fault system. Due to enhanced porosity and permeability from extensive dolomitization in the upper oolitic shoal facies, this unit has been the primary target interval for conventional production in northeastern Texas.  

Core collected from the Max J. Fletcher No. 3 in Wood County, Texas, in July 1993 has been the focus of an ongoing facies analysis. This core represents a 243 feet interval in the Smackover Formation from the East Texas Basin between the depths of 13,332 and 13,089 feet. The focus of this study has been to develop a core facies analysis in combination with X–ray fluorescence and thin section analyses. These data were used to correlate to the well log to create a type log for the Smackover in northeastern Texas. Results show decreasing dolomitization at lower depths, with upper facies influenced by the overlying Buckner Anhydrite. This correlation will help to further understand reservoir quality and trends of the Smackover in the northeastern Texas region and provide a key for developing Smackover subsurface maps and trends when correlating surrounding wells in the East Texas Basin. The detailed facies analysis will help provide additional information for depositional and diagenetic models for the Smackover Formation in northeastern Texas.