Brown Dense | Southwestern Energy

The Lower Smackover Brown Dense formation is an unconventional oil reservoir found in southern Arkansas and northern Louisiana. The formation ranges in vertical depths from 8,000 to 11,000 feet and appears to be laterally extensive over a large area ranging in thickness from 300 to 550 feet. Below is a map indicating the company’s general area of interest in the play.

The Lower Smackover Brown Dense formation is an Upper Jurassic age, kerogen-rich carbonate source rock found across the Gulf Coast region of the southern United States from Texas to Florida. The company extensively reviewed the Brown Dense across the region and has indications that the right mix of reservoir depth, thickness, porosity, matrix permeability, sealing formations, thermal maturity and oil characteristics are found in the area of Southern Arkansas and Northern Louisiana. This region of Arkansas and Louisiana has produced oil and gas from the Upper Smackover since the 1920s. The Brown Dense formation is the source rock for these Upper Smackover fields. It has the critical properties necessary to be a successful play and compares favorably to other productive oil plays in the United States. However, it has never been exploited with horizontal drilling technology until now.
Southwestern has approximately 540,000 net acres targeting the Lower Smackover Brown Dense formation in southern Arkansas and northern Louisiana. In February 2012, Southwestern completed its first well in the area, the Roberson 18-19 #1-15H located in Columbia County, Arkansas, at a total depth of approximately 9,369 feet and a horizontal lateral length of approximately 3,600 feet. After initially producing the well in February, this well was shut-in for pressure-buildup testing in March. The company continues to perform testing on the well and as of May 3rd was re-completing one stage in the heel of the well. The company’s second well, the Garrett 7-23-5H #1 located in Claiborne Parish, Louisiana, was drilled to a vertical depth in February 2012 of approximately 10,863 feet with a 6,536-foot horizontal lateral and was completed with 19 fracture stimulation stages. After 48 days of flowing up casing, this well’s highest 24-hour producing rate to date was 301 barrels of 52o API oil per day, 1,700 Mcf per day and 2,200 barrels of water per day (55% of load recovered to date). As of May 3rd, the company was running tubing in the well and believed that the rate could continue to increase until approximately 65% of the fluid load is recovered, which is estimated at the end of May. The company’s third well, the BML #31-22 #1-1H located in Union Parish, Louisiana, as of May 3rd, was drilling to a planned horizontal lateral length of approximately 4,000 feet, after sidetracking the first lateral in March due to stuck pipe. This well is scheduled to be completed in May with 30 fracture stimulation stages. The company plans to allocate more capital to the Brown Dense play in 2012 for the acquisition of additional leasehold and potentially adding another rig in the area in the third quarter. If the company’s drilling program continues to yield positive results, it expects that activity in the play could increase significantly over the next several years.

Last Updated on 05/14/12