Comstock Resources’ and Aethon’s Screaming Monster Gas Wells in the Deep Western Haynesville/Bossier Play in the East Texas Basin

 

     As reported by Hart Energy, Comstock Resources is tapping some very high-volume wells in the deeper further west part of the Haynesville/Bossier Shale play. Unfortunately, I can’t get behind the paywall, but the Haynesville well recently completed and still cleaning up after six weeks is producing at an initial rate of 35MMCf/day and is expected to increase as it continues to clean up. Previous Bossier wells drilled by the company suggests EURs in the range of 3.5BCF per 1000ft of lateral. These are among the highest reserve gas wells in North America. The wells are very deep at over 17,000 ft vertical depth. The area being drilled so far is in the East Texas Basin in Leon and Robertson counties, far west of the presumed core of the Haynesville play centered near the Texas/Louisiana border three or four counties away. Comstock has also found success in the Woodbine play, stratigraphically below the Eagle Ford equivalent, further southeast in Polk County at just over 14,000ft. The Woodbine Organic Shale is being drilled in nearby Madison County at just over 8000ft.

     Another company, Aethon, has drilled a Bossier well in eastern Robertson County that IP’d at 36.9 MMCF/day from a 6561 ft lateral, yielding and IP rate of 5.6 MMCF/1000ft of lateral. These gas wells are very high pressure and literally scream, the pressure making an audible high-pitched sound. The Aethon well was completed in late September 2022 and kept confidential.

     In Robertson County Comstock’s Cazey Black A #1H’s IP’d at 42 MMcfe/day from 7,900 ft of lateral in the Lower Bossier and its Circle M Allocation #1H, IP’d at 37 MMcf/day, also from 7,900 ft of lateral in the Lower Bossier. More wells are being drilled and completed.

 

 

Source: Hart Energy

 

     The challenges to this deep Bossier and Haynesville play are the sheer vertical depths up to 19,000 ft and the very high well costs. Geology is also thought to have some challenges. Drill bits get used up and there is a need to run stronger casing with higher pressure ratings. One big snafu could be quite costly. Thus, even though the gas is there, the play is risky. One might draw some comparisons to the deep Utica/Point Pleasant Play in Pennsylvania. However, the high reserves could lead to overcoming these challenges as more wells are drilled.

Source: Hart Energy

     The extent of this deep play has yet to be fully delineated. The trapping, whether structural, stratigraphic, or a combo of the two, is not yet known. The size of the fairway is not yet known. With bottomhole temperatures as high as 425 deg F (Haynesville core area is about 300 deg F) and bottomhole pressures as high as 17,000 psi the challenges can be considerable. With well costs at $10 to 12 million, the play can be economic if high gas rates are consistently achieved, and operations problems are minimized.

     Stratigraphically the Late Jurassic Bossier is above the Haynesville Shale. I remember reading about early deep Bossier exploration in the area in the mid-2000’s where EURs up to 13BCF were made from vertical wells producing from a single zone. Geologist Peggy Williams reports that “the Bossier in the Robertson/Leon area has [a] porosity of 6% to 12% and permeability of 0.01 to 0.1 millidarcies.” The Bossier is a rock with interbedded shale and sandstones. The Bossier play is considered to be a basin-center gas accumulation. Some of these sandstones may be turbiditic which means they are deposited by sliding down slopes off of a continental shelf in the manner of avalanches. Turbidites move by density flow, which means that changes in fluid density due to a high density of suspended particles turn the fluid into a slurry that flows. The lack of continuity and variable nature of turbidites could limit the play and increase geologic risk but that remains to be seen.

 

“Turbidites are formed by underwater avalanches at the edge of continental shelves or deep lakes with steep slopes from the shelf along the shoreline. The material that settles at the bottom of the shelf (i.e. the turbidite deposit) tends to consist of sand and similar coarse material, grading upwards into siltstone which is formed by the fine grained mud that settles more slowly than the sand particles.” Source: Wikipedia

 

Bossier Sequence Stratigraphy Model. Source: AAPG. Figure 9 (searchanddiscovery.com)

     Pipeline capacity in the areas could be an issue in the future as these high volumes are delivered, However, with reasonable proximity to LNG export markets, that is likely resolvable.   

 

References:

North Houston Haynesville Wildcat Comes in at 35 MMcf/d. Nissa Darbonne. Hart Energy. August 2, 2023. North Houston Haynesville Wildcat Comes in at 35 MMcf/d | Hart Energy

Aethon’s Screamer Well Joins Comstock’s Deep-Bossier Wildcatting. Nissa Darbonne. Hart Energy. April 10, 2023. Aethon’s Screamer Well Joins Comstock’s Deep-Bossier Wildcatting | Hart Energy

Bossier Shale & Tight Gas Play Overview. Hart Energy. July 1, 2006. Bossier Shale & Tight Gas Play Overview | Hart Energy

Turbidite. Wikipedia. Turbidite - Wikipedia