Oil and gas company Byron Energy has reached hydrocarbons in the South Marsh Island Block 71 F4 well in the U.S. Gulf of Mexico.Byron said last week that the well had reached final, total depth of 8,130 feet on February 12.The primary target D5 Upper Sand was penetrated exactly at the predicted depth and the company hit a total of 91 feet measured depth of net hydrocarbon pay (87 feet true vertical thickness) which was at the upper end of predrill expectations.The D5 Upper Sand was penetrated high on structure, exhibits high-quality reservoir characteristics with an average porosity of 30%, a low water saturation, and no water contacts were observed on the logging while drilling (LWD) logs.The company added that the LWD logs indicated the D5 Upper Sand was most likely a high gas content oil and additional isotube analysis was in progress but final hydrocarbon type would not be determined for a period of time after the well was placed into production.Additionally, 11 feet MD (10 feet true vertical thickness) of hydrocarbons were logged in the J1 Sand. The well will be cemented in a manner that would allow the J1 Sand to be produced should it be deemed necessary to efficiently produce the reserves attributed to it.According to Byron, the presence of hydrocarbons in the D5 Upper Sand also validates the company’s geologic model for the entire D5 Sand package as a complex series of amalgamated and stacked sand channels.The SM71 F4 well tested and confirmed an accumulation of hydrocarbon that is stratigraphically separated from the main D5 Sand oil production where the SM71 F1 and F3 wells have combined to produce over 2 million barrels with no formation water from the D5 Sand since production began on March 23, 2018.The company also stated that the D5 Upper Sand was drilled and evaluated 25 percent below budget.Currently, the Enterprise Offshore Drilling 264 (EOD 264) drilling rig is preparing to run seven-inch casing to bottom and once landed, completion operations will begin.The D5 Upper Sand completion will consist of frac-pack sand control measures to minimize pressure drawdown across the perforations and allowing optimized production rates. Completion operations are expected to take 16 days, after which minor work will be needed to the SM71 F platform before the well can be placed into production.Byron is the operator of SM71 and currently has a 50 percent working interest. Otto Energy holds the remaining interest in SM71. It is worth noting that Otto elected not to participate in the SM71 F4 well, giving Byron a 100 percent working interest in the well.Byron’s CEO Maynard Smith said: “The SM71 F4 well has more than met our pre-drill expectations. Once again, Byron’s RTM seismic data has proven to be an extremely accurate tool for finding oil and gas in the South Marsh Island 71 area. The short cycle time to first production will be of great value to us in our SM58 development program.“It’s also very gratifying to drill this well under time and under budget. Our team has made huge strides in finding ways to drill better wells and reduce our risk dollars.”Spotted a typo? Have something more to add to the story? Maybe a nice photo? Contact our editorial team via email. Also, if you’re interested in showcasing your company, product, or technology on Offshore Energy Today, please contact us via our advertising form where you can also see our media kit.