Oklahoma’s Anadarko Basin, one of the world’s super basins, is currently known for horizontal drilling in the Woodford Shale, the basin’s main source rock. However, above the Woodford, many attractive oil and gas fields have been sought using vertical technology over the last 100 years. As one of the deepest basins in the United States, with horizontal Woodford wells routinely drilled between 14,000 and 17,000 feet TVD, there is a lot of rock above the source in which hydrocarbons have accumulated.
Lynx Oklahoma Operating is focused on developing targets for horizontal drilling within and adjacent to existing legacy fields in the Anadarko Basin, specifically in Caddo County, Oklahoma. After analyzing multiple targets in Caddo County, including Woodford Deep, Meramec Deep, Springer Deep, Red Fork Deep and multiple Hoxbar Reservoirs, Lynx decided to initiate its horizontal program targeting crude oil at Hoxbar Marchand. The Hoxbar Marchand is a sandstone oil reservoir with a typical gravity of 42 to 48 degrees API at 9,500 FT to 10,500 FT TVD, historically developed using conventional vertical technology since the mid-1960s.
Vertical wells inherited from Hoxbar Marchand vary in performance. Many are marginal vertical producers and vertical wells drilled but never completed for various reasons, including reservoir properties considered commercially unproductive, commodity prices and operator challenges. Lynx CEO Nelson Bolen states, “These variables provide an attractive dynamic when analyzing conventional reservoirs for modern horizontal unconventional development, as vertical penetrations provide a detailed subsurface database, show producibility, but they leave behind most of the oil. Although vertical development of the Hoxbar Marchand was in coarser clean sandstones and thinner, dirtier sandstones, prospects in thinner, dirtier rock were often not developed beyond the first few pits. This provides an opportunity to add value using unconventional modern technology on legacy conventional rock.
According to Al Warner, senior vice president of geology, “Lynx’s geological approach was to first build a series of detailed cross sections correlating individual sandstone benches, usually 5′ to 25′ but in some cases as much as 50′ across. . These individual benches were then mapped to their full extent, providing targets that, in many cases, extend beyond the known boundaries of a given field or game. In a number of cases, this detailed ‘splitting’ of the sandstones included the mapping and extension of the more argillaceous sandstones over wider areas that have proven to be commercially productive.”
When targeting sandstones, such as Hoxbar Marchand, the gamma ray log is not the gospel when identifying productive or non-productive rocks. Other factors must be considered while drilling to stay in the optimal range. Hydrocarbon samples, both gas and oil, provide excellent evidence of potentially productive rocks, but are not always easily identified, especially when drilling with weighted oil-base mud. Penetration rate is another excellent primary indicator used during geosteering and for target changes.
Aiming for the best rock is critical to success, with a focus on staying in the clean sandstone and clayey sandstone intervals. Lynx has seen equally good shows in these two sandstones and in selected black organic high gamma ray shales within Hoxbar. The Woodford has been interpreted as the primary source of hydrocarbons within Pennsylvania reservoirs, including the Marchand, but the black shales may not only be a secondary source but could also contribute to production, particularly if they are in close association with the sandstones; thus providing an additional advantage. Lynx has not drilled a pure Hoxbar Shale well, but could provide a significant advantage in the future. Lynx’s current focus continues to be the Hoxbar Marchand Sandstone interval.
By optimizing drilling practices, mud system and BHA, Lynx successfully eliminated the 7” intermediate casing commonly run in this area. This allowed Lynx to use a monobore design, 5.5” casing from surface to total depth, allowing frac rates to 100 BPM under 10,000 psi treating pressure, further reducing costs and allowed a greater choice of fracturing design. Lynx is currently conducting plug and drill operations with 200 FT stages, including two sidetrack drops per stage.
Lynx recently completed drilling Sergeant Major #1HXL, one of Hoxbar’s longest horizontal wells at ~20,000 FT MD with lateral of 9,500 FT MD. A combination of soluble frac plugs and compounds were used to reduce the risk of completion. Lynx drilled all plugs to TD and did not see dissolvable plugs during milling or plug pieces on the surface, indicating the technology performed as designed. The next step in the Hoxbar completion evolution is to increase proppant volumes. Lynx is currently placing 1,800 lb/ft of proppant. While monitoring offset wells during fracturing, Lynx doesn’t see any pressure interference within 600 feet.
Main photo: Winter sunset in TD. Stumbling while preparing to run a 5-1/2” production casing at Lynx Fleet Admiral 10-21-16-11 #1HXL.
director of operations
Operation Lynx Oklahoma
Matthew Hatami is the COO of Lynx Oklahoma Operating, an Oklahoma-based oil and gas operator, and a licensed professional engineer with 22 years of experience. Prior to Lynx, he was vice president of resource development at American Energy Partners and American Energy Global Partners. He also worked as a senior asset manager at Chesapeake Energy Corporation and in corporate strategy and planning at Hess Corporation. Hatami holds a bachelor’s degree in petroleum and natural gas engineering from West Virginia University and an MBA from Columbia University.
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