ABSTRACT
This paper discusses site selection, air directional drilling, stimulations, and economic evaluation for a 72° slant well drilled in the Devonian shale, Roane County, West Virginia. The well was drilled to evaluate the concept of using directional drilling and multiple hydraulic fracturing to improve the gas production from a 450-foot naturally fractured Devonian shale section. The well trajectory remained in target for more than 1,500 feet at a preferred azimuthal direction perpendicular to the regional fracture trend and also the known production fairway.
The well was conventionally drilled to the kickoff point of 2,150 feet. Afterwards, positive displacement downhole motors were used to build hole angle up to a 72° hole angle at the top of the target zone. Once the target zone was reached at 67°, conventional rotary assemblies were used to rotate the well across a 1,500-foot target section in which inclination varied from 67° to 72° of hole angle. After reaching total depth of 4,833 feet, the well was logged using wireline and drill pipe conveyed methods. Then 5 1/2-inch casing was run and cemented with 60 rigid centralizers to improve zonal isolation.
Four stimulations were designed and completed. All stimulations will be discussed in the paper. Economic analysis was conducted to show expected improvements from the application of this technology to fractured Devonian shale. Post-stimulation well testing has been identified for each zone to show initial results.
