Abstract

An apparatus is provided for drilling concurrently a plurality of wells within a laterally confined area. The confines of the drilling apparatus employ a structure having vertically extending walls rising from a drilling floor. A plurality of wells are drilled, each employing a separate rotary drilling table and a separate draw work assembly mounted in vertical displacement from the drilling table associated there with. Preferably, the individual draw work assemblies associated with separate one of the rotary drilling tables are utilized only to feed drilling pipe assemblies into the well and to aid in the actual drilling operation. To withdraw drilling pipe assemblies, a master draw works is provided and is mounted vertically above the draw work assemblies associated with particular rotary drilling tables. In addition, the draw work assemblies are preferably located on bridges which are rotatably mounted with respect to an upright central support, so that the bridges are rotatable about the upright support and carriages forming part of the draw works are movable along the bridges so that the carriages may be moved both radially and rotationally relative to the upright support. The confining structure of the vertically extending walls renders the well drilling apparatus suitable for construction for use in drilling wells on the floor of a body of water and also for use in drilling a plurality of wells in a highly urbanized areas. This versatility is achieved by constructing the well drilling apparatus with exterior walls of the confining structure in the form of a facade, to resemble a commercial building or in the form of a water resistant cassion that may be lowered into a body of water to extend from the floor to the surface thereof.