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Horizontal Wells

Conventional approach to production - unsightly and not feasible in many situations      Conventional oil production from most reservoirs involves multiple wells, flow lines and production facilities on the surface.  In the case of diatomite reservoirs requiring closely spaced wells for optimal recovery, the impact to the surface can be significant as represented in the photo below.  This high density well field is not feasible in many areas because of land use, topography, or environmental permitting restrictions. Underground approach to production      Using specialized underground construction techniques and a combination of tunnels and shafts, a typical diatomite or other resource requiring high density wells can be drained in a much less obtrusive way, using an underground approach.  Depending on the location and dip angle of the oil-bearing resource and the topography of the area, shafts and tunnels may be dug from which horizontal wells can be drilled in high density patterns.  Because the surface footprint is so minimal with an underground approach, permitting is more feasible because of the avoidance of surface impacts.         Horizontal wells have the proven advantage of significantly more productive well bore in the pay zones than is possible from vertical wells.  In feasible locations, it is possible to install the horizontal wells from tunnels below the resource such that the wells have a slight vertical angle into the resource, permitting gravity drainage back to the well head in the tunnel.  This "inverted well" approach avoids the high cost of lifting the produced fluids to the surface and permits recovery of solvents and polymers that may be used to assist recovery.  The horizontal wells can be used to fracture the ground as required in a diatomite deposit in similar fashion to formation fracturing in vertical wells.   Well Rooms       Horizontal wells are constructed from tunnels where added space has been created for drilling.  These "well rooms as indicated in the picture below accomodates the well head and production lines outside of the main tunnel corridor.  Steam, oil and water pipelines connect between the wells and the facility room.  These well rooms contain automated equipment that can be controlled remotely, monitored for potential hazards, and measurement of production volumes.