Method and apparatus for gravel packing wells

Abstract From the Canadian patent

The annular passage defined by the interior of a perforated liner and the exterior of a stinger pipe extending through the liner is substantially restricted so that the resistance to flow in the annular passage is increased sufficiently to maintain high fluid flow velocity outside the liner during gravel packing. The increased flow velocity prevents the premature settling of gravel and stabilizes the formation of gravel dunes in the wellbore annulus, thereby significantly increasing gravel packing efficiency in inclined wells. The proper flow restriction can be obtained using a wide diameter stinger pipe. -1-