Horizontal Well Liner

Abstract

A liner for a horizontal well, the liner comprising a substantially hollow elongated body having a plurality of orifices in the liner body that each allow limited ingress of fluid into the liner body. Each orifice has a predetermined shape, size and spacing in the liner body. The shape, size and spacing of the orifices provide that pressure of fluid in an annular space located between the liner body and the horizontal well is substantially uniform along the horizontal well.

1 . A liner for a horizontal well, the liner comprising a substantially hollow elongated body having a plurality of orifices in the liner body, wherein:
 the orifices allow limited ingress of fluid into the liner body;   each orifice has a predetermined shape, size and spacing in the liner body; and   the shape, size and spacing of the orifices provide that pressure of fluid in an annular space located between the liner body and the horizontal well is substantially uniform along the horizontal well.   
     
     
         2 . A liner for a horizontal well according to  claim 1 , wherein the shape, size and spacing of the orifices collectively offset pressure losses occurring in the well due to accumulated hydraulic friction and velocity head acting on fluid in the liner. 
     
     
         3 . A liner for a horizontal well according to  claim 1 , wherein the shape, size and spacing of the orifices take into account adopted initial entry loss at an upstream end of the well. 
     
     
         4 . A liner for a horizontal well according to  claim 1 , wherein the shape, size and spacing of the orifices accommodate variations in hydraulic conductivity in geological strata adjacent to the well. 
     
     
         5 . A liner for a horizontal well according to  claim 1 , wherein the shape, size and spacing of the orifices accommodate variations in water table level adjacent to the well. 
     
     
         6 . A liner for a horizontal well according to  claim 1 , wherein the shape, size and spacing of the orifices provide a uniform rate of fluid inflow along the liner body. 
     
     
         7 . A liner for a horizontal well according to  claim 1 , wherein the annular space has a cross sectional area that is between 30% and 50% of a cross sectional area of the liner body. 
     
     
         8 . A liner for a horizontal well according to  claim 1 , wherein the shape, size and spacing of the orifices are determined using a plurality of input parameters, the input parameters including accumulated hydraulic friction acting on fluid flowing along the well. 
     
     
         9 . A liner for a horizontal well according to  claim 8 , wherein the accumulated hydraulic friction is calculated using measurements of flow rate, diameter, length and/or a roughness coefficient of the liner body section. 
     
     
         10 . A liner for a horizontal well according to  claim 8 , wherein the input parameters include variable velocity head along the liner body. 
     
     
         11 . A liner for a horizontal well according to  claim 10 , wherein the variable velocity head is calculated as V h =V 2 / 2 g, where V is liner flow velocity and g is acceleration due to gravity. 
     
     
         12 . A liner for a horizontal well according to  claim 8 , wherein approximate cumulative total head loses are calculated for the liner using the formula 0.333×L×h f  where L is a total length of the liner and h f  is head loss in meters per unit length of the liner. 
     
     
         13 . A liner for a horizontal well according to  claim 8 , wherein the input parameters include adopted initial entry loss at an upstream end of the well. 
     
     
         14 . A liner for a horizontal well according to  claim 8 , wherein the input parameters include one or more error margin corrections for hydraulic friction. 
     
     
         15 . A liner for a horizontal injection well, the liner comprising a substantially hollow elongated body having a plurality of orifices in the liner body, wherein:
 the orifices permit egress of fluid out from the liner body;   each orifice has a shape, size and spacing in the liner body; and   the shape, size and spacing of the orifices provide that pressure of fluid in an annular space between the liner body and the well is substantially uniform along the well.