Subsurface heater configuration for in situ hydrocarbon production

Abstract

A configuration of elongate subsurface heaters ( 20 ) in a subsurface oil shale formation ( 10 ) for use in hydrocarbon production. The heaters ( 20 ) are grouped into a series of columns ( 40 ), and the columns extend generally perpendicular to the sedimentary layers ( 50 ) of the subsurface oil shale formation ( 10 ). The heaters may also be grouped into a series of layers, with each layer extending in one sedimentary layer of the oil shale formation.

1 . A configuration of elongate subsurface heaters in a subsurface oil shale formation for use in hydrocarbon production,
 wherein the heaters are grouped into a series of columns, the columns extending generally perpendicular to the sedimentary layers of the subsurface oil shale formation.   
     
     
         2 . A configuration of subsurface heaters as claimed in  claim 1 , wherein the distance between adjacent columns, measured along the sedimentary layers, is between 10 and 100 metres. 
     
     
         3 . A configuration of subsurface heaters as claimed in  claim 1 , wherein the heaters are arranged to extend generally along the sedimentary layers of the subsurface oil shale formation. 
     
     
         4 . A configuration of subsurface heaters as claimed in  claim 3 , wherein the heaters are also grouped into a series of layers, each layer of heaters extending in one sedimentary layer of the subsurface oil shale formation. 
     
     
         5 . A configuration of subsurface heaters as claimed in  claim 3 , wherein the distance between adjacent heaters, measured across the sedimentary layers, is between 2 and 30 metres. 
     
     
         6 . A configuration of subsurface heaters as claimed in  claim 1 , wherein production wells are arranged between the columns of heaters. 
     
     
         7 . A configuration as claimed in  claim 1 , wherein a layer of crossing heaters is arranged in a layer above the uppermost heaters in the columns, the angle between the crossing heaters and the uppermost heaters in the columns being at least 60°, and preferably around 90°. 
     
     
         8 . A configuration as claimed in  claim 7 , wherein at least one generally vertical production well is arranged between the columns. 
     
     
         9 . A configuration as claimed in  claim 7 , wherein at least one generally horizontal production well is arranged in a layer above the crossing heaters.