THERMAL WELL METHOD OF DEVELOPING FRACTURED DEPOSIT OF EXTRA-HEAVY OIL Russian patent published in 2012 - IPC E21B43/24 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises injecting heat carrier in oil bed via inclined injection wells, fluid sampling via ascending production wells drilled in clusters to boundary section from oil bed gallery in layers distributed over bed thickness in the form of vertical fan with bottoms lined by casing strings. Note here that width of cover area around gallery is defined from average distance between fractures and length of casing string of all production well les, at least the width of said cover area with due allowance for well inclination. Injection wells are drilled in clusters toward area boundary and distributed over bed depth in vertical fan layers. Note also that injection wells feature different length to allow opening different-width bed fractures. Heat is uniformly distributed over bed depth and area via different-length casing strings. Note that casing string length is increased compared to that of injection well of previously constructed layer to cover the next bed fracture width. Bed bottom exposes the next fracture over bed width. Note that open borehole length makes at least the mean distance between fractures with due allowance for well inclination.

EFFECT: increased oil extraction.

1 ex, 3 dwg