1
Bertram T Willman: Thermal recovery of viscous hydrocarbons using arrays of radially spaced horizontal wells. Exxon Production Research Company, Michael A Nametz, October 27, 1981: US04296969 (40 worldwide citation)

Normally immobile mineral values are recovered from a subterranean formation by penetrating the formation with an access shaft and drilling two radial arrays of substantially horizontal wells out into the formation from the shaft, one array of wells being substantially shorter than the other array. ...


2
Willman Bertram T: Extraction thermique des hydrocarbures visqueux par injection dans des galeries radiales espacees, Thermal recovery of viscous hydrocarbons using arrays of radially spaced horizontal wells. Esso Resources Canada, BORDEN LADNER GERVAIS, December 6, 1983: CA1158155

ABSTRACT Normally immobile mineral values are recovered from a subterranean formation by penetrating the formation with an access shaft and drilling two radial arrays of substantially horizontal wells out into the formation from the shaft, one array of wells being substantially shorter than the othe ...