Patent US2994377 In situ combustion in carbonaceous strata Cited prior art · Joseph C Trantham · Phillips Petroleum Co · United States · 1961 NN 1.4 sNN NIFF NLA, 4. 4. INVENTOR. J. C. TRANTHAM ATTORNEYs Page 2 United States Patent Office 2,994,377 Patiented Aug. 1, 1961 reached and until