04463807 is referenced by 90 patents and cites 4 patents.

Coal is reduced to ash in place by gasification using in situ production techniques, resulting in significant void space underground, which in turn causes roof fall and subsidence. Overburden collapse is stabilized by backfilling with foaming mud cement that hardens into an expanded solid, which quenches and fills the production module and seals residual ash. Rubble volumes and subsidence cracks are sealed against water incursions and contaminated water excursions. Surface facilities above barrier pillars are protected from destructive forces of subsidence draw.

Title
Minimizing subsidence effects during production of coal in situ
Application Number
273378
Publication Number
4463807
Application Date
March 28, 1983
Publication Date
August 7, 1984
Inventor
Ruel C Terry
Denver
CO, US
Vesper A Vaseen
Wheat Ridge
CO, US
Xerxes T Stoddard
Denver
CO, US
Agent
Ruel C Terry
Assignee
In Situ Technology
CO, US
IPC
E21B 33/00
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