PROCESSES FOR PRODUCING BITUMEN FROM TAR SANDS AND METHODS FOR FORMING A GRAVEL PACK IN TAR SANDS

摘要

PROCESSES FOR PRODUCING BITUMEN FROM TAR SANDS ANDMETHODS FOR FORMING A GRAVEL PACK IN TAR SANDS(D#72,621-F)ABSTRACT OF THE DISCLOSUREA new process for producing bitumen from asubterranean reservoir of tar sands comprises basically(1) heating the casing for melting the bitumen from thetar sands adjacent the casing for forming a passage in thereservoir from upper perforations at the top of thereservoir to lower perforations at the bottom of thereservoir, (2) setting a packer in an annulus between thecasing and a tubing therein between the upper and lowerperforations, (3) circulating hot fluids from the upper per-forations and back into lower perforations for meltingmore bitumen from the tar sands for forming a predeterminedsize cavity around the casing, (4) pulling the tubing andpacker, and rerunning the tubing with the packer and a screen,(5) ejecting a gravel pack material slurry into the cavityaround the screen, (6) ejecting more hot fluids into thecavity for melting more bitumen from the tar-sands, and (7)flowing the melted bitumen through the gravel pack, lowerperforations, and screen for filtering out the sand andgravel from the melted bitumen for recovering the meltedbitumen at the surface. A modification comprises position-ing the screen in the annulus over the upper perforationsand forming the gravel pack thereover, consolidating it,and passing the hot fluids down the tubing for ejection fromthe lower perforations for producing the bitumen through theupper gravel pack, upper perforations, and screen for recoveryat the surface.Two new methods for forming a gravel pack in asubterranean reservoir of tar sands is likewise disclosed.-I-