| 摘要 |
<p>GEL AND PROCESS FOR PREVENTING LOSS OF CIRCULATION, AND COMBINATION PROCESS FOR ENHANCED RECOVERY A rapid setting gel-forming composition is provided comprising a first substance selected from the group consisting of a polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and aldehyde, and water, which is useful in preventing the loss of circulation fluids in well drilling, completion of workover operations. A combination process is also provided using a slower setting gel-forming composition for retarding the flow of waters or brines in high permeable non-productive channels in combination with a subsequent acidizing step for increasing the permeability of low porous structure in subterranean formations. The combination process is particularly useful in waterflood operations to increase the sweep efficiency of the oil recovery process while improving the flow oil and drive water in the productive parts of the reservoir.</p> |
