Prevention of lost circulation during drilling of well-bore - by using flowing crosslinked polymer gel contg. carboxylate-contg. polymer, complex capable of crosslinking polymer, and aq. solvent

摘要

Prevention of significant lost circulation while drilling a well bore in a hydrocarbon-bearing formation having a formation matrix below an earthen surface comprises: (i) admixing components of a continuous flowing gel at the surface comprising a water-soluble carboxylate-contg. polymer, a complex capable of crosslinking the polymer and formed of at least one electropositive chromium (III) species, at least one electronegative carboxylate species, and an aq solvent for the polymer and the complex and (ii) circulating the gel through the well bore while it is being drilled to prevent significant lost circulation. The circulation of drilling mud is monitored while drilling.