The invention relates to a low-
toxicity or nontoxic multi-functional
drilling fluid finishing agent used for the drilling operation of an oil-gas field. The invention has no
pollution to the environment, is nontoxic and has the functions of preventing collapse, blocking, lowering the water loss, protecting the wall of a well, protecting an oil-gas layer, generating no
fluorescence and the like. The invention has the following technical scheme of: firstly, putting water into a reaction tank, adding a dispersant MV-CMC and a glue protection agent JT888 slowly in circulation, adding an emulsifying agent OP-10 once after dissolving, circulating for 10 minutes, adding
liquid paraffin slowly and then emulsifying for 30 minutes; then, adding a defoaming agent YHP-008 and then circulating for 5-10 minutes continuously; and finally, adding 36% of
formaldehyde as a
preservative and then circulating for 5 minutes so as to obtain a product of the low-
toxicity or nontoxic multi-functional drillingfluid finishing agent. The finishing agent is used for water-base
drilling fluid, especially
polymer drilling fluid, can effectively improve the quality of a mud cake of the water-base drilling fluid, lowers the water loss, has the functions of clamping prevention,
lubrication, collapse prevention, blockage and the like, has no
pollution to the environment and can be widely used in the drilling operation.