DRILLING AGENT FOR DEVIATING HOLES Russian patent published in 2009 - IPC C09K8/12 

FIELD: oil and gas production.

SUBSTANCE: it is object of invention to develop high-tech drilling agent for deviating holes possessing high swelling inhibition capacity, successive dispersion of clay shale and easy management of structure-rheological and filtration parameters. Drilling agent for deviating holes contains, wt %: polymer reagent of high molecular weight 0.07-0.2, polymer reagent of low molecular weight 0.2-0.5, sodium hydroxide 0.02-0.05, sodium formate 0.5-0.7, xanthate biopolymer 0.1-0.2, bactericide 0.02-0.1, lubricating additive 0.2-0.5, and water - the rest. Also polymer reagent of high molecular weight is chosen from a row of high viscous poly-anionic cellulose, while polymer reagent of low molecular weight is chosen from a row of low viscous poly-anionic cellulose or polymer reagent of high molecular weight is chosen of hydrolysed acryl copolymers of high molecular weight, while polymer reagent of low molecular weight is chosen from a row of acryl copolymers of average molecular weight.

EFFECT: raised indices of swelling inhibitors of clay rock folding walls of well, of lubricating properties improving tool operation conditions at bottomhole, of capsulation and flocculation characteristics facilitating purification of solution from slime on surface; also increased rate of drilling.

3 cl, 3 ex, 3 tbl