BIOPOLYMER DRILLING MUD Russian patent published in 2022 - IPC C09K8/12 

FIELD: mining industry.

SUBSTANCE: invention relates to biopolymer drilling muds for drilling above-productive intervals and opening productive formations during the construction and reconstruction of wells. The biopolymer drilling mud contains a xanthan biopolymer, modified starch, an alkaline additive: magnesium oxide, a silicon-containing reagent: a mixture of gamma-aminopropyltriethoxylane and potassium liquid glass in a mass ratio of 1:(0.7÷10), respectively, a surfactant: a mixture of alkyltrimethylammonium chloride C12-C14 and oxyethylated amides of fatty carboxylic acids C12-C18 in in a mass ratio of 1:1, water and additionally sulfonated bitumen with the following component ratio, wt. %: xanthan biopolymer 0.2-0.4; modified starch 0.5-3; magnesium oxide 0.5-1; specified silicon-containing reagent 0.55-2.0; specified surfactant 0.3-0.7; sulfonated bitumen 0.5-2; water the rest. Biopolymer drilling mud may additionally contain a weighting agent. Biopolymer drilling mud may additionally contain at least one component from the group including sodium silicate 0.05-0.7 wt. %, hydroxyethyl cellulose 0.1-0.3 wt. %, clay powder, grade PPB 2-4 wt. %.

EFFECT: increase in the resistance of the solution to biodegradation with a simultaneous decrease in the degree of swelling and softening of rocks containing clay fraction in contact with drilling mud, a decrease in the degree of negative impact of the mud on the coefficient of restoration of permeability of oil productive rocks after its exposure.

3 cl, 3 tbl, 2 ex