DRILLING MUD AND A METHOD FOR PREPARATION THEREOF Russian patent published in 2005 - IPC

FIELD: drilling engineering.

SUBSTANCE: invention relates to technology of drilling deep wells, in particular to preparation of drilling fluids and drilling reagents. Drilling mud, including components conferring thickening and inhibition of filtering ability of drilling mud into porous medium, inhibition of swelling of clayey minerals, and reduction of stickiness of drilling mud and interfacial tension between drilling mud filtrate and hydrocarbon fluid, contains following constituents, wt %: hydroxyethylcellulose 1.0-1.2, potassium chloride 5-7, chrysotile-type asbestos 0.50-0.65, aluminum sulfate 0.50-0.65, lubrication additive (FK-2000+) 1.0-1.2, and water - the balance. Preparation procedure: (i) providing 1.0-1.2% solution of hydroxyethylcellulose in 5-7% aqueous potassium chloride solution; (ii) preparing suspension 1 consisting of mixture of chrysotile-type asbestos, aluminum sulfate (as anhydrous salt) and water at 1:1:8 weight ratio, aged for 12 h under calm conditions and dispersed using disk or ball disperser, or other similar-type device; (iii) preparing suspension 2 consisting of mixture of suspension 1 and lubrication additive at 5:1 weight ratio, dispersed using disk or ball disperser, or other similar-type device; (iv) mixing 1.0-1.2% solution of hydroxyethylcellulose in 5-7% aqueous potassium chloride solution with suspension 2 at ratio of 60-77 kg suspension per 1.0 t finished drilling mud and stirring thus obtained mixture until equalization of all parameters is completed.

EFFECT: improved anti-filtration, surfactant, and antifriction properties of drilling mud.

2 cl, 1 tbl