DRILLING FLUID FOR DRILLING OF CONTROLLED DIRECTIONAL WELLS (VERSIONS) Russian patent published in 2012 - IPC C09K8/24 

FIELD: oil and gas industry.

SUBSTANCE: as per the first version the drilling fluid contains the following, wt %: PBMA bentonite 6.0-7.0; sodium carbonate 0.1÷2.0; sodium hydroxide 0.1-0.5; Givpan 0.2-0.3; Kamtsel polyanionic cellulose PATs-VV 0.1-0.3; Lubriol lubricant 1.0; acrylate lignosulphonate reagent ALS 0.2-0.3; antifoaming agent - 10% suspension of polyethylene in solar oil or kerosene PES 0.1-0.2. As per the second version the drilling fluid contains the following, wt %: PBMA bentonite 5.0-6.0; sodium carbonate 0.1÷2.0; sodium hydroxide 0.1-0.5; Givpan 0.2-0.3; Kamtsel polyanionic cellulose PATs-VV 0.1-0.3; Kamtsel polyanionic cellulose PATs-SV 0.1-0.3; Lubriol 1.0; ALS 0.2-0.3; polyethyl siloxane fluid (PSF) 0.1-0.2. As per the third version the drilling fluid contains the following, wt %: PBMA bentonite 2.0; sodium carbonate 0.1÷0.5; sodium hydroxide 0.1÷0.5; Kamtsel polyanionic cellulose PATs-VV 2.0; Kamtsel polyanionic cellulose PATs-SV 2.0; ALS 0.2÷0.3; xanthan gum 0.1.

EFFECT: possibility of failure-free drilling of controlled directional wells in complicated mining and geological conditions.

3 cl, 6 tbl, 3 ex