METHOD OF PREPARING INVERT-EMULSION FLUID Russian patent published in 2003 - IPC

FIELD: oil and gas production. SUBSTANCE: invention relates to waterproof emulsions used when killing wells before performing underground repair operations. Preparation of invert-emulsion fluid includes preliminarily hydrophobization of asbestos followed by mixing it with hydrocarbon liquid and aqueous solution of salt (sodium, potassium, and calcium chloride). Mixing operation is performed as follows: first half-amount of hydrophobized asbestos is added to surfactant-containing hydrocarbon liquid, resulting mixture is combined with aqueous salt solution, and then second half- amount of hydrophobized asbestos is added to give emulsion fluid composed of, wt parts: hydrocarbon liquid 40, aqueous salt solution 60, hydrophobization agent 0.3-2, surfactant 2-4, asbestos 1-5. More specifically, hydrophobization agent can be polymethylsiloxane (1-2) and surfactant can be "SMAD-1" (3-4) or, respectively, imidazoline or Emultal (0.5-2 and 2-3), or imidazoline and "SMAD- 1" (0.3-0.5 and 3-4). EFFECT: increased killing fluid efficiency due to preserved filtration-capacitive characteristics of bottom zone rocks and favorable conditions for inflow of formation fluid to working face because of reduced filtration factor and increased electrical stability of emulsion. 5 cl, 5 tbl