Patent RU-2700851-C1 (RU)
Title: Method of selective treatment of bottom-hole formation zone
Inventor: Sergeev Vitalij Vyacheslavovich
IPC: E21B43/27
Filed: 2018-06-18
Granted: 2019-09-23
Abstract: FIELD: oil and gas industry. 
     SUBSTANCE: invention relates to oil industry, particularly, to intensification of oil production. In selective processing method bottomhole formation zone – BFZ performing three or more processing steps BFZ with design periodicity of stages, implementation of the second and each subsequent stage is carried out with reduction of productivity and/or daily production rate of well oil by 25 % and more for last 6 months of well operation, at first and second stages are treated successively highly stable emulsion system – HSES, acid composition – AC and aqueous solution of potassium chloride or calcium chloride with concentration of 10–100 kg/m 3  and solution density of 1,030–1,350 kg/m 3 , at the third and subsequent steps – is processed successively HSES, a surfactant and alcohols composition and the above aqueous solution of potassium chloride or calcium chloride, where HSES contains (vol.%): diesel fuel or prepared oil from the point of oil preparation and pumping 10–20, emulsifier 3, colloidal solution of hydrophobic nanoparticles of silicon dioxide with particle size from 5 to 100 nm 0.25–1 or colloidal solution of hydrophilic nanoparticles of silicon dioxide with particle size of 5 to 100 nm 0.25–1, or hydrophilic nanoparticles of dry amorphous silicon dioxide with particle size from 5 to 500 nm – 1–2, aqueous solution of calcium chloride or potassium chloride – balance, during treatment BFZ with formation temperature of less than 90 °C use an emulsifier containing (vol.%): amine amides of fatty acids 43–45, amine oxide 0.7–1, diesel fuel – the rest, and BFZ with formation temperature of more than 90 °C use an emulsifier containing (vol.%): amine amides of fatty acids 43–45, amine oxide 0.7–1, lime or bentonite 2–5, diesel fuel – the rest, colloidal solution of hydrophobic nanoparticles of silicon dioxide with particle size from 5 to 100 nm contains (vol.%): silicon dioxide 31–32.5, propylene glycol monomethyl ether 67–68.8, water – balance; colloidal solution of hydrophilic nanoparticles of silicon dioxide with particle size from 5 to 100 nm contains (vol.%): silicon dioxide 30–31 in isopropanol 67–68.5 and methyl alcohol – balance, or silicon dioxide – 29–31 in ethylene glycol – balance, CS for carbonate rocks BFZ contains (vol.%): 30 % hydrochloric acid 63.5–65, acetic acid 3.5, diethylene glycol 8–9, hydrophobisator based on amides 1.5–2, corrosion inhibitor 1.5–2, process water – balance, CS for terrigenous rocks BFZ contains (vol.%): 30 % hydrochloric acid – 60.5–61, hydrofluoric acid – 3–4, acetic acid – 3.3–3.5, diethylene glycol – 8–9, hydrophobisator based on amides – 1.5–2, corrosion inhibitor – 1.8–2, technical water – balance, composition of surfactants and alcohols contains (vol.%): monoalkylphenyl ethers of polyethylene glycol 40–41, sodium alkylimino dipropionates 2.5–3, polyglycols 15–16, methanol – the rest. 
     EFFECT: high thermal stability of the emulsion system, high rate of developing the oil and gas bearing object, longer duration of positive effect and additional oil production. 
     1 cl, 13 dwg, 13 ex