| 摘要 |
FIELD: oil and gas production. ^ SUBSTANCE: invention provides composition that can be used to intensify oil inflow and to develop well by means of acid treatment of terrigenous oil reservoir as well as to intensify oil inflow and to increase oil recovery of formations with the aid of hydraulic rupture of formation assisted by acid solutions. Composition contains borohydrofluoric acid needed to create borosilicate films prohibiting migration of particles during acid treatment. In addition, composition is characterized by lowered rate of reaction with rock at formation temperature in order to extend coverage of formation by treatment and to diminish deposit formation risk, low surface tension, low corrosion rate, and compatibility with inhibitors added to commercial acid, which will enhance efficiency of acid treatment using composition of invention. Composition is made up of, wt %: inhibited hydrochloric acid 8.0-15.0, fluorine-containing reagent (hydrofluoric acid, ammonium bifluoride, or ammonium fluoride) 1.5-10.0, boric acid 1.0-3.0, additionally isopropyl alcohol 5.0-10.0, and "Alkylfosfat-Khimeko" or "Efiroks-7", or "Fosfol-10" 0.5-2.0, and fresh water to 100%. In a method of acid treatment of the bottom area of terrigenous formation comprising consecutively pumping flushing fluid and acid composition into borehole, forcing the latter into formation by the aid of flushing fluid, giving time (up to 8 h) for reaction and subsequent removal of reaction products. Acid composition is used as it is or in the form of aqueous solution obtained by diluting composition with fresh water at water-to-composition ratio (1-5):1 in amount corresponding to 0.5-2.0 m3 per 1 m of perforated thickness of the formation. As flushing fluid, 1.5-3.0% ammonium chloride solution is used in amount 0.5-1.5 m3/m before pumping of acid composition or in amount 1.0-5.0 m3/m when used to force acid composition. ^ EFFECT: expanded useful possibilities of acid composition. ^ 2 cl, 1 dwg, 2 tbl, 4 ex |
