METHOD FOR THERMOCHEMICAL TREATMENT OF OIL RESERVOIR WITH HARD TO RECOVER RESERVES Russian patent published in 2022 - IPC E21B43/22 

FIELD: thermochemical impact.

SUBSTANCE: invention relates to a method for thermochemical impact on an oil reservoir with hard-to-recover reserves. The method includes a two-stage injection into the formation through the well, successively of a reagent of organic origin, which is either di-tert-butyl peroxide, or 1,1-di-tert-butylperoxycyclohexane, or dicumyl peroxide, or 2,2-di(cumylperoxy)propane, or isobutylcumyl peroxide, or tert-butylcumyl peroxide, or n-butylcumyl peroxide, or isopropylbenzene hydroperoxide, or dicetyl peroxydicarbonate, or tert-butyl peroxyneoheptanoate, or di(3,5,5-trimethylhexanoyl) peroxide, or dilauryl peroxide and a reaction initiator. Before injection, formation injectivity is determined, primary measurements of temperature and pressure are made in the well perforation interval, depending on which volumes and regimes of reagent supply for formation heating are calculated. The reagent is injected sequentially in two stages. At the first stage, the reagent consumption for thermochemical treatment is 20%-25% of the total volume of the reagent. First, a reagent of an organic oxygen-containing compound is pumped through the well, then 0.25–1 m active substances, then 0.25-1 m³ of buffer liquid is pumped. At the second stage, the remaining volume of the organic oxygen-containing compound reagent is pumped in, after which 0.25-1 m3 of buffer liquid is pumped in. All reagents are injected either through the same tubing or through the annulus between the production string and the tubing. In the process of treating an oil reservoir with a heating composition in the well perforation interval, temperature is controlled by a deep high-temperature sensor.

EFFECT: increasing the efficiency of oil production in the fields, in ensuring the safety of the process of influencing an oil reservoir with hard-to-recover reserves.

4 cl, 4 dwg