RU94028923A - Method for removing polymeric formations from hydrocarbon-bearing reservoirs - Google Patents

Abstract

FIELD: oil and gas production industry. SUBSTANCE: according to method, polymeric formations are removed by means of chemical reagents. Polymeric formation are destructed with high efficiency with restoring output close to initial value in liquidation of complications in driving bore-holes, treating of well before cementation of casing strings, secondary opening of producing bed, development and overhaul repair of wells. Injected into perforated zone around well is solution of salt of oxygen-containing phosphoric acid, then solution is held in bed and subsequently removed from it. Duration of holding solution in perforated zone is determined with respect to bed temperature. Removal of solution and its reaction product from bed is effected prior to appearance of fluid of constant composition corresponding to bed composition. At holding solution in bed, well can be additionally drained. Used for preparation of solution is sodium hydropyrophosphate or potassium pyrophosphate or sodium orthophosphate or calcium dihydrofluorophosphate or nitrilotrimethylenephosphoric acid. EFFECT: high efficiency.

Claims (1)

The invention relates to the oil and gas industry, and in particular to methods for removing polymer clogging formations using chemicals. Purpose: increasing the efficiency of the destruction of polymer formations by restoring the flow rate to values close to the initial ones during the elimination of complications during well drilling, treatment of the wellbore before cementing the casing strings, re-opening the reservoir, development and overhaul of the wells. This is achieved by injecting a solution of a salt of oxygen-containing acid phosphorus into the perforated near-wellbore zone, keeping it in the formation and then removing it from the formation. The exposure time of the solution in the perforated zone is determined depending on the formation temperature, and the solution and its reaction products are removed from the formation until a fluid of constant composition corresponding to the formation appears. When the solution is kept in the reservoir, they can additionally drain the well. To prepare the solution, sodium hydrogen pyrophosphate, or potassium pyrophosphate, or sodium orthophosphate, or calcium dihydrofluorophosphate, or nitrilotrimethylene phosphoric acid is used.