METHOD FOR TREATING BOTTOM-HOLE FORMATION ZONE Russian patent published in 2023 - IPC E21B43/27 E21B43/22 E21B49/00 C09K8/74 C09K8/52 

FIELD: oil industry.

SUBSTANCE: in the method of treating the bottom-hole zone, a production well with reduced well productivity or an injection well with reduced filtration is selected for at least 5 months, and a zone in the selected well with an increased skin factor caused by damage to the bottom-hole zone by clogging elements is determined. The mineralogical and fractional composition of the productive formation rock and the filtration and reservoir properties of the well are determined by laboratory studies. The composition of inorganic salts in the produced water of development objects at the site of the selected well is determined, and the mass of potential sediment falling in the bottom-hole zone of the well is determined. Calculate the required volumes of reagents to remove salts and suspended particles in wells. The percentage of the clay fraction in the rock of the productive formation is determined, and the volume of hydrochloric acid is calculated from the data obtained. Based on the results of laboratory studies, data is entered into the simulator and the penetration depth of the acid composition is calculated. Using the table of cross-compatibility of chemical reagents used when treating the bottom-hole zone of the selected well, the optimal chemical reagents and the number of separating packs of buffer process fluid between the chemical reagents are determined. Wash the treatment interval with a buffer process liquid. Sequential injection of inhibited hydrochloric acid of 15% concentration, a buffer process fluid in case of incompatibility of the inhibited hydrochloric acid and the solvent, a solvent, if necessary, a buffer process fluid, inhibited hydrochloric acid of 15% concentration, a clay acid composition containing vol.%: inhibited hydrochloric acid 12% concentration 96.5, hydrofluoric acid 40% concentration 2, surfactant 1.5. The process fluid is pressed with the addition of 0.1-0.2% surfactant and the process is held for at least 1 hour. The reaction products are squeezed deep into the formation or extracted by creating a depression and the well is put into operation.

EFFECT: increase in efficiency of treatment of the bottom-hole formation zone.

1 cl, 4 tbl