METHOD OF OPENING AND DEVELOPMENT OF HETEROGENEOUS RESERVOIRS Russian patent published in 2020 - IPC E21B43/27 E21B43/22 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to the oil-producing industry. In method of development and opening of unconventional collectors of Domanic oil deposits, including drilling, secondary opening, pumping of acid composition into well in portions, development after treatment and withdrawal of products from production well, in the well there is extracted weak permeable carbonate oil-saturated formation with average absolute permeability of collector less than 2 mD and distance from lower perforation intervals of the above formation to water-oil contact of not less than 5-10 m. During drilling, the core is sampled from the above formation; laboratory analysis of acid composition is performed on the given core. Effective parameters are acid composition, at which ratio of absolute permeability of core after pumping to absolute permeability before pumping is not less than 1000 unit fractions. Prior to performing acid treatment of bottomhole formation zone, shaft of considered well is washed and patterned, then assembly is lowered to well, bottom-up consists of funnel, tubing string, packer above roof of formation and tubing string to wellhead. Pumping of acid composition and accompanying working fluids is performed along tubing string, at the same time maximum wellhead pressure during operations must not exceed 10 MPa. Pumping is performed in 2–4 stages. Each of the stages includes sequential pumping of the following working fluids in the volume: diverter 15–40 %, solvent 10–35 %, acid solution 75–25 %. After the final stage of pumping all components pumped into the well are pumped with commercial oil, then the gate valves are closed on wellhead equipment and the well is left to wait for reaction for 3–10 h.

EFFECT: technical result is higher efficiency of development and opening of low-permeable heterogeneous reservoirs.

1 cl, 2 ex