The share of idle well stock at mature fields of the Krasnodar territory requires the implementation of effective measures for off-stream well reactivation. The most successful geological and technical measures (GTM) are recognized as the treatment of bottom-hole zones in order to remove clay-sand plugs, clean up from colmatant, as well as to intensify production, with direct impact on the productive horizon. The cleaning of the borehole must also be carried out before all other GTMs planned by subsurface users (pump change, fishing work, repair and insulation works). Ensuring the patency of production columns is also carried out at the initial stage wells liquidation. The authors propose device and technology for borehole treatment using jet cavitation effects. The device is lowered on a string of tubing or drill pipes into a well 2-2.5 m above the plug. Pumping unit is turned on, and well flushing is provided. It is possible to use direct and reverse flushing. The working fluid flows into the wellbore through the central profiled hole, as well as through the nozzles of the upper and lower tiers. If there is a sealed plug in the well not destroyed by a jet of flushing liquid (it is controlled by reducing the weight of the pipes during descent, i.e. after unloading to the current face), the flushing is stopped, a fitting (with a cavitation or hydrodynamic profile) is thrown into the column, a flow is formed to destroy the plug and clean the perforation intervals in the well. This technology has been commercially tested in wells of Vostochno-Severskoye and Klyuchevoye gas and oil fields of the Krasnodar region.
References
1. Patent RU 2796409 C1, Method for flushing clay-sand or proppant plug out of a well, Inventors: Omel'yanyuk M.V., Pakhlyan I.A.
2. Ibragimov L.Kh., Mishchenko I.T., Cheloyants D.K., Intensifikatsiya dobychi nefti (Oil well stimulation), Moscow: Nauka Publ., 2000, 414 p.
3. Omel'yanyuk M.V., Ukolov A.I., Pakhlyan I.A., Numerical simulation of turbulent submerged jets hitting a dead end when processing bottom-hole zones (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 5, pp. 72–76, DOI: https://doi.org/10.24887/0028-2448-2020-5-72-76
