WELL COMPLETION METHOD AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2023 - IPC E21B33/138 E21B34/06 E21B43/32 

FIELD: well drilling.

SUBSTANCE: invention relates to separation and fixation of reservoirs of oil and gas wells during their completion in the presence of aquifers located above and below a productive formation with an oil-water contact zone (OWC). The method includes running a casing string into the well and cementing the well, followed by a secondary opening of the productive formation. Previously, according to the available data on previously drilled wells in a given area, the thickness of the productive and aquifer and the location of the OWC are determined. A well completion device is selected (WCD) with a length that allows covering the entire thickness of the productive formation and blocking the upper and lower aquifers for a length of at least 2 meters from the OWC zone. An ultrasonic drilling device is installed on the casing string, including a body consisting of a sealing collar made in the form of a collar sleeve with an upper end in the form of a conical funnel, put behind the clamps, which are fixed on the body with clamping screws, and the lower part, rigidly fixed to the body with rings and equipped with spherical shoe with a central flushing hole. Additionally, circulation holes are made in the lower part of the body. Inside the body above the shoe there is a cementing sleeve fixed on the body with the help of shear elements. Grooves are made on the cementing sleeve with sealing rings installed on them from the outside and through circulation holes located opposite the circulation holes in the lower part of the body. Inside the cementing sleeve, on the shear elements, a locking sleeve is fixed with a hemispherical rubber end in the lower part, provided with through circulation holes. The inner cavity of the spherical shoe is configured for landing inside the shoe of the cementing and locking sleeves and their placement with overlapping of the central flushing hole of the shoe. The WCD is placed in the interval of the productive formation and the aquifers located above and below it. The flushing liquid is circulated through the WCD and the central flushing hole of the spherical shoe. Next, by dropping the ball, the locking sleeve is shifted until the central flushing hole in the shoe is completely blocked, opening through circulation holes on the WCD cementing sleeve, through which cementing is performed.

EFFECT: increased efficiency of isolating aquifers located above or below the productive formation, thereby excluding the occurrence of behind-the-casing circulations, and obtaining the planned production during well development.

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