UNIVERSAL DEVICE FOR DRILLING, CLEANING OF CAVERN AND INSTALLING OF CEMENT PLUG Russian patent published in 2014 - IPC E21B7/00 E21B37/00 E21B21/00 E21B33/10 

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to the area of well-workover operations and can be used for drilling in sludge underflow, cleaning of cavern and installing of a cement plug. The device contains a hollow barrel 1 with though radial holes 2 and outside collar 3, upper and lower sleeves 4, 5 installed with formation of tilted annular slit 6 between their upper and lower surfaces respectively. The lower sleeve 5 can move along the axis of the hollow barrel 1. The outside collar 3 of the hollow barrel 1 is formed below through radial holes 2. The lower sleeve 5 in the upper part has an inner groove 7 for the outside collar 3 of the hollow barrel 1 corresponding to the length of its axial movement along the hollow barrel 1. The lower edge of through radial holes 2 of the hollow barrel 1 is placed above the level of the tilted annular slit 6. Inner surfaces of the upper and lower sleeves 4, 5 and the lower surface of the hollow barrel matching them form an annular cavity A connected hydraulically to a cavity of the hollow barrel 1 through radial through holes 2. The device contains the upper and lower crossover shoes 8, 9. The upper crossover shoe 8 is connected from outside to the upper sleeve 4 and from inside to the hollow barrel 1; it has a prolonged bladed centraliser 10. The lower crossover shoe 9 is connected from inside to the hollow barrel 1 and presses the lower sleeve 5 through a rubber resilient element 11 with pressing force calculated as per inequality. In the middle part the lower crossover shoe 9 has an inner collar 12. In the hollow barrel 1 there are located in-series a thrust bush 13, a hollow piston 14 and a spring 15 resting on the collar 12 of the lower crossover shoe 9 with pressing force calculated as per inequality. The hollow piston 14 has a saddle for a setting ball 16; it is installed with tight covering of through radial holes 2 of the hollow barrel 1. The device contains a rock destruction tool 17 connected to the lower crossover shoe 9.

EFFECT: improving quality of cavern cleaning, installing of cement plug, increasing operating reliability and expanding technological capabilities of the device due to potential drilling into sludge underflow, automatic cleaning and centring of the device in regard to the well axis with rated diameter.

1 dwg