STEP-BY-STEP DRIVE FOR STRING OF CASINGS Russian patent published in 2000 - IPC

FIELD: mining industry, specifically, oil and gas production. SUBSTANCE: invention can be used for uniform step-by-step feed of string of casings with sufficiently great force. Power cylinders of step-by-step drive are installed in two level as minimum between stationary plates and are made fast to them. Rods of power cylinders are linked to mobile plates. Additional power cylinders which interact via tooth shoes installed in guides with cylindrical surface of casing are mounted on mobile plates radially with regard to casing. All power cylinders are hydraulically coupled via hydraulic control valve to aggregate of volumetric hydraulic drive. Control unit includes position transmitters, transducers of feedback, test and warning. In process of lowering of string of casings into well or its lifting for overhaul one group of power cylinders executes working stroke and the other group executes idle stroke at same time. If it will be necessary to enhance force applied to string of casings both groups of power hydraulic cylinders can be united to make working stroke. Step-by-step drive operates under automatic condition by definite program of control unit. It can be completed with remote control console and electron analyzer of feeding process. EFFECT: usage of proposed step-by-step drive for string of casings allows positive technical and economic effect to be obtained in case of overhaul of well or in case of clearing of failure, expanded functional capabilities. 2 dwg