1 results about "Casing string" patented technology

The invention relates to a tubular column lowering power tractor with a well grinding and repairing function, wherein the tubular column lowering power tractor is used for the oil and gas cement job. According to the technical scheme, a screw motor is used as a driving mechanism; a motor rotor and the crown portion of the tractor are connected together through a transmission shaft and a fluid director; a flow guide hole is formed in the fluid director, and water holes are formed in the crown portion of the tractor to drain drilling fluid. Hard alloy teeth are inlaid on the crown portion of the tractor. The tubular column lowering power tractor with the well grinding and repairing function can guide and lower a sleeve in under the condition that the sleeve column is not rotated, the crown portion of the tractor can break rock and broaden a hole, and the tractor ensures that the sleeve can be lowered into a designed position safely and efficiently. The rotatable and asymmetrical crown portion of the tractor has strong capacity for crossing ledge barriers in a well, after the sleeve is lowered into the designed position, a tool can be drilled with a milling bit in about a dozen minutes, and then cement is injected in to fix the well. The tubular column lowering power tractor with the well grinding and repairing function can provide an output torque which is large enough, and can be used even under the working conditions when the well conditions are very complex.