Abstract: A sliding sleeve device has an outer cylinder, a circulation hole being provided in the wall of the outer cylinder; and an inner cylinder provided in an inner cavity of the outer cylinder. In an initial state, the inner cylinder and the outer cylinder are fixed to each other to seal the circulation hole. In a first state, the inner cylinder is movable relative to the outer cylinder, thereby unsealing the circulation hole. A protection mechanism is provided in the circulation hole, which has an inner member located on the radially inner side and an outer member located on the radially outer side.

Abstract: A sliding sleeve device has an outer cylinder, a circulation hole being provided in the wall of the outer cylinder; and an inner cylinder provided in an inner cavity of the outer cylinder. In an initial state, the inner cylinder and the outer cylinder are fixed to each other to seal the circulation hole. In a first state, the inner cylinder is movable relative to the outer cylinder, thereby unsealing the circulation hole. A protection mechanism is provided in the circulation hole, which has an inner member located on the radially inner side and an outer member located on the radially outer side.

Abstract: A tool for perforating, packing and fracturing and a tubing string comprising the tool are disclosed. The tool comprises an upper connector, a connection sleeve, a mandrel, a packer, a lower connector, and an inner sleeve. The upper connector is provided with communication holes, and a nozzle is provided at each communication hole. The inner sleeve is provided on an inner wall of the upper connector to block the nozzle. Under an action of a fracturing fluid, the inner sleeve moves downwards to expose the nozzle, and the packer is packed. Then, perforating is performed through the nozzle. After perforating is finished, the nozzle is configured to be lost at a communication hole, and then fracturing is performed. When the tool is used, operation cost can be reduced, and reservoir stimulation effect can be improved.

Abstract: A tool for perforating, packing and fracturing and a tubing string comprising the tool are disclosed. The tool comprises an upper connector, a connection sleeve, a mandrel, a packer, a lower connector, and an inner sleeve. The upper connector is provided with communication holes, and a nozzle is provided at each communication hole. The inner sleeve is provided on an inner wall of the upper connector to block the nozzle. Under an action of a fracturing fluid, the inner sleeve moves downwards to expose the nozzle, and the packer is packed. Then, perforating is performed through the nozzle. After perforating is finished, the nozzle is configured to be lost at a communication hole, and then fracturing is performed. When the tool is used, operation cost can be reduced, and reservoir stimulation effect can be improved.