Abstract: A drilling tool includes an outer cylinder; a power rotary shaft arranged in an inner chamber of the outer cylinder; a percussion generator arranged below the power rotary shaft, having a transmission shaft extending in the outer cylinder and can be driven by the power rotary shaft to rotate around its axis, an output main shaft engaged with a lower end of the transmission shaft so as to be driven by the transmission shaft to rotate about its axis and is movable relative to the transmission shaft along an axial direction, and an percussion assembly The percussion assembly is arranged between an annulus formed between the upper end of the output main shaft and the outer cylinder and can generate reciprocating impact along the axial direction on the output main shaft. A drilling bit connected with the output main shaft extending out of the inner chamber of the outer cylinder.

Abstract: A drilling tool includes an outer cylinder; a power rotary shaft arranged in an inner chamber of the outer cylinder; a percussion generator arranged below the power rotary shaft, having a transmission shaft extending in the outer cylinder and can be driven by the power rotary shaft to rotate around its axis, an output main shaft engaged with a lower end of the transmission shaft so as to be driven by the transmission shaft to rotate about its axis and is movable relative to the transmission shaft along an axial direction, and an percussion assembly The percussion assembly is arranged between an annulus formed between the upper end of the output main shaft and the outer cylinder and can generate reciprocating impact along the axial direction on the output main shaft. A drilling bit connected with the output main shaft extending out of the inner chamber of the outer cylinder.

Abstract: A risk assessment-based design method for a deep complex formation wellbore structure includes: (1) preliminarily determining casing layers and setting depths; (2) calculating to obtain the risk coefficients of each layer of casing; (3) analyzing and coordinating, according to the principle that a shallow casing shares more risks and a deep casing shares less risks, the risks of each layer of casing: determining whether the risk coefficients of each layer of casing are greater than a safety threshold value K; checking the setting depth: if the safety coefficient of an ith-layer casing satisfies RNi>K, selecting a casing layer with the minimum safety coefficient from upper casing layers, and deepening the setting depth h of the casing layer; and (4) repeating the steps (2) to (3) until the casing risk coefficients of each layer of casing are less than the safety threshold value K.

Abstract: A risk assessment-based design method for a deep complex formation wellbore structure includes: (1) preliminarily determining casing layers and setting depths; (2) calculating to obtain the risk coefficients of each layer of casing; (3) analyzing and coordinating, according to the principle that a shallow casing shares more risks and a deep casing shares less risks, the risks of each layer of casing: determining whether the risk coefficients of each layer of casing are greater than a safety threshold value K; checking the setting depth: if the safety coefficient of an ith-layer casing satisfies RNi>K, selecting a casing layer with the minimum safety coefficient from upper casing layers, and deepening the setting depth h of the casing layer; and (4) repeating the steps (2) to (3) until the casing risk coefficients of each layer of casing are less than the safety threshold value K.