Under-pressure composite well drilling device and technology for deep high-temperature well

Abstract

The invention discloses an under-pressure composite well drilling device and technology for a deep high-temperature well. A ground drilling part comprises a drilling machine, a drilling fluid cooling system and drilling fluid circulating systems; an underground drilling tool part comprises a drill rod, a drill collar, a power assembly, a near-bit pressure reduction short section and a drill bit; the near-bit pressure reduction short section is provided with an annular channel; a plurality of suction flow channels are uniformly formed in the circumferential direction of the annular channel; sand mixing throat pipes communicating with the suction flow channels are arranged on the outer side wall of the near-bit pressure reduction short section in the circumferential direction; the outer side wall of the near-bit pressure reduction short section is further provided with pumping and suction flow channels; and the pumping and suction flow channels communicate with the nodes of the suction flow channels and the sand mixing throat pipes. According to the invention, the combined action of three modes of impact, rotation and thermal cracking is comprehensively utilized to destroy rocks at the bottom of a well, the near-bit pressure reduction short section generates local negative pressure in the annular channel at a near-bit position, and a drilling fluid which is just sprayed out of an energy-gathered nozzle to impact the bottom of the well and then carries rock debris to move up to the ground is sucked, so that the positive pressure difference at the bottom of the well is reduced, and the hold-down effect is reduced.

Description

technical field [0001] The invention relates to the technical fields of vertical wells, directional wells and horizontal wells, and more specifically relates to an underpressure composite drilling device and technology for deep high-temperature wells. Background technique [0002] In the process of exploration and development of deep earth resources, drilling is the most effective means to obtain underground physical data and establish production channels. Difficulties such as insufficient power at the bottom of the well have seriously affected the progress of exploration and development. At present, the commonly used method of rock breaking is rotary drilling with rotary table or compound drilling with screw drilling tools. However, as the hole depth increases, the supporting pressure of the drilling tool gradually increases, and the power transmitted from the rotary table to the bottom of the well is insufficient. Screw or turbo drilling tools are used to break rocks. It ...

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Problems solved by technology

[0002] In the process of exploration and development of deep earth resources, drilling is the most effective means to obtain underground physical data and establish production channels. Difficulties such as insufficient power at the bottom of the well have seriously affected the progress of exploration and development

At present, the commonly used method of rock breaking is rotary drilling with rotary table or c

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