Well drilling method and device

Abstract

The invention discloses a well drilling method and device, and belongs to the field of oil exploitation. The well drilling method comprises the following steps that (1) a guide assembly is connected, the guide assembly is tripped into a designated position of a casing pipe, and the guide assembly comprises an oil pipe and a guider; (2) a trepanning unit is lowered into the oil pipe through a continuous pipe, a trepanning drill bit of the trepanning unit is made to punch the casing pipe through the guider so that a first through hole can be formed, and the diameter of the trepanning drill bit ranges from 30 mm to 80 mm; (3) a drilling unit is lowered into the oil pipe through a continuous pipe, a drilling bit of the drilling unit is made to penetrate through the guider and the first through hole to punch the stratum so as to form a horizontal well hole, the diameter of the drilling bit is not larger than that of the trepanning bit, drilling fluid circulates in the drilling bit, and the horizontal well hole is formed in the oil pipe. The pressure of the drilling fluid is 40 to 60 Mpa.

Description

technical field [0001] The application relates to a drilling method and device, belonging to the field of petroleum exploitation. Background technique [0002] In recent years, the proportion of low-permeability reservoirs in oil and gas field development has gradually increased, and low-permeability reservoirs are restricted by their own reservoir geological conditions and process technology, showing low single-well production, high operating costs, and low economic benefits ( or even negative benefits) and other characteristics, so that a large number of low-permeability reservoirs cannot be economically exploited. Therefore, it is of great significance to seek a mining technology that can not only reduce the development cost but also increase the production of a single well, so as to achieve high production with fewer wells. [0003] At present, for the exploitation of low-permeability reservoirs, radial drilling technology has been developed rapidly in recent years. How...

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Problems solved by technology

[0003] At present, for the exploitation of low-permeability reservoirs, radial drilling technology has been developed rapidly in recent years. However, the traditional radial drilling technology has small casing openings (opening holes with an opening size of 22mm), and formation debris is easy to Accumulated outside the casing, squeeze the casing and cause damage to the casing, thereby affecting the normal production of the oil well and reducing the production of the oil well; in addition, for loose formations or formations with severe sand production, the wellbore channel is unstable and easy to collapse or Blockage greatly reduces the effective production time of oil wells; and due to the high cost of relocation of drilling equipment, a large operating space is required

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