A gas-dynamic automatic vertical drilling tool with partial gravity

Abstract

The invention provides an automatic vertical drilling tool on the basis of eccentric divided gas dynamics, and belongs to the field of oil-gas well drilling engineering. The automatic vertical drilling tool comprises a core barrel (1), a lower joint (3) and an eccentric outer barrel (2), wherein the lower joint (3) is connected to the lower end of the core barrel (1), the eccentric outer barrel (2) is sleeved outside the core barrel (1) and is of a streamline structure, and steel balls (5) are mounted between the core barrel (1) and the eccentric outer barrel (2). The automatic vertical drilling tool on the basis of the eccentric divided gas dynamics is convenient to operate and capable of sensing and correcting deviation automatically without any extra operations according to the principle of gravity sensing well deviation. High enough deviation correcting force can be generated under coaction of three acting forces, and jetting diameter can be regulated by changing of valves so that counter acting force generated by jet streams can be regulated. In addition, the automatic vertical drilling tool is simple in structure and high in stability, and performance can be played stably during usage owning to a pure-mechanical structure.

Description

technical field [0001] The invention belongs to the field of oil and gas well drilling engineering, in particular to an aerodynamic automatic vertical drilling tool of partial gravity flow. Background technique [0002] Gas drilling is a new technology developed in recent years that can greatly increase the ROP. Sinopec applied gas drilling technology in the Northeast Sichuan block to shorten the drilling cycle of wells with a depth of about 6000m from the original 1 to 2 years to 4 to 6 months. However, due to the lack of an effective gas drilling well deviation control system or tool, the understanding of the gas drilling well deviation mechanism is not completely clear, and it is difficult to control the well deviation. During on-site construction, it is often forced to change to drilling fluid drilling due to excessive well deviation, which seriously affects the further improvement of drilling speed. [0003] In order to solve this problem, experts at home and abroad h...

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Problems solved by technology

[0004] In the prior art, Chinese patents CN2431393, CN2532227, CN101025075, CN101358520, CN201068734, CN2895695, CN201236628, CN201129141, CN201288505, CN1519455, CN1676862 and papers "Mechanical Drilling", "Automatic Well Development, Vertical Drilling Technology, Vertical Drilling Technology" The automatic vertical drilling tools described in "Research", "Automatic vertical drilling tool design and automatic control method" have their own advantages, but also have their own limitations. The above tools are only suitable for drilling fluid drilling. During the process, the gas column pressure, pump pressure, and pressure difference inside and outside the drilling pressure are all low, and it is difficult to open the pushing mechanism of the vertical drilling tool with this pressure

[0005] Among them, patents CN2532227 and CN201236628 disclose a kind of biased or eccentric drill collar using centrifugal force to correct the deflection. second, the pendulum force of the drilling tool itself and the gravity of the eccentric drill collar can only produce very limited deflection force; third, the greater the well deviation, the smaller the deviation correction force

Using this set of vertical drilling technology, in the stratum with a formation dip angle of 60°, the drilling deviation can be controlled within 1°, the horizontal displacement is only 4m when drilling to 6700m, and the friction value is less than 120kN; the disadvantage is that it needs to be driven by drilling fluid pressure. and cannot be used for gas drilling

[0010] The technology introduced by SPE21905 is considered to be the first step towards a more multi-functional automatic drilling system, which uses drilling fluid pressure to drive the piston to the well wall to achieve declination; however, the disadvantage of this technology is that it cannot be driven by drilling fluid pressure. for gas drilling

[0011] To sum up, most of the existing automatic vertical drilling systems cannot adapt to gas drilling, and even if there are a few tools suitable for gas drilling, they are still difficult to generate a large enough down-slope force

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