RU2270312C1 - Method to increase mechanical drilling bit penetration speed during turbine motor drilling - Google Patents

Abstract

FIELD: oil production, particularly well drilling.

SUBSTANCE: method to increase penetration speed during drilling of well provided with mud pump, injection pipeline, mud hose, drilling string and turbodrill involves installing composite acoustic noise transducer, which modifies quarter-wave resonator noise in injection line between mud pump and mud hose; transforming normal low-number waves in mud pump noise spectrum into normal high-number waves along with dissipating thereof by flushing liquid; creating uniform flow movement without normal low-number drilling mud wave pulsation from drilling string into turbodrill; providing uniform turbodrill turbine rotor blade rotation by means of flushing liquid along with following smooth drilling bit cutters rotation at well bottom.

EFFECT: increased penetration speed due to reduced unevenness of turbodrill shaft rotation.

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Description

The invention relates to the oil industry, in particular to the field of drilling oil and gas wells.

A known method of increasing the mechanical speed of penetration on a bit by installing between the turbodrill and the bit a short flywheel of large diameter, which reduces the degree of uneven rotation of the shaft. Serial turbodrills and bits operate with a high degree of rotation non-uniformity σ = 30-80%, which reduces their performance [1].

The disadvantage of this method is that a flywheel is built into the structure between the turbodrill and the bit.

A known method of reducing the degree of uneven rotation of the shaft of the turbodrill, which consists in placing air compensators in the discharge line of the mud pump and significantly smoothing the pressure pulsations in the drilling fluid [2].

The maximum fluctuation range (the difference between the minimum and maximum pressure values) is 17-17.5 atm (when two U8-3M pumps are running, the pressure on the riser according to the manometer is 100-110 atm). During operation of air compensators, the maximum value of pressure pulsations is reduced from 17.5 to 12.12.5 atm due to the action of air compensators.

The disadvantage of this method is the high residual level of pressure pulsations in the drilling fluid, which is determined by the degree of pressure unevenness

where P _MAK is the maximum pressure of the flushing fluid; P _{MIN is the} minimum pressure of the flushing fluid; P _C is the static (approximately average) value of the pressure of the flushing fluid.

The results of experimental studies of the pressure P of the flushing fluid pumped by the mud pumps is 61%. The use of compensators reduces the value to 19% [2].

The objective of the invention is to increase the mechanical drilling speed by reducing the degree of uneven rotation of the shaft of the turbodrill.

The task is achieved by installing a composite acoustic noise converter from the quarter-wave resonators into the discharge line between the mud pump and the drill hose, transform the normal waves of low numbers in the noise spectrum of the mud pump into normal waves of high numbers, followed by their dispersion in the flushing fluid, create uniform movement flow without pulsations of normal waves of low mud numbers from drill pipes to a turbodrill, create uniform rotation of the rotor blades turbo-drill bins with flushing fluid, followed by jerky rotation of the bit cutters along the bottom of the well.

Comparative analysis with the prototype shows that in the proposed method carry out the alignment of the flow of washing liquid in front of the turbodrill. This leads to the fact that the blades of the rotor of the turbo-drill turbine, therefore, and the cone bits begin to rotate evenly along the bottom of the well.

Thus, the invention meets the criterion of "novelty."

Comparison of the proposed solution with other technical solutions shows that a decrease in the degree of uneven rotation of the turbo-drill shaft is known [2]. However, it is not known that using a composite acoustic noise converter from quarter-wave resonators, it is possible to convert normal low-level waves in the noise spectrum of a mud pump into high-level normal waves with their subsequent dispersion in the washing liquid and to create uniform flow movement without pulsations of normal waves of low numbers of washing liquid from drill pipes in the turbodrill, thereby creating a uniform rotation of the rotor blades of the turbine of the turbodrill with flushing fluid, followed by without jerking rotation of the cone bits on the bottom of the well. As a result, the operating mode of the turbo-drill and the load on the face change.

Thus, the invention meets the criterion of "inventive step".

The present invention can be implemented on standard means.

Thus, the invention meets the criterion of "industrial applicability".

Physical processes in solving the problem

1. It is known that elastic waves in a column of washing liquid cause pressure and fluid flow fluctuations in its turbine and, as a result, the bit rotation speed n, hydraulic force Р _Г , moment М and power N on the turbo-drill shaft, exciting longitudinal and torsional vibrations of the shaft turbodrill and chisels. As a result, the operating mode of the turbodrill and the load on the face change.

Change n ₁ ; M ₁ ; N ₁ and P _g1, respectively, on n ₂ ; M ₂ ; N ₂ and R _g2 when changing the flow rate of the washing fluid from Q ₁ to Q ₂ or the pressure from p ₁ to p ₂ (with the specific gravity of the washing fluid γ _w = const) is determined by the well-known formula (1)

2. The pressure pulsations in the liquid are estimated by sound parameters [3]. Therefore, if you reduce the sound level, namely, homogeneous normal waves of low numbers (elastic waves), you can, firstly, eliminate the uneven rotation of the turbine drill blades, and secondly, eliminate jerks of rotation of the bit cutters along the bottom of the well, i.e. change the mode of operation of the turbodrill and the load on the face, therefore, increase the mechanical speed of penetration on the bit.

3. The pipes through which sound propagates are, from an acoustic point of view, waveguides. As you know, the sound field in any waveguide is a superposition of homogeneous normal waves of different types (numbers). Inhomogeneous normal waves decay exponentially as they propagate in the waveguide; therefore, at a sufficient distance from the source, they make an insignificant contribution to the total sound field. Homogeneous normal waves propagate in the waveguide without attenuation. The simplest of these is the zero normal wave. This wave is similar to a plane wave in free space, the particle velocities in it are parallel to the direction of propagation, i.e. the walls of the waveguide.

One common way to reduce sound transmission through a waveguide is to create sound absorption on its walls, which are coated with sound-absorbing material. However, all sound-absorbing materials are effective at small angles of incidence of the sound wave, sound absorption with increasing angle of incidence rapidly decreases. For this reason, the attenuation of normal waves in a waveguide lined with sound-absorbing material slows down sharply as their number decreases. With a sufficiently long length of the lined section, only the normal wave of the lowest number remains in the waveguide. From the attenuation of this particular normal wave, the effectiveness of sound-absorbing material on the walls of the waveguide is estimated.

Therefore, a method is proposed for increasing sound attenuation in a waveguide by transforming weakly damped normal waves of low numbers into normal waves of high numbers, well absorbed in the drilling fluid. Normal waves are transformed using resonators acoustically connected to the waveguide. The type of resonator and the method of their acoustic connection to the waveguide is not of fundamental importance. When sound waves propagate in a waveguide having a frequency equal to or close to the natural frequency of the resonators, intense sound scattering occurs at the resonators. As a result of this, the normal waves of low numbers are transformed into normal waves of high numbers. If sound waves with different frequencies propagate simultaneously in a waveguide, then to increase the attenuation of sound, a set of resonators with corresponding natural frequencies must be connected to this waveguide.

4. If a normal wave of number q with frequency ω propagates in the waveguide, then for a waveguide with rigid walls this wave has the form [4]

Where

C is the speed of sound in a liquid.

The factor exp (-iωt) is omitted hereinafter. Under the action of wave (2), the resonator is excited and creates a field P (x, z). The total field in the waveguide is obtained by adding the fields P ₀ and R.

To determine the field P, the following technique is used. If the dimensions of the resonator are small compared to the wavelength, then this resonator is considered as an oscillatory system with one degree of freedom. The concentrated parameters of the system are determined by the size of the throat and the volume of the liquid cavity of the resonator. Let V ₀ denote the volume velocity created by the resonator when the incident field P _{0 is} applied to it. We express the scattered field in the waveguide in terms of V ₀ . The field created by the resonator, according to the method described in [5], is equal to

where k = ω / s; ρ = fluid density;

Hereinafter, the upper sign is chosen for x> 0, and the lower one for x <0.

The value of V ₀ and, therefore, the field P (x, z) can be found using the equation of forced oscillations of the resonator under the action of the field P ₀ (x, z). This equation has the form

where M is the effective mass (the mass of liquid in the throat of the resonator plus the attached mass);

a is the width of the throat;

χ is flexibility;

r ₀ is the friction resistance;

g is the radiation resistance.

The value of g is determined by the formula

where N is the number of normal waves propagating in the waveguide (except for the zero wave).

The solution of equation (4) can be represented in the form

Where

R = (r ₀ + r);

Therefore, the space velocity V _{0 is} written as

If the sound frequency coincides with the natural frequency of the resonator

and the friction resistance is small compared with the radiation resistance (r ₀ ≪r), then this formula takes the form

Using formulas (3) and (8), we obtain for the scattered field

where the amplitudes A _{n of} normal waves are calculated by the formula

From these formulas it follows that the amplitudes of the normal and forward scattered waves are the same. It is seen from formulas (12) that the excitation of normal waves in a waveguide does not depend on the number q of the incident wave. This is because the resonator only responds to pressure, and the pressure created by the incident wave on the rigid wall of the waveguide depends only on the amplitude of this wave. Since the amplitudes A _{n are} inversely proportional to the value ξ _n , the degree of excitation of a normal wave increases with an increase in its number. The wave has the greatest amplitude, the critical frequency of which is closer to the sound frequency. In the limiting case of coincidence of the critical frequency for a normal wave of number l with the sound frequency, we obtain

For kh = lπ, where = l is any integer, only the normal wave of number l is excited; other waves are not excited.

Thus, in a waveguide, when sound is scattered from a resonator, normal waves of low numbers are transformed into normal waves of high numbers, which are well absorbed by the drilling fluid. Consequently, the pressure pulsation is reduced and the uneven rotation of the turbo-drill turbine blades is eliminated, with the subsequent elimination of jerks of bit cone rotation along the bottom of the well and an increase in the mechanical speed of penetration of the bit.

1 is a diagram of pressure pulses generated by a mud pump in a drill string in front of a turbodrill.

Figure 2 shows a diagram of pressure pulses between a composite acoustic noise converter from quarter-wave resonators and a turbodrill.

Figure 3 shows the fluctuations in the speed of rotation of the shaft of the turbodrill.

Figure 4 shows the fluctuations in the speed of rotation of the shaft of the turbodrill after installing a composite acoustic noise converter from quarter-wave resonators in the discharge line between the mud pump and the drill hose.

Figure 5 shows the layout of a composite acoustic noise converter of quarter-wave resonators in the discharge line between the mud pump and the drill hose.

Figure 1 shows a diagram of pressure pulses (pulsations) with an uneven repetition period (jerks) after the mud pump in the discharge line and the drill string in front of the turbodrill.

The non-uniformity of the periods T following the pressure pulses (pulsations) is created due to the instability of the piston pump, where T (1) ≠ T (2) ≠ T (3).

Figure 2 shows a diagram of pressure pulses (pulsations) with a uniform period T, where T (1) = T (2) = T (3) = T (4).

The uniformity of the pulse repetition periods is explained by the absence of normal waves of low numbers in the discharge line in front of the turbodrill. This stabilizes the flow. A composite acoustic noise converter made of quarter-wave resonators is placed in the discharge line.

Figure 3 shows a diagram of the rotational speed of the bit n. The degree of uneven rotation of the turbo-drill shaft is shown.

Figure 4 shows a diagram of the bit speed n after installing a composite acoustic noise converter from quarter-wave resonators 3 (Fig. 5) in the discharge line 2 (Fig. 5) between the mud pump 1 (Fig. 5) and the drill pipe 4 (Fig. 5). The degree of uneven rotation of the bit decreased.

Figure 5 shows a diagram for implementing the proposed method, where 1 is a mud pump, 2 is a discharge line, 3 is a composite acoustic noise converter from quarter-wave resonators, 4 is a drill pipe, 5 is a drill pipe, 6 is a turbodrill.

An example of the method

First operation

Install a composite acoustic noise converter from quarter-wave resonators 3 (for example, [6]) (Fig. 5) to the discharge line 2 (Fig. 5) between the mud pump 1 (Fig. 5) and the drill hose 4 (Fig. 5).

Second operation

Normal waves of low numbers (according to Equations 11 and 21) in the noise spectrum of the mud pump are converted to normal waves of high numbers, followed by their dispersion in the wash fluid.

Third operation

Uniform flow movement is created without pulsations (jerks), FIG. 2, normal waves of low flushing fluid numbers from drill pipes 5 (FIG. 5) to turbo-drill 6 (FIG. 5).

Fourth operation

Uniform rotation of the blades of the rotor of the turbine of the turbo-drill (turbo-drill shaft) 6 (Fig. 5) is created by the flushing fluid, followed by jerky rotation of the bit cutters along the bottom of the well, Fig. 4

The proposed method for stabilizing the flow of flushing fluid, based on the conversion of normal waves of low numbers in the noise spectrum (elastic waves in the column of flushing fluid) of the mud pump into normal waves of high numbers with their subsequent dispersion in the flushing fluid), the pump passed industrial tests at the drilling rig BU -3000 UEC, at the Tarasovskoye field of the Purpeysky UBR at wells No. 4, 1, 2 and 66 with a composite acoustic noise converter from quarter-wave resonators to injection line (at a distance of 15 m from the mud pump).

In relation to the drilling parameters of previously drilled wells No. 3, 5 and 8 (without a composite acoustic noise converter from quarter-wave resonators) in the drilling interval from under the conductor (500-1500 m), the mechanical drilling speed was increased (from 37.4 m / hour to 45, 2 m / hour) by 17.5% and increase penetration on the bit by 6.3%.

Information sources

1. Balitsky P.V. The interaction of the drill string with the bottom of the well. M .: Nedra, 1975.P.22-25, 37-39.

2. Grachev Yu.V., Varlamov V.P. Automatic control in wells during drilling and operation. - M.: Gostekhizdat, 1963. S.79-85 [PROTOTYPE].

3. Handbook of technical acoustics: Per. with him./ Ed. M. Hekla and H.A. Muller. - L .: Shipbuilding, 1980. S.218-219.

4. Lapin A.D. The use of resonators to reduce the transmission of sound in pipes. / The fight against noise and vibration // M .: Literature on construction, 1966. - S.304-309.

5. Isakovich M.A. Scattering of sound waves by small inhomogeneities in a waveguide. Acoustic magazine. 1957, 3, 1, p. 37-45.

6. Patent RU 2109134, cl. E 21 B 43/25.

Claims (1)

A method of increasing the mechanical speed of penetration on a bit during turbine drilling of a well equipped with a mud pump, injection line, drill pipe, drill pipes and a drill, which involves installing a composite acoustic noise converter from quarter-wave resonators in the discharge line between the mud pump and the drill pipe, converting normal waves of low waves numbers in the noise spectrum of the mud pump into normal waves of high numbers with their subsequent dispersion in the flushing fluid, cos Contents uniform flow without pulsation waves normal low numbers from flushing fluid to the drill pipe turbodrill, the creation of uniform rotation of the turbine rotor blades turbodrill washing liquid with subsequent runs without rotating cutters on the bit bottom of the well.

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