RU1815325C - Device for cleaning of drilling fluid from mined rocks - Google Patents

Abstract

The invention relates to devices for cleaning solid inclusions of drilling fluids and allows to reduce the energy consumption for cleaning. SUMMARY OF THE INVENTION: the device comprises a sieve 2 mounted in a frame 3, elastic elements 4, a vibration exciter 5, first and second receiving troughs 6 and 8. The first receiving trough in the initial part is provided with an opening. A second receiving chute is located under the first chute. The device comprises a control system, due to which the amplitude of the oscillations of the sieves is automatically reduced upon receipt of a reduced viscosity drilling mud. 2 ill.

Description

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The invention relates to a device for cleaning solid inclusions of drilling fluids and can be used in the drilling of oil and gas wells, as well as in the chemical, construction and other industries.

The purpose of the invention is to reduce energy consumption for cleaning.

In FIG. 1 shows a functional diagram of a device; in FIG. 2 are graphs illustrating the features of the device.

A device for cleaning drilling fluid from cuttings (see Fig. 1) contains a frame 1, a sieve 2 installed in the frame 3, elastic elements 4 in the form of springs, vibration exciter 5, the first receiving chute 6, provided in the initial part with a hole 7 , a second receiving chute 8, at the outlet of which there is a sensor 9 for the flow rate of the solution flowing along the second chute, a supply pipe 10 and outlet pipes 11 and 12. The device also includes a flow-voltage converter 13, a flow adjuster 14, a comparison element 15 , flow regulator 16, Spruce control pulses 17, pulse generator 18, power amplifier 19. In FIG. 1 is indicated: H is the length of the sieve, 12 is the largest size of the opening of the first trough in the direction of its longitudinal axis. In FIG. 2 denotes: Q / S is the specific flow rate of the purified drilling fluid (i.e., flow rate per unit surface of the sieve), I is the distance from the beginning of the sieve to any cross-section of it, measured in the direction of the longitudinal axis of the sieve, p - the viscosity of the drilling fluid supplied for cleaning, And - the amplitude of the sieve.

A device for cleaning drilling fluid from cuttings works as follows.

The device is connected to a power source (not shown). At the output of the pulse generator 18, a sequence of unipolar voltage pulses is generated, which are fed to the first input of the control pulse generator 17. At the output of the shaper 17, the pulses appear with the same repetition rate with which they arrive at its first input, but with a changed duration, and the magnitude of the change in the pulse duration depends on the voltage at the second input of the shaper 17. From the output of the shaper 17, the voltage pulses through the amplifier 19, the power is supplied to a vibration exciter 5 mounted on the frame 3. Since the frame 3 is supported by elastic elements 4, its vibrations arise which

transmitted to the frame mounted on the frame 2. The amplitude of the oscillations arising is determined by the duration of the voltage pulses supplied to the vibration exciter

5, and the oscillation frequency — by tuning the 18-pulse generator. The oscillation frequency is set so that the oscillations of the sieve 2 occurred in the near-resonance mode, which increases the amplitude

0 oscillations and improves the energy of the oscillatory system.

A drilling fluid is supplied to the oscillating sieve 2 through the inlet pipe 10, which flows along the sieve. Under the influence

5 vibration, the structure of the drilling fluid is destroyed. Cuttings of cuttings remaining on the sieve slide off the frame and are removed through the outlet pipe 12. The cleaned solution passing through siito 2 is sent to the first intake chute 6, from where it passes through the outlet pipe 11 for reuse.

The intensity of the cleaning process depends on the rheological characteristics of the solution of p3i mainly on its viscosity and the amplitude of the sieve vibrations. With an increase in the viscosity of the solution at a constant amplitude of the sieve vibrations, the cleaning intensity decreases, with an increase in the amplitude of the vibrations of the sieve with a constant viscosity of the solution, the cleaning intensity increases . A feature of drilling fluids entering the treatment is a change in their viscosity over a very wide range, which

5 is associated with a wide variation in the rheological characteristics of the rock being drilled (rock characteristics depend on the depth of the wells, on the location of the wells, on the drilling mode), and the initial characteristics of the solution. In uncontrolled mode of operation (operation of the device according to the prototype scheme), because of this feature, it becomes necessary to set an increased amplitude of oscillations

5 sieves, providing effective cleaning of drilling fluids with high viscosity. Setting the device to an increased amplitude of oscillations of the sieve leads to useless energy costs in those

0 cases when the viscosity of the solution entering the cleaning process (the solution arriving at the cleaning site with a practically constant flow rate) decreases, which is illustrated by experimentally obtained flow characteristics of the device — the dependence of the specific flow rate of the Q / S solution through the sieve on the distance I, counted from the beginning of the sieve (see Fig. 2).

The decrease in the specific flow rate (Fig. 2 shows the average flow characteristics) with increasing distance from the beginning of the sieve is due to the fact that the concentration of the liquid phase decreases with increasing distance from the beginning of the sieve, i.e. the amount of the liquid phase per unit volume of the solution decreases, If, under the maximum possible viscosity / liter of solution under specific conditions, the vibration amplitude At is set at which the entire length of the I screen is working (Fig. 2a, dependence 1), then while maintaining the increased amplitude of AI vibrations and the arrival of a solution with a reduced viscosity, only part of the length I of the sieve is used for cleaning (Fig. 2 a, dependences 2,3), i.e. the preservation of the increased amplitude of the sieve vibrations during the cleaning of solutions with a lower viscosity leads to useless energy consumption.

A characteristic feature of the device is the automatic correction of the amplitude of oscillations of the sieve depending on the viscosity of the solution supplied for cleaning, namely, with a decrease in the viscosity of the solution, the amplitude of the oscillations of the sieve decreases. The possibility of correction arises from the experimental flow characteristics shown in FIG. 2 b. From the characteristics it follows that when the viscosity of the solution decreases to fi2 and p3, such a choice of lower vibrational amplitudes A2 and Az is possible at which the entire length of 1 sieve is working. This is equivalent to eliminating unnecessary energy.

Correction requires an assessment of the viscosity of the solution entering the purification. Another characteristic feature of the device is that the evaluation of the viscosity of the solution is carried out using the specific features of the cleaning process through a sieve, without using viscosity sensors, the construction of which for solutions containing cuttings of cuttings is associated with great technical difficulties.

An analysis of the changes in the specific flow rate Q / S of the cleaned drilling fluid with a change in the distance I from the beginning of the sieve and the constant oscillation amplitude (Fig. 2a) shows that in the initial part of the sieve, over its length 2, the specific consumption increases with decreasing viscosity solution, i.e. the dependence of the specific consumption on the viscosity of the solution is monotonous. This tendency also persists with sieve oscillation amplitudes lower than Ai. Only the slope of dependencies 1,2,3 in FIG. 2 a, i.e. in the initial part of the sieve there is a section of length la, which can be used to indirectly evaluate the viscosity of the solution entering the cleanup. At I la, the monotonic character of the dependence of the specific consumption on the viscosity of the solution disappears (Fig. 2a). The dependence either takes on an extreme 5 character, or with a decrease in viscosity, the specific consumption decreases, i.e. at I g, the flow characteristics are not suitable for evaluating the viscosity of a solution.

With constant geometry of the sieve, the total flow rate of the purified solution over the length h of the sieve (see Fig. 2} will also depend on the viscosity of the solution. To quantify the total flow rate over the length of 2 sieves, the first receiving trough

5 is provided with a hole 7 of length g see FIG. 1). The solution passing through the opening 7 is guided to a second receiving chute 8 in which a flow sensor 9 of this solution is installed. At the output of the flow-voltage converter 13, the input of which is connected to the flow sensor 9, a signal is generated in the form of a direct current voltage, the level of which depends on the viscosity of the solution supplied for cleaning.

5 From the second intake chute 8, the purified solution enters the same outlet pipe 11 into which the purified solution enters from the first intake chute 6.

0 To change the oscillation amplitude of the sieve with a change in the viscosity of the solution entering the purification, i.e. To eliminate unnecessary energy consumption, a set of elements is used, including for 5 a flow sensor 14, a comparison element, a flow controller 16 and a control pulse generator 17. These elements together with other elements of the device form an automatic system with

0 feedback stabilizing the total flow rate of the purified solution over the sieve length g by affecting the amplitude of the sieve oscillations. At the same time, the change in the viscosity of the solution entering the cleaning system is a perturbation for this system.

The setpoint of the flow sensor 14 is selected so that under the maximum possible in the given specific conditions

0 the viscosity of the solution, its purification took place over the entire length of the sieve, i.e. so that the solution is purified according to characteristic 1 in FIG. 2 a. In steady state operation of the system with feedback at the output

5 of the flow controller 16, there is a voltage which, acting on the control pulse generator 17, sets such a pulse duration to the vibration exciter 5 at which the signal at the output of the converter consumption voltage 13 is compared with the signal at the output of the flow controller 14. At the specified setpoint setpoint, the oscillations of the sieve 2 will occur with the amplitude that is maximally necessary in these specific conditions.

As the viscosity of the solution entering the purification decreases, its total consumption over a length of 12 sieves increases. Accordingly, the signal at the output of the flow-voltage converter 13 will increase, which in level will exceed the signal coming from the flow adjuster 14. The signal at the output of the comparison element 15 will change sign and the flow controller 16 will decrease the pulse duration at the output of the control pulse generator 17; The oscillations of the sieve 2 will occur with a reduced amplitude at which the output signals of the flow adjuster 14 and the flow-voltage converter 13 are again compared.

Thus, due to the technical solutions adopted, the amplitude of the sieve oscillations changes in accordance with the changes in the viscosity of the solution to be cleaned, in particular, when the viscosity of the solution decreases, the amplitude of the sieve 2 decreases accordingly. This eliminates unnecessary energy consumption, since lower energy amplitudes are required to obtain reduced sieve oscillation amplitudes.

An experimental verification of the operability of the device shows that in order to achieve a positive effect in the device, the relation

h (0.1 -0.2) And,

where And is the length of the sieve, 12 is the largest hole size of the first trough in the direction of its longitudinal axis.

When the inequality Is 0.1 d is fulfilled, a device such as clogging of the sieve holes with fragments of cuttings affects the device’s performance. If the inequality h 0.1 h is fulfilled, the clogging of individual sieve openings has practically no effect on the total solution flow rate through the sieve over its length h.

When the inequality h 0.2 И is met and the viscosity of the drilling fluids varies over a wide range (when cleaning drilling fluids in the range of viscosity changes

0, t) 1-40 Pa s) a violation of the monotonic nature of the dependence of the specific flow rate of the solution through the sieve on the viscosity of the solution is possible. In this case, the device loses control and a positive effect is not achieved. If the inequality la 0.2I is fulfilled, the monotonicity of this dependence is guaranteed to be preserved. Thus, the ratio of 12 (0,1 0, 2) And ensures the operability of the device.

The device can use any vibration exciters (inertia with unbalances, eccentric, etc.). However, when using electromagnetic vibration exciters, the hardware costs are minimal.

Experimental studies of the operation of the device show that its use can reduce energy consumption by an average of 34%, which is especially important when using autonomous energy sources in drilling rigs,

Claims (1)

The claims A device for cleaning drilling fluid from drill cuttings containing a bed, a sieve, elastic elements, a vibration exciter and a receiving chute, which is further provided that, in order to reduce the energy consumption for cleaning, it is equipped with a second receiving chute with the flow sensor of the solution flowing through the second trough, the flow-voltage converter, the flow controller, the comparison element, the flow controller, the pulse generator, the control pulse pulser and the power amplifier installed at its output a hole is made in the groove in the initial part, a second groove is located under the first groove, a flow regulator is connected to the first input of the comparison element, with the second input of which the flow-voltage is connected to the flow sensor, and the output of the comparison element through the flow controller is connected to one of the inputs of the control pulse generator, to the second input of which a pulse generator is connected, the output of the control pulse generator through the power amplifier is connected to the vibration exciter, while the largest opening of the first gutter g in the direction its longitudinal axis is determined from the ratio 2 (0.1-0.2) li, where And is the length of the sieve. Editor FIG. 2 Compiled by M. Berman Tehred M. Morgenthal Proofreader S. Shekmar