SU1162951A1 - Apparatus for monitoring the drilling operation - Google Patents

Abstract

A DRILLING CONTROL DEVICE, containing sensors for longitudinal and transverse vibrations of a drilling tool, connected via band-pass filters to the average unit, the zero-organ and the display unit, characterized by the fact that it is equipped with two dividers and a delay line , wherein the outputs of the averaging units are connected to the inputs of the first divider, the output of which is connected to the first input of the second divider and through the delay line to its second input, and the output of the second divider through the null organ is connected to the display unit. (Ls

Description

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The invention relates to the field of drilling oil and gas wells and can be used to automate the control of the drilling process. The purpose of the invention is to improve accuracy. The drawing shows the structures on the scheme of the device. The device contains a sensor 1 for longitudinal oscillations of a drilling tool, a sensor 2 for transverse oscillations of a drilling tool, band-pass filters 3 and 4, blocks 5 and 6 for calculating the average absolute deviated longitudinal and transverse vibrations, respectively, divider 7 mean absolute deviations of longitudinal and transverse vibrations, delay line 8, signal divider 9, null organ 10 and signaling unit 11. Each of the sensors 1 and 2 is connected via bandpass filters 3 and 4 to the inputs of blocks 5 and 6 for calculating the mean absolute variation of the longitudinal and transverse vibrations, respectively. Outputs 5 and 6 are connected to two inputs of the divider 7 average absolute deviations, the output of which is connected to one input of the second and l 9 signals through line 8 is delayed. The output of the divider 9 through the null body 10 is connected to the signaling unit 11. The device works as follows. A drill bit has two main degrees of freedom: along the vertical axis of the well and in its perpendicular bottom plane. During the drilling process, when the bit interacts with rocks, two main types of oscillations, longitudinal and transverse, are excited, which in the form of longitudinal and transverse elastic waves are transmitted to the wellhead along the drill string. In the normal drilling process, the impact load is applied to the face in the vertical direction due to the rolling of the teeth of the cutters of the bit along the face. Under these conditions, predominantly longitudinal oscillations are excited, the intensity of which is much higher than the energy level of the transverse waves. In the absence of wear and tear of weapons and bit supports in the drill string, a stationary wave process develops, and the ratio of the energy characteristics of the longitudinal and transverse waves in the string in this case is also a stable stationary random variable. When the arms are worn out and the cones are jammed, the conditions of impact load are violated by rolling the cones. The pellets slide along the face, the destruction of the face goes in an inefficient mode of surface abrasion and fatigue destruction of the rocks. By moving the bit in the bottom plane in the drill string, intense transverse oscillations occur. The stationarity of the wave process in the drillstring is broken, the ratio between the energy levels of the longitudinal and transverse waves changes, there are failures and surges in the function characterizing the ratio of the energy characteristics of the longitudinal and transverse waves. This is a signal that the normal drilling process is disrupted due to bit wear. The longitudinal and transverse elastic waves propagating from the bit are converted by sensors 1 and 2 into electrical signals, which are filtered out from the bandpass noise, filters 3 and 4 and fed to the inputs of blocks 5 and 6, designed to calculate the mean absolute deviation of the longitudinal and transverse oscillations, respectively. . The output signals of blocks 5 and 6, proportional to the average absolute deviation of the longitudinal and transverse oscillations, arrive at the inputs of the divider 7, the average absolute deviations of the longitudinal and transverse oscillations. In a normally established drilling process, the signals from blocks 5 and 6 are stationary and, by the condition of stationarity, differ only by a constant factor. As a result, a constant signal acts at the output of the divider 7 for the mean absolute deviations of the longitudinal and transverse oscillations. When the bit is jammed, the stationarity of random wave processes is disturbed, so the signals at the output of divider 7 decrease or increase.

To establish bit jamming by the moment of the signal change at the output of the divider 7, the second divider 9 serves. At one input, a signal is output from the output of the divider 7 through delay line 8, and to the second input, the output signal of the divider 7 is fed directly. The delay time of the signal is set to, for example, 20 s, which ensures the timely establishment of the bit jamming before an emergency situation occurs due to overexposure of the spent bit at the bottom.

Thus, the input of the divider 9 receives two signals: one is adequate, or synchronous to the processes at the bottom, and the second is delayed in time (for example, for 20 s). The first signal represents the state of the bit at the moment of observation i, and the second

the signal is at the preceding moment of time t - “Л, where“ f-t is the signal delay time. In the absence of jamming, the signal at the output of divider 9 is constant. If the bit is jammed at the moment -i, then at that moment the signal being analyzed becomes unsteady by the mean absolute deviation, and the preceding signal corresponding to the time -t - tft is still stationary. For this reason, the signal c / -t / cAi is cK corresponding to the output ratio

5 divider 9, significantly exceeds the threshold of a zero-body request 10, At this moment the control signal from the zero-body 10 comes to the signaling unit 11.

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The advantages of the proposed device are to provide a more accurate optimal length of slotting. The reliability of the issued information on the state of bits justified

5 by experimental verification during drilling.

Claims (1)

DEVICE FOR MONITORING THE DRILLING PROCESS, containing longitudinal and transverse vibrations of the drilling tool, connected via bandpass filters to the average value calculation unit, a zero-organ and an indication unit, characterized in that, in order to improve accuracy, it is equipped with two dividers and a delay line, moreover, the outputs of the blocks for calculating the average values are connected to the inputs of the first divider, the output of which is connected to the first input of the second divider and through the delay line with its second input, and the output of the second divider through ul-body associated with the display unit. Ξ SU,. „1162951> ϊ ·