SU1162953A1 - Method of controlling the process of rotary drilling of rock - Google Patents

Abstract

METHOD OF REGULATING THE PROCESS OF ROTATING DRILLING OF ROCKS, including monitoring the power spent on drilling, registering its increasing peak deviations and simultaneously reducing the axial load and speed of rotation until the power level stabilizes, characterized in that, in order to increase re-regulation efficiency by quickly stopping the suspension the drill bit, caused by the excitation of its rolling along the walls of the well, determine the mechanical speed of drilling, register its deviation from initially set level, corresponding to stabilization of the power level, and in case of occurrence of relaxation oscillations of the mechanical rhythm of buccane with a decrease in its average level; (3 n) with a simultaneous peak increase in power, the axial load is increased to obtain the initially specified level of mechanical speed; bureni., - O5 to 0 01 Od

Description

11 The invention relates to rotary drilling of wells, namely to methods of optimal control and regulation of the process of rotary drilling using drill pipes. The purpose of the invention is to improve the efficiency of regulation by quickly stopping the drilling rig from causing it to roll along the walls of the well. During the drilling of a well in a normal movement of the drill bit, its axis rotates around, the axis of the well or around some axis is not coincident with the axis of symmetry of the well. At the same time, the bzf projectile slides along the walls of the well or does not touch them. The maximum specific force (f) pressing the element 1 projectile against the borehole wall is determined in this case mainly by the magnitude of the centrifugal force (df mu) and the friction force vector (F) when the element slides along the borehole wall is pro-negative to the absolute velocity vector -4 .G -VF - JU. f sign: where ha is the mass of the element (unit of length) of the projectile; U) is the angular velocity of the tool; D and d are borehole diameters and projectile elements; ,, the coefficient of friction of the projectile on the borehole wall; circumferential element velocity yes; mechanical drilling speed. At the same time, the axial component of the friction forces FJ, the projectile element of the borehole is V F F, IF tg However, since during rotational drilling the rotation speed of the tool is many times greater than the mechanical speed, the axial component of the friction force (Fg) when the projectile turns It is negligible, and therefore the axial shaft of the rueck is almost completely transmitted to the wells, which ensures the stability of the level of mechanical speed with constant drilling parameters. The power spent on the rotation of the drill bit at its steady circulation is also stable. Therefore, when turning the projectile, the rotary drilling process is regulated according to the power level, since changes in the power level in this reflect mainly downhole processes. At the same time, in the process bzfeni on the selected tool rotation speeds smoothly increase the axial load until an increase in power occurs at the peak of deviations from a stable level, which reflects the transition from wet friction to su CB between rock cutting tool and the rock. When these peak deviations appear, the axial load and / or rotational speed decrease until the power level stabilizes and drilling is performed in this mode. When rolling a projectile, the specific force of pressing its element against the borehole wall increases significantly (usually more than two orders of magnitude) and is calculated by the formula ID - d fv t5g where AND W is the angular velocity of the projectile. In addition, when the projectile rolls without sliding, the force vector of friction of its element against the borehole walls is directed opposite to the axial displacement of the projectile; therefore, the axial component of the friction force (Fj) when the projectile rolls is sufficiently large and is calculated by the formula F jitf, (5) The presence of the force F directed opposite to the axial load determines the projectile hang, at which the axial load is transferred to the bottom hole partially. In turn, the sticking of the projectile causes a decrease in the mechanical drilling rate due to a decrease in the axial load on the face and polishing of diamond crowns. Usually, due to axial oscillations of the drilling projectile, the periodical slip of the projectile causes it to slip to the bottom hole 3 causes relaxation oscillations of the mechanical drilling rate with a frequency of about 0.050.5 Hz. In this case, the average value of the mechanical speed is usually reduced in comparison with the level that is observed before the projectile rolling motion. The latter, moreover, leads to an increase in the average power level with an increase in the amplitude of oscillations of its instantaneous values, which is mainly caused by oscillations of the axial load at the bottom of the well. Thus, the excitation of the rolling motion of the projectile is determined by the occurrence of relaxation oscillations of the mechanical drilling rate with a decrease in its average level and an increase in the power level spent on drilling with an increase in the amplitude of oscillations of its instantaneous values. According to the proposed method, in this case the drilling process is regulated by maintaining the initial predetermined (before driving the projectile roll) level of the mechanical drilling rate. At the same time, with the acceleration of speed bzfeni, the axial load is increased in order to overcome the action of the axial component of the friction forces, which caused the projectile to hang, and to restore the initial level of mechanical speed. These drilling operations are periodically repeated in accordance with the frequency of oscillations of the mechanical drilling rate. In the control process, the possible increase in the power level is limited by the allowable limit, for example, using an OM-40 type torque limiter. In the proposed method of controlling the rotational drilling process, the power expended in drilling is controlled, for example, using H-395 self-recording kilowatts and mechanical drilling rate, for example, using serial Kurs-441 type test instrumentation. When the levels of mechanical drilling speed and power are stabilized, for example, after disruption (elimination) of the rolling of the projectile, the transition to drilling process is again regulated according to the power level described above. It should be noted that the operations of adjusting for power levels and menisic speed based on various physical phenomena arising during rotary drilling do not have a formal similarity: when adjusting power with increasing power in the form of peak deviations, axial load decreases, and when controlled by mechanical speed, with a decrease in speed and a simultaneous increase in power (when a projectile is excited), the axial load, on the contrary, increases. FIG. Figure 1 shows a block diagram of a device that analyzes the preparatory method in the case of manual adjustment of the drilling process; Figures 2 and 3 are power output diagrams illustrating, respectively, the regulation of the drilling process by power level when the projectile is turned on and to maintain a constant level of the mechanical speed of drilling when the projectile is rocked; in fig. 4 shows a fragment of the power cost diagram reflecting the drilling process unregulated by the mechanical speed level. When manually adjusting the drilling process after turning on the drilling unit 1 - (FIG. 1), the driller 2 uses the rotary actuator handles 3 and the feed 4 to establish rational values for the drilling mode parameters — rotation speed and axial load (for example, based on previous experience or calculation) , analyzing the nature of the change in power and speed of drilling, respectively, on recorders 5 and 6, and determines the control criterion (channel). If the readings of driver power registers 5 and drilling rates 6 are stable, the driller proceeds to adjust the drilling process (search for the optimal mode) by the power parameter (first channel), for which he continues to gradually increase the axial load and / or rotation speed, controlling his actions registrars 5 and 6, which at the same time show adequate increments of power and mechanical speed. This operation continues until the recorder shows abrupt (inadequate) power increases in the form of peak 5 deviations, after which it reduces the axial load and / or rotational speed until these peaks disappear and at this optimal mode, ensuring the greatest mechanical speed and resource of the crown, drilling continues. If the driller detects a spontaneous abrupt increase in power in the form of a continuous drilling process in the form of long-term (or peak) deviations of its constant component with an increase in the amplitude of the variable component and, at the same time, relaxation (non-harmonic) oscillations of the mechanical speed with the frequency of the order 0.05-0.5 Hz and lowering its average level, the driller proceeds to regulate the drilling process according to mechanical speed (the second channel), for which, at a constant rotation speed, increase Axial loading until the relaxation oscillations of the mechanical velocity disappear and stabilizes it at the initial (before relaxation oscillations) level and reduces the axial load when this level is exceeded. Naturally, the initial level of mechanical speed is not constant and depends on the degree of wear of the crown (including during adjustment), change of rocks, etc. Therefore, the main purpose of regulation in the second channel is not to achieve the exact level of the mechanical speed, but to eliminate its relaxation oscillations and to achieve stabilization of the speed, which ensures the transfer of the optimal load on the bottom and the output to the amount of mechanical speed that can be implemented under these conditions when regulating through the first channel. In the process of adjusting for power and mechanical speed, power surges can exceed the allowable limit and then the limiting device 7 (figure 1) is triggered, disabling the rotation of the drill string. Regulation of the drilling process with consideration of the driller (operator) due to the limited physical abilities of a person in the perception and analysis of current information does not always ensure the correctness of the drilling process. Therefore, the proposed method is particularly useful in automated drilling control systems. For the implementation of the proposed method with automated control of the drilling process on the drilling unit 1, the operator’s functions can be performed by a device (for example, a microcomputer), which is equipped with appropriate algorithms built on the basis of specific features of these situations: stability of power levels and drilling speed (normal drilling), stepwise power increase in combination with relaxation fluctuations in the drilling rate (drilling with projectile loading). After the situation is recognized, the control system, through the adjustable drive 3 and the feeder 4, proceeds to implement one of the programs: power or speed control. Example. The implementation of the proposed method for regulating the rotary drilling process was carried out at one of the fields of the Soyuzglavgeologologaya NPO when drilling planned wells No. 1637 and 1642 with design depths of 800 and 1200 m. In both wells, the volumes of drilling with rolling and rolling of the projectile were distributed approximately equally. Projectile rolling was determined by operational characteristics (increase in power and fluctuations in its level, the occurrence of relaxation oscillations of the mechanical velocity with a decrease in its average level), as well as in auxiliary signs (character of core formation, tool wear, etc.). When handling the projectile, the drilling process was regulated to maintain a given power level at which the highest resistance of the diamond crowns was noted, and the level of mechanical speed was 3-3.5 m / h. A fragment of the power cost diagram, reflecting the specified regulation when drilling well No. 1642 in the interval 643.7-649.4 m, is shown in FIG. 2, Regulation was reduced to the establishment of a given power level by smoothly increasing the axial load to approximately

1300 kg, which remained almost unchanged during the penetration of the spindle stroke of the machine due to the stability of the power level and mechanical speed (in the diagram of Fig. 2, the time intervals between the projectile bindings are the same). . When the rolling motion of the projectile was excited, the oscillations of the mechanical drilling speed in the range of 3.20, 8 m / h with a frequency of 0.05–0.5 Hz were recorded using the Kurs-411 instrumentation indicator. The drilling process of adjusting at the initial level of mechanical speed (l / 3 m / h) selectively at different intervals of the drilling of wells No. 1637 and 1642 by gradually increasing the axial load while reducing the mechanical speed and decreasing the load with increasing speed above 3 m / h.

FIG. Figure 3 shows a fragment of the power cost diagram illustrating the regulation of the drilling process by the level of the mechanical drilling speed (well No. 1657, depth interval 752.2-758.0 Ω). a predetermined level (3 m / h) was kept constant (the intervals between the projectile bindings are the same).

For comparison, in FIG. Figure 4 shows the power cost diagram recorded under the same drilling conditions, but without the use of an adjustment for the level of mechanical speed. In this case, the axial load of the axial load that was set after starting the rotation of the tool did not change during the drilling of the spindle stroke interval of the machine tool. This resulted, as can be seen from the examination of the fragment of the diagram of FIG. 4, to the fluctuation of the mechanical drilling rate with a decrease in its average value when drilling almost every interval of the machine toolpath (the intervals between perekreleni are unequal and more than 30%, on average, of the corresponding intervals in the controlled process).

In addition to eliminating losses from a decrease in mechanical speed and, consequently, drilling performance, the proposed method of regulation contributes to reducing the consumption of analyzes by reducing polishing and wear of diamond crowns arising from hang-up, projectile and the absence of appropriate adjustment of the drilling process by axial load.

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Claims (1)

METHOD FOR REGULATING THE ROTARY ROTARY DRILLING PROCESS OF ROCKS, including monitoring the power spent on drilling, recording its increasing peak deviations and at the same time reducing axial load and rotation speed to stabilize the power level, characterized in that, in order to increase the efficiency of the regulation by quickly stopping the hang drill, caused by the excitation of its rolling along the walls of the well, determine the mechanical drilling speed. register its deviation from the initially set level corresponding to stabilization of the power level, and in the case of relaxation oscillations of the mechanical drilling speed with a decrease in its average level with a simultaneous peak increase in power, the axial load is increased until the initial a given level of mechanical speed _ _; drilling. , Z Figure 1