# The method of determining the degree of wear of rock cutting tool during drilling

(57) Abstract:

The invention relates to the field of drilling and can be used to determine the rock cutting tool. The objective of the invention is to increase the reliability of the moment of lifting the rock cutting tool and the possibility of practicing to the full depreciation. The way to build a straightforward calculation of the load characteristic of the turbodrill with a new bit and the estimated load characteristic of the turbodrill with a worn bit, and connect the cut zone of unstable work at these load characteristics. The length taken as the criterion of wear of rock cutting tool. The specified segment graduate, breaking it into pieces of equal length, which characterizes the amount of wear of rock cutting tools, and accept them as health criteria rock cutting tool. In the drilling process according to the measurement rotation speed and axial load at a discrete bit loading from idle mode to unstable operation of the mud motor build load characteristic for a new bit and a series of load characteristics after a preset time interval control. The degree of the of eristic, built in metering data, and the estimated load characteristics. 1 Il. The invention relates to techniques for drilling oil and gas wells, in particular to the field of control and management of the drilling process, and can be used to determine the degree of wear of rock cutting tool.There is a method of determining the degree of wear of rock cutting tools, including measuring the pulsation pressure of the wash liquid with its subsequent transformation into a spectrum of pressure fluctuations, and the criterion of wear of rock cutting tool is received bandwidth rationing spectral density, and the wear limit is characterized by the absence of the dominant frequency [1].The disadvantage of this method is that, firstly, the frequency of pressure pulsations in the pump line is variable and varies from 1 to 8 imp/s with a certain period (in the case of independence drives two pumps) [2], and secondly, in the process of rock cutting tool is offset from the spectral density at higher frequencies with the transition in the broadband spectrum. Therefore, it is difficult to determine the dominant frequency, which leads to the bottom of skim the technical essence is a method for measuring wear of a drill bit in the drilling process, for example, in the drilling process continuously measure the frequency of rotation of the bit gauge, axial load and the current value of drilling time Converter with the following calculation time bit for armaments and implement the algorithm [3]:T=(P

_{KP}- P

_{CF})(S + 1)/2An, (1)

where T - time bit due to wear his weapons;

P

_{KR}- maximum weight on bit;

P

_{CF}- the average bit load at the time of the next feed of the drilling tool;

n is an average value of rotation of the bit in the next innings drilling tool;

S - the ratio of the width of the base of the tooth to its initial tupiza;

A - coefficient taking into account the specific conditions of operation of the bit (coefficient of abrasiveness);

- magnitude depending on the model type of the bit and setting drilling.The disadvantage of this method is that, firstly, the spectrum of the drill string is unstable at different loads on the bit (serial turbodrills and chisel work with a high degree of non-uniformity of rotation in the range from 30 to 80% [4]) in the process of uneven depressions of the face, and secondly, in deviated wells due to the deformation of boilerplate it with the borehole wall, which also leads to low accuracy of prediction of the rise of rock cutting tool.The objective of the invention is to increase the reliability of the prediction of the moment of lifting the rock cutting tool.This object is achieved in that in the method of determining the degree of wear of rock cutting in the drilling process, comprising measuring the frequency of rotation of the bit and the axial load, build a straightforward calculation of the load characteristic of the turbodrill with a new bit and the estimated load characteristic of the turbodrill with a worn bit, connect the cut zone of unstable work at these load characteristics, take the length criterion for wear of rock cutting tools, graduate specified period, breaking it into pieces of equal length, which characterizes the amount of wear of rock cutting tools, and accept them as health criteria rock cutting tool, in the drilling process according to the measurement rotation speed and axial load at a discrete bit loading from idle mode to unstable operation of the mud motor build load characteristic for the new bits and the series on the nes and the degree of operation of rock cutting tool, the combination of load characteristics, built in metering data, and the estimated load characteristics.Comparative analysis of the prototype shows that the inventive method for the criterion of wear of rock cutting tool is taken as a line connecting the plots unstable operation of the mud motor to the load characteristic of the turbo-drill for new bits and worn out, which is constructed in advance according to the values of the statistical processing bits from previous wells, and for the health criteria adopted by the length of the segment, calculated by the formulas between the initial area of unstable operation of the turbo-drill for the new bits and the current segment unstable work load characteristics of the turbodrill, and the length, constructed on the basis of statistical data, pre-calibrated in the amount of wear of rock cutting tool.Thus, the present invention conforms to the criterion "novelty".A comparison of the claimed solutions with other technical solutions shows that the method of determining the degree of wear Portorose tool known [3] . However, on the basis of the accumulated material processing bits based average osennim bit. The zone of unstable operation of the turbo-drill, as the most effective work area of the turbodrill, connect a straight line (segment) and undertake the criterion of wear of rock cutting tool. Segments of equal length, when you split it apart, take the health criteria of rock cutting tool. Built load characteristics of the turbo-drill in the drilling process after a preset time interval and combined with the calculated load capacity of the turbodrill show the degree of wear of rock cutting tool and forecast.Thus, the proposed invention meets the criterion of "inventive step".The proposed solution can be repeatedly used while drilling oil and gas wells.Thus, the present invention conforms to the criterion "industrial applicability".Guidelines for selection criterion wear and health criteria of rock cutting tools and their implementation in the proposed method.1. Experimental research has shown that when you increase the load on the bit speed of the shaft of the turbo-drill (number of bit revolutions) is reduced. Sakoa close to rectilinear [4,5].2. As a result of processing diagram of recording speed of the mud motor, the capacity of the turbo-drill, drilling speed in function of the load graphs of the dependence of the parameters on the axial load. These charts with load increase is observed steep drop in the values of the specified parameters. In this area the work of the turbodrill unstable, but at the same time near this area received the best drilling performance [4].3. With increasing time mechanical drilling as a result of wear of the bearings and the armament of a roller bit load capacity of the turbodrill is reduced. The wear of bearings and arms of the roller bit causes the rotation speed of the turbo-drill with increasing axial load on the bit and, consequently, reduces the stability of the turbodrill, and thus decreases the effective range of operation of the mud motor and the braking load. The operating range of the turbo-drill down to 40%, and the braking load on 28-38,6% [6].Thus, on the basis of the first paragraph - linearity of the load characteristics of the turbodrill, the second - best performance drilling in the zone of unstable operation of the turbodrill, third paragraph - reduce and offset values of braking loads and zones of neustettin wear of rock cutting tool in the process of drilling through the nomogram calculation of load characteristics with imposing on them the actual load characteristics of the turbodrill.The drawing shows a nomogram calculation of load characteristics of the turbodrill according to the mining drill bits (for one type) in the previous wells in this field.On the horizontal axis information load on the bit G, kN, and for convenience of calculation and construction of load characteristics of the turbo-drill unit scale load on bit is given to the unit scale of the number of revolutions of the bit.The line AB is the load characteristic of the turbodrill with a new bit.Line AC - load characteristic of the turbodrill with a worn bit.The line BC represents the criterion of wear of rock cutting tool.Segments AB

_{1}, BB

_{2}, ...CC

_{9}on the segment BC characterize the health criteria of rock cutting tool as a percentage.An example of the method.Operation first. The construction of nomograms. Spend on a plane two mutually perpendicular numeric axis. On one axis (Y-axis), the values of the numbers of revolutions of the bit n, and on the other axis (X-axis) mark values of axial load G.Put on a plane three points:

1. point[x, y] (where x=G,y=n) Danna/SUB>] (where x

_{0}=G

_{0}, y

_{0}=n

_{0}data, for example (Fig.8 [4]) n

_{0}= 600 rpm and G

_{0}= 270 kN = 1500 scale units (dot corresponds to the turbodrill in the zone of unstable work for a new bit);

3. the point[x

_{10},

_{10}] (where x

_{10}=G

_{10},

_{10}=n

_{10}data, for example (Fig. 8 [4] ) n

_{10}= 400 rpm and G

_{10}= 175 kN = 700 scale units (dot corresponds to the mode of the turbodrill in the zone of instability for the worn bit).4. Are the equations of the lines:

AB: y = -0,27 x + 900;

AC: y = a-0.7 x + 900;

SU: = 0,58 X.5. Determine the length of AC, characterizing the criterion of wear of rock cutting tool according to the formula:

VS=[(x

_{0}- x

_{10})

^{2}+ (y

_{0}- u

_{10})

^{2}]

^{1/2}(2)

After substitution of the initial data and the solution of equation (2), we obtain SU= 403 large-scale units.6. Break a segment of the armed forces, for example, into 10 equal parts (% wear of rock cutting tools: BB

_{1}=10%, CC

_{2}=20%, ..., sun=100%). Each segment length of 40.3 scale units characterizes the health criteria of rock cutting tool.7. Make up a series of equations of the load characteristics AB

_{1}: y = 0.31 supranational x + 900;

AB

_{2}: y = -0,34 x + 900;

AB

_{3}: y = -0,38 x + 900;

AB

_{4}: y = -0,42 x + 900;

AB

_{5}y = -0,47 x + 900;

AB

_{6}: y = -0,51 x + 900;

AB

_{7}: y = be 0,55 x + 900;

AB

_{8}: y = -0,60 x + 900;

AB

_{9}: y = -0,65 x + 900.8. Build a series of calculated load characteristics with the criterion of wear of rock cutting tool in the form of lines SU and health criteria rock cutting tool as a percentage in the form of segments BB

_{1}, BB

_{2}, ..., SU.The second operation. Lower the drill pipe with a new bit in the borehole. Include pumps and during flushing of the face are measuring the number of revolutions of the bit in idle mode.The third operation. Lowered downhole mud motor and load it to the braking torque, while measuring the number of revolutions of the bit when the load changes discretely, for example, 30-50 kN.The fourth operation. Build a load characteristic of a turbodrill for measuring data with a new bit and combine it on the nomogram line AB.The fifth operation. Produce drilling under a given axial load on geological and technological along.The sixth operation. Produce the strong tool for 5-10 m) and then loaded it to the braking torque when the load changes discretely, for example, 30-50 kN.The seventh operation. Build a load characteristic of a turbodrill for measuring data already parabolani bit. For example, built a load characteristic of the turbodrill to apply it on the nomogram coincided with the calculated load characteristic AB

_{3}. This means that the wear of rock cutting tool is 30%.Operation eight. After receiving information about the state of rock cutting tool and given that the working area and unstable operation of the mud motor is shifted to smaller axial loads, the operator decides to continue drilling under load, for example, G=240 kN and n=550 rpm, there can be obtained the best performance drilling, in particular, the power turbodrill and drilling speed.Thus, the driller, continuous (interval time) receiving information on the degree of wear of weapons rock cutting tool, works it to the full depreciation taking into account the best indicators of drilling.Sources of information

1. A. C. 1427059, E 21 In 45/00, 1988 [similar].2. Grachev Y. C., Varlamov Century. N. Automatic control in wells during drilling and operation. - M.: Goauche the th column with the bottom hole. - M.: Nedra, 1975, S. 22 - 23 (Fig. 8), S. 143.5. Eskin, M. R., Romanov, I. E. the relationship between parameters of turbine drilling performance of the bit. In the book: Drilling, GASINCI, 1962, S. 3-41 (Fig. 7).6. Grigoryan N. A., Bagirov R. E. analysis of the process of turbine drilling. - M.: Nedra, 1982, S. 110-111 (Fig.50 and 51). The method of determining the degree of wear of rock cutting tool during drilling, comprising measuring the frequency of rotation of the bit and the axial load, characterized in that build straightforward calculation load characteristic of the turbodrill with a new bit and the estimated load characteristic of the turbodrill with a worn bit, connect the cut zone of unstable work at these load characteristics, take the length criterion for wear of rock cutting tools, graduate specified period, breaking it into pieces of equal length, which characterizes the amount of wear of rock cutting tools, and accept them as health criteria rock cutting tool, in the drilling process according to the measurement rotation speed and axial load at a discrete bit loading from idle mode to unstable operation of the mud motor build like control, and determine the degree of wear of rock cutting tool and the degree of operation of rock cutting tool, the combination of load characteristics, built on the measuring data, and the estimated load characteristics.

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FIELD: mining industry.

SUBSTANCE: system includes mathematical model of drilling process in form of combined influence of conditions at pit-face and of drilling column operation. Model of drilling process is constantly renewed by results of well measurements performed during drilling operation. On basis of renewed drilling process model a set of optimal drilling parameters is determined and sent to system for controlling surface equipment. Also, system allows surface equipment control system to automatically adjust current control sets for surface equipment on basis of renewed optimal drilling parameters. Different control scenarios are generated and executed for transferring data to surface equipment control system on basis of current drilling mode.

EFFECT: optimized operation.

2 cl, 7 dwg