CC BY
21
Setion 3. Mechanical engineering
Mustafayev Amir Gochu, Azerbaijan State Oil and Industry University
Aliyeva Irada Karim, Agarzayev Bahruz Karimbala, Abdullayeva Aynur Ramiz, Azerbaijan State Marine Academy E-mail: [email protected]
STUDY OF HEAT PROCESSES OF ROCK CUTTING (ROCK CUTTERS) TOOL
Abstract: The results of the carried out researches show that increase of the exploitation characteristics of the down-hole cutting tools depend on the cutting ability of the tool. The set up task requires all - round researches of the forces influencing the cutting capacity of the tool. It is known that cutting edges (components) of the rock cutting tool are faced with composition material. Carried out researches showthat efficiency of the cutting ability also depends on the position of the rollers (edges) and wear resistance the cutting tool. Rational distribution of the forces on the roller can significantly influence the bit sinking-drifting too. That is why study of the revealing and character of various factors and their complexes affecting heat regime of cutting tool is of great interest.
For the reliability of the set up task the research simulating the rock cutting process in the drilling has been carried out under the laboratory conditions. As a result of the research rational characteristics affecting more favorable conditions of the bit sinking have been determined. The obtained results allow to recommend rational form of the facing of the cutting edges (rollers) in designing and manufacturing of the bit.
Keywords: rock cutting, load, stress, cutting elements, drilling bit, rock.
Introduction: One of requirements made to mentally.The goal of the experimental research is es-the bit cutting ability is the biggest sinking along the tablishment relations between various factors reveal-rock depending on the condition of the strength of ing objective regularities characterizing influence of cutting tool in the drilling process [1-4]. many data on the studied process.
Study of the laws of heat formation and heat dis- The main part: Process of cutting the rock s tribution on the edges of cutting tool helps to reveal multifactor. That's why research is expedient to essence of many phenomena accompanying drilling carry out applying methods of rational planning processes and make more effective technical decisions. of the experiment.
Solution of this task and gelling more precise Choice of a number the necessary factors for car-results in small expenditure can by achieved experi- rying out experiments by this method is enough for
solution of the set up task with the required accuracy. This method allowed to cut down the volume of experimental research to 25.
The system of interorthogonal cubes has been used for main factors defining heat regime of rock cutting process. Research of heat regime of rock cutting instrument has been carried out under the laboratory conditions simulating drilling process.
For defining sizes of the model corresponding to the natural one scale factors have been determined [1].
Models of the bit have been subjected to the testing in various drilling regimes. In this case the following regime parameters have been changed: rotation frequency of the bit (rad/sec); diameter of model samples of the bit (mm); axial loading on the bit (KH); relation of rock hardness and bit materials, the time of the contact of the bit with the rock (sec.) the types of the cooling medium and their density (kg/m3), pump feeding for liquid consumption (m3/sec); and compressor feeding for air consumption (m3/sec) (table 1).
This installation has a significant advantage in comparison with other ones which were tested. It
allows to control feeding of flushing fluid air and to measure the temperature rather precisely. The installation has also been equipped with measuring devices, its assembling and disassembly don't cause any difficulties [2].
The results of the experimental researches carried out on the installation have corresponded to the development of the algorithm prognosing the character of the formation of artificial temperature field of the bit. The obtained information was used to estimate the role of each of the considered parameters in the formation of temperature field allowing to classify them due to their significance.
Achievement of the goal has been obtained at the expense of the use of the method of samples recognition based on the use of one - dimensional nonlinear transformation [3]. Due to this method the prognoses has the following form:
P = f (x 1, x 2, x 3...X ) = z
& (X, )
(1)
Where f.- are one dimensional monotone functions
X - are variable initial parameters Z - is output parameter of the function.
Table 1.
i=1
Factors Levels of factors
Bit rotation (X1)rad/sec. 3.3 4.7 6.6 8.4 12
Diameter of bit model (X2) mm 26 32 35 50 55
Axial (longetudince) loading (X3) kH 0.98 2.0 3.15 4.68 6.4
Relation of rock hardness and bit material (X4) 0.30 0.45 0.60 0.75 0.90
Contact time of the bit with the rock (X5), sec 60 120 120 248 300
Types of the cooling medium and their density (X„), kg/m3 Air 1000 Water 1300 Aero-water 1600 Drilling 1900 Dry 2200
Pump feeding (fluid consumption) (X7), m3/sec 0.0031 0.0047 0.0064 0.0075 0.010
Compressor feeding (air consumption) (X8), m3/sec 0.0004 0.0006 0.0008 0.0010 0.0011
As a result of the research dependence between value f on values X table 10 has been determined, as the graphics of function f . (X.) is of great interest in the set up task (fig. 1)
The form of these functions allow both qualitatively to evaluate the character of the influence
of variables X. on the prognosized value - the temperature in the zone of interaction of the bit with the rock. It is supposed that change of each variable is considered in an invariable values of the rest variables.
As it is seen from figure 1 functions f1 = f(X1) estimated according to a special computer program were rather different due to their scope - from minimum to maximum. It means that all factors taken for the research influence significantly on the prognosis and that is why exception of any of further consideration would be incorrect decision. Although the degree and character of this influence are different and it is confirmed by the behavior of the functions.
However the given graphics have a number of common features. As a rule, they are considerably non- linear and have zones of sensibility, where change of the data doesn't influence on the prognosis (fig. 1) Not the least practical condition while using this method was the prognosis has been carried out on the basis of only graphics of the functions Z and qn(Xi).
The prognosis is carried out due to the following sequence. According to the graphics of variability of the studied factors the functions (pi(Xi) are determined.
(i = 1,2,3,... n), then due to YUM(Xi) output function Zis determined, then due to Z q>i(Xi)
The temperature is calculated. During the process the weight ofseparate factors in the formation ofquan-tative indices of temperature field are determined.
Availability of such information allows to work out complex arrangements (constructive, geologic -technical and technological) on the reduce of influence of temperature factor in the process of drilling and cutting the rock in making deep wells. In it is turn it allows to synthesize optimal decisions on the increase of work resource of the bit in well bottom, reduce of the volume of dissent-lift operations and decrease of the cost indices of well drilling.
Conclusion
1. The obtained results allow to prognosis temperature loading ofwell bottom tools in their exploitation process.
2. Prognosis values can be basic for making decisions on the decrease of temperature loading of the tool by controlling the process parameters.
3. The results of the research can be used in the construction of oil and gas wells of various orientations.
References:
1. Mustafayev A. G., Zeynalov O. S. Experimental installation for the research of temperature regime of well cutting tools. ASOA.- 1998.- 103 p.
2. Mirzadjanzade A. K. H., Stepanov G. S. Mathematic theory of the experiment in oil and gas production - M., Nedra,- 1977.- 299 p.
3. Vinogradov V. N. and et all. Abrasive wear of drilling tool.- M., Nedra,- 1980.- 205 p.
4. Vinoqradov V. N. and et all. Durability of drilling bits - M., Nedra,- 1977.- 256 p.
