scholarly journals The design of bottomhole assembly with two rock cutting tools for directional drilling

Author(s):  
I. V. Voievidko ◽  
V. V. Tokaruk ◽  
M. A. Bodzian

On the basis of the theoretical analysis and practical studies of hole drilling of large diameter, a method for designing the BHA with two rock cutting tools is proposed, taking into account the geological and technical factors that have an impact on the formation of the trajectory. The calculation of BHA with two rock cutting tools and a different number of supporting and centralizing components for different geological conditions of drilling is carried out and the analysis of their work in the process of drilling is conducted. The graphic dependences of the deviation intensity variation and the inclination angle with the sinking of borehole of the large diameter for the BHA that can be used for the drilling of vertical and directional wells.

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Gao Xu ◽  
Zuo Minghui ◽  
Shu Yanmin

Based on the engineering background, the 41051 working face of the 65th coal mine in Qitaihe Xinxing Mine was regarded as the engineering background, by using of the comprehensive research methods such as theoretical analysis and calculation, FLAC3D numerical simulation, physical parameters of coal and rock in laboratory, and the field industrial measurement, to research on the large drilling relieving rock burst mechanism and parameter setting in reasonable. The distribution of stress and plastic zone in drilling surrounding rock and its influence parameters are clarified, and the distribution of the “butterfly plastic zone” and the mutation condition of the “butterfly plastic zone” in trigger stress state are explored. On the basis, combined with theoretical analysis and numerical simulation, studying the rock burst prevention and treatment mechanism in large drilling, through the statistics of the Xinxing mine pressure characteristics, the measurement of the physical parameters of coal and rock and the test of ground stress finding is that the coal satisfies “Three hard” condition in Xinxing mine and is affected by larger horizontal tectonic stress. Combined with the real geological conditions, the layout parameters of relief pressure large drilling are simulated, and the result shows that the drilling of 600 diameters and 10 m pitch of hole and throughout the working face is reasonable, and the effect is obvious about pressure relief. For the practical implementation, the electromagnetic radiation monitoring is used to evaluate the effect in field; to comprehensive analysis, the relief pressure large drilling has obvious control effect to the 41051 workface rock burst.


Air blast drilling is effective in the most unfavorable conditions for liquid flushing: when drilling in areas with significant circulation losses, when there are difficulties with water supply, in high mountainous or difficult terrain, or in areas with harsh climates. However, air has a low heat capacity compared to liquid flushing solutions, this affects the operation of rock cutting tools through high contact temperatures with irreversible consequences such as deformation of matrices, destruction of diamonds, grinding, reduction of diamond hardness and tool burns. To prevent these problems, there is a need to develop technical means and technology to effectively ensure the temperature regime of the rock-cutting tool. This article discusses the possibility of normalizing and regulating the temperature regime of the rock-cutting tool due to forced cooling of the cleaning air at the bottom hole to negative temperatures, and a new design of the drilling projectile for drilling with air purging is developed. The results of experimental studies of the developed design of the drilling projectile are also presented.


2016 ◽  
Vol 20 (1) ◽  
pp. 1-5
Author(s):  
Li Guohui ◽  
Ma Xiaocheng ◽  
Yang Chunling

<p>The Yangtze River Crossing Project, which is part of the Chinese gas pipeline trunk network and aims to transmit the natural gas to the Yangtze River Delta area, sets up a record for the length of Horizontal Directional Drilling (HDD) in the world. The term of pipeline installed is 3300m, and the diameter is 40in. Many technical difficulties have been inevitably encountered in a large diameter hole reaming in fine sand, the calculation of section scour depth which determines the minimum buried depth of the pipe, protection of outside coating and the method of long distance pilot hole drilling, such other challenges. In view of this, it was recommended that two pipelines of 711mm should be installed to replace the existing one of 1016mm in diameter and 1% flooding scour depth obtained by reliable statistical analysis. In period of installation, application glass fiber reinforced epoxy resin as a protective coating, executing the pilot hole by Intersect Method. As a result, this super project is finished successfully on May 21.2013. The experience can be applied to any pipeline engineering the installed by horizontal directional drilling or similar works.</p>


2020 ◽  
pp. 71-74
Author(s):  
R. U. Dzhuraev ◽  
◽  
M. V. Merkulov ◽  
V. A. Kosyanov ◽  
A. M. Limitovsky ◽  
...  

The practice of drilling has proven that the use of compressed air as a cleaning agent provides a significant increase in ROP (rate of penetration) and reduces the time spent on eliminating geological complications, which sharply increases the productivity and economy of drilling operations. However, air has a low heat capacity compared to liquid flushing solutions. This affects the operation of rock cutting tools through high contact temperatures with irreversible consequences such as deformation of matrices, destruction of diamonds, grinding, reduction of diamond hardness and tool burns. The current geological conditions of drilling require improvement of the technology and enhancement of drilling performance via engineering of new and highly effective drilling tools. The introduction of new drilling tolls having high durability and increased penetration rate improves performance of drilling rigs. The best results are obtained with a vortex tube placed directly at the well bottom. This article discusses the possibility of normalizing and regulating the temperature regime of the rockcutting tool due to forced cooling of the cleaning air to negative temperatures at the bottom hole. A new design of the drilling assembly with air purging is developed. The pilot tests of the designed drilling assembly are carried out. The tests proved efficiency and serviceability of the drilling assembly design with vortex cooler. The rock-drilling tool temperature is decreased by 50–60 °C and the drilling penetration rate is increased.


2020 ◽  
Vol 14 (3) ◽  
pp. 128-133
Author(s):  
Vasyl Moisyshyn ◽  
Igor Voyevidko ◽  
Vasyl Tokaruk

2012 ◽  
Vol 57 (2) ◽  
pp. 363-373
Author(s):  
Jan Macuda

Abstract In Poland all lignite mines are dewatered with the use of large-diameter wells. Drilling of such wells is inefficient owing to the presence of loose Quaternary and Tertiary material and considerable dewatering of rock mass within the open pit area. Difficult geological conditions significantly elongate the time in which large-diameter dewatering wells are drilled, and various drilling complications and break-downs related to the caving may occur. Obtaining higher drilling rates in large-diameter wells can be achieved only when new cutter bits designs are worked out and rock drillability tests performed for optimum mechanical parameters of drilling technology. Those tests were performed for a bit ø 1.16 m in separated macroscopically homogeneous layers of similar drillability. Depending on the designed thickness of the drilled layer, there were determined measurement sections from 0.2 to 1.0 m long, and each of the sections was drilled at constant rotary speed and weight on bit values. Prior to drillability tests, accounting for the technical characteristic of the rig and strength of the string and the cutter bit, there were established limitations for mechanical parameters of drilling technology: P ∈ (Pmin; Pmax) n ∈ (nmin; nmax) where: Pmin; Pmax - lowest and highest values of weight on bit, nmin; nmax - lowest and highest values of rotary speed of bit, For finding the dependence of the rate of penetration on weight on bit and rotary speed of bit various regression models have been analyzed. The most satisfactory results were obtained for the exponential model illustrating the influence of weight on bit and rotary speed of bit on drilling rate. The regression coefficients and statistical parameters prove the good fit of the model to measurement data, presented in tables 4-6. The average drilling rate for a cutter bit with profiled wings has been described with the form: Vśr= Z ·Pa· nb where: Vśr- average drilling rate, Z - drillability coefficient, P - weight on bit, n - rotary speed of bit, a - coefficient of influence of weight on bit on drilling rate, b - coefficient of influence of rotary speed of bit on drilling rate. Industrial tests were performed for assessing the efficiency of drilling of large-diameter wells with a cutter bit having profiled wings ø 1.16 m according to elaborated model of average rate of drilling. The obtained values of average rate of drilling during industrial tests ranged from 8.33×10-4 to 1.94×10-3 m/s and were higher than the ones obtained so far, i.e. from 181.21 to 262.11%.


2012 ◽  
Vol 461 ◽  
pp. 652-655
Author(s):  
Ying Wu ◽  
Peng Zhang ◽  
Xiao Li

Directional drilling technology is an important and very promising trenchless pipeline crossing technology. On the basis of the related literature research at home and abroad and our pipeline construction site investigation, focuses on several common soil properties are introduced, and then the formation adaptability of directional drilling is analyzed. The drilling selection methods are made when drilling in the specific geological conditions, and the possible risks of the construction process have been classified in the directional drilling.


2021 ◽  
Vol 117 ◽  
pp. 104159
Author(s):  
Sheng Huang ◽  
Chao Kang ◽  
Alireza Bayat ◽  
Kent Heath ◽  
Cainan Trovato ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document