Sectionalized Mechanical Models of Drilling Tool of Trenchless Directional Drilling

2012 ◽  
Vol 268-270 ◽  
pp. 1190-1193
Author(s):  
Hui Xia ◽  
Yi Hua Dou ◽  
Xin He Wang ◽  
Jiang Wen Xu
Keyword(s):  
Axial Compression ◽  
Working Conditions ◽  
Mechanical Analysis ◽  
Drill String ◽  
Drill Bit ◽  
Straight Section ◽  
Directional Drilling ◽  
Drilling Tool ◽  
Horizontal Section ◽  
Axial Tension

There are three working conditions namely drilling a guide hole, expanding the guide hole and pulling back pipeline in trenchless directional drilling. The position of drill string in the wellbore and loads exerted on the drill string varied in different working conditions. The models of buckling analysis of drill strings under compression, mechanical analysis of drill string under axial compression near drill bit in inclined straight section, mechanical analysis of drill string with multi-centralizers under axial compression near drill bit in inclined straight section, mechanical analysis of drill string near drill bit under axial compression in horizontal section, mechanical analysis of drill string near drill bit under axial tension in horizontal section, mechanical analysis of drill strings near drill bit under axial tension in inclined straight section and mechanical analysis of drill string in failed well are established based on the characteristic of loads and trajectories in each section. The establishment of sectionalized mechanical model of drilling tool is the fundament of further study of force analysis, deformation analysis and stress analysis.

scholarly journals Development of torque clutch drilling tool and evaluation of drag reduction performance

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880665 ◽  
Author(s):  
Xingming Wang ◽  
Ping Chen ◽  
Wanzhi Huang ◽  
Jiayan Zou
Keyword(s):  
Drag Reduction ◽  
Theoretical Calculation ◽  
Oil And Gas ◽  
Integrated Design ◽  
Drill String ◽  
Directional Drilling ◽  
Working Pressure ◽  
Drilling Tool ◽  
Horizontal Section ◽  
Horizontal Drilling

Horizontal well is one of the important methods of unconventional oil and gas resource development. As increasing length of horizontal section, there is a serious problem that axial force cannot transfer to bit. The drilling field needs a low-friction and low-cost drag reduction tool. This article summarized existing technologies of drag reduction in the horizontal and inclined well and proposes an integrated design of torque clutch. Detailed design of tool sub-systems is introduced. The tool includes three sub-systems: clutch, hydraulic system, and monitoring system. The clutch is consisted of multiple clutch units mounted in a parallel arrangement. Power of hydraulic control system adopts difference in pressure between inside and outside of drill pipes. It can efficiently reduce power consumption. The design function and minimum working pressure are validated and obtained by indoor test. According to theoretical calculation, reasonable distance from tool to bit can be obtained for an actual drilled well. During directional drilling mode, the tool can reduce more than 30% axial drag of drill string according to theoretical calculation. The tool can effectively improve the capacity of transfer weight to bit and overcome the excessive drag in horizontal drilling. No similar tools are reported in the current field.

Fatigue Life Prediction of Cold Rolled Rotary Shouldered Threaded Connections

2018 ◽  
Author(s):  
Fei Song ◽  
Michael Du ◽  
Ke Li
Keyword(s):  
Fatigue Life ◽  
Cold Rolling ◽  
Fatigue Resistance ◽  
Element Model ◽  
Drill String ◽  
Directional Drilling ◽  
Drilling Tool ◽  
Threaded Connection ◽  
Threaded Connections ◽  
Cold Rolled

The bottom hole assembly (BHA) of a modern drill string for directional drilling mainly comprises a drill bit, a rotary steerable system, and a measurement while drilling tool. The tools and subs used on a BHA are screwed together through rotary shouldered threaded connections. Each connection is made up with a pin and a box. These connections are the weakest links when the BHA undergoes a large number of revolutions in a curved well section. When the fatigue life of a connection is consumed during a drilling job, a twist-off would occur, which could result in an enormous amount of non-productive time and possibly loss of the bottom BHA section in the hole. Cold rolling has proven to be able to improve fatigue resistance of a threaded connection by pressing a rolling wheel against the thread root and generating a layer of compressive residual stress at the root. Understanding how cold rolling improves fatigue resistance of a threaded connection is important for optimization of the rolling parameters and prediction of the BHA service life in a given drilling condition. In this paper, a predictive method is presented for fatigue life of a cold rolled threaded connection. A finite element model was developed to simulate the cold rolling process. The resulting deformation and stress states at the root were carried over through makeup of the pin and the box as well as through cyclic bending of the connection. The fatigue life predictions were found to be in favorable agreement with the experimental measurements from full-scale fatigue tests at different bending moment levels applied.

A Novel Model for Catenary Drilling and Drill String Induced Stresses

2017 ◽  
Author(s):  
Catalin Teodoriu ◽  
Arash Asgharzadeh
Keyword(s):  
Great Depth ◽  
Drill String ◽  
Directional Drilling ◽  
Horizontal Section ◽  
Horizontal Drilling ◽  
Deep Wells ◽  
Bending Stresses ◽  
Novel Method ◽  
Extended Reach Drilling ◽  
Novel Model

Petroleum engineers are aware of the advantages of directional and horizontal wells. In case of intermediate deep wells, the preference is the customary solution, in which a well is drilled vertically to the kick off point, and then moved directionally to the reservoir level. Nowadays, due to the advent of extended reach drilling, this approach does not satisfy the meant goal anymore. In extended reach drilling, the concern lies on the drill pipe’s strength. Because of the great depth of the borehole, the torque and tension below the drill floor increase and could reach the drill pipe’s strength. Therefore, in order to extend the wellbore reach, it is necessary to minimize the torque and drag. Several authors have mentioned that catenary profile may help reduce torque and drag. The purpose of the paper is to analyze the mechanics of the drill string, and to understand the stress distribution along the drill string and the geometry of the well configurations while bringing the borehole from a vertical to a horizontal position. . This will be achieved by means of an analytical comparison between the catenary profiles and the conventional well configurations. A novel catenary profile which improves the previous models is also presented in this paper. The modified catenary has a larger curvature of the drill string; particularly in the upper parts of the borehole the bending stresses are small. The modified catenary profile, which resembles a free hanging cable, can be a novel method in directional drilling of deep and extended reach wells. Thus, the build rate in the modified catenary is being continuously increased until it reaches the desired position. It is different from conventional methods used especially in horizontal drilling to connect the vertical and the horizontal section, where the build rate is kept constant. The focus of this paper lies on the study of catenary’s geometry as a complex well path and the induced stress. Different approaches are used and compared.

The Finite Element Analysis of the Rollers in a Rotary Steerable Drilling Tool

2013 ◽  
Vol 390 ◽  
pp. 641-645
Author(s):  
Guang Wei Zhang ◽  
Li You ◽  
Zhao Li
Keyword(s):  
Low Cost ◽  
Major Change ◽  
Drill String ◽  
Design Parameters ◽  
Directional Drilling ◽  
Element Analysis ◽  
Rotary Drilling ◽  
Drilling Tool ◽  
Thrust Bearings ◽  
Drilling Technology

Rotary steerable system (RSS) is a system complete the oriented features in real-time while a drill string rotary drilling. It is a major change since the 1990s in directional drilling technology. RSSs drilling frictional and torsional resistance is small, has a high drilling speed, low cost, the well trajectory is smooth and easy to control, it is considered to be the development direction of modern steering drilling technology .When the system working ,drilling pressure and torque are passed by the thrust bearings in the controlled bend sub oriented tool; therefore it is necessary to analysis the rollers load distribution to verify the design parameters of variation cardan shaft, thrust bearings and roller are correct or not, This article analyzed thrust bearings rollers by ANSYS. Determine its maximum stress, etc. Providing more intuitive and scientific basis for its structural optimization [1].

scholarly journals INFLUENCE OF DRILLING RIG DESIGN ON WELL DRILLING EFFICIENCY

2020 ◽  
Vol 12 (3) ◽  
pp. 383-393
Author(s):  
Vasily ANISCHENKO ◽  
◽  
Viktor ATRUSHKEVICH ◽  
Keyword(s):  
Average Length ◽  
Drill Pipe ◽  
Hydraulic Drive ◽  
Drill String ◽  
Alternative Methods ◽  
Drilling Speed ◽  
Directional Drilling ◽  
Horizontal Section ◽  
Main Research ◽  
Drilling Rig

The purpose of research in the extraction of minerals is the development of technologies that will make it possible to drill wells specially designed for the extraction of ores with a length of several kilometers and a diameter of 300 mm to 2 m. The main research method is an experiment, during which drilling of wells by alternative methods under the same conditions is compared according to a single the selected performance criterion. Drilling of wells with an average length of 1500 meters with an end diameter of 295 mm at a depth of 200 to 400 meters was carried out in soft rocky ground in two alternative ways. The productivity of a directional drilling rig is determined by the efficiency of related interconnected processes,the correlation of which is characterized by graphs, for example, the dependence of the load on the bit on the drilling speed. To calculate the load on the drill pipe, Young’s modulus and the moment of inertia of its section were used. The axial force for drilling the well is determined by calculation using experimental data. By modeling in the EXCEL program, the maximum WOB value was determined. To compare the drilling speeds of a traditional rig and a new generation rig, the speed with a 5 ton bit load and a 15 ton bit load is considered, at which, if other things are equal,the ROP increases three times. The drilling speed of wells with an inclined head of the new technology will be 167 m per day versus 105 m with traditional technology, and the operational productivity of drilling with one rig will be 71 m per day versus 51 m. Universal mobile rack rigs with automatic centering of the drill string and mast in vertical and inclined position and gearless hydraulic drive for rotation and movement of the drilling carriage ensure drilling of wells with a horizontal section length of 1500 meters and a diameter of 300 mm.

scholarly journals Optimization of Drillstring Design to Produce More Stable Dynamic Drilling on Horizontal Drilling by Applying Different Stiffness Combinations

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Dundie Prasetyo ◽  
Ratnayu Sitaresmi ◽  
Suryo Prakoso
Keyword(s):  
Data Acquisition ◽  
Oil And Gas ◽  
Drill Pipe ◽  
Drill String ◽  
Drilling Process ◽  
Directional Drilling ◽  
Horizontal Section ◽  
Stick Slip ◽  
Horizontal Drilling ◽  
Drilling Operation

<p>Horizontal drilling technique is one of the methodologies that have been widely implemented recently to improve the production of oil and gas wells. Several directional drilling technologies can be utilized to drill the horizontal wells, vary from the simple mud motor technology to Bottom Hole Assembly (BHA) with the advanced motorized rotary steerable system. The most common challenges that are faced on horizontal drilling process are on the torque and the stick-slip throughout drilling process, which can be a technical limiter for the length of horizontal section that would be achieved. Stick-slip is the vibration <br />that occurs due to cyclical rotation acceleration and deceleration of the bit, BHA or drill string. This speed fluctuation can be zero to rate of penetration (ROP) or far in excess of twice the rotational speed measured at the surface. Stick-slip can significantly decrease the ROP, increases tool failures and damage, affects borehole quality, and impacts the data acquisition. Several studies had been done on the stick-slip prevention and mitigation throughout creation of new technology and drilling parameters envelope throughout drilling operation, however no study has ever been done on the modification of the design and <br />arrangement of the BHA itself to produce more stable BHA. Drill pipe is the longest component of the drill string and hence it has biggest contribution towards the drill string dynamic. This study will focus on the analysis of the combination of several designs of the drill-pipe and heavy weight drill-pipe (HWDP) that has different stiffness and characteristic to produce less <br />vibration, more efficient drilling operation and to create zero impact on the data acquisition measured while drilling. FEA drilling dynamic simulator was used to optimize the drill sting configuration. The calculation is made from the depth of 750 m to 2801 m. Based on the drilling simulation results of FEA modeling, it is concluded that the minimum stiffness ratio to give stability of the drill string of Well-Z7 BHA and Well-Z6 BHA is 0.012175272 and 0.07366999, respectively.</p>

scholarly journals Kinematics and dynamics analysis of new rotary-percussive PDM drilling tool

2021 ◽  
pp. 146134842198915
Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Drill String ◽  
Structure Design ◽  
Drilling Process ◽  
Analysis Model ◽  
Drilling Tool ◽  
Stick Slip ◽  
Rate Of Penetration ◽  
Bottom Hole ◽  
Bottom Hole Assembly ◽  
The Impact

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.

The Effect of Axial Tension and Borehole Curvature on Torsion Limit of Drill String Threaded Connections

2021 ◽  
pp. 105555
Author(s):  
Feng Chen ◽  
Yonghao Huo ◽  
Haiyi Zhao ◽  
Qinfeng Di ◽  
Wenchang Wang ◽  
...  
Keyword(s):  
Drill String ◽  
Axial Tension ◽  
Threaded Connections

Study of stick–slip suppression and robustness to parametric uncertainty in drill strings containing torsional vibration tool using sliding-mode control

2021 ◽  
pp. 146441932110452
Author(s):  
Jialin Tian ◽  
Jie Wang ◽  
Siqi Zhou ◽  
Yinglin Yang ◽  
Liming Dai
Keyword(s):  
Torsional Vibration ◽  
Complex Dynamics ◽  
Sliding Mode ◽  
Parametric Uncertainty ◽  
Drill String ◽  
Lumped Parameter Model ◽  
Drilling Process ◽  
Drill Bit ◽  
Stick Slip ◽  
Drilling Operations

Excessive stick–slip vibration of drill strings can cause inefficiency and unsafety of drilling operations. To suppress the stick–slip vibration that occurred during the downhole drilling process, a drill string torsional vibration system considering the torsional vibration tool has been proposed on the basis of the 4-degree of freedom lumped-parameter model. In the design of the model, the tool is approximated by a simple torsional pendulum that brings impact torque to the drill bit. Furthermore, two sliding mode controllers, U1 and U2, are used to suppress stick–slip vibrations while enabling the drill bit to track the desired angular velocity. Aiming at parameter uncertainty and system instability in the drilling operations, a parameter adaptation law is added to the sliding mode controller U2. Finally, the suppression effects of stick–slip and robustness of parametric uncertainty about the two proposed controllers are demonstrated and compared by simulation and field test results. This paper provides a reference for the suppression of stick–slip vibration and the further study of the complex dynamics of the drill string.

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