scholarly journals Optimal design of a global force-balanced polycrystalline diamond compact bit considering wear condition

2019 ◽  
Vol 11 (12) ◽  
pp. 168781401989445
Author(s):  
Yachao Ma ◽  
Zhanghua Lian ◽  
Zhiqiang Huang ◽  
Wenlin Zhang ◽  
Dou Xie

Polycrystalline diamond compact bits are one of the most widely used oil and gas drilling tools in the world. With wear, a large unbalanced lateral force and bending moment exist. These force and moment contribute not only to bit lateral vibration and whirl but also to wellbore tilt and enlargement, which will then cause early bit failure and low drilling efficiency. In this article, considering wear condition, a single cutter force model is proposed. Lateral force and bending moment models are constructed based on space-force theory. An optimal cutter layout model considering cutter wear is established. The matching approach for the optimal model is discussed based on Kriging surrogate model and genetic algorithm. Then, an optimization case is presented. The results show that the bit force models are in line with the actual drilling condition. The optimal approach is efficient. After optimization, the lateral force to weight on bit ratio is reduced by 10.99%, and the bending moment to torque on bit ratio is reduced by 30.43%. This result is a significant improvement in the force condition and stability of the polycrystalline diamond compact bit; ultimately, the whirl and tilt motion can be reduced, and the drilling efficiency can be improved.

Author(s):  
Demeng Che ◽  
Weizhao Zhang ◽  
Kornel F. Ehmann

Polycrystalline diamond compact (PDC) cutter, as a major cutting tool, has been widely applied in oil and gas drilling processes. The understanding of the complex interactions at the rock and cutter interfaces are essential for the advancement of future drilling technologies, yet, these interactions are still not fully understood. Linear cutting of rock, among all the testing methods, avoids the geometric and process complexities and offer the most straightforward way to reveal the intrinsic mechanisms of rock cutting. Therefore, this paper presents an experimental study of the cutter’s cutting performance and the rock’s failure behaviors on a newly developed linear rock cutting facility. A series of rock cutting tests were designed and performed. The acquired experimental data was analyzed to investigate the influences of process parameter and the rock’s mechanical properties on chip formation and force responses.


Author(s):  
Demeng Che ◽  
Weizhao Zhang ◽  
Kornel Ehmann

Polycrystalline diamond compact (PDC) cutters, as a major cutting tool, have been widely applied in oil and gas drilling processes. The understanding of the complex interactions at the rock and cutter interfaces is essential for the advancement of future drilling technologies; yet, these interactions are still not fully understood. Linear cutting of rock, among all the testing methods, avoids the geometric and process complexities and offers the most straightforward way to reveal the intrinsic mechanisms of rock cutting. Therefore, this paper presents an experimental study of the cutter’s cutting performance and the rock’s failure behaviors on a newly developed linear rock cutting facility. A series of rock cutting tests were designed and performed. The acquired experimental data was analyzed to investigate the influences of process parameters and the rock’s mechanical properties on chip formation and force responses.


2020 ◽  
Vol 103 (3) ◽  
pp. 003685042093097
Author(s):  
Dou Xie ◽  
Zhiqiang Huang ◽  
Yuqi Yan ◽  
Yachao Ma ◽  
Yuan Yuan

Polycrystalline diamond compact bits have been widely used in the Oil and Gas drilling industry, despite the fact that they may introduce undesired vibration into the drilling process, for example, stick-slip and bit bounce, which accelerate the failure rate and lead to higher drilling costs. First, we develop an innovative ridge-ladder-shaped polycrystalline diamond compact cutter, which has ridge-shaped cutting faces and multiple cutting edges with stepped distribution, in the hope of reducing vibration and improving drilling speed. Then, the scrape tests of ridge-ladder-shaped and general polycrystalline diamond compact cutters are carried out in a laboratory, indicating that the cutting, lateral, and longitudinal forces on ridge-ladder-shaped polycrystalline diamond compact cutters are smaller and with minor fluctuations. Due to different rock-breaking mechanisms, ridge-ladder-shaped polycrystalline diamond compact cutters have higher cutting efficiency compared to general polycrystalline diamond compact cutters, which is also verified experimentally. Finally, the drilling characteristics of a new polycrystalline diamond compact bit fitted with some ridge-ladder-shaped polycrystalline diamond compact cutters are compared to those of a general polycrystalline diamond compact bit by means of finite element simulation. The results show that introducing ridge-ladder-shaped polycrystalline diamond compact cutters can not only reduce the stick-slip vibration, bit bounce, and backward rotation of drill bits effectively, but also improve their rate of penetration.


Author(s):  
Demeng Che ◽  
Jacob Smith ◽  
Kornel F. Ehmann

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.


Author(s):  
Jialin Tian ◽  
Gang Liu ◽  
Lin Yang ◽  
Chunming Wu ◽  
Zhi Yang ◽  
...  

Polycrystalline diamond layer peel-off is a hot topic in oil and gas drilling engineering. When an integrated polycrystalline diamond compact cutter suffers overload, there is a rapid decline in its rock-breaking performance and drilling rate of penetration. To modify the comprehensive performance of polycrystalline diamond compact, we innovatively propose a new embedded polycrystalline diamond compact. According to geometric analysis theory combined with the linear combination rule, the three typical embedded design schemes – the imitation palm-shaped, imitation Z-shaped and ring-embedded designs – are discussed. The influences of the number, size, location and combination of the embedded polycrystalline diamond layer on the polycrystalline diamond compact wear mechanism and rock-breaking performance are analysed. The results show that the embedded element and carbide matrix are combined by brazing welding, which not only exerts high abrasion resistance on the polycrystalline diamond layer but also combines with the good impact performance of carbide matrix. Compared with ordinary polycrystalline diamond compact, the intake amount of a single-embedded polycrystalline diamond compact is smaller, and it wears more evenly during the rock-breaking process. Comparing the results from before and after drilling, it effectively prevents the ordinary polycrystalline diamond compact from easily peeling off when suffering overload. The unique wear analysis model can be applied to other types of polycrystalline diamond compact by adjusting the embedding method. The research conclusions provide useful insights into the study of the polycrystalline diamond compact wear mechanism and rock-breaking performance.


Author(s):  
Abdelsalam N. Abugharara ◽  
John Molgaard ◽  
Charles A. Hurich ◽  
Stephen D. Butt

Abstract This work concentrates on the investigation of enhancing drilling performance through increasing drilling rate of penetration (ROP) by using a passive vibration assisted rotary drilling (pVARD) tool. It also involves analysis of how ROP was significantly increased when drilling using pVARD compared to drilling using conventional system “rigid” using coring and drilling in shale rocks. The apparatus used was a fully instrument laboratory scale rig and the bits were dual-cutter polycrystalline diamond compact (PDC) bit for drilling and diamond impregnated coring bit for coring. The flow rate was constant of (7 litter / min) using clean water at atmospheric pressure. In addition, for accuracy data recording, a data acquisition system (DAQ-Sys) using a LabVIEW software was utilized to record data at 1000HZ sampling rate. The output drilling parameters involved in the analysis included operational rpm, torque (TRQ), and ROP. All the output-drilling parameters were analyzed with relation to downhole dynamic weight on bit (DDWOB). The result of this work explained how pVARD can increase the DDWOB and improve ROP. The result also demonstrated generating a balanced and concentric increase in DDWOB and minimizing the wide-range fluctuation of DDWOB generated in rigid drilling, particularly at high DDWOB.


Author(s):  
Parham Pournazari ◽  
Benito R. Fernández ◽  
Eric van Oort

Accurate control of weight-on-bit (WOB) in oil and gas drilling plays an important role in achieving high rates of penetration (ROP) and minimizing drillstring vibrations. In this paper, we propose a nonlinear, stochastic model of downhole WOB, and provide a framework for estimation, and control of the proposed model. We focus on real-time estimation of modeling and measurement uncertainties, and use these estimates to adapt the controller characteristics accordingly. The presented methodology is simulated for various scenarios, and benchmarked against existing control techniques in the industry.


Author(s):  
B. A. Lingwall ◽  
C. H. Cooley ◽  
T. N. Sexton

Polycrystalline diamond (PCD) bearings are designed for use in extreme environments; this includes process-fluid-lubricated applications such as those in oil and gas drilling turbines and marine hydrokinetic (MHK) energy machines. Past uses of PCD bearings in oil and gas down-hole tool applications have proven them to be robust, long lived, and rugged [1]. To be effective in MHK machines, PCD bearings must demonstrate adequate bearing efficiency and life in a submerged marine environment not nearly as severe as an oil well bore or a gas well bore. This paper discusses the advantages PCD bearings could provide when used in underwater MHK energy machines. Laboratory test results are presented that can help predict the performance of PCD in these MHK applications. Results from three types of tests are presented including tests that measure bearing capacity, those that observe and qualify hydrodynamic properties during testing, and those that evaluate diamond wear rates through a test representing the life time of a bearing in a MHK energy application. Failure tests conducted to measure bearing capacity revealed the PCD bearing could well endure conditions found in MHK machines, and coefficient of friction (COF) tests demonstrated the PCD ability to move from a boundary lubrication regime, to mixed mode lubrication, and then become hydrodynamic. The PCD wear test was designed to simulate years in the life of a tidal stream power generator, an MHK energy machine, and showed the PCD life is more than adequate for the MHK application. Bearing capacity, COF, and wear observed during laboratory testing illustrate that PCD thrust bearings can provide a robust, long lasting, and low maintenance bearing in MHK applications.


2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Luiz F. P. Franca

This paper presents a new model of the drilling response of roller-cone bits. First, a set of relations between the weight-on-bit W, the torque-on-bit T, the rate of penetration V, and the angular velocity Ω is established in the spirit of the model developed for polycrystalline diamond compact (PDC) bits. In contrast to models that depend on a precise description of the bit, the drilling response is investigated by lumping the effect of the bit geometry into a few parameters and on averaging the drilling quantities (W,T,V,Ω) over at least one revolution of the bit. Within the framework of the model, quantitative information from drilling data related to rock properties, bit conditions, and drilling efficiency can be extracted. Finally, a series of laboratory tests at atmospheric pressure conducted with an in-house designed drilling rig, together with published experimental data, is used to evaluate the proposed model. The good match between the experimental results and the theoretical predictions are promising in regard to the potential use of this model to investigate the drilling response of roller-cone bits.


Sign in / Sign up

Export Citation Format

Share Document