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The Stinger PDC cutter has superior impact resistance, wear resistance, and rock-breaking efficiency compared to the conventional PDC cutter. Thus, hybrid PDC bits that combine conventional and Stinger PDC cutters have significant advantages in drilling hard, interbedded, and highly abrasive rocks. Although the hybrid PDC bit has demonstrated outst...
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... In numerical study of Zhu et al. (2022), based on basic cutter profiles (rectangular cutter, circular cutter and conical cutter), the cutting efficiency of specially-shaped cutters was analyzed and some indicators to evaluate the rock-breaking performance of specially-shaped cutters were also proposed, see Fig. 26. Moreover, a recent experimental investigation by Xiong et al. (2022) using mixed tool explored the cutting of granite. Experimental results showed that the different rock-breaking performances and efficiencies could be obtained when cutting using changed cutting sequences of mixed tool. ...
... Filed experiment of Durrand et al. (2010) observed that Stinger PDC Cutter was not more subjected to wear and fracture. Similarly, Xiong's experimental results (Xiong et al., 2022) indicated that Stinger PDC was more prone to penetrate into rock. Thus, analysis and design of specially-shaped cutter is conducive to tackle the issues encountered by conventional cutters. ...
... Since shaped cutters are always used along with conventional cutters on a PDC bit, more studies begin to investigate the combined cutting process of shaped and conventional cutters. For example, Xiong et al. (2022) conducted cutting tests with different combinations of stinger cutters and round cutters, and studied the influence of cutting parameters on cutting efficiency, e.g. cutter sequence, cutter distance and the difference in cutting depth of the cutters (see Fig. 18). ...
... Cutting rock by combined shaped cutter and conventional cutter(Xiong et al., 2022). ...
... According to the former experiment research, the cutting speed has nearly no effect on the cutting force and MSE for the Stinger PDC cutter breaking rock at atmosphere conditions. 39,40 And the related research reports no evidence that the cutting speed has a considerable effect on the cutting force at confining pressure. 41 Thus, for improving the simulation efficiency, the cutting speed of the Stinger PDC cutter is set to 2 m/s. ...
... Specific energy (SE), defined as the energy required to excavate unit volume of rock, is usually taken as an index of the mechanical efficiency of a rock-working process (Xiong et al. 2022). The specific energy of an abrasive water jet drilling of rocks is defined as : ...
Swirling impeller abrasive water jet (SAWJ) is a viable alternative for larger-diameter drilling of mining and oil and gas extraction. Abrasive material plays an important role in eco-efficient drilling of SAWJ. Here, we investigate performances of six types of abrasive materials during SAWJ drilling of hard granite. Rock breaking performances and abrasive particles characteristics before and after impact were studied. Besides, reusability, efficiency and economy of different abrasive materials were discussed. The results indicated that SAWJ would create a large-diameter (63–71 mm) hole with a conical bulge on the bottom regardless of the abrasive material used in it. Abrasive particles size distribution and shape factor before and after impacting with granite had slight changes. Moreover, median diameter of the particles and shape factor were used for estimating the reusability of the abrasive particles after impacting with granite, and the results indicated that all the abrasive materials had excellent reusability. Besides, the efficiency and economy analyses showed that the garnet abrasive had the best rock breaking performance. Therefore, we recommend garnet as the abrasive during swirling impeller abrasive water jet drilling of granite.
... Considerable research efforts, both experimental and/or analytical investigations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and numerical studies [16][17][18][19][20][21][22][23][24][25][26][27], have been devoted to rotary drilling with PDC bits. The major aim is either to measure, in experiments, or to predict, in modelling, the cutting force (F c in Figure 1) as a function of various drilling technical parameters, such as cutting depth (controlled by adjusting the WOB or F p for a single cutter, in Figure 1), rake angle, cutter size, and cutting speed. ...
Featured Application: The numerical method presented in this paper is designed to estimate the cutting force and the removed material volume during rotary rock drilling by a single PDC cutter. Abstract: This paper presents a relatively simple numerical approach to predict the cutting force during PDC (polycrystalline diamond contact) cutting of rock. The rock failure model is based on a damage-viscoplasticity model, with the Drucker-Prager yield surface and the modified Rankine surface as the tensile cutoff. The damage part of the model has separate scalar damage variables for tension and compression. The PDC cutter is idealized to a rigid surface and its interaction with the rock is modelled by contact mechanics, while solving the global equations of motion explicitly in time. A damage-based erosion criterion is applied, to remove the contact nodes surrounded by heavily damaged elements. The eroded elements are left in the mesh as ghost elements that do not contribute to the load transfer but preserve the mass conservation. Numerical simulations on granite, demonstrate that the method reliably predicts the cutting force of a single PDC cutter at different cutting depths and rake angles.
... The effects of cu er geometry parameters, cu ing angle, impact load, and cu ing speed on crack propagation, debris formation, and damage evolution of rock were extensively studied [26,27]. Xiong et al. [28] (2021) investigated mixed tool cu ing of granite with stinger PDC cu ers and conventional PDC cutters, and they pointed out that the hybrid PDC bits that combine conventional and stinger PDC cu ers have significant advantages in drilling hard, interbedded, and highly abrasive rocks. Dong and Chen [29] (2018) conducted a 3D full-scale PDC bit model to study the dynamic damage characteristics of anisotropic shale during impact rotary drilling. ...
Downhole vibrations caused by rock breaking when drilling through pebbled sandstone formations negatively affect the rate of penetration (ROP) and the safety of downhole tools. Therefore, it is of great significance to study the cutting characteristics of pebbled sandstone and find a method of reducing the drilling vibrations of pebbled sandstone formations. Based on the DEM (discrete element method), a simulation model of pebbled sandstone considering the random filling of high-strength gravels was established by using the random polygon distribution method. The influence of gravel content on the strength parameters and the breaking state of the pebbled sandstone samples was analyzed. Additionally, a DEM model of PDC cutting rocks loaded by a spring–mass system was established, and the Stribeck effect of contact friction between the PDC cutter and the rock was analyzed. The periodic vibration and the stick–slip phenomenon of the cutting system during the drilling process were presented by this model. The model was employed to simulate and explore the influence of composite impact load on stick–slip vibration during PDC cutting of pebbled sandstone. The simulation results showed that the composite impact load had a more obvious effect on mitigating the vibration of PDC cutting of pebbled sandstone under the condition of a higher horizontal impact amplitude coefficient (qh = 40%). Based on the simulation results, a composite impactor with a large impact angle α = 70° was selected to conduct the field tests in the pebbled sandstone formation of Well T1. The results showed that, compared to conventional drilling, the average WOB (weight on bit) of the section drilled with the composite impactor decreased by 57.13%, the standard deviation of the WOB decreased by 57.29%, and the average ROP increased by 98.31%. The employing of composite impactors in pebbled sandstone formations can significantly reduce drilling vibration, improve ROP, and protect bits and downhole instruments.
The Stinger PDC cutter has high rock-breaking efficiency and excellent impact and wear resistance, which can significantly increase the rate of penetration (ROP) and extend PDC bit life for drilling hard and abrasive formation. The knowledge of force response and mechanical specific energy (MSE) for the Stinger PDC cutter is of great importance for improving the cutter's performance and optimizing the hybrid PDC bit design. In this paper, 87 single cutter tests were conducted on the granite. A new method for precisely obtaining the rock broken volume was proposed. The influences of cutting depth, cutting angle, and cutting speed on cutting force and MSE were analyzed. Besides, a phenomenological cutting force model of the Stinger PDC cutter was established by regression of experimental data. Moreover, the surface topography and fracture morphology of the cutting groove and large size cuttings were measured by a 3D profilometer and a scanning electron microscope (SEM). Finally, the rock-breaking mechanism of the Stinger PDC cutter was illustrated. The results indicated that the cutting depth has the greatest influence on the cutting force and MSE, while the cutting speed has no obvious effects, especially at low cutting speeds. As the increase of cutting depth, the cutting force increases linearly, and MSE reduces with a quadratic polynomial relationship. When the cutting angle raises from 10° to 30°, the cutting force increases linearly, and the MSE firstly decreases and then increases. The optimal cutting angle for breaking rock is approximately 20°. The Stinger PDC cutter breaks granite mainly by high concentrated point loading and tensile failure, which can observably improve the rock breaking efficiency. The key findings of this work will help to reveal the rock-breaking mechanisms and optimize the cutter arrangement for the Stinger PDC cutter.
