With the development of global oil and gas exploration and development to deep and ultra-deep wells, the problems such as underground high temperature environment and unreasonable selection of drilling parameters in field operation make the bit wear increasingly serious. In order to prolong the bit life and improve the rock breaking efficiency, a 3D simulation model of polycrystalline diamond compact(PDC) cutters marble was established, and the effects of different cutting depth, cutting speed and bit caster on the PDC cutters surface temperature and rock breaking efficiency were analyzed. The results show that the temperature rise of the cutting gear can be divided into three stages: ascending period, transitional period and stable period, and the crushing form of the rock changes from plastic to brittle when the cutting depth increases to a certain extent. With the increase of cutting speed, both temperature and crushing work ratio increase. With the increase of cutting depth and bit caster, the crushing work ratio increases and the temperature increases first and then decreases. The response surface method was used to optimize the cutting speed, cutting depth and bit caster, and the optimal parameter combination was given. The research results can provide guidance for efficient rock breaking of PDC bit in field.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |