An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed. Experiments include both the cutting of PDC fixed at different angles on the granite core or bar...An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed. Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite. The effects of the rough degree of rock surface, cutting angles, and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed. The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.展开更多
In order to develop a rotary percussive bit with diamond enhanced cutters assisted by high pressure water jets, it is necessary to study the damage mechanism and the penetration properties of PDC cutters subject to di...In order to develop a rotary percussive bit with diamond enhanced cutters assisted by high pressure water jets, it is necessary to study the damage mechanism and the penetration properties of PDC cutters subject to different impact load level and rock types. Therefore the impact experiments of the single PDC cutters with different attack angles in four rocks: black basalt, Missouri red granite, Halston limestone, and a very soft (Roubidoux) sandstone were carried out, and the effects of rake angles of PDC cutters on both the penetration and impact resistance of PDC cutters have been discussed in detail. Test results show that a PDC insert can withstand a very strong impact in compression but is easily damaged by impact shearing, the PDC cutters are more easily damaged by shearing if the attack angles are relatively small, the 45? PDC cutters have the least penetration resistance among the cutters tested. Thus it is suggested that the attack angles of PDC cutters should be larger than 30? for bits which must withstand impact from a hammer.展开更多
The capability of several types of flat PDC cutters to withstand combined loads were tested and evaluated by the impact and cutting of single PDC cutter on granite in a linear impact cutting table. The primary failure...The capability of several types of flat PDC cutters to withstand combined loads were tested and evaluated by the impact and cutting of single PDC cutter on granite in a linear impact cutting table. The primary failure modes of PDC cutters withstanding different combined loads were investigated and analyzed. The suggestions of enhancing PDC cutters to be suitable for drilling very hard rock have been made.展开更多
基金Project (5 0 1740 5 6)supportedbytheNationalNaturalScienceFoundationofChina project (DE -FG0 3 )supportedbytheNovatekundertheDepartmentofEnergy USA
文摘An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed. Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite. The effects of the rough degree of rock surface, cutting angles, and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed. The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.
文摘In order to develop a rotary percussive bit with diamond enhanced cutters assisted by high pressure water jets, it is necessary to study the damage mechanism and the penetration properties of PDC cutters subject to different impact load level and rock types. Therefore the impact experiments of the single PDC cutters with different attack angles in four rocks: black basalt, Missouri red granite, Halston limestone, and a very soft (Roubidoux) sandstone were carried out, and the effects of rake angles of PDC cutters on both the penetration and impact resistance of PDC cutters have been discussed in detail. Test results show that a PDC insert can withstand a very strong impact in compression but is easily damaged by impact shearing, the PDC cutters are more easily damaged by shearing if the attack angles are relatively small, the 45? PDC cutters have the least penetration resistance among the cutters tested. Thus it is suggested that the attack angles of PDC cutters should be larger than 30? for bits which must withstand impact from a hammer.
基金Project(5 0 1740 5 6)supportedbytheNationalNaturalScienceFoundationofChina project(De -FG0 3 )supportedbytheNevatakUndertheDepartmentofEnergy USA
文摘The capability of several types of flat PDC cutters to withstand combined loads were tested and evaluated by the impact and cutting of single PDC cutter on granite in a linear impact cutting table. The primary failure modes of PDC cutters withstanding different combined loads were investigated and analyzed. The suggestions of enhancing PDC cutters to be suitable for drilling very hard rock have been made.
