泥浆对钻头WC基胎体材料冲蚀磨损的试验研究

Experimental research on erosion and corrosion of WC-base matrix materials for drill bits under impingement of drilling mud

采用双喷嘴闭路循环试验装置,测试了钻头胎体材料在泥浆冲蚀作用下所产生的总质量损失TML和由纯机械冲刷作用所产生的质量损失E。通过计算得到了由腐蚀及机械冲刷与腐蚀相互作用所产生的质量损失C+S。结果表明,钻头胎体材料的冲蚀磨损不是纯由机械冲刷作用引起,而是由机械冲刷、腐蚀及他们的相互作用共同引起。因此,在有腐蚀性的泥浆中设计和选用PDC(金刚石复合片)钻头时,除了考虑胎体材料的抗冲刷磨损性能外,还应考虑钻头胎体材料的抗腐蚀性。

In oil drilling the erosion and corrosion resistance of the matrix is one of the key factors affecting the quality of PDC bits. In order to understand the degradation mechanism of matrix materials for drill bits, a kind of loop recirculation rig is adopted to measure total mass loss TML, mass loss E by pure mechanical erosion, and then through calculation the mass loss C ＋ S by corrosion and their synergy is obtained. The tested and calculated results show that TML of matrix materials is not only caused by pure mechanical erosion, but also by corrosion and their synergy of mechanical erosion and corrosion, which tells us that the corrosion resistance of matrix materials should be considered carefitlly besides their erosive resistance in the design and selection of PDC drill bits used in the corrosive drilling mud.