Influence of Hardness on Casing Wear Resistance in Polysulfide Water Based Drilling Fluid
Worn casing often appears in deep and ultra deep well which effected by many factors in drilling process, such as casing grades, drilling fluid density and contact forces, and so on. Using polysulfide water-based drilling fluid, simulating the actual bit pressure, rotary speed and other influencing factors, the wear experiments of TP140,VM140,P110 and N80 casing which often are adopted in the oilfield are completed, and the wear efficiency and friction coefficient which are adopted to predict down hole casing wear are obtained. The experimental results show that the higher casing steel grade, the greater the hardness, the better wear performance. The experiments can help deepen the understanding of the mechanism of casing wear. Adopting the results which are obtained in research the prediction accuracy of down hole casing wear can be improved.