INFLUENCE OF THE WEIGHTING MATERIAL ON CASING WEAR IN IMPACT- SLIDING TEST CONDITION

摘要

The weighting material in drilling fluid has very important effect on casing wear. By using the DCWT-1000 tester, a new impact-sliding tester for casing wear, a series of tests in impact-sliding work condition have been performed to investigate the effects of different weighting material doped in drilling fluid. The OE and SEM analysis presents that the iron ore powder doped in the drilling fluid led to the change in the wear mechanism from abrasive wear and adhesion wear to severe plastic flow and fatigue wear. The adhesion wear increasingly become severe with increasing iron ore powder content. While the barite doped in the drilling mud was beneficial to decreasing the adhesion wear and plastic deformation of the casing. Moreover, it is found that mixed weighting material with iron ore powder and barite in certain ratio has better effect on decreasing casing wear.