Casing Wear and Wear Factors: New Experimental Study and Analysis

Abstract

To understand and quantify casing wear during drilling operations, an experimental setup with real drill pipe joints (DPJ) and casings was designed and used to carry out wear tests, simulating various operating conditions and environments. P110 steel casing samples were tested under dry and wet conditions. Actual field oil- and water-based fluids were utilized to lubricate the contact area at two different side loads (1000 N and 1400 N) and DPJ speeds (115 and 207 rpm). The results show that for the same testing conditions, the casing wear volume and wear factor under water-based lubrication were more than twice those obtained under oil-based fluid testing. As expected, the wear volume and wear factor were highest under dry conditions. Moreover, it was noticed that, as the normal load was increased at a constant rotational speed (rpm), the wear factor increased. On the other hand, raising the rotational speed at the same applied load reduced the casing wear factor, due to the observed absence of adhesive wear and possible localized softening effects at higher speeds. SEM analyses of the worn areas showed that under dry conditions, the main wear mechanisms were abrasion and delamination. However, both adhesive wear and abrasive wear mechanisms were observed under oil-based lubrication. The energy dispersive spectroscopy (EDS) analysis of the worn surface revealed that at higher loads and speeds, a heavy transfer of particles from the oil-based lubricant took place. On the other hand, some contaminants of the water-based lubricant were observed on the worn surfaces.

Wear factors and mechanisms of L-80 steel casings

“…These results prove that because of the lower viscosity of WBM, the casing wear volume was on average more than 150% higher than that of OBM. Similar findings were reported by other researchers [18,23]. In general, oil-based drilling muds are preferred, due to their better lubrication performance at various operating conditions, including high temperature and high pressure, compared to environment-friendly water-based drilling fluids [24].…”

“…The wear factor values of L-80 casing material (figure 6), are found to be higher than those obtained for P110 casing samples tested at the same conditions, and reported in our previous study [18]. This can be directly related to the lower carbon content of L-80 as well as lower strength and hardness.…”

“…The system was designed and programmed to maintain the applied side load at a selected set-point value using a feedback loop. Details of the designed system can be found in the previously published works [17,18]. A 25 mm wide circular section was cut at sixty degrees from an L-80 real casing pipe and mounted on the casing holder which in turn is fixed on the dynamometer.…”

Tribological Characterization of a Novel Ceramic–Epoxy–Kevlar Composite

“…Table 2 below illustrates the mechanical properties as provided by the supplier. The wear tests were performed using the experimental setup, consisting of a modified late machine developed in earlier work [28][29][30][31], wherein the conventional cutting tool was replaced with a custom test specimen holder. Additionally, the tool joint was securely installed into the rotating spindle of the machine to simulate rotation; schematics of the setup are shown in Figure 2.…”

“…fied late machine developed in earlier work [28][29][30][31], wherein the conventional cutting tool was replaced with a custom test specimen holder. Additionally, the tool joint was securely installed into the rotating spindle of the machine to simulate rotation; schematics of the setup are shown in Figure 2.…”