Latin American Operator Protects Casing in Low-ROP Drilling

Low ROP Creates Casing Wear Concern 
Operator concerned with high casing wear while drilling multiple hole sections across the surface casing with a ROP as low as 2ft/hr and 120-150 RPM using a RSS.  Up to 3,800 lb/jt side forces were analyzed in the build section at 6,500ft MD. With the low ROP and higher RPM, several million drill pipe revolutions were 
expected within the 11 ¾” casing which can create casing integrity issues.  

WWT NRPs Create Drill Pipe Stand Off 
WWT’s SS3-578 Non-Rotating Protectors (NRPs) were installed 5ft above the tool joint connection to create a stand-off between the drill pipe and casing. Due to the high chance for severe casing wear, NRPs were installed to protect the entire 11 ¾” casing. 

USIT Log Indicates Casing Protection 
After drilling 3 hole sections, a maximum casing wear of only 13% was measured by a USIT log within the 11-3/4” casing where side forces were highest.  The 7” liner, without protectors, experienced up to 26% wear while only drilling the 6” hole section. Backmodeled casing wear factors (WF) correspond to 0.75-4.5 in the 
areas with NRPs installed and 12-60 without NRPs.  Applying the wear factors experienced in the 7” liner to the 11 ¾” casing would have resulted in severe casing wear. The results strongly indicate that NRPs are effective in minimizing casing wear.