Formation damage studies of lubricants used with drill-in fluids systems on horizontal open-hole wells

Abstract

Tests were conducted to evaluate the effect of lubricants in formation damage. Two types of lubricants were tested along with two types of drill-in fluids. The DIF's tested included a sized-calcium carbonate (SCC) and a sized-salt (SS). Also a set of variables including drill solids content (2%-6%), hydrochloric acid concentration (2%-10%), and temperature (110°F-160°F) were changed during the testing procedure. A matrix design was used to determine the behavior in regain permeability and break through time depending on the different variables in the testing, and two devices were used to measure responses, Conoco cell and ceramic disc cell respectively. Results have shown that regain permeability and break through time responses are not affected in a greater degree when lubricants (Idlube or Mil-Lube) are added to the DIF systems (SS and SCC). When comparing results between lubricants, Idlube gives a higher regain permeability percentage and faster break through time at higher concentrations than Mil-Lube in both DIF systems. Overall, sized calcium carbonate seems to be a better DIF system than Sized salt for these types of experiments, being much more efficient in reducing break through times than in increasing regain permeability.