Completing Ultra Extended-Reach Wells: Overcoming the Torque and Drag Constraints of Brine

Abstract

The use of invert emulsion drilling fluids as a key enabler to successfully drill extended reach wells and access hydrocarbons that were previously out of reach has been common practice across the industry for decades. One of the more recent, but less frequently discussed, topics is how to effectively design a solids-free, brine-based completion fluid to facilitate the running of the completion by reducing torque and drag. The choice of lubricant for brine-based completion fluids is primarily driven by technical performance, both in terms of torque reduction and compatibility with the brine, potential brine contaminants, such as divalent ions, invert emulsion drilling fluid, and crude oil that may be encountered in the field. During the planning phase for a recent ultra-extended-reach drilling campaign located offshore Sakhalin Island, it was highlighted that, without a lubricant in the completion brine, neither the upper nor the lower completion would be able to reach the required total depth, based on historical friction factor data. The brine planned for use as a completion fluid must demonstrate lubricity features near that of an invert-emulsion drilling fluid for the well to be completed successfully. This paper summarizes the laboratory test results to validate the lubricant selection and provides details about the operational procedures and results achieved after using the new lubricant in the field for the first time.

Confronting ethical and social issues related to the genetics of musicality

“…Such uses, in addition to the ethical problems they pose, are based on a distortion of these scores' predictive accuracy. Cross-talk between the fields of ethnomusicology, music cognition, and human genetics is seeding an urgently needed ethical and social agenda at the time when discussions of such work on social media 16 and in the press, carry both the opportunity to engage with the broader public and the potential for inaccuracies or mischaracterizations to go viral.…”