I am astonished that for the moment, no research have been done to improve casing thread by diffusing Nickel or this kind of stuff, which would be useful for tubingless completion. Can you tell me if I am wrong?
What would be the objective of the Nickel? To improve corrosion or reduce galling? If the latter, various phosphate based coatings are used with some success.
"Tubingless" completions are already used extensively in high-volume gas wells and are otherwise known as monobore wells.