Microemulsion or in-situ microemulsion for releasing stuck pipe

Nanoemulsion, macroemulsions, miniemulsions, microemulsion systems with excess oil or water or both (Winsor I, II or III phase behavior) or single phase microemulsions (Winsor IV) improve the removal of filter cakes formed during hydrocarbon reservoir wellbore drilling with OBM. Such filter cakes and their particles can contact, impact and affect the movement of the drill string undesirably resulting in a "stuck pipe" condition. The macroemulsion, nanoemulsion, miniemulsion, microemulsion systems with excess oil or water or both or single phase microemulsion removes oil and solids from the filter cake, thereby releasing the drill string from its stuck condition. In one non-limiting embodiment, the emulsion system may be formed in situ (downhole) rather than produced or prepared in advance and pumped downhole.