Provided are treatment fluids that comprise a base fluid and an
orthoester-based surfactant. In some instances, the treatment fluid may
have a pH of about 8.5 or greater. Also provided are emulsified treatment
fluids that comprise an oleaginous phase, an aqueous phase having a pH of
about 8.5 or greater, and an orthoester-based surfactant. Methods of
using the treatment fluid and methods of facilitating flow through a
conduit also are provided.