The present disclosure provides a bulk treatment for introduction into a hydrocarbon bearing formation, the bulk treatment comprising a volume of a treatment fluid comprising chlorine dioxide, wherein the volume is such that when the treatment fluid is introduced into a wellbore that penetrates the hydrocarbon bearing formation, the fluid is expected to extend into the formation to a radius that goes beyond the near wellbore region. Such a bulk treatment can act to draw out hydrocarbons from a hydrocarbon-bearing formation, thereby enhancing recovery of oil and/or gas. Also provided herein are mixtures comprising chlorine dioxide, water, an organic non-polar solvent, and optionally one or more additional components (e.g., an acid or chelating agent and/or a surfactant or cosolvent). The mixtures are useful for enhancing recovery of oil and/or gas and for removing residues that contain hydrocarbons. Apparatus for making the mixtures, and methods of making and using the mixtures, e.g., to mitigate damage and/or enhance recovery of oil and/or gas from a petroleum well, are also disclosed.
