Re-crosslinkable interpenetrating polymer network preformed particle gels (IPN PPGs) and compositions containing re-crosslinkable IPN PPGs, are provided, as well as methods of re-crosslinking the re-crosslinkable IPN PPGs with ionic crosslinkers, and the resultant re-crosslinked IPN PPG compositions. In addition, the use of the re-crosslinkable and re-crosslinked IPN PPGs are provided, e.g., in methods, processes, and techniques related to enhanced oil recovery, e.g., conformance control, wherein the use of said re-crosslinked IPN PPGs may improve hydrocarbon recovery, e.g., by improving sweep efficiency. These re-crosslinked IPN PPGs are also useful in water and gas shutoff, fluid loss control, zone abandonment, water and gas coning, squeeze and recompletion, chemical liner completions and lost circulation during drilling operations and plugging during drilling and drilling completion.