In-situ method and system for removing heavy metals from produced fluids

摘要

Methods and systems relate to the in-situ removal of heavy metals such as mercury, arsenic, etc., from produced fluids such as gases and crudes from a subterranean hydrocarbon-bearing formation. A sufficient amount of a fixing agent is injected into formation with a dilution fluid. The fixing agent reacts with the heavy metals forming precipitate, or is extracted heavy metals into the dilution fluid as soluble complexes. In one embodiment, the heavy metal precipitates remain in the formation. After the recovery of the produced fluid, the dilution fluid containing the heavy metal complexes is separated from the produced fluid, generating a treated produced fluid having a reduced concentration of heavy metals. In one embodiment, the dilution fluid is water, and the wastewater containing the heavy metal complexes after recovery can be recycled by injection into a reservoir.

主权项

1. A method for recovering hydrocarbons from a subterranean hydrocarbon-bearing formation while simultaneously removing heavy metals from the hydrocarbons, comprising:
providing a dilution fluid containing a fixing agent dissolved in a diluent; injecting the dilution fluid containing the fixing agent dissolved in a diluent into the formation; exposing the heavy metals in the hydrocarbons in the formation to the fixing agent in the dilution fluid for the fixing agent to react in-situ in the formation with the heavy metals forming heavy metal complexes in the dilution fluid; and recovering the hydrocarbons having a reduced concentration of heavy metals and the dilution fluid containing the heavy metal complexes as a mixture from the formation via a production well.