Method for drilling a hydrogen sulfide-containing formation
AssigneeKing Fahd University of Petroleum and Minerals
InventorsSalah El-Din Elkatatny, Reyad Awwad Shawabkeh, Mohamed Ahmed Nasr El-Din Mahmoud
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Abstract
A drilling fluid composition comprising an aqueous base fluid, a viscosifier, and a H2S scavenger comprising copper nitrate, wherein the drilling fluid composition has a H2S sorption capacity from about 4.0 to about 6.0 gram per one milliliter of the drilling fluid composition; and a method of drilling a subterranean geological formation using thereof are provided. Various embodiments of the drilling fluid composition and the method are also provided.
Claims7
A method of drilling a wellbore into a hydrogen sulfide-containing subterranean geological formation, comprising:
- driving a drill bit to form the wellbore into the subterranean geological formation thereby producing a formation fluid that contains H2S;
- and
- injecting a drilling fluid composition into the subterranean geological formation through the wellbore,
- wherein the drilling fluid composition comprises
- an aqueous base fluid,
- a polymeric viscosifier, and
- a H2S scavenger comprising copper nitrate, wherein the H2S scavenger is present in an amount of 0.5-5 lbs/bbl based on the volume of the drilling fluid composition, and
- wherein copper nitrate present in the drilling fluid composition reacts with H2S present in the formation fluid to form copper sulfide;
- recovering the copper sulfide from the drilling fluid composition;
- and
- treating the copper sulfide with nitric acid to regenerate copper nitrate while concurrently forming elemental sulfur.
Dependencies are inferred from the claim text.