Hydrocarbon liquid based chemical compositions and treatment methods using same for remediating H2S and other contaminants in fluids and mixtures of contaminated fluids

A treatment process for remediating H2S, CO2 and other contaminant(s) in a fluid mixture stream of contaminated liquid and contaminated gas, comprising steps of:

• adding a dosage of a treatment composition to the fluid mixture stream to bring a pH of the fluid mixture stream having the treatment composition added thereto to be about 12 but not more than 12.5 in a localized pocket where the treatment composition is added to the fluid mixture, the treatment composition comprising a hydrocarbon based liquid and at least one hydroxide compound dispersed or dissolved into the hydrocarbon based liquid, wherein the at least one hydroxide compound dispersed or dissolved into the hydrocarbon based liquid constitutes 30-50 wt % of the treatment composition, the at least one hydroxide compound includes at least one of potassium hydroxide and sodium hydroxide, a pH of the treatment composition is in a range of 13-14.0,
• flowing the fluid mixture stream having the treatment composition added thereto through a pipeline to permit the treatment composition to remediate contaminants in the fluid mixture,
• wherein the fluid mixture stream contains a liquid water component, a liquid hydrocarbon component and a natural gas component, and the treatment process includes further steps of:
• separating the liquid water based component from the liquid hydrocarbon based component and the natural gas component of the treated mixed fluid stream,
• combining the liquid hydrocarbon based component and the natural gas component as a new fluid mixture stream,
• adding a further dosage of the treatment composition to the new mixed fluid stream, and
• permitting the treatment composition to further remediate contaminants in the new mixed fluid stream.