Oil and Gas Water Treatment Chemical Market Size & Forecasts 2026-2035, By Segments (Distribution Channel, Chemical Composition, End User, Application Area, Type), Growth Opportunities, Innovation Landscape, Regulatory Shifts, Strategic Regional Insights (U.S., Japan, China, South Korea, UK, Germany, France), and Competitive Dynamics (BASF, Ecolab, Dow, Schlumberger, Nalco Champion)