澳洲大学石油工程讲座59-8500 and 59-8510-surface facilities for waterflooding and salt disposal.ppt

Copyright Rike Service, Inc., 2005 SURFACE FACILITIES FOR WATERFLOODING SALT WATER DISPOSAL FILTER EQUIPMENT Backwashing required with all filters Velocity sufficient to fluidize media to 150% of volume Frequent backwashing required indicates poor water quality at inlet (50 ppm or less turbidity at inlet) PUMPING EQUIPMENT Largest single cost of system—factors to consider: Volume of water Discharge pressure required Suction head available Space requirements Load variations Flexibility required Prime mover required Corrosive nature of water Pump efficiency FILTER EQUIPMENT Duplex piston-type pumps used when pressure is below 500 psi Lower initial cost/lower maintenance cost 85% efficiency Rod packing piston cups biggest maintenance problem FILTER EQUIPMENT Multiplex plunger pumps for pressures above 500 psi 90% efficiency More costly maintenance Plungers are available in corrosive resistant alloys materials CORROSION Controlling corrosion Remove the agent Isolate metal from the agent Inhibit against it CORROSION Most systems require removal of oxygen Vacuum de-aeration Chemical de-aeration with scavengers (Sodium sulfite, sulfur dioxide) CORROSION Methods to isolate agents from steel Coatings (cement, organic, ceramic, plastic, etc.) Corrosive resistant materials (alloys, porcelain, plastic, fiberglass, etc.) CORROSION Inhibitors are film-forming organic compounds Change wettability of steel Not effective when oxygen is greater than 1 ppm BACTERIA Sulfate reducing bacteria Causes severe corrosion Plugs off injection wells Small curved rod- or spiral-shaped Occur in soil, sewage, fresh water seawater Anaerobic, but grow in several ppm O2 Not killed by aeration Abundant in produced water CORROSION Corrosion process is removal of hydrogen formed at cathodic areas of metals Reduces sulfate to sulfide Increases corrosion anaerobically CORROSION Products formed by sulfate reducing bacteria Hydrogen sulfide gas Insoluble ferrous sulfide CORROSION Results of sulfate redu