| Corrosion: | | | | pressure as water rises to the surface. Scale is |
| The causes of corrosion vary but are almost always | | | | almost always calcium carbonate, however, calcium |
| related to water chemistry. | | | | sulfate, strontium sulfate, and barium sulfate can |
| - pH - acidic or basic solutions are corrosive | | | | form in waters high in sulfate. |
| - TDS - high salt content results in higher ionic | | | | Laboratory Analysis: |
| strength and leads to corrosion | | | | Determining the chemical composition of production |
| - Chloride - forms soluble iron chloride | | | | water can give operators an indication of the |
| - Sulfate - food for bacteria that form corrosive | | | | tendency of the water to generate scale or cause |
| hydrogen sulfide | | | | corrosion. Proper treatment of the water based on |
| - Bacteria - can produce organic acids that lower pH | | | | the chemical analysis prevents scale or corrosion and |
| Corrosion Products: | | | | minimizes downtime increasing production. |
| A corrosion Product is a solid that appears as scale | | | | Water analyzes can be plotted as Stiff diagrams |
| (clogs pipes) and is a result of corrosion somewhere | | | | creating a unique image of each water layer within a |
| in the system. Typical Corrosion Products are: | | | | well. Future analyzes can be plotted and compared to |
| - Iron carbonate | | | | the original Stiff diagram. Significant changes in major |
| - Iron sulfide | | | | ions could indicate leaks or scale formation. |
| - Iron oxide | | | | Sudden increases in iron and manganese imply that |
| - Trace metals such as Mn, Cr, Cu, Ni, and Mo can | | | | there is corrosion down hole. |
| indicate the source of the corrosion. | | | | These are just a few of the possibilities of an often |
| Scale: | | | | overlooked valuable resource. Production engineers |
| Scale is caused by a decrease in the saturation limit | | | | searching for increased production of oil and gas |
| of ions in the formation water. Water at depth | | | | producing wells should consider the routine monitoring |
| generally holds more salt in solution than water at the | | | | of water from their wells. |
| surface. Scale can form in pipes due to a loss in | | | | |