A Review of Corrosion Resistance Alloy Weld Overlay Cladding Material for Geothermal Applications

Abstract

Geothermal is known as renewable energy and a clean energy source but inherent properties make this energy clean. Minerals and deposits in geothermal reservoirs create a scale that is persistent in its corrosive nature. In addition, heat extremes and pressure variations present challenges to the integrity of the wellhead components and the downhole casing. Such challenges need to be mitigated to achieve maximum output from these aging or even newly commissioned wells. The geothermal power industry has reported a wide range of corrosion problems. Given the highly corrosive conditions to be treated in the geothermal sector and the benefits of reduced unplanned downtime, operating cost savings would be expected if more CRAs clad products were used. In many cases, only the material's surface requires corrosion resistance and carbon or alloy steel can be clad with a more corrosion-resistant alloy. Up to 80% of the cost of using solid alloy can be saved by cladding. Carbon or low-alloy steel cladding can be carried out by overlay welding. This paper reviews available literature on corrosion in the geothermal environment and presents the successful use of clad products in other industries to support the rising demand for Philippine geothermal applications.