Materials for deep well, gas and water exploration

07 October 2019

With the passage of time, oil and gas exploration will be performed in deep wells specifically in deepwater. Unlike to shallow wells, the deep wells demand durable materials. The well conditions include hydrogen sulfide, carbon dioxide, chlorides and sulfur and also the temperatures go up to 260°C and pressure 25000 psi. Due to this, it becomes crucial to make the right material choice. The selected material should be corrosion resistant, economical, reliable and possess the desired strength level for satisfactory service. Due to vigorousness of these conditions, material options include duplex stainless steel and Nickel-based superalloys such as Inconel 625 and Incoloy 825.

Age hardened and cold processed solid nickel-based alloys have several advantages that are useful for service in deep well conditions for example high strength, toughness, supreme corrosion resistance, and nominal magnetic permeability. Material choice for a specific set of conditions depends on various factors such as mechanical and corrosion-resistant properties.

The strength of age-hardened materials is essential specifically for offshore industries for example to explore the high-pressure deep wells where weight affects the budget of mining project. The material choice for downhole and well head systems for example hangers, sub surface safety valves, pumps and packers for age hardenable alloys to receive the desired strength in larger cross-sections that cannot be reinforced by cold processing. Nickel alloys such as Monel and Inconel 718 have high mechanical properties for use in oil country applications.

Age hardened alloys are used at different strength levels on the basis of their application. For example, the strength of Inconel 718 wire is 827 MPs which is enhanced by suitable heat and mechanical processing during production.

Inconel 625 offers supreme resistance to general corrosion in test conditions and even significantly higher performance as compare to Inconel 718.