Smart Autoclaves for High Temperature/High Pressure Corrosion Assessment.

Lead Research Organisation: University of Leeds
Department Name: Mechanical Engineering

Abstract

Context of research:
Controlling corrosion in Oil and Gas, Carbon Capture and Storage (CCS) or Geothermal applications is important to mitigating equipment failure as a result of severe corrosion mechanisms going undetected. As we move to deeper resources, natural environments become very aggressive, increasing the risk and complexity of corrosion failures and scaling and in turn endangering the efficiency and longevity of the equipment. High temperature and pressure conditions, as well as corrosive salt and dissolved gases represent a major threat to the integrity of the various components, including liners and well casings, well heads, turbines, pumps, valves, heat exchangers, pipes, separators, condensers, H2S abatement systems, etc.
Understanding the complex nature of corrosion processes observed in such industries that occur under high pressure and high temperature (HPHT) environments is the key mitigating corrosion-related failures. Corrosion mechanisms and reactions in HPHT environments can be extremely rapid and the investigation of the corrosion behaviour (in particular electrochemical corrosion measurements) can be very challenging experimentally. An accurate system is required to measure the electrochemical behaviour in order to capture the corrosion reactions and corrosion product kinetics at temperatures up to 250C and pressures up to 10 MPa. The suitable system should include the electrochemical cell, electrode designs, solution/sample preparation and experimental protocol.

Aims and objectives.
Literature review:
- Understand and review the literature surrounding electrochemistry of corrosion and CO2/H2S corrosion in Oilfield, Carbon Capture & Storage and Geothermal Applications
- Identify current industry needs and gaps in the literature
- Perform a critical analysis of the current technology and systems used for HPHT corrosion studies
- Define the current limitations of commercially available technology and systems used for HPHT corrosion studies.
System design:
- Development of a new dual autoclave system with integrated electrochemistry and the capability of maintaining a stable solution chemistry with O2 levels <10 ppb (initially moderate pressures/temperatures - control pH & Fe2+)
- To design and develop a new system with the capability of maintaining a stable solution chemistry in HPHT dynamic conditions.

Project Stages
1: Understand and review the literature surrounding electrochemistry of corrosion and CO2/H2S corrosion in Oilfield, Carbon Capture & Storage and Geothermal Applications (0 - 3 months)
2: Understanding of the testing standards and current limitations using autoclave for corrosion testing (0 - 3 months)
3: Identify the hardware and components essential for a dual-autoclave set-up: Use existing equipment in-house using two glass cells as proof of concept (3-6 months)
4: Data collection from LBBC Baskerville standard autoclave (6-9 months)
5: Design and development of dual-autoclave with integrated Electrochemistry (6-12)
6: Corrosion study using dual-autoclave set-up with integrated electrochemistry (9-12 months)
6.1. Proof of concept of developed system:
- Compare results with and without pre-corrosion through heat-up time
- Method for reducing O2 in system to < 10 ppb
- Obtaining accurate corrosion rate data in-situ
7: Development of sensory capabilities for pH and water chemistry in dual-autoclave in a CO2 environment at low pCO2 (<10 bar) and low temperature (<150 C)
8: Development of a fully automated advanced autoclave system with the capability of (12-18 months):
- Maintaining a stable solution chemistry in HTHP (100 bar and 200 C) dynamic conditions
- Dosing/sampling chemicals in-situ
- Method for monitoring O2/pH in-situ
9: Corrosion study based on proposed experimental plan with detailed analysis techniques (18 -36 months)
9.1. Proof of concept of developed system:
- Compare results with and without evolving solution chemistry

Publications

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