Steam-assisted gravity drainage (SAGD) involves inherently challenging operating conditions that often impact operational performance and reliability. SAGD is an enhanced oil recovery technology used to recover bitumen from oil sands. SAGD utilizes a stacked pair of horizontal wells and an advanced form of steam stimulation to recover bitumen. Steam is injected at a high pressure and temperature of 300-340°C (572-644°F) into the top well to reduce the viscosity of the bitumen, allowing it to separate from the sand and be recovered in the form of a bitumen and condensed steam emulsion from the lower well.
SAGD facilities in Alberta must take careful consideration when selecting industrial fluid systems to accommodate the challenging process conditions. Many units within a SAGD facility involve process conditions with high temperatures, high pressures, and the presence of hydrogen sulfide, chlorides, and total dissolved solids which can contribute to high corrosion rates.
Let’s take a look into newer industrial fluid systems and services that can aid in improving SAGD reliability.
The challenging process conditions involved in SAGD require careful attention and consideration when selecting industrial fluid systems, such as valves, fittings, tubing, instrumentation, sample cylinders, and sampling system components. Implementing newer technologies and services which cater to such operating conditions can reduce downtime caused by corrosion-related failures.
Common material selections, such as austenitic stainless steel, for components, tubing, sample cylinders, and instrumentation may not be suitable for SAGD process conditions and can result in high rates of corrosion and a shortened life cycle or catastrophic failure if corrosion is not caught in a timely manner. To reduce corrosion rates, materials such as 316L stainless steel or special alloys, such as the following, can be utilized:
In addition to material selection, corrosion in tubing and sample cylinders can be reduced significantly through surface treatments and finishes applied to their interior surface. Coatings may also be implemented in sample cylinders to help ensure a representative sample of the process is obtained. Options include:
Some industrial fluid system manufacturers may offer the ability to customize sampling systems to accommodate difficult SAGD process conditions. Beyond material selection and surface treatments and finishes, there are several customizations that can be added to sampling systems to improve sampling reliability in SAGD. For example, sample lines can be insulated and heat traced to help ensure proper flow of the process fluid to the sample point. As crude oil is highly viscous, proper considerations must be made to ensure the oil is maintained at a high enough temperature for adequate flow.
A handful of industrial fluid system manufacturers offer onsite services to evaluate sampling systems to troubleshoot problems or inefficiencies and suggest solutions that can boost overall sampling performance. Solutions may include upgrades to the sampling system or changes to the actual implementation of the system into the process.
Working with a local vendor who offers the flexibility to optimize industrial fluid systems for your specific SAGD operations can greatly improve overall reliability and the operational life of components and systems.
At Edmonton Valve & Fitting, we understand the unique challenges of SAGD applications. Beyond our extensive selection of high-quality components, corrosion-resistant materials, and sampling systems, we also offer expert Field Advisory services to provide onsite support and advice. Our Field Advisors can perform grab sampling audits, provide design advice, and conduct facility health checks to help address problems or inefficiencies within your SAGD operations.