SAGD products must have precise chemical compositions based on customer specifications, government regulations, and other industrial fluid management guidelines. Managing these composition requirements calls for regular sampling and analysis of the process fluid.
Sample analysis is only useful, however, if samples are collected from well-designed, properly installed sampling systems using good operating practices. In this post, we’ll look at some industrial fluid management guidelines for SAGD fluid systems and how proper sampling system design and best operating practices can help ensure safe, reliable operations.
SAGD operations depend on rotating equipment like emulsion well pads, boiler feed pumps, water treatment pumps, and export pumps—and, seal flush systems are critical to their functioning. When a seal or flush system fails, the system must be shut down until the cause is determined and addressed. If onsite engineers can’t identify the cause of the problem, unplanned downtime can become a major problem.
Seal flush systems must be able to withstand the harsh fluid conditions of SAGD to optimize fluid management and prevent seal failures. When an issue arises during SAGD operations in remote locations, timely containment and corrective action are critical. Below are a few of the most common fluid system challenges in SAGD operations.
When designing a grab sampling station, there are countless options and configurations to choose from. Good design choices depend on the details of the application. Below are some important factors to consider.
A well-designed grab sampling station includes all features mounted on a single panel, including a geared valve assembly for ease of use, quick-connect couplings for repeatable connections, a flexible connection hose, a pressure gauge, and cylinder support (if using sample cylinders).
Samples must be as representative of the process conditions as possible. A sample must be fully mixed in the process line and cannot be contaminated during or after sampling. These guidelines will help you ensure your samples are clean and representative of the process.
After collecting a sample, it is important to use a container that can maintain the sample as close to process conditions as possible. Sample cylinders are required for gases or volatile liquids to prevent evaporation and fractionation. Bottles can be used if the sample is an unpressurized, non-volatile, non-toxic liquid.
Purge the line and container before sampling. Collect the sample with a smooth bore, not a corrugated hose. Analyze the sample as soon as possible to minimize the risk of contamination.
Evaporation or condensation in the sampling line will alter the composition of the sample so it is not representative of the process. Avoid phase changes by maintaining adequate pressure and temperature during collection. Consult the P-T diagram of the fluid to understand the pressure and temperature needed to prevent phase changes. Never sample a fluid close to its phase change point.
Draw the sample from the middle third of the process line. The faster-moving fluid in the centre of the line is more likely to be well-mixed, while the slower-moving fluid near the wall may be less representative. In particular, avoid the bottom of the line where solids can collect.
Dead legs are spaces in the system with no flow—tees, pressure gauges, and temperature indicators—where solids and old fluid accumulate. Avoid drawing samples downstream of dead legs, and try to install these components downstream of the sampling station so they won’t affect sample integrity.
Mount cylinder supports or bottle shrouds and stirrups in grab sampling stations to securely hold vessels in place. This reduces stress on the quick-connect couplings, increasing their service lives and ensuring operator safety.
Whether using a cylinder or bottle, do not fill the sample container beyond 80 percent of its capacity.
Edmonton Valve & Fitting understands the challenges of processing heavy crude oil in Alberta SAGD operations. Whether you need a new sampling system, an upgrade, or support during troubleshooting, we can help. Our Field Advisors can perform a fluid systems evaluation to determine the best solution to improve performance and reliability for your SAGD operation. We also offer fitting kits and specialty fittings and connections to reduce leak points and minimize rotating equipment downtime.
We make grab sampling stations to order right here in Edmonton. We'll be happy to discuss your specific needs so we can help you understand the applicable industrial fluid management guidelines and make the right design choices for your SAGD operation. To help get you started, download the Grab Sampling Systems Application Guide.
About Tristian McCallion, Custom Solutions Manager, Edmonton Valve