Solids production in the gas industry remains one of the main challenges that needs to be addressed to avoid integrity issues or loss of production. Even though most problems are found at the well and usually do not exist beyond the separator, sometimes solids are detected in the transportation lines or even where gas is stored.
In recent times, our customers are seeing an increasing challenge with solids in their underground gas storage (UGS) facilities. The gas received and injected is normally clean of any debris, however when the “gas season starts” (usually around the October/November part of the year) the need for solids production monitoring becomes an essential element of production capacity. The main concern is not necessarily how much solids are produced but knowing when this happens and how big of a risk an integrity breach poses. Most of the time the mitigation strategy for UGS is usually decreasing the gas flow or even shutting down the facility completely. The key goal for an UGS facility is to make sure that it gets to the end of the gas extraction season (usually March or April the following year) without any safety incidents and at the same time producing as much as possible at an optimal level. In this situation, deploying the appropriate monitoring technology that evaluates both risk and accurately measure presence of solids, becomes one of the important decisions to make.
Sand Acoustic Monitor
One of the best tools to evaluate the production of solids is by deploying a Roxar™ Sand Acoustic Monitor (SAM) – a sensor which is mounted on the bend of a pipeline and is able to differentiate distinct signature noises of sand particles hitting the inner wall. This type of technology can be installed even in remote storage facilities as it requires a reduced footprint in terms of power and communication, making it the preferred choice for almost all solid detection needs. It can be configured and calibrated to perform everything from simple solid production alerts to being able to evaluate the quantity of solids produced in g/s with an accuracy of +/- 5%. The action based on the information received ranges from flagging a certain storage for closer inspection to reducing gas flow due to separation capacity.
Retrievable Sand Erosion Probe
Once the monitoring of solids is in place, the next logical step forward is to assess the risk the solids production poses. The best tool for that is Roxar Electrical Resistance (ER) probe technology. The intrusive multi-element design can capture any traveling solids inside the pipeline and translate the resulting erosion rate into an erosion risk meter. From a mitigation perspective, this translates into managing the production well to match both separation capacity but also integrity targets.
Non-Intrusive Corrosion and Erosion Monitoring System
This brings us to the third element of monitoring which is focused on integrity and being able to safely operate the storage until depletion. Rosemount™ Wireless Permasense non-intrusive UT wall thickness measurements focused on erosion hot spots can complete the cause/effect picture but can also be used to plan inspection and maintenance routines.
Plantweb Insight Inline Corrosion Application
Being able to integrate all three types of data (solids production detection and quantification, erosion risk, and erosion impact) into a single data dashboard but also being able to share it in relevant data metrics to different stakeholders (e.g. production engineer, maintenance manager) is the definition of actionable data and would enhance all sides of production for an underground storage facility. The Emerson Plantweb™ Insight software platform with its versatility and metric/dashboard customization capabilities can easily create actionable data by integrating all types of measurement coming from all types of sources and creating the much sought-after situational context.
Obtaining UGS operational efficiency and profitability is not the hardest goal to achieve given the current market context, rather keeping that level year by year and doing it without compromising safety and storage integrity is the more difficult task. Emerson, leveraging its wide portfolio of products and experience, is more than able to help its UGS customers by implementing the appropriate monitoring technology connected to a comprehensive software platform and delivering actionable data. With all the monitoring needs being taken care of the only remaining item is to make sure the underground storage is full and that the delivery needs are met in time.
