Insights: The operational benefits of a smart desander

With 70% of wells globally facing potential solids related issues during their lifetime1, the reality for most energy companies is that solids management will be a concern at some point in the well lifecycle. When this happens, a desander is the most efficient method to manage the solids produced in the wellbore.

Desanders come in a variety of guises, ranging from manually operated desanders to highly automated smart desanders. The purpose of this article is to outline the operational benefits of a smart desander, and to demonstrate how it improves upon traditional methods. Throughout, this article we will use the DualFlow 5K PSI as a reference point when discussing smart desanders.

There are many features of a smart desander that directly deliver key operational benefits and efficiencies. Major benefits include increased ESG metrics, enhanced safety and cost control features.

Historically flushing, or the removal of solids, from a manually operated desander carried with it a number of safety risks for operators. This was because every valve was required to be manually manipulated, opening up the possibility for human error. Using automation, it was clear from inception stage that smart desanders would directly remove these concerns.

The design of the DualFlow means that all automated valves are interlocked and safeguarded. An interlocked valve is a valve designed to prevent certain operations or actions from occurring unless specific conditions are met. The safeguarded valves are designed as an additional safety feature; they ensure that the valve operates safely and reliably even under adverse conditions.

The remote-control features of DualFlow directly reduce the need for Personnel on Board (POB). With DualFlow, legacy methods surrounding flushing have also been replaced and updated. In the past, hydrocarbon pressure was used for flushing the system. For example, once solids accumulated in a gas well, the pressure of the gas was used for flushing the solids from the system. This created an opportunity for hydrocarbons to escape into the environment, creating unnecessary emissions.

Solids are a prolific issue in wells across the globe. However, there are instances where energy companies may choose not to put a desander on a well. If a well is choked back, solids will accumulate either in the wellbore or in the separator. When they build up in the separator, there are two traditional methods to address this:

Oil contaminated solids are collected in the separation tanks are in some regions jetted to sea. However, this naturally results in environmental harm as it means the oil contaminated solids cause hydrocarbons to enter the sea.

If there is no jetting system in place, the solids will fill up the separators. These will need to be manually emptied with a shovel and bucket. This approach requires production from the whole platform to be shut down or reduced - making it an expensive option with heightened safety concerns.

If solids accumulate in the wellbore, it can be produced out of the well through a desander. If the well is fully plugged,coiled tubing or another intervention activity is needed. Basic desanders are a solution. However, they only provide one piece to the puzzle and focus solely on a specific part of the solids lifecycle, normally the collection of solids.

By deploying a smart desander on a well, the difference lies in the approach. The technology can handle the full solids lifecycle in one piece of equipment. The DualFlow collects solids, before automatically flushing and disposing of the solids.

Project efficiencies exist when a DualFlow is deployed as ‘solids experts’ manage the hydrocarbon production. The crew that supports the DualFlow are flowback and solids experts with vast experience across many projects impacted by solids.

The DualFlow boasts a sophisticated control system. A key operational benefit of the control system is its ability to be ‘expanded’ easily to incorporate another DualFlow or other auxiliary equipment. Real-world examples include situations where you have another well that requires a desander, or you have a well with an increased flow capacity. From an operational perspective, this provides added project flexibility. To add another DualFlow, a simple software update to the control system is all that is needed. This means that you can control all of the systems involved in the solids management project from the one device, with no further POB required.

This sets the DualFlow apart from competitors, as it means adding extra capacity is just a software update. Whereas for other desanders, a hardware update is needed - with physical technology that links back to a control system. While there is a cost attached to the extra units, the speed, ease and removal of the need for additional POB means that the DualFlow is a cheaper approach in the long run. Less chance of troubleshooting also exists thanks to the user-friendly Human Machine Interface (HMI). Since all elements can connect to one system, it is possible to easily oversee everything on one screen.

Basic desanders with inner liners must optimise the inserts based on the fluid composition and flow rates. They are designed for specific pressures and, should the flow deviate either way, efficiency will drop down. A well is always going to vary, so this means that basic desanders containing multiliners are not operating efficiently in most situations.

The dual cyclone design of the DualFlow is not constrained in this way. The DualFlow has been designed specifically for production optimisation and not just for well testing –historically what multiliners were designed for. Basic well testing requires a desander to capture only 70% of solids and not for optimizing production.

In addition, due diligence is carried out before projects are confirmed. Before installing a DualFlow the flow range is checked by the team. This step is taken to ensure the project falls within the optimal flow range for the technology. Compared with others, the DualFlow system has a very broad flow range.

Enhanced safety flows through every detail of the DualFlow. A key safety area that the DualFlow tackles is erosion. Erosion is a huge concern offshore. Where basic desanders are impacted, is whether a cyclone has a high velocity combined with sand in return. If this is the case, it can cause erosion, and create an erosion hotspot.

To tackle this head on, the DualFlow has been designed with an inner liner consisting of a robust material inside a pressure envelope. Therefore, even if eroded, nothing would give way as there is contingency built in as standard. All typical components, like inner liners, are contained within pressure vessels. Further, the hotspots in the pipe routing are protected by erosion blocks. This means that nothing is exposed to the environment and makes for a much safer system. Taking the fight against erosion one step further, the smart erosion software that is built into the control system provides additional backup against erosion, with full control over ‘potential’ erosion as well. The SMART system that is programmed into the control system can predict maintenance and therefore prevent the need for unnecessarily replacing equipment.

Boosting safety metrics further is the fact that the DualFlow is designed as a closed-loop system. As all valves are automated, the manual turning of valves within the system is no longer necessary. This design feature means there is no exposure to harmful gases. Further, before the flushing of the unit for solids, the unit is depressurised and valves inflow tested by the control system. This is unique to the market. The highly reliable system has a Non-Productive Time (NPT) of 0.07% over 130 000h of operation (link to overview). Meaning uptime is maximised and expensive shut in/issues relating to solids management are minimised.

With no exposure to hazardous chemicals, such as benzene. The closed-loop solution and depressurized system create a safer working environment.

Deploying a smart desander on a project will have a positive impact on ESG reports. This is directly attributed to the reduction in CO2 emissions associated with logistics, equipment and POB. However, emissions are not the only environmental factor that is improved.

No need for dispensations for jetting to sea. DualFlow is the BAT (Best Available Technology) when it comes to removal of solids. Energy companies are required by the Petroleum Safety Authority Norway (PTIL) to choose BAT to reduce environmental harm and emissions(PTIL reference).With the DualFlow, there is no need to jet solids to sea. Previously, technology was the missing link in this process. However, by using the DualFlow, it is possible to remove the need for companies to avail of the dispensations caused by not managing solids correctly. This directly boosts their ESG scores, creating a cleaner environment for all.

Improved water quality: Produced water is industrial waste, which is then subsequently dumped to sea. If the separation of oil contaminated solids is insufficient, like with a legacy desander, it is likely to leave oil traces in the produced water.

When the DualFlow is located upstream of the separator, the cyclonic separation units deliver a proven separation efficiency of 99.8% over a dynamic range of 20 microns to 10mm solids. By removing solids at this point, carryover to the following separators is reduced, and separation efficiency is increased. This directly improves water quality.

Reporting sand (produced sand). For a more environmentally friendly system to exist, strong environmental reports must be carried out. This is where technology can help. Produced solids are an emission that impacts environmental reports. Through the use of data, the DualFlow technology can help operators to gather correct data and properly report their emissions. A requirement by PTIL. This has not been carried out effectively until now and is the first real step towards reducing emissions and ensuring cleaner oil and gas production.