CYCLOTECH SCARPA Separator Continuous and Batch Sand

Proprietary sand removal technology effective in continuous and batch modes

The proprietary CYCLOTECH SCARPA (Sand Conveying And Removal apPAratus) system is designed to remove sand and other solids from a production separator. The technology is effective on either a continuous or batch basis.

The modular system can be retrofitted into existing separators as well as incorporated into new-build plants. The CYCLOTECH SCARPA system can convert a three-phase separator into a true four-phase separator, or a two-phase separator into a true three-phase separator. The system has been developed for both topsides and subsea production separators.

Whether in continuous or batch mode, the CYCLOTECH SCARPA system needs less water than a conventional jetting operation. It also is much less disruptive of the oil/water separation process and removes solids more efficiently. Typically,  a longer flushing period is required in batch mode,  but sand removal operations generally are not time-critical.

Regardless of the amount of sand in the separator, the CYCLOTECH SCARPA system will not allow the discharged sand concentration to rise above a preset peak. This effectively trades operation time for higher availability and reliability.

Conventional Separation Problems

The CYCLOTECH SCARPA system overcomes the problems of conventional methods of removing solids from production separators, such as:

• Allowing the solids to settle in the separator and be removed manually during periodic shutdowns
• Allowing the solids to settle in the separator and be batch-jetted using conventional nozzle or swirling flow-based jetting systems
• Conventional nozzle and swirling flow-sand jetting systems are batch-operated and provide violent, localized agitation of settled solids to allow removal through drain points in the bottom of the vessel or through internal outlet manifolding. These systems can encounter the following problems:
• Remixing: Oil and water phases can remix as well as wide dispersal of the sand, leading to greatly reduced separator performance and significant sand carryover
• Sand Residue: A high proportion of sand residue is generally left behind following the completion of the sand-jetting procedure. This is particularly significant with swirling flow devices as they have a very limited area of influence
• Erosion: Enhanced erosion can occur where these high velocity flows impact the separator wall
• Reliability: The periodic nature and the highly variable solids concentration of the jetting process means that sand progressively builds up within the separator, reducing the effective volume of the water pad. This allows time for deposits to consolidate resulting in enhanced corrosion and fluidization problems
• High Discharge Sand Concentrations: Initial peak sand concentrations in the early stages of a sand jetting operation can be as high as 70%wt. High sand concentrations can cause blockage and sand carryover. These concentration must be avoided to ensure a robust and reliable sand-management solution.

Principle of Operation

The CYCLOTECH SCARPA system is a continuously or batch-operating sand transport and removal system that creates a low-velocity flow. Specialized eductor nozzles send the flow along the bottom of the separator. An eductor is an established solids conveying device that uses a small flow of high-pressure motive fluid to pump a much higher flow, lower-pressure fluid. Their suction from behind/discharge in front format means they can be hydraulically balanced. This generates a dynamic layer of water of comparatively low velocity along the bottom of a separator. This prevents sand from settling and acts as an effective solids transport system with minimal radial (vertical) disturbance.

This hydraulic conveyor can be directed towards one or more discharge outlet nozzles in the bottom of the separator. The flow is then  routed to the suction of an external CYCLOTECH Sandscape unit that provides controlled ejection of the solids from the separator. Where fine solids are encountered, the CYCLOTECH Sandshield can incorporate a profiled baffle. The baffle is located above the eductor nozzle in the downstream section of the vessel to provide extra solids carryover protection.

The Benefits

The CYCLOTECH SCARPA system offers a wide range of benefits, including:

• Lower pumped flow rate requirements. Owing to the CYCLOTECHSCARPA eductor nozzle The fluid within the separator is used as the jetting fluid.  The actual jetting flow rate is approximately three times the pumped jetting flow rate
• No impact on the separator oil/water separation performance
• Maximizes separator water pad residence time as sand is not allowed to build up when in continuous operation mode
• No sand carryover to water and oil outlet streams
• Limits residue sand to less than 5% of total
• Reduced potential erosion and corrosion of separator
• Sand is easier to remove as it has less time to solidify in place. It takes considerably more energy to fluidize sand than to maintain its fluidity once fluidized. The “cementing” of oil-wet sand over time only serves to exacerbate this problem
• Minimizes and controls sand concentrations in outlet pipe work, which optimizes the availability and performance of downstream sand handling equipment. Cyclone-based receiving systems often experience solids carryover if the inlet solids concentration is above ~10%wt
• Limits the size and complexity of the downstream receiving equipment
• In the event of an unplanned process shutdown, high concentration solids will not be in any part of the process minimizing the risk of blockage