SCARPA^® Sand Jetting System Overview

In either continuous or batch mode, the SCARPA^® system needs less water, is much less disruptive of the oil/water separation process and removes solids more efficiently than a conventional jetting system. Irrespective of the amount of sand in the separator, the SCARPA^® will limit the discharged sand concentration and trade operation time for higher availability and reliability.  Conventional methods of removing solids from production separators comprise:

• Allowing the solids to settle in the separator and remove manually during periodic shutdowns;
• Allowing the solids to settle in the separator and batch jet using conventional nozzle or swirling flow based jetting systems;

Conventional nozzle and swirling flow sand jetting systems are batch operated and provide aggressive, localised 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
  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 localised area of influence. This will lead to a residence time reduction in the water pad and increase the potential for enhanced corrosion;
• Internal Manifolding
  Conventional systems require a high volume of internal pipework manifolds, support structure, branch piping which in many cases can “steal” separation volume from the water pad and disrupt the flow patterns inducing eddies and remixing. This is particularly true of swirling flow devices which have BOTH internal flush water inlet and internal slurry outlet manifold pipework. This also increases the amount of internal support structure required;
• Erosion
  Enhanced erosion can occur where these high velocity flows impact the separator wall;
• 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 carry over and are to be avoided to ensure a robust and reliable sand management solution.

Principle of Operation

Eductors are an established solids conveying device that use a flow of high pressure motive fluid to “pump” a flow of lower pressure suction fluid. Their suction from behind / discharge in front format means that they can be hydraulically balanced to generate a dynamic layer of water of comparatively low velocity along the bottom of a separator. This prevents sand from settling and acts as an "hydraulic conveyor", 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, which is then routed to the suction of an external SANDSCAPE^® unit providing controlled ejection of the solids from the separator. For application with fine solids, a SANDSHIELD louvered profiled baffle can be incorporated above the SCARPA^® sand exit nozzles in the downstream section of the vessel to negate the impact of any radial entrainment of fine solids caused by the change of flow direction as the slurry passes through the exit nozzle at the base of the separator.

 

Benefits

• Low flush water flowrate requirement due to efficient design of SCARPA^® eductor nozzles;
• No impact on the separator oil/water separation performance;
• Maximises separator water pad residence time as sand is not allowed to build-up when in continuous operation mode;
• No sand carry over to water and oil outlet streams;
• Removes in excess of 95% of sand content in batch mode;
• Reduced potential erosion and corrosion of separator;
• Minimises and controls sand concentrations in outlet pipe work which optimises the availability and performance of downstream sand handling equipment. Cyclone based receiving systems often experience solids carry over if the inlet solids concentration is above ~5%wt;
• Limits the size and complexity of the downstream receiving equipment;
• Minimal internal manifolding and supports required which minimises impact on separator flow patterns and eases retrofit issues..
• In the event of an unplanned process shutdown, high solids concentration solids will not be in any part of the process minimising the risk of blockage.

New Builds

Field Testing

Please contact us if :

• You are proposing to install a sand jetting system;
• Your swirling flow based sand jetting system is causing process upsets within the separator or leaves a high sand residue;
• You are having problems with your sand jetting receiving system;
• You wish to stop manually removing sand from your production separator on a regular basis.