SMS evaluated the efficiency of a produced water solids removal package at a client’s gas plant, comparing desander and desilter vessel performance to confirm adequate separation. SMS deployed a dynamic imaging particle analyser with a high-speed camera and light source flanking a central flow cell. As fluid passes through, it captures suspended particulates; advanced software distinguishes particles from bubbles, providing size, shape, and concentration data.

Challenges:

• Filter Fouling : Solids were fouling filters upstream of recovery systems, especially when new or worked over wells were put online.
• Operational Downtime : Fouling was so acute that filters required cleaning almost every hour, blocking nearly instantly.
• HSE Risks : The presence of H2S necessitated restricted “closed” sampling and testing methodologies.
• Fine Particle Capture : Separation particularly challenging as the target solids were typically very fine particles.

Solution:

1. Validate a Multistage Desanding System : SMS integrated a specialised Canty Image Processing Camera system for high-fidelity solids analysis.
2. Containment Maintenance : To avoid H2S exposure, 500ml pressurised sample bombs were used to collect fluid from the inlet and various outlet stages.
3. Homogeneous Analysis : Samples were decanted into a non-pressurised container equipped with a magnetic stirrer to maintain a uniform suspension.
4. Visual Measurement : A peristaltic pump moved the fluid through a flow cell where a CCD camera captured multiple images for software-based analysis.
5. Multi-Stage Integration : The analysis system monitored performance across three hydrocyclone stages (a DL2 Desander, a DS1 Desilter, and a DS5 Ultra Desilter).

Results:

• No major solids production was observed with most samples being classed as solids free. This conclusion is based on the output analysis of the particle analyser output and through visual inspection of samples.
• There is an increasing upwards trend in volumetric concentration (PPM). As such, this increase may indicate the arrival of small particulates at the terminal.
• It is expected that this increase will continue to trend upwards as the produced solids migrate down the offshore pipeline to the terminal.
• It is therefore recommended to continue with sampling and particle analysis to verify the concentration of solids and their corresponding size characteristics.

Value to Client:

Reduced HSE Risk to Personnel
The use of pressurised bombs and a dedicated analysis procedure minimised the risk of potential exposure to harmful contaminants.

Dynamic Decision Making
Accurate Particle Size Distribution (PSD) data allowed engineers to determine exactly how many cyclone stages were required to protect downstream filters.

Reduced OPEX Cost
Minimal personnel and equipment required on-site.

Repeatable and Reliable

• The trial proved the system could maintain 90% efficiency despite the fine nature of the drilling solids PSD data obtained directly from well flowline upstream of any process / separation.
• Sufficient solids samples captured for representative sample data.