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Insights: How a smart desander can aid sustainability goals

Solids are an unwanted byproduct of hydrocarbon and crude oil production. The presence of solids in the process is a challenge for operators – both in terms of production output and environmental impact.

Traditionally the main approach to solids management was to retain any solids in the reservoir. This approach involves technologies such as downhole screens, which successfully ensure no solids enter the production facility. However, these methods come with some limitations:

• Restricting the solids production downhole also has the knock-on effect of restricting hydrocarbon production output.
• Screens are susceptible to erosion and tend to fail after some years of production.
• Expensive and time-consuming recompletion activities may be required if the screens fail.

This article will look at the ESG issues that arise from solids production and discuss how a smart desander can solve the problem, as well as help with ESG reporting.
ESG concerns regarding solids management and how a smart desander can solve them

When you have solids in a production facility, they accumulate in the production separator. These solids must be removed and cleaned through a multi-stage process. Current technologies, such as screens, are installed downhole to prevent solids from migrating topside. However, screens are designed to let oil (and solids) pass through a pre-determined mesh size while keeping most solids in the reservoir. This means they don’t eliminate solids production completely. With screens, oil contaminated fine particles (smaller than the screen mesh size) are produced to the separator and carry over through the water line. Typically, screens work very well initially but wear out due to erosion after 2-3 years*. Failure to successfully eliminate solids from the production separator directly causes several issues:

1. Oil-contaminated produced water

There are three distinct phases in hydrocarbon production – oil, gas and water. Some reservoirs produce high quantities of water (‘produced water’). To separate the three phases, separators are installed as part of the processing system offshore. The conventional approach requires hydrocarbons to pass through multiple separators to split the phases. A consequence of multiphase separation is that solids accumulate in the production separator. As the solids build-up in the separator efficiency is reduced, solids will carry over and contaminate the produced water.

Currently, operators are required to measure oil concentration in the produced water. If discharged to sea, dispensations only allow for a certain amount. However, this is a cumulative number. Meaning that once it is reached, an operator must stop production and change their approach to ensure that no further oil-coated solids are discharged to sea.
2. Solids in the process facilities being jetted to sea

If solids have already entered the production separator, they must be removed to maintain separation efficiency. From an ESG perspective, the final location of the solids that have been removed is key. While some operators choose to use a reinjection well Case study or have them sent to onshore facilities to be managed, sustainability questions are raised when solids are discharged to sea.

The concentration of oil in produced water that can be discharged to sea is regulated by each country or region. Current methods don’t eliminate oil completely but removing oil contaminated solids from the equation improves the results. The current dispensation for solids discharged to sea is with one weight percent oil appendage in the North Sea**. It may be far greater in other areas. While dispensations exist, they don’t remove the environmental impact that the oil discharged to sea will have – meaning that ESG reporting will still be impacted.

A solution to eliminate the issue of solids being jetted to sea is to use a smart desander. The location of the desander in the process becomes critical as this will ensure no solids enter the process facility. By managing the solids proactively, 99.8% of solids can be eliminated entirely from the process. This means almost no oil-contaminated solids are discharged to sea.
3. Integrity issues, such as erosion

Solids cause erosion and integrity failure in process equipment. This is because the solids cause damage to the piping, valves, and instrumentation. This ultimately exposes offshore operators to HSE risks, such as discharge to the environment i.e. gas leaks or exposure on pressurised parts during replacement operation. As a result, increased reactive maintenance is required to manage erosion on these parts.

To proactively manage erosion, a smart desander can be installed to protect the integrity of the equipment. Applied as a preventative solution, a smart desander actively improves asset integrity.

Further to this, smart erosion software is built into some proprietary desanders, such as the DualFlow 5K. This means that equipment is managed against the threat of erosion, and its lifespan can be maximised through a proactive maintenance program. Erosion software can be used to predict when wear and tear will occur. This means maintenance can be handled in a proactive rather than reactive manner and significantly reduces the need for replacement of parts. To avoid erosion DNV*** has set standards, and solids management experts adhere closely to those guidelines.
4. Manual handling of solids and POB challenges

Conventional methods of solids management require a significant amount of POB and manual handling. This includes activities such as:
• Time-consuming manual sampling of solids at the production separator
• Confined space entry required to clean out solids from the production separator
• Exposure to hazardous chemicals, such as H2s and Benzene, during testing and at the clean out stage

By removing the solids before they enter the production separator, these manual handling activities are no longer necessary. This means that by using a smart desander, such as the DualFlow 5K with remote capabilities, POB can be reduced. The continuous separation abilities offered by the desander can eliminate the need for heavy intervention activities, such as coiled tubing.

This results in a cleaner and safer working environment for all. It also supports the 8th UN sustainability goal**** to promote sustained, inclusive, and sustainable economic growth, full and productive employment, and decent work for all.
How a smart desander directly aids ESG goals

Instead of preventing the removal of solids, a smart desander, such as the DualFlow 5K, actively separates the solids at the surface. When installed, it is normally placed between the well and the separator. The system can be connected to any of the valves on the x- tree.

The DualFlow 5K desander is the first solids management system with automated and remote operation capabilities on the market. The system delivers solids-free production flow while reducing operational costs and eliminating risks related to human error. Its modular, compact design (2x2 meter) design was strategically developed to create a flexible, stackable and compact solution. It weighs less than 10t and can be easily integrated onto a crowded rig floor. Together with 3D rig-ups prior to mobilisations, the DualFlow 5K enables lean planning during the front-end engineering phase. From an ESG perspective, the DualFlow 5K directly addresses each element and guarantees to aid operators reach their sustainability goals.

Link: ESG benefits using FourPhase DualFlow desander on sand producing wells
References

* SPE-38190-MS - Causes of Sand Control Screen Failures and Their Remedies
**OSPAR Decision 2000/03 on the Use of Organic-Phase Drilling Fluids (OPF) and the Discharge of OPFContaminated Cuttings
***DNV-RP-O501 Managing sand production and erosion
****Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all - https://sdgs.un.org/goals/goal8