Managing sand production from poorly consolidated formations is essential for maintaining wellbore productivity and integrity, minimizing damage to screens and tubulars and ensuring a safe condition. Fines migration can also impair production rates.
CURRENT CONSOLIDATION TECHNOLOGY HAS ROOM FOR IMPROVEMENT
The challenge is to safely and cost-effectively mitigate the issues caused by sand production without impairing the formation. This is thrown further into sharp relief in the current climate of the persistently low oil price, and needs to be achieved at an acceptable cost.
Using traditional mechanical intervention or chemical sand control consolidation to remediate wells and optimize production in poorly consolidated formations can be a lengthy, ineffective, and sometimes cost-prohibitive, process.
Widely-employed mechanical sand control measures often limit the production rate, while current chemical methods, generally based on the use of resins, are problematic for a number of reasons including placement issues, excess permeability reduction and lack of reversibility.
A NEW GENERATION OF CHEMICAL CONSOLIDATION
Building on its pioneering enzyme-mediated sand consolidation, Cleansorb is developing a new generation of chemical consolidation systems for use in-situ across a broad range of upstream applications, including:
- Increasing unconfined compressive strength (UCS) of the rock matrix
- Tackling fines migration
- Remediation of failing gravel packs
- Remediation of deteriorating propped fracs
The new generation systems are based on the controlled deposition of minerals, particularly calcium carbonate.
Now, as work on the technology moves further from the concept phase into the development and field trial stage and in line with its mission to devise high performance reservoir technologies that are safe to use and environmentally benign, Cleansorb is looking for interested partners to participate in field trials and collaborate on the commercialization of these groundbreaking chemistries.
MAXIMIZE ASSET VALUE, MINIMIZE RISK
This technology has enormous potential, and will deliver significant benefits for operators looking for innovative ways to complete wells and increase production: ensuring they safely and cost-effectively maximize wellbore integrity, reduce production downtime, avoid expensive repairs, and mitigate risk.
Overcoming the limitations of current systems, it uses novel decarboxylation reactions to deposit calcium carbonate from an aqueous solution at a controlled rate: achieving cementation between sand grains with no requirement for enzymes, catalysts or oxidizing agents.
One new system has recently been evaluated in independent laboratory tests carried out on behalf of an operator. The aim was to stop fines migration in a core material that was prone to this. The effectiveness of the consolidation system to prevent fines migration was successfully demonstrated. This was achieved without any significant reduction in permeability of the cores.
The tests, conducted at a European university, used optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results demonstrated the new chemical consolidation technology prevented fines migration from poorly consolidated sandstone by the controlled, in-situ cementation of sand grains.