Internally Catalyzed Aqueous-Based Emulsion of Curable Epoxy Resin Sand Consolidation Treatment Extends Economical Production in Austria's Mature Oil and Gas Fields.

Abstract

Sand production is one of the major challenges for mature fields in Austria. With increasing water production, the severity of the sand migration augments, leading to the shut-in of the wells. Eliminating or substantially reducing sand production at the sand face is the most viable option to continue hydrocarbon production. The project's target was to research and apply a technically sound solution readily available in Europe, with reduced HSSE risks and little economic impact. To control intervention costs, it was decided to favor sand control solutions for rig-less interventions. Collaboratively, the teams evaluated formation rock consolidation with the help of an internally catalyzed aqueous-based emulsion of curable epoxy resin (ICABECER). Laboratory testing demonstrated the system's suitability for the target wells and confirmed the viability of the planned operations scheduled to deploy the treatment via coiled tubing (CT), as well as limiting concerns about permeability reduction. Finally, field operations of the application, clean-up, and production face were monitored and evaluated. The major concern when using resins to agglomerate sand grains in a reservoir rock is that the pore space is reduced, jeopardizing the rock permeability. Laboratory testing confirmed that the permeability of the rock can be retained. Due to the simplicity of the intervention, the treatment could be deployed with standard equipment keeping it within the budgetary constraints of very mature fields. To mitigate possible risks, wells having challenging production backgrounds and scheduled for plug and abandon were selected. In these wells, previous conventional sand control measures failed, such as gravel pack installations or attempting to produce sand and separate it on surface. Post-job results demonstrated that the in-situ consolidation generated a reduction of sand content to a level allowing production of the wells. During the clean-up period of the gas well, sufficient sand was produced to erode the choke. After the well start-up period, sand production was eliminated, and the well was returned to the target rate. Monitoring of solid contents in the flow and the evaluation of coupons confirmed the suitability of the technique to establish flow with acceptable risks contributing to economic success. The cost-effective ICABECER chemical treatment, along with the methodology, opens new opportunities for the asset to prolong well life and increase the overall recovery factor from the reservoir. Technical simplicity and the reduced environmental impact of the chemicals are key for resource-saving and sustainable operations in mature fields.