Curing Sand Production Problems with an Aqueous-Based Resin Sand Consolidation Treatment to Optimize the Hydrocarbon Recovery Factor in Austrian Gas Fields

Abstract

Unconsolidated fine formation sand in mature Austrian gas fields jeopardizes production rates and well productivity as increasing water cut enhances fines and sand production to the well bore. The wells peak production was years ago, making well intervention challenging to stay within tight economic limits. Stabilizing the formation rock with aqueous-based resin eliminated sand production and reduced intervention costs to restore target rates. To remain within economical budget levels for the projects, engineering-focused its research on treatments that can be applied rig-less and are suitable for the Austrian gas field reservoir parameters with moderately low temperatures, reasonable interval length, depleted reservoir pressure, and dis-stacked perforations. Team collaboration resulted in proposing a rock consolidation treatment with an Internally Catalyzed Aqueous-Based Emulsion of Curable Epoxy Resin (ICABECER). Thorough planning and pre-job lab testing reduced operational risks, saved costs, and optimized outcomes. The placement technique and displacement precautions resulted in reservoir rock without notable flow path reduction, allowing quickly anticipated target rates to be reached. The treatment outcome confirmed laboratory testing where rock permeability was retained, and only small amounts of residue sand were produced during the cleanup period. The intervention's simplicity allowed using standard field equipment, minimizing cost, and calculating a business case according to tight budgetary constraints. The wells, scheduled for plug and abandon because of pretreatment sand production, demonstrated a stable gas flow with reduced sand content enabling economic gas production. During the cleanup period, sufficient sand was produced to erode surface equipment; however, after the start-up period, sand production was reduced to zero, and the well was returned to the target rate. The technical simplicity of the chemical treatment and a collaboratively engineered and optimized application open new opportunities for the asset to reduce or eliminate sand production without the need for expensive sand control installations at the sand face. Furthermore, the chemical reservoir rock stabilization prolongs well life and increases the overall recovery factor. Reducing environmental impact is also key for resource-saving and sustainable operations in mature fields.