A Wholistic Approach for Successful Chemical Sand Consolidation Treatments in High Sand Producing Wells

Abstract

Sand production in oil and gas wells is a challenge which results in operational issues and can ultimately lead to significant losses. Chemical sand consolidation treatments can be a viable alternative to mechanical solutions in certain scenarios and can provide additional recovery benefits over operational sand control methods. This paper examines a chemical sand consolidation option for successful sand control treatments using a North Sea scenario. While the chemistry presented herein has been used in previous scenarios, this paper aims to bridge the gap in treatment success by utilising a wholistic approach from product selection, laboratory qualification, candidate well selection, to field deployment and therefore provide a template for successful chemical sand control deployments. The selected chemistry, which is an oil based organo-silane chemistry aims to increase the maximum sand free production rate with minimal formation damage. Laboratory qualification for the specific field application was conducted using core flood testing on field core. Coreflood tests examined a blank (for baseline damage and sand loss) and a 6% (in diesel) product application to assess formation damage and consolidation. Several diagnostic analyses methods were employed to track product deposition in the core and assess its overall effectiveness in sand reduction. Advanced sand loss tests using reservoir rock was used to quantify consolidation as a percentage of sand loss. Product compatibility with field oil was also assessed. A candidate well was considered and selected based on field experience and success criteria for the chemical. This well is presently shut-in due to excessive sand production and resumption of production is unlikely without some form of intervention. The selected chemistry showed no incompatibility with field condensate and the proposed carrier oil. The baseline Coreflood test showed no evidence of formation damage. When 6% of the product was applied, an acceptable level of permeability loss was recorded. Diagnostic scanning electron microscopy (SEM) images of the core showed a network of the organo-silane product between the sand grains which is responsible for tightly binding the grains together. Baseline sand loss test on crushed reservoir sand showed 86% sand loss and this was reduced to 16% when the sand was treated with 4% of the organo-silane chemistry. Core flood test data combined with diagnostic SEM and sand loss analysis show a potentially effective treatment, with a combination of permeability recovery and the deposition of a sand consolidating coating on the pores that remained in place after multiple pore volumes of brine and oil backflush. These advanced qualification steps paved the way for field treatment design, and for deployment of this product in the selected well. This paper highlights a chemical sand consolidation product which has the potential to improve consolidation and increase the maximum sand free rate for enhanced production. This technology offers the potential to deploy a cost-effective chemical solution to excessive sand production without the requirement for mechanical intervention or well re-completion. Importantly, this paper bridges the critical knowledge gap in product selection and laboratory qualification while highlighting appropriate well candidacy and deployment as critical factors for successful field treatments.