Summary
This article presents results of laboratory and field testing regarding the
effectiveness of an improved, one-component, low-viscosity resin-consolidation
system. The system is designed to stabilize or strengthen the unconsolidated
formation sand surrounding a wellbore and to overcome the effects of cyclic
loading, while minimizing reduction of original permeability. Treatment-fluid
volumes, overflush fluid, and the chemical composition of the consolidation
material were found to directly impact the consolidation performance and the
retained permeability of the treated formation sand. The treatment renders
formation fines immobile so that migration and plugging do not occur.
This study determined that application of a consolidation material
containing a specific solvent chemistry for clay-laden sands resulted in
excellent strengths, even at high clay contents. This finding indicates that
the consolidation material was drawn onto the mineral surfaces, resulting in
minimal loss in effective porosity. Scanning electron micrographs of the
consolidated-core material clearly revealed the entrapment of fines as the
consolidation material formed a thin film on the mineral surfaces, causing
little damage to the porosity and permeability of the formation.
Results of field testing indicate that the consolidation treatment
effectively stopped the production of formation sand and fines while
maintaining the production of the wells at desirable flow rates. The technique
provides a very attractive alternative to conventional sand-control completions
in lower quality reservoirs, as well as an effective through-tubing completion
alternative.
Introduction
When a wellbore or a perforation tunnel is introduced into a friable sand
formation, a plastic zone develops, and formation failure may follow.
Production and cyclic loading are significant reasons why the plastic-failure
zone expands into the formation. Formations considered soft or poorly
consolidated are often plagued by formation-sand production. Production of
formation sand or fines can result in plugged gravel packs, screens,
perforations, tubulars, surface flowlines, and surface equipment. In extreme
cases, lost production, or even wellbore failure, may result.
© 2006. Society of Petroleum Engineers
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History
- Original manuscript received:
18 June 2004
- Revised manuscript received:
13 October 2005
- Manuscript approved:
1 November 2005
- Version of record:
20 August 2006
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