This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 173092, “Chemical Sand Consolidation: Developing a Strategic Capability Across a Wide Portfolio,” by Dana Aytkhozhina, SPE, David Mason, SPE, Raul Marulanda, Bukola Orekha, Josue Villesca, and Paul Beaumont, BP, prepared for the 2015 SPE/IADC Drilling Conference and Exhibition, London, 17–19 March. The paper has not been peer reviewed.
Chemical sand consolidation works by pumping chemicals downhole to strengthen the formation and stop sanding. In most cases reported in the industry, chemical consolidation has been used in short production intervals (less than 100 m). Our approach was to develop a laboratory program to test various industry chemicals and to achieve a good understanding of how these can be applied. Candidate wells were matched to chemicals to identify which system or systems would fit best.
Sand Remediation: Mechanical and Chemical Options
In theory, chemical consolidation should be operationally attractive and a fairly low-cost option to reduce sanding and increase production from the problem well. However, because of negative experiences with early solvent-based resin systems, it is still often viewed as a temporary measure to extend hydrocarbon production for a period of time before recompletion or well abandonment. Early-generation consolidation systems had challenging health, safety, and environmental profiles; required several overflushes to restore permeability and induce curing; and carried a risk of significantly damaging the permeability and productivity of the well.
In the last decade, however, several types of novel chemical treatments have become commercially available. To access the potential of novel chemical treatments to present a real alternative to mechanical remediation methods, an extensive laboratory-testing program was conducted. The aim was to establish the effectiveness of chemical treatments in increasing maximum sand-free rate (MSFR), to confirm that consolidation will not cause any significant loss of permeability, and to identify conditions for optimal performance of each treatment.
During the initial testing phase, identified as Level 1, the standard test matrix was deployed: Sandpacks of two permeabilites (low and high) were treated at two different temperatures (the majority of the well stock falls into the temperature envelope between the selected values). In each of four tests, permeabilities of the sandpacks before and after treatment and the formation damage associated with consolidating the sandpacks were established. In total, six different treatments designed for matrix sand consolidation were tested during the Level 1 phase. In addition, three chemicals designed for proppant-flowback remediation were tested with a similar approach.
Level 1 testing resulted in a deeper understanding of treatment performance under a range of reservoir properties. After the Level 1 phase was completed, more-extensive laboratory testing was conducted on the highest-performing products from Level 1 to complete qualification for field application.
