A Laboratory Study of the Effect of Installation of Reticulated Expandable Liners on Sand Production in Weakly Consolidated Sandstone Formations

摘要

Using novel physical model experiments involving large size andstone specimens, an investigation was conducted on the effect of reticulated expandable liners with various perforation sizes on the rate of sand production. A series of experiments were conducted using Hollow Cylinder Samples (HCS) completed with no internal support and with support using reticulated liners, or stiffener. The main objective of the investigation performed was to observe whether sanding could occur in wellbores supported by stiffeners and if so, what would be the role of the mesh opening size to the grain size on the onset and severity of sanding. Quantification of the effects of supporting the wellbore by the stiffener on wellbore productivity is another objective of the paper. The experiments on weakly-consolidated sandstones showed that the stiffener is effective in preventing any shear failure around the wellbore. Under excessive drawdown / depletion, however, pore collapse was seen as a potential failure mecha nism in the material. Despite this, much less sanding occurred compared to an openhole case and this improvement was attributed to (1) an enhanced grain-to-grain friction resistance due to higher effective stress state at the wellface, and (2) reduced loss of sand face integrity in a state where the material undergoes pore collapse. Other useful findings include the role of the stiffener on increasing the mean effective stress around the wellbore which in turn reduces the porosity and permeability of the material in that region due to compaction. This is in spite of the fact that dilation due to shear failure can substantially increase the permeability and porosity of the material within the near vicinity of the well opening and perforation tunnels. As a result of material compaction, the overall porosity and permeability of the sample showed a declining trend during the experiments. However, this gradual decline of permeability can be compensated by applying a greater drawdown with little increase of the potential of sanding. The findings of this study provide a deeper insight into therole of reticulated liners as a cost effective measure for sand control. Such potential applications will be discussed in this paper.