Sand production and the sand control technique selected to mitigate or eliminate it can have a critical influence on the performance of horizontal wells in gas storage reservoirs. A completion that provides adequate sand control is usually required, but an overly conservative completion design can have an unnecessary, negative consequence on gas well productivity and injectivity. The selection of the appropriate sand control design depends on the characteristics of the reservoir formation, the in-situ stress state, the maximum and minimum values of the reservoir pressure during gas storage operations, the drawdown pressure, the near-well fluid saturations, the well trajectory and the capacity for handling sand in the well tubulars and surface facilities.

This paper reviews the principal causes of sand production from borehole and perforation collapse, and demonstrates the application of commercial software programs for assessing sand production risks. The influence of formation damage, compressible and non-Darcy gas flow effects, reservoir pressure changes and rock strength reduction due to cyclic loading will be illustrated. Additional risks, such as exceeding the fracture breakdown pressure in the reservoir during injection, or collapsing weak, interbedded shale strata that are locally penetrated by the horizontal well, are also described. Numerical geomechanical modelling techniques suitable for more complex material behaviour and fluid flow phenomena are also described, as well as a novel procedure for estimating initial produced sand volumes.

Several field examples are presented, illustrating results for reservoirs ranging from relatively strong rocks, in which no sand control is required, to poorly cemented sandstones which require gravel-packed or screened completions.

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