Integration of reservoir particle size distribution data into unconsolidated reservoir management: applications in permeability prediction, drilling fluid design, sand control, and formation damage assessment

Unconsolidated sandstone reservoirs present significant reservoir management challenges due to potential well-operation-induced formation damage and sand production. Reliable reservoir particle size distribution (PSD) characterization is critical for addressing these challenges; however, practical workflows demonstrating the integration of PSD data across multiple reservoir management applications remain limited. This study presents a comprehensive workflow for the effective use of PSD data in the management of an unconsolidated gas-bearing laminated sandstone reservoir. PSD characterization was performed using sieve analysis and laser particle size analysis, as well as less commonly used techniques such as thin section imaging, microscopic view and scanning electron microscopy (SEM). Core samples, sidewall cores, drill cuttings, debris, solids and precipitation products, and proppants were evaluated. Representative PSD data were subsequently applied to permeability estimation, drilling fluid design, cased hole gravel pack completion design and formation damage evaluations. A strong correlation was established between measured air permeability from confined core plugs and permeability calculated from PSD data with coefficient of determination reaching up to 0.9, enabling permeability prediction in un-cored intervals. Conventional core samples provided the most representative PSD measurements, while sidewall cores and drill cuttings consistently underestimated the particle size. PSD-based drilling fluid optimization identified properly sized calcium carbonate as an effective bridging agent, resulting in the formation of high-quality filter cakes and minimal drilling-induced formation damage. PSD analysis was also used to optimize screen and proppant selection for cased hole gravel pack completions. Field observations indicated effective sand control, with no significant sand production observed during the monitored production period. In addition, PSD characterization of precipitates generated during formation damage lab tests and well operations provided valuable insights into scaling, precipitation and permeability impairment mechanisms. The results demonstrate that representative PSD data can serve as a fundamental basis for reservoir characterization, drilling optimization, sand control design, and formation damage assessment in unconsolidated reservoirs. By integrating PSD data across multiple stages of reservoir development and management, this study establishes a practical workflow that may serve as a guideline for similar unconsolidated reservoirs.