Origin and distribution of calcite concretions in Cretaceous Wall Creek Member, Wyoming: Reservoir-quality implication for shallow-marine deltaic strata

Cements are confined to the middle parts of the sandstone body, suggesting that initial preferential flow paths become sites for later cementation and reduction of porosity. This will potentially reduce overall reservoir volumes and may impede fluid flow in both horizontal and vertical directions. The 3D distribution of concretion must be taken into account in reservoir modeling and fluid flow simulations to avoid overestimation in recovery factors.