Sand injectites are described as an increasingly common occurrence in hydrocarbon reservoirs, in particular in deep-water clastic systems, where they are known to influence reserves distribution and recovery. Seismically detectable injected sand bodies constitute targets for exploration and development wells, and subseismic sand bodies provide excellent intrareservoir flow units that create fieldwide vertical communication through depositionally extensive, low-permeability units. Because sand injectites form permeable conduits in otherwise low-permeability units, they facilitate the expulsion of basinal fluids; hence, they act both as a seal risk as well as mitigating timing and rate of hydrocarbon migration. Injected sand bodies form intrusive traps, which are distinct from structural or stratigraphic traps. Reservoir quality is typically excellent, with a high level of connectivity between sand bodies of all sizes. In a production context, sand injections enhance sweep efficiency but may cause more rapid-than-expected water breakthrough if wells are placed too near injectite complexes. Despite experience from the North Sea, recognition of sand injectites and their significance in hydrocarbon basins globally are at an early stage.