The most attractive option to increase hydrocarbon recovery from the Brent and Statfjord reservoirs (Brent field, North Sea) is a gradual decrease of the reservoir fluid pressure. To provide laboratory data upon which estimates of the resulting reservoir compaction and surface subsidence could be made, we performed uniaxial compaction experiments at room temperature and in-situ stress conditions. Experimental observations suggest that the reloading of core samples to in-situ stress conditions closed coring-induced microcracks. Most Brent samples (porosity 6% to 30%) showed a compressibility that was constant with increasing effective stress (i.e., linear compaction) and increased with porosity. There was 30% to 75% strain recovery during unloading and an average permanent shortening of about 0.7%. Some high-porosity (25% to 30%) Brent samples showed a relatively high uniaxial compressibility that increased with stress (nonlinear compaction). Nearly all the Statfjord samples showed nonlinear compaction. The Statfjord samples from Core A, with a porosity of 8% and 20% to 22%, showed about 45% strain recovery upon unloading and an average permanent shortening of 0.6%. The Statfjord samples from Core B (porosity 22% to 28%) showed only 24% strain recovery and an average permanent shortening of 3.2%. Microscopy analysis of the Brent samples revealed no evidence for a compaction-induced change in microstructure. In contrast, the Statfjord samples from Core B (22% to 28% porosity) displayed numerous intergranular and transgranular cracks in quartz and feldspar grains, which probably triggered grain sliding and grain rotation. These inelastic brittle mechanisms, which occur together with elastic deformation of the load-bearing grain framework, seem dominant in high-porosity (Statfjord-type) sandstones and should be incorporated into predictive models of production-induced compaction of quartz-rich reservoir rock.