Enhanced Oil Recovery Patents – 2018/2019 CO2 Injection
Carbon Dioxide injection has been used effectively for enhanced oil recovery from reservoirs, since at high pressures it forms a miscible mixture with oil, increasing the volume of the oil, and allowing it to dislodge additional material from the rock as it pushes through the formation. CO2 injection is often used in a process known as water alternated with gas (WAG), where the gas and water are alternately injected into the well, thereby mitigating the tendency of the lower density gas to migrate to the top of the reservoir and bypass other sections. Interest in CO2 injection continues, not simply in conventional oil reservoirs, but in unconventional reservoirs as well. Not surprisingly, aspects of CO2 injection find their way into patent claims.