Carbon Footprint and Energy Intensity Assesment For Improving water Injection Through Bulk Gels: Casabe Field Case

Summary Casabe oilfield is in the Colombian Middle Magdalena basin. Since 1980, oil recovery through water injection process has been carried out successfully in part of this field. Several factors can negatively affect waterflooding processes. One of them is the reservoir heterogeneity that causes the injected water to have a fast advance towards producers through high permeability or fractured areas. This causes water cut increment and large unswept oil volumes, causing a low volumetric efficiency and consequently, a low recovery factor. Channeling control and deep chemical conformance treatments have been implemented in 10 Colombian fields to improve and modify the injection profiles near and far from the injector well, increasing the volumetric sweep efficiency to increase the oil recovery factor. Between 2021 and 2022, gel injection treatments were performed in 18 patterns in Casabe field. The gel injection was carried out in five (5) stages, increasing the polymer concentration from 2500 to 6000 ppm, to guarantee the injectivity and mobility of the gel within the channel, before increasing its consistency and elasticity. The injection pressure limit was set without exceeding the formation fracture pressure. Oil production increased by 300 KBO, improving carbon and energy intensity. The contribution of each stage of production / injection in the total carbon footprint of crude oil production was calculated after and before (baseline production) gel injection. The carbon footprint of both cases was calculated for three years. The results show that the carbon intensity of the crude oil baseline production in the 18 patterns is 16.3 kg CO2-eq/BO (barrels of oil) on average and decreased to 15 kg CO2-eq/BO in waterflooding post conformance and energy intensity reduced from 21.7 kWh/BO to 17.3 kWh/BO. It led to more than 700 t of CO2-eq being avoided and improved the energy performance of waterflooding by more than 20%. These changes were attributed mainly to energy use optimization in crude oil lifting.