Polymer Enhanced Foams to Improve Oil Recovery in Qatari Reservoirs. Increasing Foam Flow Understanding & Developing an Innovative Technology for Water & Gas Conformance in Heterogeneous Reservoirs
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In a world context where the demand in energy and in hydrocarbons resources increases year by year, and oil prices are low, it is essential to develop new low cost technologies to improve the recovery ratio of hydrocarbons worldwide. Indeed, today the base of the oil production is mainly constituted by mature fields (70 % of oilfields are more than 20 years old) and the share of mature fields is still to grow in the future. Since the end of the 1980s and more particularly since the beginning of the year 2000s, different Enhanced Oil Recovery (EOR) and Improved Oil Recovery (IOR) technologies were optimized and applied in the field. A high potential has been attributed to EOR as a mean to increase recovery and improve sweep efficiency in oil reservoirs. Nevertheless, EOR requires important investments and its performance can be strongly reduced in highly heterogeneous reservoirs. The objective of this project entitled â Polymer Enhanced Foams to Improve Oil Recovery in Qatari Reservoirsâ is to develop innovative foam formulations to optimize and improve the recovery in mature oilfields set in Qatar. Porous media studies will be carried out to improve the understanding of Polymer-Enhanced-Foam flow in carbonate reservoirs. Numerical models of Polymer Enhanced Foam behavior in porous media will be used to develop a methodology to upscale Foam numerical models from the laboratory scale to the full-field Qatari reservoirs scale. An additional target will be to limit the effects of produced fluids on the environment (reduce water and gas recycling and treatment) by developing a new foam technology strengthened by polymers for the correction of water and gas injection profiles (reservoir conformance) in heterogeneous hydrocarbons reservoirs. These technologies can also improve existing EOR schemes such as Water Alternating Gas (WAG) injection. Foams present specific characteristics which make them very attractive for reservoir conformance applications: - Foam naturally forms in high permeability zones largely swept by gas and water that do no longer provide oil production, while diverting injection fluids towards oil rich zones that were left unswept; - Foam strength and permeability reduction is proportional to permeability of the porous media, which makes foams of great interest to treat matrix and fractured reservoirs where permeability contrast is high between unswept reservoir and preferential channels; - Foams is unstable and breaks if oil saturation is high, so the foam does not block oil bearing zones; - Foams are a temporary blocking agent which limits the risk of blocking wellbore regions permanently when zone isolation is not possible (i.e. long horizontal drains). In the existing literature, foams have been mainly used to improve gas injection profiles, but recently potential to improve water injection has also been studied (Hernando, et al, 2016). The addition of polymer increases the viscosity of the aqueous phase and slows down the drainage of foam films or lamella increasing the foamâ s stability and its permeability reduction in porous media. The present project presents both a scientific and a technological challenge, providing improved understanding of polymer-enhanced flow in porous media, developing advanced reservoir simulation schemes, and producing a high-performance foam for conformance under heterogeneous Qatari reservoir conditions (temperature, pressure, salinity, oil viscosity...). Five partners (Texas A&M University at Qatar.........
