Application of flue‐gas foam in thermal‐chemical flooding for medium‐depth heavy oil reservoirs

Abstract

Heat loss in wellbore during steam injection is considerable due to the deep burial of medium‐depth heavy oil reservoirs, leading to a low steam quality in the bottom of well. As for hot water flooding, the mobility ratio between oil and water is small, which decreases oil recovery. Flue‐gas foam assisted thermal‐chemical flooding is a new method for heavy oil reservoir. Compared to hot water flooding, flue‐gas foam assisted thermal‐chemical flooding can decrease oil viscosity, achieving higher sweep efficiency. However, the combined mechanisms of all the injected components have not been studied systematically. In this work, the role of CO2, viscosity reducer and hot water for oil viscosity reduction and distribution characteristics of residual oil were studied using the numerical simulation methods. Results show that although the percentage of viscosity reduction contribution of viscosity reducer can be as high as 60%, only wider range of this effect can help recover more remaining oil effectively. In the presence of flue‐gas foam, CO2 and viscosity reducer can decrease oil viscosity in the upper and bottom layers of the reservoir, respectively. Two parameters of the area proportion of removed‐oil (ARRO) and the average removed‐oil saturation (SDRO) are defined. It is believed that both ARRO and SDRO are quite small for the hot water flooding, which is assisted by viscosity reducer. The flue‐gas foam can obviously expand the area of removed‐oil, but the average removed‐oil saturation is slightly lower. The combination of flue‐gas foam and viscosity reducer is a promising displacement method.

Facile Synthesis of Functionalised Hyperbranched Polymers for Application as Novel, Low Viscosity Lubricant Formulation Components

“…Recently, there have been a number of examples of branched polymers being used to modify viscosities in lubricant and heavy oil applications, including transportation [35][36][37][38][39]. However, polymer addition has been reported to lead to a reduction in oil/lubricant quality [40,41]. In this respect, the importance of the oil solubility of these polymers has been shown to be important in minimising these issues and also improving traditional additives [42].…”

Investigation of Nanoclay-Surfactant-Stabilized Foam for Improving Oil Recovery of Steam Flooding in Offshore Heavy Oil Reservoirs

“…8 Wang et al carried out physical simulation experiments to prove that the flue gas foam-assisted steam flooding technology had a good ability to improve the recovery of steam flooding. 9,10 It is well-known that the foam thermal stability is the key problem in steam flooding to improve the sweep efficiency. In general, the polymer has been widely used for foam stabilizers to improve the foam stability.…”

“…Besides, the foam also has the selective blocking characteristics, which can block the big pores rather than the small pores and block the water layers rather than the oil layers. , It is indicated that the foam is an ideal high-temperature profile control and flooding agent, and thus, foam is widely used in steam flooding for improving heavy oil recovery. , The experimental results by Bagheri and Clark showed that foam-assisted steam flooding could achieve good results, which verified the application prospect of foam-assisted steam flooding in the Canadian thermal recovery project being developed in northwest Alberta . Wang et al carried out physical simulation experiments to prove that the flue gas foam-assisted steam flooding technology had a good ability to improve the recovery of steam flooding. , …”

Experimental Study on the Cyclic Steam Stimulation Assisted by Flue Gas Under Shallow Heavy-Oil Reservoir Conditions: Optimization of the Steam-Flue Gas Ratio

“…The main mechanisms of steam flooding include reducing the viscosity of crude oil, steam distillation, thermal expansion of crude oil, and steam drive (Fan et al, 2019). Currently, steam flooding is a large-scale industrial application of thermal recovery technology, which is an effective method to increase the oil recovery factor after CSS with achieved results (Dong et al, 2019;Du et al, 2019;.…”