Experimental study on residue oil distribution after the supercritical CO2 huff-n-puff process in low permeability cores with Nuclear Magnetic Resonance (NMR)

Du, Dongxing; Li, Chaofan; Song, Xiakai; Liu, Qingjie; Ma, Nianhao; Xin-rong, Wang; Shen, Ya; Li, Yingge

doi:10.1016/j.arabjc.2021.103355

Cited by 27 publications

(7 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This research found that the recovery factor increased with increasing soaking time, but the final recovery factor increment is limited. This finding is supported in the following study from other research work [39].…”

Section: Introductionsupporting

confidence: 87%

Experimental Study on Polymer flooding-assisted CO2-based Cyclic Solvent Injection Process for Enhancing Oil Recovery in Heavy Oil Reservoirs

Zeyu,

Lin,

et al. 2023

Preprint

View full text Add to dashboard Cite

CO2-based cyclic solvent injection (CSI) process is widely applied for enhancing heavy oil recovery in petroleum industry. However, the rapid decrease in oil production after 2 or 3 cycles will be encountered in previous CO2-based CSI research due to the reduction in oil saturation near the producer. Therefore, five groups of experiments were conducted using a 1D sand-pack model to explore the EOR potential in CO2-based CSI process via polymer injection assistance to increase oil saturation around the producer. Two polymer flooding assistance modes were investigated, including injection after every cycle and injection after the cycle when oil recovery factor is less than 1%. Two slug size of polymer flooding assistance were evaluated, including volume of 1 PV and the volume of total liquid produced in the previous CO2-based CSI process. Three different concentration of polymer solution, 0ppm, 250ppm and 1000ppm, were also studied. The experimental results show that the oil recovery factor is significantly improved after polymer flooding assistance during the CO2-based CSI process. The polymer flooding assistance effectively push the remaining oil toward the producer and form an oil bank for the following CO2-based CSI section, increasing the oil saturation near the producer. The highest recovery factor (70.72%) is achieved in polymer flooding-assisted CO2-based CSI process when polymer (1000 ppm concentration) was injected after the cycle that oil recovery factor is less than 1%, and the slug size equals to the volume of total liquid produced in the previous CO2-based CSI section. The economy evaluation results show the assistance mode of conducting 1000ppm polymer flooding assistance after each cycle has the lowest material cost. Moreover, a field application of this novel technique was designed and implemented in eastern China, and a significant increase in daily oil production and decrease in water cut were achieved. In conclusion, this work innovatively combines the CO2-based CSI process with polymer flooding, and a polymer flooding-assisted CO2-based CSI technology for heavy oil reservoirs is proposed. Experimental results in both the laboratory and field reveals the excellent EOR potential and economic benefit of this novel technology for heavy oil reservoirs.

show abstract

Section: Introductionsupporting

confidence: 87%

Experimental Study on Polymer flooding-assisted CO2-based Cyclic Solvent Injection Process for Enhancing Oil Recovery in Heavy Oil Reservoirs

Zeyu,

Lin,

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…During the early stage, the crude oil at the injection end of the core is mainly produced. The remaining oil increases with the distance from the inlet increasing, and this is because the mass transfer and the diffusion between the CO2 and the crude oil require a long period of time [49]. At the same time, we found that the residual oil at the core inlet increased in the later cycles.…”

Section: Resultsmentioning

confidence: 61%

The Displacement Behaviors of Different Pore-Scales during CO2 Flooding and Huff-n-Puff Processes in Tight Oil Reservoirs Using Nuclear Magnetic Resonance (NMR)

Yang,

Huang,

et al. 2023

Processes

View full text Add to dashboard Cite

Injecting CO2 into tight oil reservoirs is a potential approach for enhanced oil recovery (EOR) and CO2 sequestration. However, the effects of different pore-scales on EOR are poorly understood, and this has a significant impact on recovery. In this paper, a pore size correction model based on X-ray computerized tomography (CT) and nuclear magnetic resonance (NMR) was developed in order to establish the relationship between the pore radius and the transverse relaxation time. Different pore-scales are divided according to the cumulative distribution characteristics of the transverse relaxation time (T2). CO2 flooding and huff-n-puff experiments were conducted to investigate the dynamic displacement behaviors in different pore-scales. The results indicate that there are three pore-scales: micropores (T2 < 0.3 ms), intermediate pores (0.3 ms < T2 < 100 ms), and macropores (100 ms < T2). However, there are also pseudo-sweep pores (PPs), equilibrium pores (EPs), and sweep pores (SPs) in the intermediate pores, depending on whether crude oil has been produced. Interestingly, the pressurization process causes some crude oil in the large pores to be squeezed into small pores. The recovery of CO2 huff-n-puff (19.75%) is obviously lower than that of CO2 flooding (51.61%). Specifically, it was observed that the micropores (−8%) and the pseudo-sweep pores (−37%) have a negative impact on oil recovery, whereas all pore-scales exhibit positive effects during CO2 flooding. In addition, it was found that the critical pore radiuses of CO2 flooding and huff-n-puff were 2.61 ms (0.15 µm) and 25 ms (1.5 µm), respectively, in the experiments, and that there is also more oil remaining in the macropores and the sweep pores during CO2 huff-n-puff. These results provide a deeper understanding of the displacement behaviors of different pore-scales in tight oil reservoirs.

show abstract

“…The findings suggested that large pores contributed most to promoting oil production. Oil in the small pores was hardly produced with large amounts of residual oil trapped, as shown in [35]. Li et al (2019) carried out huff-n-puff, engaging shale cores with the injection media of CO 2 and N 2 , respectively.…”

Section: Introductionmentioning

confidence: 99%

Study on Oil Composition Variation and Its Influencing Factors during CO2 Huff-n-Puff in Tight Oil Reservoirs

et al. 2023

View full text Add to dashboard Cite

With immense potential to enhance oil recovery, CO2 has been extensively used in the exploitation of unconventional tight oil reservoirs. Significant variations are observed to occur in the oil’s composition as well as in its physical properties after interacting with CO2. To explore the impacts of oil properties on CO2 extraction efficiency, two different types of crude oil (light oil and heavy oil) are used in CO2 huff-n-puff experiments. Moreover, numerical simulation is implemented to quantitatively inspect the impacts of different influencing factors including production time, reservoir pressure and reservoir temperature on physical properties as well as on the oil composition variation of the crude oil. The findings of the experiments demonstrate that, whether for the light oil sample or for the heavy oil sample, hydrocarbon distribution becomes lighter after interacting with CO2 compared with the original state. In addition, it is also discovered that the hydrocarbon distribution variation is more significant for the light oil sample. The findings of the numerical simulation suggest that production time, reservoir pressure and reservoir temperature have significant impacts on the produced oil composition and properties. The hydrocarbon distribution of the oil becomes lighter with the increasing of production time and formation pressure, while it becomes heavier with the increasing of reservoir temperature. At the very beginning of the oil production, the properties of the produced oil are worsened. Compared with the original state, the oil density and viscosity are 25.7% and 200% higher, respectively. It is suggested that viscosity reducers are added into the well to improve the oil properties in this period. With the continuing of the oil production, the oil properties are continuously promoted. At the end of the simulation time, the oil density and viscosity are 3.5% and 15.1% lower compared with the original oil, respectively. This paper has great significance for the implementation of CO2 huff-n-puff in tight oil reservoirs.

show abstract

Experimental study on residue oil distribution after the supercritical CO2 huff-n-puff process in low permeability cores with Nuclear Magnetic Resonance (NMR)

Cited by 27 publications

References 42 publications

Experimental Study on Polymer flooding-assisted CO2-based Cyclic Solvent Injection Process for Enhancing Oil Recovery in Heavy Oil Reservoirs

Experimental Study on Polymer flooding-assisted CO2-based Cyclic Solvent Injection Process for Enhancing Oil Recovery in Heavy Oil Reservoirs

The Displacement Behaviors of Different Pore-Scales during CO2 Flooding and Huff-n-Puff Processes in Tight Oil Reservoirs Using Nuclear Magnetic Resonance (NMR)

Study on Oil Composition Variation and Its Influencing Factors during CO2 Huff-n-Puff in Tight Oil Reservoirs

Contact Info

Product

Resources

About