Effect of fracture on production characteristics and oil distribution during CO2 huff-n-puff under tight and low-permeability conditions

Bai, Hao; Zhang, Qiliang; Li, Zhaomin; Li, Binfei; Zhu, Di; Zhang, Liaoyuan; Lv, Guojun

doi:10.1016/j.fuel.2019.02.107

Cited by 71 publications

(31 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…And the experimental procedures were as follows: 8 1. And the experimental procedures were as follows: 8 1.…”

Section: Methodsmentioning

confidence: 99%

“…In this study, the experiments were carried out at 338 K and 14 MPa, respectively. And the experimental procedures were as follows: 8 1. Proceed to the experiments, the core was placed in an oven and dried at 393K for 2 days.…”

Section: Methodsmentioning

confidence: 99%

“…[1][2][3] Low-permeability oil reservoirs have insufficient natural energy because of their poor physical properties and low fossil pressure, which has resulted in the lack of natural productivity. [6][7][8] After the fracturing construction, CO 2 is injected into formation to dissolve with the oil. [6][7][8] After the fracturing construction, CO 2 is injected into formation to dissolve with the oil.…”

Section: Introductionmentioning

confidence: 99%

“…4,5 Accordingly, artificial fractures need to be formed through hydraulic fracturing to enhance the fluid flowability in low-permeability oil reservoirs. [6][7][8] After the fracturing construction, CO 2 is injected into formation to dissolve with the oil. As a consequence, more oil can be produced and oil recovery can be enhanced by reducing oil viscosity, expanding oil volume, and extracting the light components of crude oil.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Experimental investigation on influencing factors of CO₂huff and puff under fractured low‐permeability conditions

Bai

et al. 2019

Energy Science & Engineering

Self Cite

View full text Add to dashboard Cite

The fracture system is a vital component of fractured low‐permeability reservoirs. The presence of fractures can improve reservoir flow capacity and injected carbon dioxide (CO2) utilization, thus leading to higher oil recovery. In this study, the effects of the presence of fracture, fracture morphology, soaking time, and CO2 injection volume on CO2 huff and puff were investigated through 11 low‐permeability cores with different properties. The experimental results indicated that the presence of fractures enhanced cyclic oil recovery and increased the effective cycle numbers during CO2 huff and puff in low‐permeability cores. Moreover, compared with low‐permeability cores without fractures, ultimate oil recovery of CO2 huff and puff was risen up by ~11% in fractured cores. Longer soaking time was conducive to enhancing ultimate oil recovery of CO2 huff and puff in fractured low‐permeability cores, but the excessive soaking time had little effect on ultimate oil recovery. Meanwhile, excessive CO2 injection volume did not significantly improve the performance of CO2 huff and puff, but it did reduce the CO2 utilization. Moreover, gravity caused the produced oil to deposit on the bottom surface of the blowout end of the fracture, which made oil recovery of the core with a horizontal fracture slightly higher (~7%) than that of the core with a vertical fracture. In addition, variation in the intersection angle of fractures had little effect on ultimate oil recovery of CO2 huff and puff in fractured low‐permeability cores. It, however, did change the conductivity of the entire core, thus affecting oil recovery during the first two cycles remarkably.

show abstract

“…And the experimental procedures were as follows: 8 1. And the experimental procedures were as follows: 8 1.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental investigation on influencing factors of CO₂huff and puff under fractured low‐permeability conditions

Bai

et al. 2019

Energy Science & Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

“…The mode is conducted by a cyclical operation with three distinct procedures: (1) Inject gas into the inclined reservoir; (2) shut-in wells and sufficient time is allowed for gas to migrate up-dip by gravity segregation; (3) the gas injection well is converted to produce until the production well is gas flooded. The production mode is similar to the Huff 'n' Puff process [27][28][29][30]. Based on the production mode, Kimbrell et al [31] designed a sand pack model with the gas injection (oil production) well in the middle to conduct an attic oil development experiment.…”

Section: Introductionmentioning

confidence: 99%

A Novel Assisted Gas–Oil Countercurrent EOR Technique for Attic Oil in Fault-Block Reservoirs

Jiang

et al. 2020

Energies

View full text Add to dashboard Cite

As the mature oil fields have stepped into the high water cut stage, the remaining oil is considered as potential reserves, especially the attic oil in the inclined fault-block reservoirs. A novel assisted gas–oil countercurrent technique utilizing gas oil countercurrent (GOC) and water flooding assistance (WFA) is proposed in this study to enhance the remaining oil recovery in sealed fault-block reservoirs. WFA is applied in our model to accelerate the countercurrent process and inhibit the gas channeling during the production process. Four comparative experiments are conducted to illustrate enhanced oil recovery (EOR) mechanisms and compare the production efficiency of assisted GOC under different assistance conditions. The results show that WFA has different functions at different stages of the development process. In the gas injection process, WFA forces the injected gas to migrate upward and shortens the shut-in time by approximately 50% and the production efficiency improves accordingly. Compared with the basic GOC process, the attic oil swept area is extended 60% at the same shut-in time condition and secondary gas cap forms under the influence of WFA. At the production stage, the WFA and secondary gas cap expansion form the bi-directional flooding. The bi-directional flooding also displaces the bypassed oil and replaced attic oil located below the production well, which cannot be swept by the gas cap expansion. WFA inhibits the gas channeling effectively and increases the sweep factor by 26.14% in the production stage. The oil production increases nearly nine times compared with the basic GOC production process. The proposed technique is significant for the development of attic oil in the mature oil field at the high water cut stage.

show abstract

Study on Profile Control and Water Shut‐Off Performance of Interpenetrating Network Polymer Gel Composite System in Shallow Low Temperature Fractured Oil Layer

2019

View full text Add to dashboard Cite

In order to solve the problem/address the issue of oil saturation reduction in the near‐wellbore region of low‐temperature fractured reservoir in Fuyu oilfield, it is especially necessary to carry out in‐depth profile control plugging technology research. In this paper, composite system of particle plugging agent and new interpenetrating network gel were optimally designed, and the non‐fractured cores and fractured cores were used for plugging experiment and oil displacement, the in‐depth profile control mechanism of the composite system was obtained. The results show that the gelation time of the new interpenetrating network gel system can reach 6–7 hours under low temperature conditions (30 °C), with strong shear resistance and viscosity retention. The waterflooding efficiency of fractured core is lower than that of non‐fractured core. After injection of different profile control system, improved recovery efficiency of fractured core is larger than that of non‐fractured core, but the ultimate oil recovery of fractured core is still smaller than that of non‐fractured core. The gelation effect and strength of the composite system are better than that of new interpenetrating network gel agent. The addition of the expanded particles in the system greatly enhances the overall strength and anti‐interference ability. This study can provide theoretical guidance for in‐depth profile control of low temperature fractured reservoirs.

show abstract

Effect of fracture on production characteristics and oil distribution during CO2 huff-n-puff under tight and low-permeability conditions

Cited by 71 publications

References 28 publications

Experimental investigation on influencing factors of CO₂huff and puff under fractured low‐permeability conditions

Experimental investigation on influencing factors of CO₂huff and puff under fractured low‐permeability conditions

A Novel Assisted Gas–Oil Countercurrent EOR Technique for Attic Oil in Fault-Block Reservoirs

Study on Profile Control and Water Shut‐Off Performance of Interpenetrating Network Polymer Gel Composite System in Shallow Low Temperature Fractured Oil Layer

Contact Info

Product

Resources

About

Effect of fracture on production characteristics and oil distribution during CO2 huff-n-puff under tight and low-permeability conditions

Cited by 71 publications

References 28 publications

Experimental investigation on influencing factors of CO2huff and puff under fractured low‐permeability conditions

Experimental investigation on influencing factors of CO2huff and puff under fractured low‐permeability conditions

A Novel Assisted Gas–Oil Countercurrent EOR Technique for Attic Oil in Fault-Block Reservoirs

Study on Profile Control and Water Shut‐Off Performance of Interpenetrating Network Polymer Gel Composite System in Shallow Low Temperature Fractured Oil Layer

Contact Info

Product

Resources

About

Experimental investigation on influencing factors of CO₂huff and puff under fractured low‐permeability conditions

Experimental investigation on influencing factors of CO₂huff and puff under fractured low‐permeability conditions