Core scale analysis of low viscosity oil injection in enhancing oil recovery of heavy oil reservoirs

Lyu, Chaohui; Zhong, Liguo; Wang, Qing; Zhang, Wei; Han, Xiao; Chen, Mingqiang; Zhu, Yan; Yang, Jiaying

doi:10.1016/j.energy.2023.127432

Cited by 13 publications

(4 citation statements)

References 26 publications

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“…Further insights from Geng et al focused on well-network densification effects in the Daqing Oilfield, China, revealing that sand body scale and well spacing significantly impact sweep effect of water flooding. Additionally, Zhang et al, Janaghi et al, and Lyu et al proposed that factors such as oil–water viscosity and rock–fluid interface tension play a role in influencing oil displacement efficiency. These studies primarily analyzed the impact of various factors on productivity or sweep effect in TTISR, without delving into its effect on recovery efficiency.…”

Section: Introductionmentioning

confidence: 99%

Factor Analysis and Prediction on Recovery Efficiency in Offshore Sandstone Reservoirs with Thick–Thin Interbedding

Wu,

Yuan,

Gao

et al. 2024

Energy Fuels

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Chinese oil companies have formulated an empirical recovery efficiency model derived from an analysis of over 140 waterflooded oilfields. Initially successful in thick sandstone reservoirs (TSR), the industry has shifted focus to thick−thin interbedded sandstone reservoirs (TTISR). The empirical formula, however, falls short of the desired accuracy (below 60%) in TTISR due to the unique challenges posed, including diverse sand body scales, strong heterogeneity, and easily developed faults. To address these challenges, a comprehensive prediction model (CPM) has been introduced. This model integrates key parameters and refines the predictive capabilities. Noteworthy relationships include the arctangent function correlation between water flooding control (E s ) and well density, as well as the linear relationship between the fault interference coefficient (E f ) and fault block. Reservoir heterogeneity, assessed using Lorenz coefficient L, is intricately incorporated into the CPM. The resulting relationship with the heterogeneity interference coefficient (E L ) follows a quadratic function. The presence of these typical features results in a lower recovery efficiency for TTISR compared to TSR. The CPM unfolds in a three-stage pattern, featuring a concaveascending trend, followed by a period of linear increase, and concluding with a convex-ascending trend as well density grows. This implies that the incremental oil yield diminishes in later stages compared to earlier stages. The effectiveness of the CPM is substantiated by verifying recovery data from the A area of the PL oilfield, achieving an impressive accuracy rate of 91%. Furthermore, the CPM facilitates the swift prediction of well numbers in the B area, showcasing its practical utility. This method not only serves as a robust tool for predicting recovery efficiency but also offers valuable insights for optimizing well numbers in similar oilfield development schemes.

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Section: Introductionmentioning

confidence: 99%

Factor Analysis and Prediction on Recovery Efficiency in Offshore Sandstone Reservoirs with Thick–Thin Interbedding

Wu,

Yuan,

Gao

et al. 2024

Energy Fuels

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“…Steam and solvent injection assisted gravity drainage (ES-SAGD) is a combination of a thermal method with a miscible method (Lyu et. al 2023), where the addition of solvent is a resource used to increase thermal efficiency in relation to steam assisted gravity drainage (SAGD), (Wu et.…”

Section: Introductionmentioning

confidence: 99%

Energy lost study for the steam and solvent assisted gravity drainage process, using reservoirs with Brazilian northeast characteristics

Silva,

Dutra Junior,

Barillas

2024

RSD

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In Brazil, especially in the Northeast, there are still reservoirs containing heavy oils that are being operated by smaller companies that need to produce the fields, reducing production costs. There are different processes to recover heavy oil, one of which is steam and solvent assisted gravity drainage process, which uses two parallel horizontal wells, where the injector is placed above the producer. In this process, a solvent can be used with the steam, to try to reduce the steam rate injected. Process is carried out by injecting a hydrocarbon additive in low concentration together with steam. Steam contributes with the heat to reduce oil viscosity and solvent helps with miscibility, reducing the interfacial tension. The main force acting in this process is gravitational. The mobility of the displaced fluid is then improved, which may imply at an increase of oil recovery. In this study, a semi-synthetic model was analyzed, with average characteristics of the Brazilian northeast, where there is heavy oil in onshore reservoirs. Several simulations were carried out using a commercial oil reservoir thermal simulation software, where the influence of some operational parameters on oil recovery and energy in the reservoir were verified. The main objective of this study was to find a distance between producer and injector wells that allows reducing heat losses to the overburden and underburden when solvent and steam are injected into the process. It was found an optimal vertical distance to improve oil recovery.

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“…For example, light hydrocarbons as a steam additive or steam replacement fluid achieved success in expanding-solvent steam-assisted gravity drainage, vapor extraction, and cyclic solvent injection, wellbore dilution and crude oil transportation, and the dissolve of plugging by hot oil injection [41][42][43]. Consequently, the viscosity, pour point, colloidal content, and asphaltene concentration of heavy oil are significantly reduced with low viscosity oil dilution, improving oil quality of crude oil [44,45]. With the dilution ratio increasing, highly condensed aromatic basic, nonpolar, and acidic asphaltene multilayered films stabilizing emulsions were precipitated once the solvent diluent added beyond the critical dilution concentration [46].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Water-in-Heavy-Oil Droplets Stability and Viscosity Variations in the Dilution Process of Water-in-Heavy-Oil Emulsions by Light Crude Oil

Liu,

Bai,

Guo

et al. 2024

Energies

Self Cite

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The main objective of this study is to put forward effective schemes for alleviating reservoir choke caused by emulsification or Jamin’s effect using the dilution method by light crude oil, as well as sharply increased viscosity. In this study, water-in-heavy-oil (W/O) emulsions with varying water fractions were prepared with heavy oil from Bohai Bay, China. Mixtures of W/O emulsions and light crude oil samples (light oil and light heavy oil) with varied dilution ratio (1:9, 2:8, 3:7) are tested, respectively by the electron microscope and by the rheometer. W/O droplets’ distribution and viscosity variations are obtained to evaluate the emulsion stability and viscosity reduction effects by dilution. Results show that W/O droplets, size distribution range increases with the increase of water fractions. W/O droplets with larger size tend to be broken first in the dilution process. Light oil could reduce emulsions’ viscosity more effectively than light heavy oil. Viscosity reduction mechanisms by dilution could be concluded as the synergistic effects of dissolving heavy components and weakening oil–water film stability. Therefore, light oil is suggested as the optimal one for solving formation plugging. The poor performance of Richardson model is related to the re-emulsification between free water and crude oil favored by light heavy oil, and demulsification favored by light oil. The modified model shows a significant improvement in prediction accuracy, especially for W/O emulsions with large water fractions. This study demonstrates a promising and practical strategy of solving heavy oil well shutdown problems and viscosity increasing by injecting light crude oil in the thermal stimulation.

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Core scale analysis of low viscosity oil injection in enhancing oil recovery of heavy oil reservoirs

Cited by 13 publications

References 26 publications

Factor Analysis and Prediction on Recovery Efficiency in Offshore Sandstone Reservoirs with Thick–Thin Interbedding

Factor Analysis and Prediction on Recovery Efficiency in Offshore Sandstone Reservoirs with Thick–Thin Interbedding

Energy lost study for the steam and solvent assisted gravity drainage process, using reservoirs with Brazilian northeast characteristics

Experimental Study on Water-in-Heavy-Oil Droplets Stability and Viscosity Variations in the Dilution Process of Water-in-Heavy-Oil Emulsions by Light Crude Oil

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