A multicomponent diffusion model for gas charges into oil reservoirs

Pan, Shu; Zuo, Julian Y.; Wang, Kang; Chen, Yi; Mullins, Oliver C.

doi:10.1016/j.fuel.2016.04.055

Cited by 18 publications

(18 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thousands of solutions to the 3D-diffusion equation can be developed depending on the specifics of the diffusion process and the boundary conditions . One diffusive regime that is recurrent in oilfield studies is associated with a case where the concentration of a particular analyte is a fixed constant (sometimes zero) at one boundary and a different value throughout the bulk as the initial condition. − This boundary can be at the oil–water contact or the gas–oil contact depending on the particular case. As time proceeds, the analyte diffuses in accordance with eq .…”

Section: Structure–dynamic Function: Oilfield Reservoirsmentioning

confidence: 99%

Structure–Dynamic Function Relations of Asphaltenes

et al. 2021

Self Cite

View full text Add to dashboard Cite

Asphaltene molecular and nanocolloidal structures have largely been resolved enabling development of structure–function relations of asphaltenes. Atomic force microscopy (AFM) and scanning tunneling microscopy (STM) have provided the first direct molecular structures of many asphaltenes with extension into broader distributions of petroleum pitch. These studies confirmed previous findings of dominant island architecture, moderate-sized polycyclic aromatic hydrocarbons (PAHs) with significant variability in the number and geometry of these rings. The Yen–Mullins model of centroids of molecular and nanocolloidal species of asphaltenes continues to provide foundations for thermodynamic treatment of crude oils, for both bulk and surface. Herein, these asphaltene structures are subject to the stringent test of modeling dynamic function along with static function. Recent results impact evaluation of the molecular management of heavy oil refining for the hydrotreatment process. Roughly, 25,000 reactions were considered acting on ∼17,000 molecules. Reactants and products are probed with ultrahigh-resolution mass spectrometry. In modeling, consistency is required with AFM molecular imaging results of asphaltenes. Excellent agreement is obtained between modeling and experiment, increasing accuracy and robustness. Thermodynamic treatments of asphaltenes in bulk and surface are shown within a structure–dynamic function setting. Two oilfield reservoirs are reviewed which are undergoing different diffusive processes in geologic time. The dynamic model to evaluate both reservoirs couples the simplest solution of the diffusion equation with a quasi-equilibrium state employing the Yen–Mullins model in parts distant from the diffusive process, and excellent agreement between modeling and measurement is obtained. For interfacial tension (IFT), a static model employing the simple Langmuir equation successfully treats solutions of moderate asphaltene concentrations and is consistent with AFM images of asphaltenes. A first-order dynamic correction of time evolution of the IFT can be accounted for considering some molecular polydispersity. Structure–dynamic function relations are established for asphaltenes in three very different arenas.

show abstract

Section: Structure–dynamic Function: Oilfield Reservoirsmentioning

confidence: 99%

Structure–Dynamic Function Relations of Asphaltenes

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…C t , g , R , and T represent the total molar concentration, the gravitational acceleration, the gas constant, and the temperature, respectively. The first term of eq is the molecular diffusion flux as defined previously . The [ B ] matrix of the drag effects can be derived from the Maxwell–Stefan diffusivities: …”

Section: Modeling For Reservoir Fluid Geodynamicsmentioning

confidence: 99%

“…Systematics in RFG processes are evident, and it is now routine to use an RFG perspective to evaluate reservoirs. Published case studies include reservoir compartmentalization, , and its inverse reservoir connectivity and fluid equilibration, ,,,− diffusive gradients in oilfields, − asphaltene migration via density inversions, − heavy oil and tar formation, − heavy oil equilibration, ,− biodegradation with a single reservoir charge of oil, biodegradation with multiple charges of oil, , biodegradation with spill-fill reservoir filling, and water washing of crude oil, , among many other concerns …”

Section: Introductionmentioning

confidence: 99%

Reservoir Fluid Geodynamics: The Chemistry and Physics of Oilfield Reservoir Fluids after Trap Filling

et al. 2017

Self Cite

View full text Add to dashboard Cite

Oilfield reservoirs exhibit a wide array of complexities that have great impact on the efficiency of oil production. Major challenges include delineating overall reservoir architecture and the distributions of the contained fluids. Reservoir crude oils consist of dissolved gases, liquids, and dissolved solids (the asphaltenes); the corresponding compositional variations and phase transitions within reservoirs greatly impact production strategies and economic value. Standard workflows for understanding reservoir (rock) architecture are subsumed in the discipline “geodynamics”, which incorporates the initial rock depositional setting and subsequent alterations through geologic time to yield the present-day reservoir. However, reservoir fluids are not generally treated in such a systematic manner. Petroleum system modeling provides the timing, type, and volume of hydrocarbon fluids that charge into reservoirs. However, there is little treatment regarding how these fluids change after filling the reservoir. A significant limitation had been the lack of thermodynamic treatment of asphaltenes in reservoir crude oils. Consequently, projecting reservoir fluid properties away from the wellbore has been problematic. “Reservoir fluid geodynamics” (RFG) is the newly formalized discipline that incorporates changes in the distributions of reservoir fluids and phase transitions over geologic time. A key enabling advance is the recently developed ability to treat asphaltene gradients in oilfield reservoirs using the Flory–Huggins–Zuo equation of state (FHZ EoS) with its reliance on the Yen–Mullins model of asphaltenes. In addition, in situ downhole fluid analysis in oil wells provides accurate vertical and lateral fluid gradients in reservoirs in a cost-effective manner. Thermodynamic equilibrium can now be recognized; equilibrated fluids imply connected reservoirs, meaning a single flow unit. Disequilibrium fluid gradients imply ongoing or recent fluid processes in geologic time. The analysis of 35 oilfields (with more than 100 oil reservoirs) has allowed the identification of various reservoir fluid geodynamic processes. Some processes, such as biodegradation, have long been studied; nevertheless, even in these cases, inclusion of the thermodynamic modeling yields accurate predictions of distributions of key fluid attributes. Many other RFG processes are elucidated herein and are shown to impact major reservoir concerns for production. The resulting fundamental understanding of the physics and chemistry of these RFG processes enables measurements made at the wellbore to be used as a basis for accurate prediction of fluid properties throughout the reservoir.

show abstract

“…Adsorbed PHs, including volatiles and oil or light non-aqueous phase liquid (LNAPL), undergo natural attenuation processes, including biodegradation by the intrinsic soil microbial community. Mullins and the team developed multicomponent diffusion models based on field data and column studies to simulate both oil and gas charges and degradation in soil, which are simple and provide excellent guidance to diffusion over geologic time (Zuo et al, 2015;Pan et al, 2016). Many studies have focused on the impacts on the soil ecosystem when oil pollution occurs (Uzoije and Agunwamba, 2011;Nudelman et al, 2002;Everett, 1978;Mercer and Cohen, 1990;Williams et al, 2002Williams et al, -2003Barakat et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…Physical impacts include clumping soil particles into plaques, decreasing porosity, enhancing resistance to penetration, and increasing hydrophobicity (Uzoije and Agunwamba, 2011). Chemical impacts include boosting soil organic matter by creating anaerobic conditions that eliminate most aerobic microorganisms and reducing cation exchange capacity (Pan et al, 2016). (Everett, 1978;Nudelman et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

The Key Factors for the Fate and Transport of Petroleum Hydrocarbons in Soil With Related in/ex Situ Measurement Methods: An Overview

Wang

Cheng

Naidu

et al. 2021

Front. Environ. Sci.

View full text Add to dashboard Cite

Once petroleum hydrocarbons (PHs) are released into the soil, the interaction between PHs and soil media is dependent not only upon the soil properties but also on the characteristics of PHs. In this study, the key factors influencing the interactions between PHs and soil media are discussed. The key factors include: 1) the characteristics of PHs, such as volatility and viscosity; and 2) soil properties, such as porosity, hydraulic properties and water status, and organic matter; and 3) atmospheric circumstances, such as humidity and temperature. These key factors can be measured either ex-situ using conventional laboratory methods, or in situ using portable or handheld instruments. This study overviews the current ex/in situ techniques for measuring the listed key factors for PH contaminated site assessments. It is a tendency to apply in situ methods for PH contaminated site characterisation. Furthermore, handheld/portable Fourier transform infrared spectroscopy (FTIR) instrument provides tremendous opportunities for in-field PH contaminated site assessment. This study also reviewed the non-destructive FTIR spectroscopy analysis coupling with handheld FTIR for in-field PH contaminated site characterisation, including determining the concentration of total PH, dominant PH fractions and soil key properties for PH transport modelling.

show abstract

A multicomponent diffusion model for gas charges into oil reservoirs

Cited by 18 publications

References 18 publications

Structure–Dynamic Function Relations of Asphaltenes

Structure–Dynamic Function Relations of Asphaltenes

Reservoir Fluid Geodynamics: The Chemistry and Physics of Oilfield Reservoir Fluids after Trap Filling

The Key Factors for the Fate and Transport of Petroleum Hydrocarbons in Soil With Related in/ex Situ Measurement Methods: An Overview

Contact Info

Product

Resources

About