Evaluation of In-Situ Generation of Nitrogen Gas for Foam Applications using Two Salt Solutions

2021 ◽  
Author(s):  
Zuhair AlYousef ◽  
Ali Altaq ◽  
Muhammad Almajid ◽  
Lyla Almaskeen
Keyword(s):  
Porous Media ◽  
Apparent Viscosity ◽  
Oil And Gas ◽  
Salt Solutions ◽  
Nitrogen Gas ◽  
Conformance Control ◽  
Foaming Agent ◽  
Foam Generation ◽  
Eor Processes ◽  
Mobility Reduction

Abstract Foams are used in many oil and gas applications including conformance control during EOR processes, fracturing, and acidizing operations. Foams are defined as dispersions of gas bubbles into a continuous liquid phase. Typically, foams are generated when an injection gas such as nitrogen, carbon dioxide, or flue gas is mixed with an injection fluid containing a foaming agent. This method, however, requires a gas source to be present for foams to be generated. The objective of this study is to evaluate a new alternative technique for foam generation using two salt solutions. Nitrogen gas is generated as a result of the reaction of the two salt solutions at specific conditions. This generated nitrogen gas is then used for foam generation in porous media. The foam generated using the two salt solutions is tested in a microfluidic device (rock-on-a-chip) to study the gas mobility reduction in porous media. A Foam rheometer apparatus is also used to measure foam apparent viscosity when the two salt solutions are mixed with a foaming agent. The results are compared with those obtained when nitrogen gas is injected into the system independently in the absence of the two salt solutions. Results reveal that the amount of added salts significantly impact the produced nitrogen volume. Additionally, the test conditions especially the temperature, significantly impacts the reaction rate. The rate of nitrogen gas generation is directly proportional to the temperature when tested at 25-80°C. In addition, experiments demonstrate that the foams generated using the two salt solutions reaction have almost identical characteristics as those produced when nitrogen gas is injected into the foam rheometer apparatus independently. Both methods generate the same foams with comparable foam apparent viscosity. In the microfluidic system, the foam obtained using the two salt solutions in the presence of a foaming agent shows excellent resistance to gas flow and subsequently exhibit large gas mobility reduction. This experimental study, for the first time, confirms the ability of the two salt solutions reaction to generate nitrogen gas spontaneously upon contact under certain conditions. The generated gas is used to generate foams in the presence of a foaming agent. This newly proposed technique of foam generation could significantly impact many oil and gas operations including conformance control during EOR processes, fracturing, and acid stimulation operations.

scholarly journals A Generalized Capillary Imbibition Model for Porous Media in Tight Reservoirs

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiyuan Wang ◽  
Zhengming Yang ◽  
Yunhong Ding ◽  
Wei Lin ◽  
Ying He ◽  
...  
Keyword(s):  
Porous Media ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Oil And Gas ◽  
Water Injection ◽  
Capillary Imbibition ◽  
Gas Reservoirs ◽  
Oil And Gas Development ◽  
Tight Reservoirs ◽  
Tight Porous Media

Capillary imbibition models have been widely studied in oil and gas development field over the past decades. However, the existing models applied to the tight reservoirs rarely take fluid flow resistance and apparent viscosity into account. To investigate the capillary imbibition characteristics of fluids in tight porous media, a generalized capillary imbibition model considering the flow resistance and apparent viscosity of fluids in tight porous media is derived. By comparing with the results of other capillary imbibition models and experimental data, the derived capillary imbibition model is verified. In addition, compared with the conventional capillary imbibition models, the derived capillary imbibition model is more consistent with the experimental results and has a wider applicability. The imbibition distance of water in tight reservoirs can also be obtained using the derived capillary imbibition model, which will facilitate the study on water injection development in tight oil and gas reservoirs.

scholarly journals Fracture Initiation Model of Shale Fracturing Based on Effective Stress Theory of Porous Media

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yuwei Li ◽  
Dan Jia
Keyword(s):  
Porous Media ◽  
Mechanical Characteristics ◽  
Oil And Gas ◽  
Elastic Anisotropy ◽  
Special Kind ◽  
Fracture Initiation ◽  
Propagation Mechanism ◽  
Stress Theory ◽  
Unconventional Oil And Gas ◽  
Initiation Pressure

Unconventional oil and gas are important resources of future energy supply, and shale gas is the focus of the development of unconventional resources. Shale is a special kind rock of porous medium, and an orderly structure of beddings aligned in the horizontal direction where causing the strong elastic anisotropy of shale is easy. A new model has been established to calculate the fracture initiation pressure with the consideration of mechanical characteristics of shale and the anisotropic tensile strength when judging rock failure. The fracture initiation model established in this paper accurately reflects the stress anisotropy and matches well with the actual situation in porous media. Through the sensitivity analysis, the results show that σv/σH, Ev/EH, υv/υH, m/s, and A/B have a certain impact on the tangential stress when the circumferential angle changes, and there is a positive relationship between the initiation pressure and the above sensitive factors except for A/B. The results can provide a valuable and effective guidance for the prediction of fracture initiation pressure and fracture propagation mechanism under special stratum conditions of shale.

Foam Generation in Porous Media

2002 ◽  
Author(s):  
P.A. Gauglitz ◽  
F. Friedmann ◽  
S.I. Kam ◽  
W.R. Rossen
Keyword(s):  
Porous Media ◽  
Foam Generation

A FRACTAL SCALING LAW BETWEEN TORTUOSITY AND POROSITY IN POROUS MEDIA

Fractals ◽  
2020 ◽  
Vol 28 (02) ◽  
pp. 2050025
Author(s):  
PENG XU ◽  
LIPEI ZHANG ◽  
BINQI RAO ◽  
SHUXIA QIU ◽  
YUQING SHEN ◽  
...  
Keyword(s):  
Porous Media ◽  
Chemical Engineering ◽  
Oil And Gas ◽  
Scaling Law ◽  
Morphological Characteristics ◽  
Fractal Model ◽  
Statistical Characteristics ◽  
Scale Model ◽  
Reservoir Water ◽  
Flow Through

Hydraulic tortuosity is one of the key parameters for evaluating effective transport properties of natural and artificial porous media. A pore-scale model is developed for fluid flow through porous media based on fractal geometry, and a novel analytical tortuosity–porosity correlation is presented. Numerical simulations are also performed on two-dimensional Sierpinski carpet model. The proposed fractal model is validated by comparison with numerical results and available experimental data. Results show that hydraulic tortuosity depends on both statistical and morphological characteristics of porous media. The exponents for the scaling law between tortuosity and porosity depend on pore size distribution and tortuous fractal dimension. It has been found that hydraulic tortuosity indicates evident anisotropy for asymmetrical particle arrangements under the same statistical characteristics of porous media. The present work may be helpful to understand the transport mechanisms of porous materials and provide guidelines for the development of oil and gas reservoir, water resource and chemical engineering, etc.

Modeling Foam Displacement with the Local-Equilibrium Approximation: Theory and Experimental Verification

SPE Journal ◽  
2010 ◽  
Vol 15 (01) ◽  
pp. 171-183 ◽  
Author(s):  
Q.. Chen ◽  
M.G.. G. Gerritsen ◽  
A.R.. R. Kovscek
Keyword(s):  
Porous Media ◽  
Local Equilibrium ◽  
Population Balance ◽  
Entrance Region ◽  
Balance Model ◽  
Population Balance Model ◽  
Gas Bubble ◽  
Foam Generation ◽  
Foam Model ◽  
Bubble Sizes

Summary The gas-mobility-control aspects of foamed gas make it highly applicable for improved oil recovery. Gas-bubble size, often referred to as foam texture, determines gas-flow behavior in porous media. A population-balance model has been developed previously for modeling foam texture and flow in porous media. The model incorporates pore-level mechanisms of foam-bubble generation, coalescence, and transport. Here, we propose a simplified foam model to reduce computational costs. The formulation is based on the assumption of local equilibrium of foam generation and coalescence and is applicable to high- and low-quality foams. The proposed foam model is compatible with a standard reservoir simulator. It provides a potentially useful, efficient tool to predict foam flows accurately at the field scale for designing and managing foamed-gas applications. There are three main contributions of this paper. First, foam-displacement experiments in a linear sandstone core are conducted. A visualization cell is employed to measure the effluent foam-bubble sizes for a transient flow as well as to estimate the in-situ foam-bubble sizes along the length of the core during steady-state flow. These appear to be the first measurements of foam-bubble texture in the entrance region of a core. Additionally, the evolution of aqueous-phase saturation is monitored using X-ray computed tomography (CT), and the pressure profile is measured by a series of pressure taps. Second, the population-balance representation of foam generation by gas-bubble snap-off is modified to extend the capability of the population-balance approach to predict foam-flow behaviors in both the so-called high-quality and low-quality regimes. Third, a simplified population-balance model is developed and implemented with the local-equilibrium approximation. Good agreement is found between the experimental results and the predictions of the simplified model, with a minor mismatch in the entrance region.

Experimental Study of Foam Generation, Sweep Efficiency, and Flow in a Fracture Network

SPE Journal ◽  
2016 ◽  
Vol 21 (04) ◽  
pp. 1140-1150 ◽  
Author(s):  
M. A. Fernø ◽  
J.. Gauteplass ◽  
M.. Pancharoen ◽  
A.. Haugen ◽  
A.. Graue ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Fractured Reservoirs ◽  
Surfactant Solution ◽  
Fracture Network ◽  
Mobility Control ◽  
Fractional Flow ◽  
Sweep Efficiency ◽  
Foam Generation ◽  
Gas Mobility ◽  
Mobility Reduction

Summary Foam generation for gas mobility reduction in porous media is a well-known method and frequently used in field applications. Application of foam in fractured reservoirs has hitherto not been widely implemented, mainly because foam generation and transport in fractured systems are not clearly understood. In this laboratory work, we experimentally evaluate foam generation in a network of fractures within fractured carbonate slabs. Foam is consistently generated by snap-off in the rough-walled, calcite fracture network during surfactant-alternating-gas (SAG) injection and coinjection of gas and surfactant solution over a range of gas fractional flows. Boundary conditions are systematically changed including gas fractional flow, total flow rate, and liquid rates. Local sweep efficiency is evaluated through visualization of the propagation front and compared for pure gas injection, SAG injection, and coinjection. Foam as a mobility-control agent resulted in significantly improved areal sweep and delayed gas breakthrough. Gas-mobility reduction factors varied from approximately 200 to more than 1,000, consistent with observations of improved areal sweep. A shear-thinning foam flow behavior was observed in the fracture networks over a range of gas fractional flows.

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