Mesoscale structure, mechanics, and transport properties of source rocks’ organic pore networks

Berthonneau, Jérémie; Obliger, Amaël; Valdenaire, Pierre-Louis; Grauby, Olivier; Ferry, Daniel; Chaudanson, Damien; Levitz, Pierre; Kim, Jae Jin; Ulm, Franz‐Josef; Pellenq, Roland J.‐M.

doi:10.1073/pnas.1808402115

Cited by 46 publications

(44 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nanopores with the radii < 5 nm do not increase gas flow rate, and do not increase the overall permeability of the source rock. Additionally, experimental and numerical results show the creation of the highly permeable channels close to larger nanopores (Berthonneau et al, 2018). Thus, the small nanopores must be connected to the larger nanopores as the continuous gas feeders, creating a multiscale network of pores and microcracks that together sustain long-term production from a horizontal gas well.…”

Section: Resultsmentioning

confidence: 99%

A Physics Based Model of Enhanced Gas Production in Mudrocks

Haider¹,

Patzek²

2020

Proceedings of the 8th Unconventional Resources Technology Conference

View full text Add to dashboard Cite

The URTeC Technical Program Committee accepted this presentation on the basis of information contained in an abstract submitted by the author(s). The contents of this paper have not been reviewed by URTeC and URTeC does not warrant the accuracy, reliability, or timeliness of any information herein. All information is the responsibility of, and, is subject to corrections by the author(s). Any person or entity that relies on any information obtained from this paper does so at their own risk. The information herein does not necessarily reflect any position of URTeC. Any reproduction, distribution, or storage of any part of this paper by anyone other than the author without the written consent of URTeC is prohibited.

show abstract

Section: Resultsmentioning

confidence: 99%

A Physics Based Model of Enhanced Gas Production in Mudrocks

Haider¹,

Patzek²

2020

Proceedings of the 8th Unconventional Resources Technology Conference

View full text Add to dashboard Cite

show abstract

“…Stimulation techniques, such as horizontal drilling and hydraulic fracturing, could create fracture and to engender hydrocarbons migration to the wellhole [6,7]. Yet, the impressive progress of horizontal drilling and hydraulic fracturing technologies in the field of petroleum development have improved access to oil and gas from source rock formations [2,3,[8][9][10]. As a result, the proportion of hydrocarbons derived from unconventional reservoirs have been on the rise, and the knowledge about these reservoirs is gradually abundant [7,11].…”

Section: Introductionmentioning

confidence: 99%

“…From a traditional perspective, the multitype tests could provide insight into the interplay among pore structures, lithology, physical property electric character, and hydrocarbon-bearing conditions [29][30][31][32]. In contrast to other unconventional reservoirs such as tight sandstone and tight carbonate reservoirs, the hydrocarbons which generated within organic agglomerates (kerogen) play a significant role [8,23,33]. Therefore, from a geochemical perspective, the pore structure data may show quantitative correlation with organic matter parameters.…”

Section: Introductionmentioning

confidence: 99%

Geochemical Properties and Pore Structure Control on Oil Extraction of Shale

Liu

et al. 2021

Lithosphere

View full text Add to dashboard Cite

Despite geochemical properties and pore structures for shale oil extraction, the interplay among shale chemistry, pore network, and hydrocarbon movability still is an open question. Here, by using hybrid experimental methods, including backscatter scanning electron microscopy, X-ray diffraction, adsorption/desorption isotherm, and nuclear magnetic resonance, we provide a general characteristic of geochemistry and pore structures of Chang 7 (C7) shale in Ordos basin and figure out how these properties impact the shale oil extraction. Our results confirmed that the C7 shale in Ordos basin could be divided into three types based on the mineral components with various pore structures, and the proportion of the pores that radius below 4.8 nm (from adsorption branch) or 3.8 nm (from desorption branch) play a dominant role in the determination of pore size distributions. The kerogen index that is derived from maceral types was the most significant geochemical indicator; high kerogen index was corresponding to large pore volumes and surface areas, but low pore diameters. We identify the pore structure mechanism—mesopores predominantly or micropores abundantly (increase free fluid index) and absence of inorganic or organic pores (decrease free fluid index)—responsible for the oil extraction capability and show that the unmovable fluid stained in the voids would lead to the slow rate decay of the curves, which caused the nonsignal disturbance. Our results demonstrate the powerful control of maceral components and pore diameters on shale oil extraction and show the markedly different flow behavior of various types of shale.

show abstract

“…Contacts between the organic matter and the inorganic matter in these shales are the surfaces of mechanical weakness that are stimulated after hydrofracturing and expose nanopores to high permeability pathways. Berthonneau et al [29] showed that the largest pores are the potential crack areas at those weakness surfaces. These cracks create multiscale connectivity even at the pore scale.…”

Section: Introductionmentioning

confidence: 99%

The Key Factors That Determine the Economically Viable, Horizontal Hydrofractured Gas Wells in Mudrocks

2020

View full text Add to dashboard Cite

We assemble a multiscale physical model of gas production in a mudrock (shale). We then tested our model on 45 horizontal gas wells in the Barnett with 12–15 years on production. When properly used, our model may enable shale companies to gain operational insights into how to complete a particular well in a particular shale. Macrofractures, microfractures, and nanopores form a multiscale system that controls gas flow in mudrocks. Near a horizontal well, hydraulic fracturing creates fractures at many scales and increases permeability of the source rock. We model the physical properties of the fracture network embedded in the Stimulated Reservoir Volume (SRV) with a fractal of dimension D < 2 . This fracture network interacts with the poorly connected nanopores in the organic matrix that are the source of almost all produced gas. In the practically impermeable mudrock, the known volumes of fracturing water and proppant must create an equal volume of fractures at all scales. Therefore, the surface area and the number of macrofractures created after hydrofracturing are constrained by the volume of injected water and proppant. The coupling between the fracture network and the organic matrix controls gas production from a horizontal well. The fracture permeability, k f , and the microscale source term, s, affect this coupling, thus controlling the reservoir pressure decline and mass transfer from the nanopore network to the fractures. Particular values of k f and s are determined by numerically fitting well production data with an optimization algorithm. The relationship between k f and s is somewhat hyperbolic and defines the type of fracture system created after hydrofracturing. The extremes of this relationship create two end-members of the fracture systems. A small value of the ratio k f / s causes faster production decline because of the high microscale source term, s. The effective fracture permeability is lower, but gas flow through the matrix to fractures is efficient, thus nullifying the negative effect of the smaller k f . For the high values of k f / s , production decline is slower. In summary, the fracture network permeability at the macroscale and the microscale source term control production rate of shale wells. The best quality wells have good, but not too good, macroscale connectivity.

show abstract

Mesoscale structure, mechanics, and transport properties of source rocks’ organic pore networks

Cited by 46 publications

References 54 publications

A Physics Based Model of Enhanced Gas Production in Mudrocks

A Physics Based Model of Enhanced Gas Production in Mudrocks

Geochemical Properties and Pore Structure Control on Oil Extraction of Shale

The Key Factors That Determine the Economically Viable, Horizontal Hydrofractured Gas Wells in Mudrocks

Contact Info

Product

Resources

About