scholarly journals Experimental Investigation into the Effects of Fracturing Fluid-Shale Interaction on Pore Structure and Wettability

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yan Zhang ◽  
Zhiping Li ◽  
Fengpeng Lai ◽  
Hao Wu ◽  
Gangtao Mao ◽  
...  
Keyword(s):  
Contact Angle ◽  
Pore Structure ◽  
Oil And Gas ◽  
Pore Space ◽  
Nitrogen Adsorption ◽  
Fluid Distribution ◽  
Fracturing Fluid ◽  
Fracturing Process ◽  
Fracking Fluid

One of the main techniques for the exploitation of shale oil and gas is hydraulic fracturing, and the fracturing fluid (slick water) may interact with minerals during the fracturing process, which has a significant effect on the shale pore structure. In this study, the pore structure and fluid distribution of shale samples were analyzed by utilizing low-pressure liquid nitrogen adsorption (LP-N2GA) and nuclear magnetic resonance (NMR). The fractal analysis showed that the pore structure of the sample was strongly heterogeneous. It was also found that the effect of slick water on pore structure can be attributed to two phenomena: the swelling of clay minerals and the dissolution of carbonate minerals. The swelling and dissolution of minerals can exist at the same time, and the strength of them at different soaking times is different, leading to the changes in specific surface area and pore size. After the samples were soaked in the slick water for two days, the contact angle reached the minimum value (below 8°), which means the sample is strongly hydrophilic; then the contact angle increased to above 38° with longer soaking times. The connected pore space in the shale matrix is enlarged by the soaking processing. Therefore, an in-depth understanding of the interaction between the fracking fluid and shale is essential to deepen our understanding of changes in the pore structure in the reservoir and the long-term productivity of shale gas.

Nanopetrophysical characterization of the Mancos Shale Formation in the San Juan Basin of northwestern New Mexico, USA

2019 ◽  
Vol 7 (4) ◽  
pp. SJ45-SJ65
Author(s):  
Qinhong Hu ◽  
Richard Kalteyer ◽  
Jingyi Wang ◽  
Hesham F. El-Sobky
Keyword(s):  
Contact Angle ◽  
Pore Structure ◽  
Oil And Gas ◽  
Pore Space ◽  
Water Immersion ◽  
Reservoir Quality ◽  
San Juan ◽  
Microscopy Imaging ◽  
San Juan Basin ◽  
Mancos Shale

The Mancos Shale of the San Juan Basin has been an important resource for the exploration and development of oil and gas. However, as with most unconventional plays, the shales have low porosity and extremely low permeability with predominantly nanometer-sized pores. Thus, it is critical to understand the nanopetrophysical properties of the reservoir so a proper assessment of the reservoir quality can be made. Working with three as-received core samples from three different wells of the Tacito Marine Bar and Offshore Mancos play types, we have developed an initial understanding of the nanopetrophysical properties of the pore structure as well as fluid-rock interactions in these tight reservoirs. We have performed a suite of integrated tests, such as mercury intrusion porosimetry (MIP), low-pressure nitrogen physisorption, core plug porosity and permeability, scanning electron microscopy imaging, water immersion porosimetry after vacuum pulling, contact angle, and fluid imbibition. In addition, we obtained supplementary data for total organic carbon, X-ray diffraction, and pyrolysis to further evaluate reservoir quality. The Mancos Shale samples exhibit petrophysical characteristics that are controlled by a predominant presence of nanometer-sized pore space, with 56%–96% pore volumes present as 3.4–50 nm in pore-throat sizes, as shown by the MIP approach. Contact angle and fluid imbibition tests demonstrate that samples are oil wet to mixed wet, with a tendency of pore networks to imbibe oil over water. The findings from integrated pore structure and wettability studies provide a database and some insights, from the perspectives of nanopetrophysical characterization, into the reservoir quality of the Mancos Shale.

scholarly journals Pore Structure Characterization and the Controlling Factors of the Bakken Formation

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2879 ◽  
Author(s):  
Yuming Liu ◽  
Bo Shen ◽  
Zhiqiang Yang ◽  
Peiqiang Zhao
Keyword(s):  
Pore Structure ◽  
Oil And Gas ◽  
Vitrinite Reflectance ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Controlling Factors ◽  
Structure Characterization ◽  
Bakken Formation ◽  
Main Controlling Factors ◽  
Bakken Shale

The Bakken Formation is a typical tight oil reservoir and oil production formation in the world. Pore structure is one of the key factors that determine the accumulation and production of the hydrocarbon. In order to study the pore structures and main controlling factors of the Bakken Formation, 12 samples were selected from the Bakken Formation and conducted on a set of experiments including X-ray diffraction mineral analysis (XRD), total organic carbon (TOC), vitrinite reflectance (Ro), and low-temperature nitrogen adsorption experiments. Results showed that the average TOC and Ro of Upper and Lower Bakken shale is 10.72 wt% and 0.86%, respectively. The Bakken Formation develops micropores, mesopores, and macropores. However, the Upper and Lower Bakken shale are dominated by micropores, while the Middle Bakken tight reservoir is dominated by mesopores. The total pore volume and specific surface area of the Middle Bakken are significantly higher than those of the Upper and Lower Bakken, indicating that Middle Bakken is more conducive to the storage of oil and gas. Through analysis, the main controlling factors for the pore structure of the Upper and Lower Bakken shale are TOC and maturity, while those for Middle Bakken are clay and quartz contents.

Robust Leakage Modeling for Plug and Abandonment Applications

2019 ◽  
Author(s):  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Catalin Teodoriu
Keyword(s):  
Oil And Gas ◽  
Pore Space ◽  
Differential Pressure ◽  
Cement Slurry ◽  
High Pressure And Temperature ◽  
Gas Leakage ◽  
Fluid Leakage ◽  
Well Integrity ◽  
Cement Plug

Abstract Oil and gas wells that require to be shut off forever, after depleting their reserves, need to be plugged and abandoned. Plug and Abandonment (P&A) operations induce many arduous challenges worldwide. The aim of P&A is to isolate and prevent fluid leakage in the wellbore in such a way that all fluids are contained in their formation for an undefined time. Failure of P&A in isolating and preventing fluid leakage can jeopardize the well integrity. Cement plugs that are used in this operation play a crucial role in maintaining the well integrity. Cement is considered as a porous medium that has an ultra-low permeability that can be achieved when some additives are used in the cement slurry to reduce its permeability and pore space. The cement plug may deteriorate with time under harsh downhole conditions, such as high pressure and temperature and exposure to different fluids. Cement plug deterioration will result in increasing the cement permeability or the overall permeability by creating channels or microannuli. In this study, several scenarios are presented for gas leakage through cement plugs. In these leakage scenarios, the differential pressure across the cement plug was varied. The aim of generating these scenarios is to investigate the current required cement plug length. In each scenario, four different permeability values were used to assess the risk associated with each value. In addition, the cement plug length was varied to investigate how the cement plug length is going to help ensure good well integrity. The leakage scenarios presented revealed that longer cement plugs have a longer leakage time. In addition, the results show an increase of leakage time as microannulus gap permeability decreases. Differential pressure exerted on the cement plug have a strong effect on the leakage time. To achieve a long term well integrity in P&A phase, an ultra-low permeable cement plug with excellent bonding, longer cement plug, and a lower differential pressure across the cement must be considered.

Correlation of Pore Structure and Permeability by SEM-Image Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 428-429
Author(s):  
C. A. Callender ◽  
Wm. C. Dawson ◽  
J. J. Funk
Keyword(s):  
Image Analysis ◽  
Pore Structure ◽  
Imaging System ◽  
Pore Space ◽  
Simulation Models ◽  
Image Analyzer ◽  
Imaging Data ◽  
Sem Images ◽  
Thin Sections ◽  
Rock Types

The geometric structure of pore space in some carbonate rocks can be correlated with petrophysical measurements by quantitatively analyzing binaries generated from SEM images. Reservoirs with similar porosities can have markedly different permeabilities. Image analysis identifies which characteristics of a rock are responsible for the permeability differences. Imaging data can explain unusual fluid flow patterns which, in turn, can improve production simulation models.Analytical SchemeOur sample suite consists of 30 Middle East carbonates having porosities ranging from 21 to 28% and permeabilities from 92 to 2153 md. Engineering tests reveal the lack of a consistent (predictable) relationship between porosity and permeability (Fig. 1). Finely polished thin sections were studied petrographically to determine rock texture. The studied thin sections represent four petrographically distinct carbonate rock types ranging from compacted, poorly-sorted, dolomitized, intraclastic grainstones to well-sorted, foraminiferal,ooid, peloidal grainstones. The samples were analyzed for pore structure by a Tracor Northern 5500 IPP 5B/80 image analyzer and a 80386 microprocessor-based imaging system. Between 30 and 50 SEM-generated backscattered electron images (frames) were collected per thin section. Binaries were created from the gray level that represents the pore space. Calculated values were averaged and the data analyzed to determine which geological pore structure characteristics actually affect permeability.

The Belt and Road Initiative: Goals and Challenges

2020 ◽  
pp. 167
Author(s):  
Adnan Khalaf i Hammed Al-Badrani ◽  
Hind Ziyad Nafeih
Keyword(s):  
Development Strategy ◽  
Soft Power ◽  
Oil And Gas ◽  
Power Lines ◽  
Belt And Road Initiative ◽  
Belt And Road ◽  
Ancient Silk Road ◽  
Main Engine ◽  
The Belt And Road

The Belt and Road Initiative is an initiative to revive the ancient Silk Road, through networks of land and sea roads, oil and gas pipelines, electric power lines, the Internet and airports, to create a model of regional and international cooperation.       It is essentially a long-term development strategy, launched by the Chinese president in 2013 to become the main engine of Chinese domestic policy and foreign diplomacy and within the framework of the soft power strategy, to enhance its position and influence in the world as a peaceful and responsible country.   The study includes identifying the initiative and setting goals for China, as well as the challenges and difficulties that hinder the initiative.

Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration

2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Mixed Matrix Membranes ◽  
Recovery Ratio ◽  
Mixed Matrix ◽  
Water Contact ◽  
Membrane Performance ◽  
Metal Organic ◽  
Matrix Membranes

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>

Trends and Prospects of Development of the Oil and Gas Sector in the Context of Digitalization

2020 ◽  
Vol 26 (1) ◽  
pp. 35-45 ◽  
Author(s):  
A. G. Kazanin
Keyword(s):  
Oil And Gas ◽  
Digital Technologies ◽  
Oil And Gas Industry ◽  
Global Market ◽  
The Arctic ◽  
Business And Society ◽  
Gas Industry ◽  
Exploration And Production ◽  
Oil And Gas Sector

The modern oil and gas industry is heavily dependent on the processes and trends driven by the accelerating digitalization of the economy. Thus, the digitalization of the oil and gas sector has become Russia’s top priority, which involves a technological and structural transformation of all production processes and stages.Aim. The presented study aims to identify the major trends and prospects of development of the Russian oil and gas sector in the context of its digitalization and formation of the digital economy.Tasks. The authors analyze the major trends in the development of the oil and gas industry at a global scale and in Russia with allowance for the prospects of accelerated exploration of the Arctic; determine the best practices of implementation of digital technologies by oil and gas companies as well as the prospects and obstacles for the subsequent transfer of digital technologies to the Russian oil and gas industry.Methods. This study uses general scientific methods, such as analysis, synthesis, and scientific generalization.Results. Arctic hydrocarbons will become increasingly important to Russia in the long term, and their exploration and production will require the implementation of innovative technologies. Priority directions for the development of many oil and gas producers will include active application of digital technologies as a whole (different types of robots that could replace people in performing complex procedures), processing and analysis of big data using artificial intelligence to optimize processes, particularly in the field of exploration and production, processing and transportation. Digitalization of the oil and gas sector is a powerful factor in the improvement of the efficiency of the Russian economy. However, Russian companies are notably lagging behind in this field of innovative development and there are problems and high risks that need to be overcome to realize its potential for business and society.Conclusions. Given the strategic importance of the oil and gas industry for Russia, its sustainable development and national security, it is recommendable to focus on the development and implementation of digital technologies. This is crucial for the digitalization of long-term projection and strategic planning, assessment of the role and place of Russia and its largest energy companies in the global market with allowance for a maximum number of different internal and external factors.

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