Different Flow Behaviors of Low-Pressure and High-Pressure Carbon Dioxide in Shales

SPE Journal ◽  
2018 ◽  
Vol 23 (04) ◽  
pp. 1452-1468 ◽  
Author(s):  
Bao Jia ◽  
Jyun-Syung Tsau ◽  
Reza Barati

Summary Understanding carbon dioxide (CO2) storage capacity and flow behavior in shale reservoirs is important for the performance of both CO2-related improved oil recovery (IOR) and enhanced gas recovery (EGR) and of carbon sequestration. However, the literature lacks sufficient experimental data and a deep understanding of CO2 permeability and storage capacity in shale reservoirs under a wide range of pressure. In this study, we aimed to fill this gap by investigating and comparing CO2-transport mechanisms in shale reservoirs under low- and high-pressure conditions. Nearly 40 pressure-pulse-transmission tests were performed with CO2, helium (He), and nitrogen (N2) for comparison. Tests were conducted under constant effective stress with multistage increased pore pressures (0 to 2,000 psi) and constant temperature. The gas-adsorption capacity for CO2 and N2 was measured in terms of both Gibbs and absolute adsorption. Afterward, the gas apparent permeability was calculated incorporating various flow mechanisms before the adsorption-free permeability was estimated to evaluate the adsorption contribution to the gas-transport efficiency. The results indicate that He permeability is the highest among the three types of gas, and the characteristic of CO2 petrophysical properties differs from the other two types of gas in shale reservoirs. CO2 apparent porosity and apparent permeability both decline sharply across the phase-change region. The adsorbed phase significantly increases the apparent porosity, which is directly measured from the pulse-decay experiment; it contributes positively to the low-pressure CO2 permeability but negatively to the high-pressure CO2 permeability.

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2351 ◽  
Author(s):  
Jirui Zou ◽  
Xiangan Yue ◽  
Weiqing An ◽  
Jun Gu ◽  
Liqi Wang

The Klinkenberg slippage theory has widely been used to obtain gas permeability in low-permeability porous media. However, recent research shows that there is a deviation from the Klinkenberg slippage theory for tight reservoir cores under low-pressure conditions. In this research, a new experimental device was designed to carry out the steady-state gas permeability test with high pressure and low flowrate. The results show that, unlike regular low-permeability cores, the permeability of tight cores is not a constant value, but a variate related to a fluid-dynamic parameter (flowrate). Under high-pressure conditions, the relationship between flowrate and apparent permeability of cores with low permeability is consistent with Klinkenberg slippage theory, while the relationship between flowrate and apparent permeability of tight cores is contrary to Klinkenberg slip theory. The apparent permeability of tight core increases with increasing flowrate under high-pressure conditions, and it is significantly lower than the Klinkenberg permeability predicted by Klinkenberg slippage theory. The difference gets larger when the flowrate becomes lower (back pressure increases and pressure difference decreases). Therefore, the Klinkenberg permeability which is obtained by the Klinkenberg slippage theory by using low-pressure experimental data will cause significant overestimation of the actual gas seepage capacity in the tight reservoir. In order to evaluate the gas seepage capacity in a tight reservoir precisely, it is necessary to test the permeability of the tight cores directly at high pressure and low flowrate.


Author(s):  
Eric R. Morgan ◽  
Tom Acker

Northern Arizona University has developed a methanol synthesis unit that directly converts carbon dioxide and hydrogen into methanol and water. The methanol synthesis unit consists of: a high pressure side that includes a compressor, a reactor, and a throttling valve; and a low pressure side that includes a knockout drum, and a mixer where fresh gas enters the system. Methanol and water are produced at high pressure in the reactor and then exit the system under low pressure and temperature in the knockout drum. The remaining, unreacted recycle gas that leaves the knockout drum is mixed with fresh synthesis gas before being sent back through the synthesis loop. The unit operates entirely on electricity and includes a high-pressure electrolyzer to obtain gaseous hydrogen and oxygen directly from purified water. Thus, the sole inputs to the trailer are water, carbon dioxide and electricity, while the sole outputs are methanol, oxygen, and water. A distillation unit separates the methanol and water mixture on site so that the synthesized water can be reused in the electrolyzer. Here, we describe and characterize the operation of the methanol synthesis unit and offer some possible design improvements for future iterations of the device, based on experience.


2021 ◽  
Vol 61 (2) ◽  
pp. 606
Author(s):  
Jamiu M. Ekundayo ◽  
Reza Rezaee ◽  
Chunyan Fan

Gas shale reservoirs pose unique measurement challenges due to their ultra-low petrophysical properties and complicated pore structures. A small variation in an experimental parameter, under high-pressure conditions, may result in huge discrepancies in gas contents and the resource estimates derived from such data. This study illustrates the impact of the equation of state on the gas content determined for a shale sample. The gas content was determined from laboratory-measured high-pressure methane adsorption isotherms and theoretically described by a hybrid type model. The modelling involved the use of the Dubinin–Radushkevich isotherm to obtain the adsorbed phase density followed by the Langmuir isotherm to describe the resultant absolute adsorptions. Significant variations were observed in measured adsorption isotherms due to the variations in gas densities calculated from different equations of states. The model parameters and the gas in-place volumes estimated from those parameters also varied significantly.


2014 ◽  
Vol 917 ◽  
pp. 301-306
Author(s):  
Wong Mee Kee ◽  
Azmi Mohd Shariff ◽  
Mohammad Azmi Bustam ◽  
Lau Kok Keong ◽  
Turgkaraaj Karikalan ◽  
...  

Carbon dioxide (CO2) is the major cause of accelerating global warming. It is important to employ efficient method to capture CO2. Absorption is the most established technique to separate CO2 and amines are most commonly used as solvent. In this study, density and viscosity of an amine based novel solvent named Stonvent were investigated at temperature ranging from 298.15 K to 338.15 K. CO2 solubility in Stonvent was measured at varying pressures, temperatures and concentrations. The experiments were conducted at temperatures (303.15, 318.15 and 333.15) K, and at pressures (0.5, 1, 1.5 and 3) MPa over a wide range of concentration (10, 20, 30 and 100) mass %. Solubility of CO2 was determined from pressure drop due to absorption of CO2 into solvent within equilibrium cell. Absorption capacity of Stonvent increases significantly with increasing pressure. Solubility of CO2 in Stonvent is higher compared to Monoethanolamine (MEA), 1-amino-2-propanol (MIPA) and 2-amino-2-methyl-1,3-propanediol (AMPD) at elevated pressure, hence posing Stonvent as an attractive alternative for acid gas absorption in high pressure conditions. Substantial increase in CO2 loading was observed when concentration of Stonvent is increased and when temperature is decreased.


Author(s):  
Jacob Riglin ◽  
Adam Wachtor ◽  
Robert Morgan ◽  
Ryan Holguin ◽  
John Bernardin

Abstract Under-expanded jets have wide range of application from fuel injection to rocket propulsion. In the present work, a numerical model was generated to investigate the fluid mechanics behavior of under-expanded jet formation and wall interaction of a jet produced by exhausting a high pressure cylinder through a narrow tube into a low pressure cylinder. Axisymmectic, Reynolds Averaged Navier Stokes simulations were conducted employing the ANSYS FLUENT explicit, Coupled Pressure-Velocity solver to determine the stagnation pressure at the wall downstream of the orifice. Transient cases were conducted using timestep sizes of 1.0 × 10−8 s and 5.0 × 10−9 s. Various gases were investigated with Hydrogen being the primary working fluid with pressure ratios ranging from 10 to 100. This paper will focus primarily on the Hydrogen jets for pressure ratios of 10, 20, and 70. Numerical results were validated from both experimental results and higher fidelity Large Eddy Simulation results specifically analyzing the jet formation. Error between Mach disk height, Mach disk width, and Prandtl-Meyer expansion fan angles of the jet for pressure ratios of 10 and 70 were kept below 5%. The peak stagnation pressures at the center of the far wall for pressure ratios of 10, 20, and 70 were observed to be 86,843 Pa, 127,786 Pa, and 315,843 Pa, respectively. The predicted peak pressures show a linear relationship with respect to the initial pressure ratio existing between the high pressure and low pressure regions when the ratios are bounded between 10 and 70.


2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Eric R. Morgan ◽  
Thomas L. Acker

A methanol synthesis unit (MSU) that directly converts carbon dioxide and hydrogen into methanol and water was developed and tested. The MSU consists of: a high-pressure side that includes a compressor, a reactor, and a throttling valve; and a low-pressure side that includes a knockout drum, and a mixer where fresh gas enters the system. Methanol and water are produced at high pressure in the reactor and then exit the system under low pressure and temperature in the knockout drum. The remaining, unreacted recycle gas that leaves the knockout drum is mixed with fresh synthesis gas before being sent back through the synthesis loop. The unit operates entirely on electricity and includes a high-pressure electrolyzer to obtain gaseous hydrogen and oxygen directly from purified water. Thus, the sole inputs to the trailer are water, carbon dioxide, and electricity, while the sole outputs are methanol, oxygen, and water. A distillation unit separates the methanol and water mixture on site so that the synthesized water can be reused in the electrolyzer. Here, we describe and characterize the operation of the MSU and offer some possible design improvements for future iterations of the device, based on experience.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4054
Author(s):  
Michał Kuk ◽  
Edyta Kuk ◽  
Damian Janiga ◽  
Paweł Wojnarowski ◽  
Jerzy Stopa

One of the possibilities to reduce carbon dioxide emissions is the use of the CCS method, which consists of CO2 separation, transport and injection of carbon dioxide into geological structures such as depleted oil fields for its long-term storage. The combination of the advanced oil production method involving the injection of carbon dioxide into the reservoir (CO2-EOR) with its geological sequestration (CCS) is the CCS-EOR process. To achieve the best ecological effect, it is important to maximize the storage capacity for CO2 injected in the CCS phase. To achieve this state, it is necessary to maximize recovery factor of the reservoir during the CO2-EOR phase. For this purpose, it is important to choose the best location of CO2 injection wells. In this work, a new algorithm to optimize the location of carbon dioxide injection wells is developed. It is based on two key reservoir properties, i.e., porosity and permeability. The developed optimization procedure was tested on an exemplary oil field simulation model. The obtained results were compared with the option of arbitrary selection of injection well locations, which confirmed both the legitimacy of using well location optimization and the effectiveness of the developed optimization method.


Author(s):  
Andy Chadwick ◽  
Dan Smith ◽  
Chris Hodrien ◽  
Sue Hovorka ◽  
Eric Mackay ◽  
...  

2018 ◽  
Vol 105 (3) ◽  
pp. 276-284 ◽  
Author(s):  
SD Soligon ◽  
ME Lixandrão ◽  
TMPC Biazon ◽  
V Angleri ◽  
H Roschel ◽  
...  

Low-intensity resistance exercise with blood-flow restriction (BFR) promotes similar adaptations to high-intensity resistance exercise (HI-RE). Interestingly, BFR has been demonstrated to be effective for a wide range of occlusion pressures. However, the occlusion pressure magnitude may alter the psychophysiological stress related to BFR as measured by rating of perceived exertion scale (RPE) and rating of pain. We aimed to compare the RPE and pain levels across different magnitudes of occlusion pressures, promoting new knowledge regarding occlusion pressure on stress related to BFR. All BFR protocols ranging between 40% and 80% of total arterial occlusion (BFR40, BFR50, BFR60, BFR70, and BFR80) were compared to HI-RE in 12 participants using a randomized and crossover design 72 h apart. BFR protocols and HI-RE were performed with 30% and 80% of one-repetition maximum (1RM) test value, respectively. RPE and pain levels were measured before exercise and immediately after each set. BFR protocols (i.e., BFR40 and BFR50) presented overall lower RPE response compared to higher-pressure BFR (i.e., BFR70 and BFR80) and HI-RE conditions. For pain levels, low-pressure BFRs (i.e., BFR40 and BFR50), and HI-RE showed lower values than high-pressure BFR protocols (i.e., BFR60, BFR70, and BFR80). In conclusion, low-pressure BFR protocols promote lower RPE and pain compared to high-pressure BFR protocols (between 60% and 80% of occlusion pressure), when total training volume (TTV) is equalized. In addition, HI-RE promotes similar levels of pain, but higher RPE than low-pressure BFR, probably due to the higher TTV.


1950 ◽  
Vol 162 (1) ◽  
pp. 149-166 ◽  
Author(s):  
L. J. Kastner ◽  
J. R. Spooner

The air ejector, in its various forms, is a device which has many applications in engineering practice, and several attempts have been made to analyse its mode of action, some of these having been supported by experimental work. Most of the experimental results available are related to ejectors in which relatively high-pressure steam is utilized as the driving fluid, but even in these cases the information provided is restricted to a narrow field. The investigation described relates to an air ejector employing as the driving fluid air at a relatively low pressure, not exceeding 40 lb. per sq. in. (abs.), and covering a wide range of operating conditions by means of interchangeable nozzles. Two distinct experimental arrangements were built—one for the set of conditions in which the ejector draws in a relatively small quantity of suction fluid and pumps it through a relatively high pressure-ratio, and the other covering conditions in which the quantity of suction fluid is much larger, but the pressure ratio is quite small. For a given initial pressure and quantity of driving fluid, the rate of mass flow of suction fluid depends chiefly on the diameter of the combining tube, in which the driving and suction fluids mix; in the experiments, the ratio of com-bining-tube area to driving-nozzle area was varied in twelve steps, covering a range of area ratios from 1·44 to 1,110·0, and compression ratios ranging from about 3 to about 1·001. Efforts were made to find the best proportions of those parts of the ejector which exert a major influence on performance, and certain conclusions are drawn from the results of the experiments. Theoretical aspects of the problem are briefly discussed.


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