scholarly journals Using Zeolite-Zirconia-Copper Nanocomposites as a New Asphaltene Inhibitor for Improving Permeability Reduction during CO 2 Flooding

2021 ◽  
Author(s):  
Mohsen Mansouri ◽  
Yaser Ahmadi
Keyword(s):  
Carbonate Reservoir ◽  
Isotherm Models ◽  
Core Flooding ◽  
Asphaltene Precipitation ◽  
Precipitation Inhibition ◽  
Porosity Reduction ◽  
Dynamic Phase ◽  
Static Phase ◽  
Static Conditions ◽  
Copper Nanocomposites

Abstract Using nanoparticles for adsorbing asphaltene was known as an efficient method among researchers for crude oil upgrading and in this study, Zeolite-zirconia-copper nanocomposites (NCs) has been synthesized and characterized with SEM, XRD, BET, and EDX for asphaltene precipitation inhibition in the static phase and solving asphaltene deposition problems of dynamic CO2 flooding in low permeability carbonate reservoir. CO2-oil IFT tests, isotherm models, natural depletion tests at static phase were performed in the presence of NCs and the results were compared with zeolite nanoparticles. Then, CO2 core flooding tests at dynamic phase were designed in the presence of NCs at obtained static conditions for surveying permeability/porosity reduction in porous media. After adding NCs and zeolite nanoparticles, the 2nd to 1st slope ratio in CO2-oil IFT tests increased from 19.697 % to 20.895 % and 29.851 %, respectively which shows NCs adsorbed more asphaltene in comparison to zeolite nanoparticles which confirmed UV-Vis results. NCs was decreased asphaltene precipitation more than zeolite at same points during natural depletion tests and it was selected for dynamic CO2 tests. After adding NCs, asphaltene depositions which occurs after CO2 injection was decreased and permeability/porosity reduction parameters were improved.

Saturated carbon dioxide nanofluids enhanced oil recovery in carbonate reservoir cores using nuclear magnetic resonance

2021 ◽  
Author(s):  
Yongsheng Tan ◽  
Qi Li ◽  
Liang Xu ◽  
Xiaoyan Zhang ◽  
Tao Yu
Keyword(s):  
Carbon Dioxide ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Residual Oil ◽  
Core Flooding ◽  
Nuclear Magnetic

<p>The wettability, fingering effect and strong heterogeneity of carbonate reservoirs lead to low oil recovery. However, carbon dioxide (CO<sub>2</sub>) displacement is an effective method to improve oil recovery for carbonate reservoirs. Saturated CO<sub>2</sub> nanofluids combines the advantages of CO<sub>2</sub> and nanofluids, which can change the reservoir wettability and improve the sweep area to achieve the purpose of enhanced oil recovery (EOR), so it is a promising technique in petroleum industry. In this study, comparative experiments of CO<sub>2</sub> flooding and saturated CO<sub>2</sub> nanofluids flooding were carried out in carbonate reservoir cores. The nuclear magnetic resonance (NMR) instrument was used to clarify oil distribution during core flooding processes. For the CO<sub>2</sub> displacement experiment, the results show that viscous fingering and channeling are obvious during CO<sub>2</sub> flooding, the oil is mainly produced from the big pores, and the residual oil is trapped in the small pores. For the saturated CO<sub>2</sub> nanofluids displacement experiment, the results show that saturated CO<sub>2</sub> nanofluids inhibit CO<sub>2</sub> channeling and fingering, the oil is produced from the big pores and small pores, the residual oil is still trapped in the small pores, but the NMR signal intensity of the residual oil is significantly reduced. The final oil recovery of saturated CO<sub>2</sub> nanofluids displacement is higher than that of CO<sub>2</sub> displacement. This study provides a significant reference for EOR in carbonate reservoirs. Meanwhile, it promotes the application of nanofluids in energy exploitation and CO<sub>2</sub> utilization.</p>

scholarly journals Two prototypes for medium rotation forestry harvesting

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
L. Pari ◽  
V. Civitarese ◽  
A. Del Giudice ◽  
A. Scarfone
Keyword(s):  
The Self ◽  
Energy Crop ◽  
High Yield ◽  
Working Capacity ◽  
Dynamic Phase ◽  
Static Phase ◽  
Area Unit ◽  
Harvesting Costs ◽  
Cutting System

Five years old poplar (Populus spp.) plantation represents an interesting model of productivity. The most attractive characteristics of this energy crop are the handling flexibility, the high yield of biomass per area unit and the good quality of the chips obtainable. The mechanical harvesting of five-years old poplar plantations requires the use of specialized forest machineries such as harvester, feller, forwarder and chipper. Usually, after felling, the working phases consist of extraction, stacking and chipping. Generally, the last one is carried out in a “static phase”, where the product is taken from staked logs by using a hydraulic arm having a gripper that feed the chipping machine. In order to introduce technological innovations for the medium rotation forestry harvesting, the Consiglio per la Ricerca e la sperimentazione in Agricoltura, Unità di ricerca per l’Ingegneria agraria (CRAING) of Monterotondo (Rome, Italy) has developed a five years poplar cutwindrower and a self-propelled chipper equipped with a pick up system. The prototype of cut-windrower is a semi-trailed machine powered by a 95 kW tractor (at least). It mounts a cutting system and a double pincer with variable positioning. During the cutting phase the plant is grasped by the double pincer which conveys and unloads the stem along the inter-row. The trees are placed parallel to the progress of the tractor, but oriented in the opposite direction. The biomass windrowed is then chipped in a dynamic phase directly from the inter row using the self-propelled chipper equipped with the pick-up head. In the first tests, the cut-windrower has reached an operative working capacity of 0.22 ha h-1, with an operative production of 44 t h-1. On the other hand, the self-propelled chipper has showed an operative working capacity equal to 0.18 ha h-1, and an operative production of 35 t h-1 about. Both machines have shown good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

scholarly journals Compatibility evaluation of modified seawater for EOR in carbonate reservoirs through the introduction of polyphosphate compound

2019 ◽  
Vol 17 (2) ◽  
pp. 393-408 ◽  
Author(s):  
Bisweswar Ghosh ◽  
Liying Sun ◽  
Nithin Chacko Thomas
Keyword(s):  
Oil Recovery ◽  
Economic Benefits ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Core Flooding ◽  
Systematic Screening ◽  
Flood Water ◽  
Scaling Potential ◽  
Original Oil In Place ◽  
New Formulation

Abstract Waterflood-assisted oil recovery with sulfate-spiked seawater would cause incompatibility scaling in carbonate reservoirs and reduce economic benefits. This research investigated the benefits of polyphosphate compounds in reducing scaling potential as well as its effect on oil recovery when mixed in high sulfate flood water. Severity of scaling potential of sulfate-spiked water in a carbonate reservoir environment was measured, followed by systematic screening of a polyphosphate compound, which successfully inhibited the sulfate scale precipitation at concentration as low as 100 ppm. The new formulation (seawater with four times sulfate and phosphate, SW4SP) was evaluated and compared with benchmark formulation (modified seawater with four times sulfate, SW4S). Contact angle, ζ-potential and drainage studies show that SW4SP changed the rock wettability from oil wet to water wet to a larger degree compared to SW4S. Improved recovery efficiency of SW4SP was confirmed through a set of core flooding studies in the tertiary and quaternary flood modes. Whereas SW4S recovered 7.7% of original oil in place (OOIP), SW4SP recovered about 8% of OOIP in the tertiary mode under approximately identical flow conditions. Flooding with SW4SP in the quaternary mode following a tertiary flood with SW4S on the same core resulted in 1.7% additional oil recovery, showing improved efficiency of the new flood water formulation.

Determinants of fasting hypertriglyceridemia in ventromedial hypothalamic obesity in rats

1993 ◽  
Vol 265 (4) ◽  
pp. R786-R791 ◽  
Author(s):  
S. Inoue ◽  
S. Satoh ◽  
K. Tanaka ◽  
Y. Takamura ◽  
T. Murase
Keyword(s):  
Adipose Tissue ◽  
Plasma Insulin ◽  
Plasma Triglyceride ◽  
Elevated Plasma ◽  
Hypothalamic Obesity ◽  
Positive Correlation ◽  
Dynamic Phase ◽  
Triglyceride Secretion ◽  
Static Phase ◽  
Heparin Plasma

The present study investigated the mechanism of fasting hypertriglyceridemia in ventromedial hypothalamic (VMH) obesity by measurement of post-heparin plasma lipoprotein lipase (LPL) activity, triglyceride secretion rate (TGSR), and plasma insulin. One week after VMH lesions, when the lesioned rats were gaining weight rapidly (the dynamic phase), they showed normal plasma triglyceride levels with increased plasma LPL activity and TGSR. There was a positive correlation between hyperinsulinemia and elevated plasma LPL activity or TGSR in VMH-lesioned rats, while no correlation was observed in control rats. Ten weeks after VMH lesions, when the rats had become obese and reached a steady-state weight gain (the static phase), they showed hypertriglyceridemia with increased plasma LPL activity and TGSR. There was, again, a positive correlation between hyperinsulinemia and elevated plasma LPL activity or TGSR in VMH-lesioned rats. These results suggest a possible mechanism of fasting hypertriglyceridemia in these rats; in the dynamic phase adipose tissue adequately takes up circulating triglyceride because the tissue has sufficient take-up capacity and hence hypertriglyceridemia does not develop. In the static phase the tissue cannot adequately take up circulating triglyceride because of a limitation of its capacity, resulting in hypertriglycemia despite enhanced triglyceride secretion and increased LPL activity in both phases.

scholarly journals Application of VES Acid System on Carbonate Rocks with Uninvaded Matrix for Acid Etching and Fracture Propagation

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 159
Author(s):  
Yahong Wu ◽  
Weiwei Luo ◽  
Xunan Jia ◽  
Haoqing Fang ◽  
Honggang Wang ◽  
...  
Keyword(s):  
Fracture Propagation ◽  
Ct Scanning ◽  
Reaction Rates ◽  
Carbonate Reservoir ◽  
Fluid Viscosity ◽  
Acid System ◽  
Core Flooding ◽  
Structure Variation ◽  
The Core ◽  
The Impact

We investigated the performance of viscoelastic surfactant (VES) solution when applied in treatment on the uninvaded matrix using core flooding tests to analyze the impact of VES/CaCl2 concentration on fluid viscosity. In this paper, core samples from Tahe carbonate reservoir, with an average permeability less than 0.02 × 10−3 μm−2 and a small average porosity in the range of approximately 0.04–5.24% are used in the experiments. Computed tomography (CT) scanning is used to provide a detailed description of inner structure variation of cores after the acid system treatment. The results confirmed that a large pressure difference contributed to fracture propagation and the relative permeability of water increased significantly after the treatment. It was also found that higher concentrations of VES and/or Ca2+ induced higher viscosity and a stronger fracturing effect, while a lower concentration improved the reaction rates and etching effect, generating small worm holes inside the core. Foam in-situ produced during the etching process is the major contributor to the fluid viscosity enhancement. The permeability of fracture formed on the surface of the core is more sensitive to the confining pressure. These findings can help better understand the rheological properties of the acid system and etching and fracturing mechanisms during acid treatment, and which provides instructions for field implementation.

Differential diagenetic evolution and hydrocarbon charging of the tight limestone reservoir of the Da’anzhai Member in the central Sichuan Basin, China

2020 ◽  
Vol 8 (4) ◽  
pp. T1007-T1022
Author(s):  
Jiao Su ◽  
Zepu Tian ◽  
Yingchu Shen ◽  
Bo Liu ◽  
Qilu Xu ◽  
...  
Keyword(s):  
Sichuan Basin ◽  
Large Scale ◽  
Depositional Environments ◽  
Carbonate Reservoir ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Porosity Reduction ◽  
Hydrocarbon Charging ◽  
Pore Evolution ◽  
Central Sichuan Basin

The tight lacustrine carbonate reservoir of the Da’anzhai Member, Lower Jurassic Ziliujing Formation, in the central Sichuan Basin is a typical tight oil reservoir, and it is one of the crucial petroleum exploration targets in the Sichuan Basin. The porosity of the limestone ranges from 0.5% to 2%, and the permeability ranges from 0.001 to 1 mD. The Da’anzhai limestone experienced multiple diageneses, including compaction, cementation, dissolution, and recrystallization. Different diageneses occurred in the burial process due to the various fabrics and depositional environments, eventually forming distinct rock types; therefore, the pore evolution and hydrocarbon charging characteristics are inconsistent. In our research, there are two stages of major maturation and hydrocarbon expulsion in the source rocks of the Da’anzhai Member. The first large-scale expulsion of hydrocarbon is oil-based and gas-supplemented, whereas the second expulsion is dominated by gas. Hydrocarbon-filling characteristics are different in different types of reservoir rocks. Compared with the bioclastic grainstone and crystalline limestone, we have considered that the argillaceous shell packstone and bioclastic packstone deposited in the shallow and semideep lake environment still contain residual intergranular pores, which have not become fully compacted and are partly filled with hydrocarbons. The presence of hydrocarbon fluid hindered the secondary porosity reduction and was helpful for reserve space preservation.

Paper 16: A Preliminary Investigation into the Effects of Applying a Locking Device to a Position-Controlled Externally Powered Prosthesis

1968 ◽  
Vol 183 (10) ◽  
pp. 93-97
Author(s):  
J. M. Pottinger ◽  
N. D. Ring
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Preliminary Investigation ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Time Control ◽  
Dynamic Phase ◽  
Static Phase ◽  
Powered Prosthesis

The application of position control to externally powered prosthetic arms leads to increased function and versatility when compared to a prosthetic system with open-loop control. However, various compromises are necessary owing to the limited number of available control sites. An investigation is being conducted into the possibility of combining the advantages of position control during the dynamic phase of movement with the locking facility of velocity–time control during the static phase, which leads to a larger number of available control sites and thus a greater number of degrees of freedom.

Study on a Self-Diverting Acid System for Well Stimulation Based on Novel Visco-Elastic Surfactant

2011 ◽  
Vol 287-290 ◽  
pp. 3120-3126 ◽  
Author(s):  
Fu Jian Zhou ◽  
Chun Ming Xiong ◽  
Yang Shi ◽  
Xian You Yang ◽  
Sheng Jiang Lian ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Carbonate Reservoir ◽  
Scanning System ◽  
Low Permeability ◽  
Acid System ◽  
Core Flooding ◽  
Well Stimulation ◽  
Core Permeability ◽  
Carbonate Formations ◽  
Oil Gas

Carbonate reservoir, widely distributed in china, is an important resource of oil and gas. Most of carbonate reservoir are very tight and need to be stimulated to increase the permeability for the flowing of oil/gas. Acid treatment is a kind of stimulation. However, the ordinary acid system cannot stimulate carbonate reservoir effectively because of the heterogeneity among formations. Based on a novel visco-elastic surfactant, this paper develops a self-diverting acid system (DCA) for carbonate formations. This system had been applied in the treatment of carbonate reservoirs successfully. Experiments studying the diverting mechanism had been conducted with HTHP Rheometer, parallel core flooding system and MRI Scanning system. The results indicate that: the viscosity of reacted acid can reach to 200 times higher than that of fresh acid. The injecting pressure of DCA is 20 times higher than that of ordinary acid (HCl) during the parallel core flooding experiment. MRI scanning images of the cores after acid flooding show that DCA can stimulate the cores with middle and low permeability more effectively. In middle and low permeability cores, the length of wormhole created by DCA is 4-8 times longer than that created by ordinary acid. At the same time, the relationship between flooding pressure and core permeability is also studied. This paper reveals the diverting mechanism of DCA through these experiments.

METABOLIC EFFECTS OF HYPERPHAGIA IN THE HYPOTHALAMIC-HYPERPHAGIC RAT

1966 ◽  
Vol 44 (4) ◽  
pp. 641-650 ◽  
Author(s):  
K. K. May ◽  
J. R. Beaton
Keyword(s):  
Spontaneous Activity ◽  
Body Weight Gain ◽  
Costal Cartilage ◽  
Metabolic Effects ◽  
Male Rats ◽  
Dynamic Phase ◽  
Static Phase ◽  
Electrolytic Lesions ◽  
Altered Thyroid

Metabolic effects of hyperphagia have been investigated in male rats in which hyperphagia was induced by bilateral, electrolytic lesions in the region of the ventromedial nuclei of the hypothalamus. In the early dynamic phase of hyperphagia, it would appear that increased body weight gain is a direct effect of increased energy intake not balanced by the observed increased spontaneous activity. In these animals increased lipogenesis (14C-acetate and 14C-glucose) and decreased lipolysis in vitro were evident with no evidence of altered thyroid function. Further, as determined by 35S incorporation in costal cartilage, the hyperphagia did not elicit an increased rate of skeletal growth. In the static phase, spontaneous activity was not increased, metabolic patterns were significantly altered in the direction of increased lipogenesis and decreased lipolysis, and there appeared to be a decreased uptake and release of 131I by the thyroid, which is suggestive of thyroid hypofunction.

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