•The designed 2D apparatus can reflect gravity segregation environment.•Oil recovery is heavily influenced by gravitational effect in immiscible case.•Reservoir thickness is not crucial criteria for ...CO2 flooding in near-miscible case.•Relationship of CO2 storage and oil production is important in designing CO2 EOR.
In this study, we attempted to analyze CO2 sequestration and oil production in the environment of gravity segregation, and ultimately making a relationship between them during the CO2 flooding. In order to utilize the depleted oil field after finishing the CO2 flooding as CO2 storage, quantitative characteristics of CO2 storage efficiency to be possible in that oil field should be understood for preventing a leak through fractures generated by high-pressured CO2 of free gas state prior to the injection of CO2. As an experimental system, we designed a two dimensional CO2 flooding apparatus equipped with sandstone plate. The apparatus had dip angles of 0° (horizontal system) and 90° (vertical system) to simulate gravity segregation condition. Experimental results for the vertical system showed that oil production was heavily influenced by gravitational effects for immiscible condition. This situation is analogous to thick reservoirs in which gravity dominates over viscous forces. However, for near-miscible condition, the gravity override phenomenon was not significant, and these results suggest that reservoir thickness should not be a criterion when using CO2 flooding. CO2 storage efficiency for near-miscible system was found to be much better than that for immiscible system regardless of the gravitational effect. For designing the CO2 EOR scheme in terms of relationship between CO2 storage and oil production, particularly in the case of high permeable homogeneous sandstone, we found out that the trapped CO2 as free gas state and oil recovery during the CO2 flooding were monotonically decreased without critical value of inflection point corresponding to CO2 injection rate increase.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Although DNA damage is considered a driving force for aging, the nature of the damage that arises endogenously remains unclear. Replicative stress, a source of endogenous DNA damage, is prevented ...primarily by the ATR kinase. We have developed a mouse model of Seckel syndrome characterized by a severe deficiency in ATR. Seckel mice show high levels of replicative stress during embryogenesis, when proliferation is widespread, but this is reduced to marginal amounts in postnatal life. In spite of this decrease, adult Seckel mice show accelerated aging, which is further aggravated in the absence of p53. Together, these results support a model whereby replicative stress, particularly in utero, contributes to the onset of aging in postnatal life, and this is balanced by the replicative stress-limiting role of the checkpoint proteins ATR and p53.
Full text
Available for:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Zein colloidal nanoparticles can adsorb at the oil–water interface to form Pickering emulsion. However, zein Pickering emulsion is usually not stable due to the poor wettability of zein colloidal ...nanoparticles. The objective of this study was to modify the surface of zein nanoparticles using sodium caseinate (NaCas) and assess the properties of zein/NaCas nanocomplexes and the resultant oil-in-water Pickering emulsions. One percent (w/w) of zein/NaCas colloidal nanocomplexes were formed, with the zein:NaCas ratios (w/w) ranging from 10:1 to 10:4 at pH = 3 by an ultrasound treatment. The zeta-potential of the zein/NaCas nanocomplexes showed altered surface charges, indicating that NaCas adsorbed on the surface of the zein colloidal nanoparticles. Three-phase contact angle measurements suggested that the original zein colloidal nanoparticles were preferentially wetted in water. The incorporation of 0.1%–0.2% (w/w) NaCas significantly enhanced its wettability in the oil, and intermediate wettability was achieved at a zein:NaCas ratio of 10:3. Confocal laser scanning microscope (CLSM) images showed that the incorporation of NaCas improved the interfacial coverage of the Pickering emulsions. When the zein:NaCas ratio ranged from 10:1 to 10:3, the interface was composed of zein/NaCas nanocomplexes. At a zein:NaCas ratio of 10:4, NaCas can competitively adsorbed to the interface and formed a hybrid interfacial structure. The Zein/NaCas nanocomplexes stabilized the Pickering emulsions and exhibited greater centrifugal stability than plain zein emulsions at most pHs and ionic strengths. The underlying mechanisms of the improved emulsion stability are discussed in this paper. This study explored a novel approach to stabilizing Pickering emulsions via the surface modification method using a food-grade protein.
Display omitted
•Zein colloidal nanoparticle wettability can be tuned by sodium caseinate.•Surface modification of zein improves Pickering emulsion centrifugal stability.•Surface loading of Pickering emulsions is higher than conventional emulsions.•Above a critical zein:NaCas ratio, NaCas competitively adsorbs to the interface.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Crossfield is located in the province of Alberta in Canada and is one of the most well-known reservoirs of hydrocarbons. Since the 1950s, there has been continuous exploitation of more than 10 ...formations such as Cardium, Viking, Ellerslie, Elkton, Shunda, and Wabamun. Because of its location near the Foothills, the southwestern part of the Western Canada Sedimentary Basin, the Crossfield area has a complex geology and relatively deeper reservoirs, therefore requiring an in-depth examination of each formation. In this study, geological, technical, and economic analyses were performed on each formation within the 10 sections of the study lands in the Crossfield area. As the result of the study, there was potential for drilling 48 horizontal wells in the Cardium A zone and the Viking formation. In addition, it turned out to be economically feasible even at the WTI price of 60 dollars per barrel considering Alberta’s Royalty Framework, which is determined by the production rate and the price of oil, and the Horizontal Oil New Well Royalty Rate feature. A further study is required to investigate the exploitation potential of the Cardium B zone, the Ellerslie, and the Elkton formations in this area.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
For the stable supply of oil and gas resources, industry is pushing for various attempts and technology development to produce not only existing land fields but also deep-sea, where production is ...difficult. The development of flow assurance technology is necessary because hydrate is aggregated in the pipeline and prevent stable production. This study established a system that enables hydrate diagnosis in the gas pipeline from a flow assurance perspective. Learning data were generated using an OLGA simulator, and temperature, pressure, and hydrate volume at each time step were generated. Stacked auto-encoder (SAE) was used as the AI model after analyzing training loss. Hyper-parameter matching and structure optimization were carried out using the greedy layer-wise technique. Through time-series forecast, we determined that AI diagnostic model enables depiction of the growth of hydrate volume. In addition, the average R-square for the maximum hydrate volume was 97%, and that for the formation location was calculated as 99%. This study confirmed that machine learning could be applied to the flow assurance area of gas pipelines and it can predict hydrate formation in real time.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
DNA damage is considered to be a prime factor in several spinocerebellar neurodegenerative diseases; however, the DNA lesions underpinning disease etiology are unknown. We observed the endogenous ...accumulation of pathogenic topoisomerase-1 (Top1)-DNA cleavage complexes (Top1ccs) in murine models of ataxia telangiectasia and spinocerebellar ataxia with axonal neuropathy 1. We found that the defective DNA damage response factors in these two diseases cooperatively modulated Top1cc turnover in a non-epistatic and ATM kinase-independent manner. Furthermore, coincident neural inactivation of ATM and DNA single-strand break repair factors, including tyrosyl-DNA phosphodiesterase-1 or XRCC1, resulted in increased Top1cc formation and excessive DNA damage and neurodevelopmental defects. Notably, direct Top1 poisoning to elevate Top1cc levels phenocopied the neuropathology of the mouse models described above. Our results identify a critical endogenous pathogenic lesion associated with neurodegenerative syndromes arising from DNA repair deficiency, indicating that genome integrity is important for preventing disease in the nervous system.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Purpose Dupilumab is recommended to be administered biweekly to treat adult patients with moderate-to-severe atopic dermatitis (AD). Real clinical practice data on the clinical efficacy of monthly ...dupilumab therapy are limited. We analyzed real clinical practice data on the clinical efficacy of monthly dupilumab therapy and predictive markers for favorable clinical responses to the therapy. Methods Medical records of 57 adult patients with moderate-to-severe AD who received dupilumab therapy every 4 weeks for 16 weeks were analyzed retrospectively. Eczema Area and Severity Index (EASI) were recorded at baseline and week 16. Clinical responses to monthly dupilumab therapy were defined as the proportion of patients with decreased EASI scores of at least 50% or 75% from baseline at week 16 (EASI-50 or EASI-75). Blood eosinophil counts and serum lactate dehydrogenase (LDH) levels were measured at baseline and week 16. Results Monthly dupilumab therapy showed EASI-50 and EASI-75 clinical responses in 48 (84.2%) and 27 (47.4%) of 57 patients at week 16, respectively. The percentage decrease in EASI scores from baseline at week 16 was significantly inversely correlated with baseline blood eosinophil count (correlation coefficient r = −0.405, P = 0.002) and baseline serum LDH level (r = −0.466, P < 0.001). The EASI-75 response rate was higher in patients with low (< 500/µL, 73.3%) than in those with high (≥ 500/µL, 37.5%) baseline blood eosinophil counts (P = 0.032), and was higher in patients with low (< 400 U/L, 55.6%) than those with high (≥ 400 U/L, 10.0%) baseline serum LDH levels (P = 0.013). Conclusions Monthly dupilumab therapy was clinically effective in adult patients with moderate-to-severe AD in real clinical practice. Baseline blood eosinophil count and serum LDH level could be predictive markers for clinical response to dupilumab therapy.
Electrical submersible pump (ESP) operation is compromised by free gas, resulting in premature pump failure and production losses in new wells. It is essential to detect the onset of abnormal ...operations. We develop a model that predicts abnormal ESP operation when the free gas level increases in the pump. The model compares operation parameters with the parameters of normal operating ranges; it shuts down the ESP when necessary. We used a Schlumberger PIPESIM software (version 2017.01) to perform nodal analysis technique; we tested the model using the other multiphase correlation model and field case studies (where the gas problem in ESP was reported). We employ a homogenous model to calculate the differential pump pressures at various gas volume fractions. Nodal analysis of the intake and discharge point predicted the commencement of abnormal ESP conditions and the associated parameters (critical gas fraction, minimum operating pump intake pressure, and pump discharge pressure). The model results were similar to other surging correlation models (e.g., Romero, Dunbar, Turpin, Cirilo, and Zhou models); they were also identical to field case studies. We identify three performance stability phases when an ESP is exposed to free gas. These are the normal and abnormal operating ranges, as well as the ESP shutdown condition. Modeling permits careful monitoring of ESP operations that can be compromised by free gas.
PDF
