Effect of salinity degree of injected water on oil recovery from carbonate reservoir

32-37Water injection is considered the most successful and widespread secondary recovery method. Low salinity water injections is a well-established and proved technique for water flooding application in sandstone rocks to enhance the recovery efficiency; where the water salinity is adapted to a certain degree to extract the highest amount of oil from a reservoir. Reserve-estimation statistics show the significance of oil reserves in carbonate reservoirs, hence this work deals with the carbonate rocks where water flooding may fail due to many reasons, and the most common one is fractures existence in the carbonate rocks. This work applied the water injection for six carbonate (limestone) core samples from Belayim Formation of Middle Miocene age that extracted from an Egyptian offshore oil field in the Gulf of Suez. This carbonate facies is hard, vuggy, fragmented, dolomitic, and highly saturated with oil and considered a good reservoir. Relative permeability test was carried out to investigate the reservoir response in terms of recovery efficiency hence residual oil saturation, when flooding the reservoir with waters having different salinity ratios. Results showed an increase in recovery efficiency for all the tested samples, on applying the low salinity water injection, where all the relative permeability curves displayed wettability modification/alteration toward water wetness properties

Effect of acidizing rate on enhanced oil recovery for Eocene Thebes limestone, Eastern of the Gulf of Suez, Egypt

38-42Thebes Limestone of Eocene age contributes to oil producing reservoir of Abu Rudeis Field. Acidizing process has been applied successfully for many years to increase the productivity of petroleum wells in carbonate formations, consequently demands of application acidizing techniques are increasing. Carbonate acidizing differs than that occurs in sandstone because the reactive nature of a carbonate rock, as a result of this, carbonate acidizing causes formation of large flow channels in some portions of the rock comparing with the original pore size distrubution, in addition enlarging of some aspects as diameters, areas and volumes of original pores. This study investigated that the presence of oil slows reaction rate of HCL acid with a carbonate reservoir rock, where the treatment of carbonate reservoir rock with high concentrated HCL acid speeds up the acidizing rate, decreases the effect of oil within the rock and creates much new channels that facilitate injectivity and productivity of oil wells. The effects of acidizing on carbonate rocks at various conditions were different and obvious, consequently help us to improve the oil recovery from reservoir rocks

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

A new processing for improving permeability prediction of hydraulic flow units, Nubian Sandstone, Eastern Desert, Egypt

Abstract Fifteen surface sandstone samples of Late Cretaceous age were compiled from Wadi Kareem area in Eastern Desert, Egypt. Samples were subjected to permeability and porosity measurements to show their distributions and possibility of separating them into different hydraulic flow units. It is known that hydraulic flow unit is a volume of rock within a reservoir that has petrophysical and lithological attributes that affect flow properties and differ from those of surrounding units. It was found out that the normal application of Amaefuleʼs hydraulic flow unit approach using the relation of normalized porosity index (ϕ Z) versus reservoir quality index (RQI) and FZI values at (ϕ Z) = 1 leads to deviation of predicted permeability from the measured one in case of scattered data of (ϕ Z-RQI) relation having a unit slope trend line. In the present study, the additional new processing leads to close matching between the measured and predicted permeability, hence reservoir description improvement. This is simply done through differentiation of all samples that lie on the unit slope trend line and those lie scattered on both sides of it, into three sub-flow units regardless their slopes and the use of (FZI) arithmetic average for each sub-unit instead of that at (ϕ Z) = 1. Permeability prediction has been improved after applying the new additional processing. Capillary pressure-derived parameters for some selected samples as micropores, mesopores, and macropores, used to support the new concept

Miocene reservoir rocks: pore throat size distribution as a strong controller on petrophysical attributes is a reflection of facies change

Abstract Pore throat size distribution (PSD) is considered a finger print for each rock type and has strong effects on many petrophysical parameters, so a comparative study was done on irregular subsurface rock samples that belong to Kareem and Rudeis Formations of middle and early Miocene, respectively. These samples were collected from San El-Hagar-1 well which is located to the East of the Nile Delta to show the effect of the different lithologies on pore throat size distribution and hence many related reservoir parameters such as displacement pressure, macroporosity, microporosity, mean hydraulic radius and permeability distribution function (PDF). For achieving the previous purpose, helium porosity and capillary pressure by mercury injection were carried out. Permeability measurements were canceled due to the non-cylindrical irregular nature of the tested samples. Porosity showed a great difference between the results of the samples of the two formations. Capillary pressure results showed the presence of characterized pore throat size distribution and hence capillary pressure-derived parameters for samples of each formation. PDF showed that samples of Kareem Fm. have better reservoir flow properties (permeability) in contrast to those of Rudeis Fm. which have tight reservoir flow properties. In addition, petrographical study through thin sections and scanning electron microscope displayed the presence of two facies which are feldspathic quartz wacke (sandstone facies) of Kareem Fm. and bioclastic sandy wackestone (calcareous facies) of Rudeis Fm. All results were consistent and confirmed the influence of facies change on PSD and hence the reservoir parameters

Lower Paleozoic reservoir zonation into different flow units using turbulence factor and their relations to diagenesis

Abstract Surface Lower Paleozoic sandstone samples were collected from southeast central Sinai. These samples subjected to petrophysical measurements which are porosity and permeability. It is known that turbulence factor (β) is a good tool to describe turbulent flow level, hence it was used to detect the flow properties distribution that corresponds to the nature of the pore system, so turbulence factor (β) was correlated with porosity, permeability, and reservoir quality index using many equations, where porosity correlation shows the presence of three groups having same porosity ranges but correspond to different values of turbulence factor, this refers to the presence of different flow zones. Porosity–permeability relation confirmed also the presence of similar three groups, where there are nearly same porosity ranges but with different permeability values. Consequently, samples with nearly same porosity values and representing the three groups were selected for capillary pressure by mercury injection to reveal the flow properties that characterize each group. Capillary pressure results confirmed that each group has their own pore system and flow regime. Petrography was done by optical polarizing microscope (OPM) through thin sections. The results indicated that the studied sandstone is composed mainly of quartz arenite microfacies of fine, angular to subrounded, moderately well sorted monocrystalline quartz grains. There are several features indicating that the investigated sandstones have been subjected to diagenesis processes. Diagenetic events identified in these sandstones include considerable compaction during burial diagenesis at higher temperatures and low flow rates, cementation by clay minerals and iron oxides, dissolution and alteration of unstable clastic grains, and tectonically induced grain fracturing. Unstable clastic grains like feldspars suffered considerable alteration to kaolinite when exposed to meteoric water of low ionic strength near the surface. The distribution of this kaolinite rather than the post-depositional iron oxides in pores of the studied sandstone leaded to differentiating these sandstones into three different flow units. This zonation indicates that the turbulence properties are proportional to the diagenetic effects inside the pores

Magnetic susceptibility as an indication of reservoir properties of the Nubia Group in Aswan-Komombo, Southern Egypt

The magnetic susceptibility is a reflection of minerals like the iron oxide that affect the pore system. This work applied the magnetic susceptibility as an effective indicator of reservoir quality. A total of (38) sandstone samples were collected from the Nubia Group exposed in Northeast Aswan, representing the Sabaya, Abu Agag and Um Bramil Formations. The samples were petrophysically examined in terms of porosity, grain density, bulk density, permeability and magnetic susceptibility (κ). Reservoir quality index (RQI) and distribution of the sample within the Global Hydraulic Elements (GHEs) were determined. Several relations constructed between (κ) as a function of iron oxides and the measured properties. The results showed Sabaya and Abu Agag samples are characterized by the highest average values of κ, (287 &amp; 219SI) respectively, matched with the lowest average values of porosity, permeability, RQI and the highest average values of grain &amp; bulk density, hence most samples lie in the lower quality zones (GHE-1, 2, 3 and 4). On the contrary, the lowest average value of (κ) is (37.9 SI) for Um Bramil samples, matched with the highest average values of porosity, permeability, RQI and the lowest average values of grain &amp; bulk density, hence most samples lie in the higher quality zones (GHE-6, 7 and 8). Petrographic description showed the tight and wide pore system relation to the magnetic susceptibility values. The novelty here is utilizing the magnetic susceptibility as an effective pointer for the reservoir quality expectation and classification into hydraulic units

Evaluating the effect of Perfluoropropane assisted pneumatic vitreolysis in cases of symptomatic focal vitreomacular traction

Purpose The aim of this study was to evaluate the effect of pneumatic vitreolysis (PVL) in the management of symptomatic focal vitreomacular traction (VMT). Patients and methods This prospective non-comparative interventional study was conducted on 21 eyes of 20 patients with isolated focal VMT detected by optical coherence tomography (OCT). All patients were symptomatic complaining of decreased vision and/or metamorphopsia with persistence of VMT for at least 3 months before intervention. All patients received a single intravitreal injection of 0.3 ml pure perfluoropropane (C3F8) and were followed up for 6 months post-injection. During the follow up period, the patients were evaluated regarding the occurrence of release of VMT as detected by OCT, the change in best corrected visual acuity (BCVA), and the change in central macular thickness (CMT) by OCT. Results The single intravitreal gas injection of C3F8 resulted in the release of VMT in 16 (76.2%) eyes. The mean BCVA significantly improved from 0.71±0.16 LogMAR (range: 1–0.5) at baseline to 0.38±0.22 LogMAR (range: 1.0–0.2) by the final visit at 6 months postoperatively (P<0.001). In addition, the mean CMT significantly decreased from 461.67±68.60 µm (range: 318–573 µm) at baseline to 331.55±90.27 µm (range: 278–568 µm) at 6 months postoperatively (P<0.001). One patient developed a retinal break and was treated by retinopexy, and one patient developed a full-thickness macular hole that was treated by vitrectomy. Conclusions PVL was found to be an effective method for treatment of symptomatic VMT

Cyclodepsipeptides: Isolation from Endophytic Fungi of Sarcophyton ehrenbergi and Verification of Their Larvicidal Activity via In-Vitro and In-Silico Studies

Culex pipiens mosquitoes are vectors to many viruses and can transmit diseases such as filariasis and avian malaria. The present study evaluated the larvicidal activity of marine-derived endophytic fungi Aspergillus nomius and Aspergillus flavus from the soft coral Sarcophyton ehrenbergi along with two known cyclodepsipeptide compounds, scopularide A (1) and B (2), isolated from A. flavus extract, against third-instar larvae of C. pipiens, using distilled water as a negative control and toosenedanin as a positive control. The structures of the isolated compounds were confirmed by various spectroscopic analyses. The lethal concentrations (LC50 and LC90) were calculated by probit analysis. Scopularide A was the most potent after 96 h treatment, with LC50 and LC90 values of 58.96 and 994.31 ppm, respectively, and with 82.66% mortality at a concentration of 300 ppm. To unravel the biochemical mechanism of the tested extracts and compounds, their effects against protease, chitinase, phenoloxidases and lipase enzymes from the whole-body tissue of C. pipiens were evaluated after 72 h treatment at LC50 dose. Superior activity was observed for A. flavus extract against all tested enzymes. A molecular docking study was conducted for scopularide A and B on the four tested enzymes, to further verify the observed activity. Results revealed good binding affinities for both compounds as compared to the docked ligands, mainly via a number of hydrogen bonds. This was the first study to report the isolation of endophytic fungi A. flavus and A. nomius from the marine soft coral S. ehrenbergi. The endophytic fungal extract of A. flavus was found to be a promising source for a natural larvicidal agent against C. pipiens populations