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Journal of Petroleum Science and Technology *Corresponding author AN EXPERIMENTAL INVESTIGATION OF GRAVITY DRAINAGE DURING IMMISCIBLE GAS INJECTION IN CARBONATE ROCKS UNDER RESERVOIR CONDITIONS
No full textABSTRACT Gravity drainage is one of the important recovery mechanisms in fractured carbonate and conventional reservoirs. It occurs due to density difference between the gas in fracture and the oil in matrix as well as in conventional tilted reservoirs. Oil phase will form films which are produced under gravity forces (film flow). Many gas injection experiments have been done on laboratory scales with dead oil, but, herein, we would like to recombine oil under reservoir conditions. In this paper, the gravity drainage process is considered during immiscible gas injection in carbonate core saturated with recombined oil at reservoir temperature and pressure. Recombined oil was prepared from dead oil and a solvent (methane and propane) mixed in recombination apparatus. In these experiments, nitrogen gas is injected in a single matrix block at different rates and directions. Since the recovery of oil depends on the gas injection flow rate, the recovery of oil is maximized at a specific flow rate. The results show that gas injection at gravity drainage rate gives the maximum recovery, and ultimate recovery decreases at much higher injection rates. Comparing the gas injection results in horizontal and vertical directions shows that the recovery is higher in the vertical direction than the horizontal direction
High resolution planktonic foraminiferal biostratigraphy of the Gurpi Formation, K/Pg boundary of the Izeh Zone, SW Iran
No full textPalaeoenvironmental study and sequence stratigraphy of Sanghaneh Formation in Qalehjegh section (North of Bojnord) using organic matter contents of the rock unit
No full textIntroduction Kopeh-Dagh basin is located northeast of Iran and in this basin the sedimentary beds began from middle Jurassic. The Sanghaneh Formation is one of the lower Cretaceous rock units in sections. One of the important fossils group are palynomorphs that described very abundant in this formation. Dinocysts diversity on this formation is more than other palynomorph groups. Palynological studies are done by keshmiry et al. (2014), davtalab et al. (2007) and etc. This formation here is laying on Sarcheshmeh Formation and is covered by Aitamir Formation. The age of this formation in the Qalehjegh section based on the dinoflagellate assemblage, is Late Aptian – Early Albian. Purpose of this research is palaeoenvironmental study base on palynofacies interprets and to separate sedimentary sequence Kopeh-Dagh sedimentary basin. Qalehjegh section is located between 57 ˚ 23 ’ 03 ” E and 37 ˚ 43 ’ 17 ” N. The formation comprises mainly calcareous shale and shale with siltstone and interlaminations of limestone and argillaceous limestone. The Sanghaneh Formation is studied base on several group of fossils in other using organic matter contents of the rock unit. Material & Methods For palaeoenvironmental and sequence stratigraphy purposes, 127 rock samples collected from the formation and prepared in the palynology laboratory.Standard preparation methods were used (Traverse 2007). Cold hydrochloric (30%) and hydrofluoric (30%) acids were used to dissolve carbonates and silicates. No oxidants or alkalis were used. The residue was neutralized and centrifuged in ZnCl2 (specific gravity 1.9), then sieved at 20 µm using a nylon mesh, and mounted on microscope slides using liquid Canada balsam and then the slides were examined in the transmittal microscope. Discussion of Results & Conclusions Palaeoenvironmental interpretation: Three main groups of sedimentary organic matter (SOM) can be distinguished: (1) amorphous organic matter (AOM), (2) phytoclasts including black and translucent matter and (3) palynomorphs including (dinocysts, acritarchs, foraminifera linings, spores and pollen grains). Compositional changes in palynofacies are useful in palaeoenvironmental interpretations of sedimentary rocks (Tyson, 1993). The results of all are plotted on an AOM– Phytoclasts–Palynomorphs ternary diagram after Tyson (1995). Studying Sanghaneh Formation in Qalehjegh section based on the three major groups of organic matter debris found in palynology slides (Palynomacerals or Phytoclasts, Marine Palynomorphs and Amorphous Organic Matters), four types of palynofacies were recognised: palynofacies II: Marginal basin, III: Proximal shelf, IV: Shelf to basin transition, V: Distal shelf. Pf1: This palynofacies is marked by an increase in phytoclasts content (65-90%) compared to palynofacies III and IV, and low frequency of marine palynomorphs (5-15%) and AOM (5-25%). AOM diluted by high phytoclast input, but AOM preservation moderates to good. Generally low AOM preservation. This facies was represented Marginal dysoxic - anoxic basin . It represents type II kerogen of Tyson. This palynofacies was recognised in samples 1058, 1053, 1040, 970, 963, 918, 907, 820, 808, 772, 762, 759, 750, 744, 4946, 4944, 4907, 4894 and 4892. Pf2: This facies is characterized by high phytoclasts (50-80%), low AOM (5-15 %) and common marine palynomorphs (15-45%). This facies was represented Heterolithic oxic shelf ("proximal shelf") and it was represented type III kerogen of Tyson (1993). This palynofacies was founded in samples 1036, 1012, 991, 987, 983, 978, 974, 952, 942, 931, 922, 910, 904, 899, 897, 885, 859, 841, 833, 830, 827, 816, 810, 791, 781, 766, 756, 5012, 5007, 5005, 5003, 5000, 4998, 4991, 4980, 4942, 4928, 4926, 4922, 4920, 4916, 4914, 4909, 4888, 4884, 4882, 4878, 4872 and 4870. Pf3: This is characterized by low marine palynomorphs (10-25%), 4-45% AOM and a predominance of phytoclasts 40-80% of the total particulate organic matter [POM]). The facies is proportionate with fourth palynofacies (IV) of Tyson (1993). This facies is represented Shelf to basin transition and it was recognised in samples 1061, 1042, 1032, 1028, 1027, 1017, 1004, 966, 950, 948, 945, 934, 881, 877, 874, 869, 855, 851, 845, 838, 813, 806, 802, 794, 774, 5016, 5014, 5010, 4994, 4989, 4975, 4966, 4948, 4940, 4932, 4924, 4918, 4912, 4898, 4896, 4890, 4886, 4880 and 4874. Pf4: This facies is characterized by a moderate to high abundance of Marine palynomorphs (30–70%), a moderate abundance of phytoclasts (20–45%) and a low to moderate abundance of AOM (5–30%). Rising of marine palynomorphs depends to offshore condition. The facies is proportionate with fifth palynofacies (IV) of Tyson (1993) and it represented distal shelf sedimentary environment. This palynofacies was founded in samples 1024, 1020, 1008, 955, 939, 894, 889, 879, 865, 788, 786, 4959, 4938, 4903 and 4901. Federova (1977) and Duringer & Doubinger (1985) have used plots of spores, pollen, and microplankton in a ternary diagram to indicate general depositional environments and associated regressive-transgressive trends. This ternary is considered here as a useful tool for recognizing and indicating the possible depositional environments and changes in trends of marine sedimentation. Based on this plot, sedimentary environment of Sanghaneh Formation recommended as from shallow marine (neritic) to offshore (moderately deep). Assimilating palynofacies with palynology plot data, sedimentary environment setting of the formation on Qalehjegh section is recommended shelf area and with a suboxic-dysoxic conditions. Separating sequences of the Sanghaneh Formation: One of approach in sequence stratigraphy is using from palaynologycal agents. In this study is used almost some agents of palynology to separate sequences. The palaynologycal agents used here is inclusive: phytoclacts percentage, opaque phytoclasts percentage, brown phytoclasts percentage, opaque to brown phytoclasts ratio, cubic to lath opaque phytoclasts ratio, AOM percentage, terrestrial palynomorphs absolute abundance, marine palynomorphs percentage and dinocysts diversity. In Transgressive System Tract (TST) is increased marine palynomorphs (Leckie et al. 1992), AOM (Tyson 1993), dinocysts diversity (Habib 1982) and lath opaque phytoclasts contents. In contrast in this systems tract phytoclasts contents (Tyson 1993) and terrestrial palynomorphs are decreased (e.g. Habib 1982). But from TST to Highstand System Tract (HST) is descended marine palynomorphs, AOM, dinocysts diversity and lath opaque phytoclasts contents and phytoclasts, terrestrial palynomorphs and cubic opaque phytoclasts contents is ascended. In sequence boundary brown phytoclasts content and terrestrial palynomorphs are abundant (Tyson 1993) and in maximum flooding surface (mfs) opaque phytoclasts contents and marine palynomorphs are most abundant (Habib 1982). Based on palynofacies analysis tree genetic stratigraphic sequences (A, B and C) w ere recognized. Genetic sequence A is extended until depth of 0-720 m. In this sequence TST started may be is part of the Sarcheshmeh Formation until depth of 350 m, and HST was begun from depth of 350-720 m. Genetic sequence B is bounded by the sequence boundary A (Sb1) and the sequence boundary B (Sb2). It is started form depth of 720-1350 m. HST and HST is placed from 720-1140 and 1140-1350 m. Genetic sequence C is bounded from down by the sequence boundary C (Sb3) and up boundary is not distinct.In this sequence TST is started from depth of 1350-1600 m and HST is started from 1600 m and continues to end of the formation. Studying the Sanghaneh Formation in Qalehjegh section based on the three major groups of organic matter debris found in palynology slides, four types of palynofacies were recognized: II, III, IV and V. According to palynofacies analysis, the formation depositional setting varies from shallow to moderately deep environment under suboxic-dysoxic conditions. In the interpreted palaeoenvironment using ternary palynomorph plot, it is recommended that sedimentary environment of the formation is shallow marine to offshore. Statistical studies on palynofacies factors and palynomorphs plot represent sedimentary environment setting of Sanghaneh Formation in Qalehjegh section as a shelf area with suboxic-dysoxic conditions. Similarly the stratigraphic analysis of palynofacies changes led to the separation of three sequences with their boundaries
Late Campanian to Paleocene Planktic Foraminiferal Biozonation for Izeh, the Zagros Basin, Iran
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Palaeobathymetry of the Abderaz Formation using foraminifera, Iran
Get PDFAbderaz Formation at its type section with an age of Turonian-early Campanian and a thickness of 300 m contains light grey shale and marl. The study of the planktonic foraminifera in isolated form led to differentiate three morphotype groups. The first group is characterized by trochospiral tests usually indicate shallow waters, the second group contains forms with strong ornamentations and the primary keels representing mid waters and finally compact trochospiral tests with keels known as deep water indices are included in the third group. Studies on the morphotypes showed a regressive cycle for Abderaz Formation. Also the planktonic to benthic ratio was calculated using Depth = e^(3.58718 + (0.03534 × %*p)^ equilibrium which explains that at the deposits 400 meter at total part of in this Formation. This study was intended to explore the marine sedimentation of Abderaz Formation in (outer neritic-upper bathyal) restrict and the provided curves from morphotypes changes are in full agreement with the curves of the sea level changes and planktonic foraminifer to epifauna benthic ratio
The study of the umbilical system in planktonic foraminifera in relation with depth of the Abderaz Formation at type section, IRAN
Get PDFProspect of changes in such umbilical structures as Lip, Portici and Tegilla throughout Turonian-Campanian was also investigated. The phylogenic trend show that Lip structure in primary morphogroups turns gradually to tegilla in more developed forms in which the opening become also entirely umbilical. Statistical an analysis showed that the trends of changes are correlatable with increase in water depth while a decrease in depth result in development of lip in the planktonic foraminifera studied. The changes are considered to be in accord with Pascal law
Palaeobiogeographic implications of Late Bajocian–Late Callovian (Middle Jurassic) dinoflagellate cysts from the Central Alborz Mountains, northern Iran
No full textVariations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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