Reservoir Quality Controlling Factor of the Asmari Reservoir in an Oil Field in Dezful Embayment, SW Iran

The Asmari Formation Oligo-Miocene in age is one of the most important reservoir rocks in SW Iran and Zagros basin and composed of carbonate rocks and locally sandstones and evaporates. In this research, reservoir quality controlling factors have been investigated in a well in one of the oil fields in Dezful Embayment, SW Iran. Based on this research, depositional environment, diagenesis and fracturing have been affected on reservoir quality. 3 distinct depositional settings can be recognized in the studied interval including tidal flat, lagoon, and shoal. Among these depositional setting, shoal environment with ooid grainstone microfacies along with interparticle porosity shows good reservoir characteristics. Diagenetic processes also play an important role on reservoir quality;dolomitization and dissolution have positive effects on porosity and enhances reservoir quality, while cementation, anhydritization and compaction have negative effect on it. Fracturing is another important factor affected on the carbonate reservoirs especially in the Asmari Formation.

Facies Analysis of Fahliyan Formation in North Dezful Embayment,Southwest Iran:Implications for Porosity Distribution

Fahliyan Formation(Neocomian) is one of the important hydrocarbon reservoirs of Khami group in southwest of Iran.This Formation has 332 m thickness in typical section and mainly consists of carbonate rocks.In this study,the Fahliyan Formation was investigated in subsurface section of AZN#B Well in the north Dezful embayment(with 281 m thickness).The lower boundary of Fahliyan Forma-

Application of Multi-well Subsidence Analysis of the Beryl Embayment,Viking Graben,Northern North Sea

The Beryl Embayment is situated at the south end of the North Viking Graben in the North Sea. Three sets of normal faults, with N-S, NW-SE and NE-SW orientations, have been recognized in the Beryl Embayment. High-resolution subsidence analysis of 73 wells, combined with some seismic data, has been used to document Middle to Late Jurassic subsidence patterns in this area. The high temporal resolution achieved （1 to 2 million years per data point） has also allowed an assessment to be made of temporal evolution of faults with different orientations, and a study made of how and when the East Shetland Fault was linked and controlled sedimentary facies distributions. The results indicate that the East Shetland Fault can be divided into northern and southern parts which were linked together during the Early-Mid Oxfordian. The Mid-Late Jurassic syn-rift phase can be divided into four stages： minor active extension stage during the Bathonian-Middle Callovian, early syn-rotational stage during the Late Callovian-Early-Mid Oxfordian, syn-rotational climax stage during the Late Oxfordian-Early Volgian, and late syn-rotational stage during the Mid-Late Volgian. The results also show that there was a sequential variation of extension direction of active normal faults with different orientations, with an overall shift in the dominant orientation of active normal faults from N-S in the Bathonian-Middle Oxfordian, through NNW-SSE in the Late Oxfordian-Early Volgian （≈N30°E）, to NW-SE （≈N45°E） in the Mid-Late Volgian.

Factor Controlling Reservoir Properties and Flow Unit Determination in the Ilam Formation of Dezfol Embayment at Zagros Fold-Thrust Belt, Southwest of Iran

Dezfol embayment in the Southwest of Iran is located in the Zagros fold-thrust belt, which is one of the world’s largest petroleum provinces. Ilam Formation (Santonian-Companian) is one of the reservoir formations in this area that has been less studied. This paper focused on reservoir properties in this formation using petrography and petrophysics data. According to the petrography studies Ilam Formation composed of limestone as dominant lithology. Detailed petrographic analyses, have led to identification of 10 micro-facies which are represented as a carbonate ramp depositional model. Also petrographic analyses are revealed that cementation, dissolution, compaction and dolomitization are most important digenetic processes. Detailed petrographic analyses and petrophysics data showed that due to mud-supported nature of more facies (inherited low reservoir potential from their depositional settings), diagenetic process plays an important role in increasing of reservoir quality. However cementation and dissolution had negative and positive effects on Ilam reservoir formation, respectively. Finally at the end for better correlation and to create a flow unit, according to the petrography data and using petrophysics log, this reservoir is divided into 5 units (flow unite) by using Geolog software and then they have been correlated across the field.

Geochemical Discriminant for Provenance Characterization and Palaeogeography of Shales from Dahomey Embayment, Southwestern Nigeria

The geochemical compositions [major, trace and Rare Earth Elements (REE)] of Cretaceous-Tertiary shales from Gbekebo-1 well were used to characterize provenance, paleogeography, source area weathering and tectonic setting of the study area located in the southwestern part of the Dahomey Embayment, Nigeria. Core samples (eight) of shales were obtained and analyzed geochemically using the combined methods of major elements Fusion Inductively Coupled Plasma (FUS-ICP) and trace elements Fusion Inductively Coupled Plasma Emission/Mass Spectrometry (FUS-ICP/MS). An A-CN-K (Al2O3-CaO + Na2O-K2O) ternary plot, geochemical discriminant function of major elements and chondrite normalized plots of REE suggest an upper continental crust provenance of felsic to intermediate or mixed igneous rocks of tonalite to granodiorite composition. High values of chemical index of alteration (CIA, 82.22 - 96.39) and chemical index of weathering (CIW, 88.10 - 99.17) indicated a palaeogeographic condition marked by wet tropical climate where intense chemical weathering and erosion prevailed. The Cretaceous-Tertiary shales from Gbekebo-1 well are inferred to have been deposited in passive margin setting based on various geochemical tectonic setting discrimination diagrams.

Fundamental study on mixing layer and horizontal circulation in open-channel flows with rectangular embayment zone

A part of mean kinetic energy in a main-channel is used for production of a large-scale horizontal circulation in the side cavity. However, the details of the mechanism such as energy transport are poorly understood. Therefore, we conducted PIV mea- surements in a laboratory flume and compared space distributions of mean velocity components and Reynolds stress by varying a cavity geometry. In particular, a practical calculation method of Reynolds stress was also developed and its accuracy was examined by comparison with the measured data. Furthermore, contributions of components in an energy transport equation were revealed quantitatively.

Provenance, Tectonic Setting and Geochemistry of Ahwaz Sandstone Member(Asmari Formation, Oligo-Miocene), Marun Oilfield, Zagros Basin, SW Iran

The Asmari Formation deposited in the Zagros foreland basin during the OligoceneMiocene.Lithologically,the Asmari Formation consists of limestone,dolomitic limestone,dolomite,argillaceous limestone,some anhydrite （Kalhur Member） and sandstones （Ahwaz Member）.This study is based on the analysis of core samples from four subsurface sections （wells Mn-68,Mn-281,Mn-292 and Mn-312） in the Marun Oilfieid in the Dezful embayment subzone in order to infer their provenance and tectonic setting of the Ahwaz Sandstone Member.Petrographical data reveal that the Ahwaz Sandstone comprises 97.5% quartz,1.6% feldspar,and 0.9% rock fragments and all samples are classified as quartz arenites.The provenance and tectonic setting of the Ahwaz Sandstone have been assessed using integrated petrographic and geochemical studies.Petrographic analysis reveals that mono-and poly-crystalline quartz grains from metamorphic and igneous rocks of a craton interior setting were the dominant sources.Chemically,major and trace element concentrations in the rocks of the Ahwaz Sandstone indicate deposition in a passive continental margin setting.As indicated by the CIW index （chemical index of weathering） of the Ahwaz Sandstone （average value of 82） their source area underwent ＂intense＂ recycling but ＂moderate to high＂ degree of chemical weathering.The petrography and geochemistry results are consistent with a tropical,humid climate and low-relief highlands.

GRACE RL05-based ice mass changes in the typical regions of antarctica from 2004 to 2012

The Antarctic ice sheet is the largest block of ice on Earth, a tiny change of its ice sheet will have a significant impact on sea level change, so it plays an important role in global climate change. The Gravity Recovery and Climate Experiment （GRACE） mission, launched in 2002, provides an alternative method to monitor the Antarctic ice mass variation. The latest Release Level 05 （ RL05 ） version of GRACE time-variable gravity （TVG） data, derived from GRACE observations with improved quality and time-span over 10 years, were released by three GRACE data centers （CSR, JPL and GFZ） in April 2012, which gives us a chance to re-estimate the ice mass change over Antarctic more accurately. In this paper, we examine ice mass changes in regional scale, including Antarctic Peninsula （AP, West Antarctica）, Amundsen Sea Embayment （ASE, West Antarctica）, Lambert-Amery System （LAS, East Antarctica） and 27 drainage basins based on three data sets. The AP mass change rates are -12.03±0.74 Gt/a （CSR, 2004-2012）, -13.92±2.33 Gt/a （JPL, 2004 -2012） , -12.28±0.76 Gt/a （GFZ, 2005-2012） , with an acceleration of -1.50±0.25 Gt/a^2, -1.54±0.26 Gt/a^2, -0. 46±0.28 Gt/a^2 respectively, the ASE mass change rates are -89.22±1.93 Gt/a, -86.28± 2.20 Gt/a, -83.67±1.76 Gt/a with an acceleration of -10. 03±0. 65 Gt/a^2, -8.74±0. 74 Gt/a^2 and -5.69 ±0.68 Gt/a^2, and the LAS mass ehange rates are -4.31±1.95 Gt/a, -7.29±2. 84 Gt/a, 1.20±1.35 Gt/a with an acceleration of -0. 18±0.62 Gt/a^2, 3.55±0.95 Gt/a^2 and 0.97±0.49 Gt/a^2. The mass change rates derived from the three RL05 data are very close to each other both in AP and ASE with the uncertainties much smaller than the change rates, and mass losses are significantly accelerated since 2007 in AP and 2006 in ASE, respectively. However, the mass change rates are significantly different in LAS, negative rate from CSR and JPL data, but positive rate from GFZ data, the uncertainties are even larger than the correspondent change rates. With regard to the 27 drainage basins, seven basins （basin 3-9） located in the east Antarctica show positive mass change rates, and the rest twenty basins are characterized by negative mass change rates during the time span of the three RL05 data.

Land-Sea Interactions in Punta China(Baja California,Mexico):Addressing Anthropic and Natural Disturbances in a Retrospective Context

In extensive SCUBA-diving surveys of kelp forests along 350 km of the Baja California peninsula coastline from the US-México borderline to Sacramento Reef, benthic species richness has been satisfactorily explained by environmental structural features such as bottom rugosity. However, values at Punta China embayment (PCE) departed significantly from the model whereas the adjacent Santo Tomás cove (STC) did not. In addition, in August 20, 2011, visibility was under 1 m at PCE and over 10 m at STC;these conditions presumably reflect the influence of the limestone extraction industry located on land. In order to investigate the case allowing for temporal comparisons, we set a regional research scenario similar to a 1993 pioneer study, comprising PCE and two contrasting sites (STC to the North, and San José embayment, SJE, to the South). Land and sea side were addressed separately, and a 1950-2012 time-span period was set in order to perform the analysis of retrospective data. Our results suggest that the current scenario results from the combined influence of a local, anthropic and chronic land-based disturbance represented by the progressive expansion of limestone extraction industry, and the episodic influence of a natural, large scale and acute disturbance represented by the 1982-83 and 1997-98 El Nino events. The influence of both driving forces, however, is not necessarily equally distributed in space, yielding a regional mosaic of natural and social conditions. Our results confirm and expand previous knowledge in the area, and may contribute to?future basic and applied research.