Protecting wetlands and the life in them requires recognizing the biodiversity of these ecosystems. waterfowl and shorebirds that are ecologically dependent on wetlands are used as environmental in dicators. Bishe Dalan wetland with an area of ​​913.5 hectares is one of the largest wetlands in Lorestan province, which is located in the south of Boroujerd city and on the edge of Silakhor plain. In this study, species diversity indices (Shannon-Wiener and Simpson photos), species uniformity (Smith-Wilson indices and Simpson dominance) were used to study the species diversity of Bisheh Dalan (2017-2020). In Bisheh Dalan wetland, 9 Orders out of 22 Orders, 13 Families out of 78 Families and 48 Species out of 545 Species Identified in Iran, Census and registration, which are 40.09 percent of the order, 16.66 percent of the family and about 8 percent of Iranian bird species have lived in Bishe Dalan wetland. the results of bird species diversity study in Bishe Dalan wetland showed that 67.90 percent of the bird abundance of three species of green duck (Anas platyrhynchos), Common fox (Fulica atra) and Gypsy rooster (Vanellus vanellus) and about 41.66 percent of birds in the situation is protected and endangered. In terms of species diversity and species uniformity, 2019 had the highest rate of indicators. in general, the trend of heterogeneity and uniformity indices in the forest wetland is a sinusoidal corridor.

The Zagros orogeny as a central part of the Alpine-Himalayan orogenic belt is one of the most seismically active intracontinental fold-and-thrust belts on the Earth, and has an important role in active tectonics of the Middle East. The Hormuz Salt and several intermediate decollement levels, appears to be responsible for the most aseismic deformation of the Zagros sedimentary cover, and also to control the development of a large panel of fold structures, from detachment to fault-propagation folds with varying wavelength and rooting depth. The Dalan anticline located in the Fars province and mantled by soft Oligo-Miocene sediments in SW of the Central Zagros. For the kinematic and geometric analysis of the anticline based on satellite images, geological maps and field observations, three structural cross section perpendicular to fold axis have been studied. Comparing the position of the Dalan fold axis and axial plane in the aa', bb' and cc' cross sections indicates that in the axis of the anticline was rotated about 15 degrees toward the southeast. Regard to interlimb angle estimations and Ramsay classifications from all three cross sections, Dalan anticline is the open fold and 1B-1C classes, respectively. Based on geometrical and kinematic analysis and comparison from studied models such as Sattarzadeh et al, (2000) and Mitra (2003), the Dalan anticline is detachment fold type and compatible with the Lift –off Model With syncline evacuation model. In this model, limb rotation, migration of ductile sediment in outer hinges and syncline to core of anticline occurred.

The South Pars gas field is one of the Southwestern fields of Iran in Zagros sedimentary basin and consists of two Kangan and Dalan reservoirs. The Kangan and Dalan Formations belong to Dehram Group and are the most important gas reservoirs in Persian Gulf area. Petrophysical characteristics in the studied well were evaluated by the data of the well logs and cores. For an accurate evaluation, the necessary corrections were applied on logs by considering the places of wash out, environment effects, gas and shale effects. After that, the lithology of the Kangan and Dalan Formations were determined by using of cross plots of neutron-density, neutron-sonic, M-N plot, MID plot. On the based of Lithology, shale volume, presence of evaporite sediments and porosity, the Kangan Formation has been zoned to K1 and K2, and also the Dalan Formation has been zoned K3 and K4. The results show that the zone K2 of the Kangan Formation and the zone K4 of the Dalan Formation have an apporiate reservoir in terms of gas saturation level, porosity and Lithology. Kangan Formation, Dalan Formation, South Pars field, Petrophysical evaluation, Water saturation and gas

The main reservoir facies of the Upper Dalan Member consists of grain-supported ooilithic facies. This facies has been studied in terms of reservoir characterization and a core interval of the Upper Dalan Member (about 272m thick) was studied in the subsurface section of the Persian Gulf. According to sedimentological study, the facies can be subdivided into three microfacies; fine-grained peloid / ooid grainstone, medium-grained ooid grainstone and coarse-grained intraclast / bioclast ooid grainstone. These facies belong to lower intertidal (beach ridge) and oolithic-bioclastic shoal sedimentary environment. Effective factors on the reservoir subdivided into two sets; textural and diagenetic factors. Some cross plots and petrographical studies showing the significant effects of each parameter on the reservoir. Textural factors consist of grain size, grain shape, sorting and fabric and diagenetic factors as negative and positive effects includes of compaction, cementation, dissolution, dolomitization, anhydritization and fracturing.

The giant oil and gas fields in the northern Persian Gulf correspond to reservoir intervals which comprise Surmeh and Dalan formations. The main production units in these formations are their upper carbonates with typically ooid grain stone to dolostone lithofacies. As a comparative study the petro physical characteristics of these formations were considered based on core logging, well logging and petrography of thin sections. The upper carbonate unit of the Surmeh Formation was studied in the Tabnak Field and the Dalan Formation in the South Pars Field. The average porosities were 17.15% and 8.50% for the Surmeh and Dalan reservoirs respectively. Their permeability’s were 308 md for the Surmeh and 30 md for the Dalan reservoirs. This contrast in porosity-permeability data of the studied reservoirs correspond to their depositional and diagenetic history. The high reservoir potential of the Surmeh Formation correspond to its interparticle primary porosity partly remained after partial early cementation and its intercrystalline porosity due to dolomitization. This is different in the Dalan Formation which had a different diagenetic history and its porosity mainly reduced during compactional processes during the burial as well as burial cementation. However, although the Surmeh reservoir has a higher porosity and permeability, it has a lower production yield, because of its limited source rock and migration pathways.

South Pars gas field, is one of the field in south west of Iran in the Zagros Sedimentary basin. In this evaluation we have checked properties suchas porosity, water saturation, shale volume and lithology. Lithology of Kangan Formation in zone K1 consists of anhydrite, dolomite to limy dolomite and dolomitic limestone with some shale and average effective porosity in this zone is 8.6%, average effective water saturation is 16.6% and average shale volume is 3.6%. Lithology of zone K2 consists of limestone to dolomitic limestone, dolomite with some anhydrite and shale. Average effective porosity in this zone is 9.4%, average effective water saturation is 12.4% and average shale volume is 0.4% holds reservoir potential. Lithology of Upper Dalan Formation in zone K3 consists of dolomitic limestone, dolomite to limy dolostone with some anhydrite and shale. Average effective porosity in zone K3 is 7.5%, average effective water saturation is 11.5% and average shale volume is 7.9%. Lithology zone K4 consists of limestone to dolomitic limestone, dolomitic to limy dolostone and anhydrite with some shale. In this zone Average effective porosity 11.8%. Average effective water saturation is 10.3% and average shale volume is 2.7% holds reservoir potential.

The results may support the geologists to recognize the type of layers, layer thickness, sedimentary structures, fractures and separation of depositional environments. Therefore, study on formation lithology makes it possible for geologists to select appropriate strategies for drilling all kinds of wells and solving Study of formation lithology in oil and gas fields plays a significant role in view of drillers and geologists. any unpredicted problems during drilling operation. This paper aims to review drilling, geological reports, logs, cores of 26 drilled wells in the field and also using geostatistical methods to build models of drilled formations structure in the first step and thenas the second step to determine types of layers, layer thickness and their geologic age.

Permian deposits (Kubergandian-Lopingian) at Il-e Beyk section located in Bakhtiyari Zard Kuh, High Zagros, was studied comprehensively in regard to its fusulinids faunas for the first time. In this study 30 species belong to 14 genera were recognized and in addition one species (Rugososchwagerina zagroensis) was described systematically. Five Zones were distinguished in the studied section. The oldest one is Praeskinerella parviflucta-Chusenella? pseudocompacta is situated in the lower 120 m of the succession and is assignable to Kubergandian. The second zone is Eopolydiexodina persica occurs from 120 through 320 meters in the section and is referable to Early-Middle Murgabian. The Third zone is Chusenella schwagerinaeformis-Rugososchwagerina zagroensis that is found in a very narrow horizon within 320-350 m of the succession and yield late Murgabian-Early Midian age. The fourth zone is Parafusulina crassispira established from 360 to 435 m in the succession and is dated to Early Midian. The fifth zone is Afghanella schencki extended from 438 through 687 m and of latest Midian age. The strata rested in 920 m above the base of the section contain small foraminifers including Paraglobivalvulina sp. and Dagmarita sp. that can be considered Lopingian in age. The interval from 687 through 920 m yield no fossil and can be assigned to either Guadalupian or Lopingian age. Fusulinids studied in this paper demonstrate western Tethyan affinity.

One of the significant challenges in studying the oil and gas fields is assessing the fractured reservoirs. The existence of such fractures plays a crucial role in productivity and the amount of final offtake from hydrocarbon reservoirs, specifically, in carbonate formation. Hence, presenting a practical method in the identification and determination of fractures intensity is necessary. Image log tools are the first informative references in studying the fractured reservoir by which geologists can identify the details of layers, faults, fractures, and lithological status. FMI (Fullbore formation microimager) image logs are powerful tools in identifying fractures in wellbore surroundings. FMI image logs are indirect images with high resolution from wellbores. This study aims to employ the FMI image logs and optimal seismic attributes in assessing the fracture distribution in the field that we are about to study. To reach the target, 3D post-stack seismic data and FMI image log data of three wells (A, B, and C) that existed in the field are deployed. Two out of three wells (A and B) are utilized for determination and identification, and the third well (C) is utilized for validation which such identifications are carried out by “Geolog” software. As a result, fractures were identified in well A with a total of 152 open and closed fractures with a general trend of northeast-southwest, in well B with a total of 235 open and closed fractures with a general trend of north-south, and zones with high fracture density were determined. Therefore, with the usage of optimal seismic attributes in the “Hampson Russell”, the fracture density in the whole field was determined. Moreover, by using the distribution of fracture density, the field faults were determined. The results show that using the integration of FMI Image logs and seismic attributes is a practical method in studying and assessing the fracture distribution in fractured reservoirs.

This study focuses on the facies modeling and reservoir characterization of the Permian-Triassic age Dalan and Kangan formations, defined as the main reservoirs in the giant South Pars Gas Field in the Persian Gulf. Based on the main characteristics on petrographical observations, 12 facies are identified and classified into 4 facies associations representing tidal flat (LFAs 1), lagoon (LFAs 2), shoal (LFAs 3), and open marine (LFAs 4) conditions on a carbonate ramp. In uncored wells, a neural network approach (self-organizing maps) was employed to predict litho-facies and litho-facies associations (LFAs). The method was found satisfactory (87.5%) in litho-facies prediction using GR, DT, NPHI, RHOB, and PEF logs. The predicted LFAs were compared with the core-derived facies and rock types to generate a 2D facies model within the sequence stratigraphy framework for geologic modeling and subsequent reservoir simulation. Finally, geostatistical techniques are employed to prepare a 3D facies distribution and depositional model for the entire field. The stochastic simulation method was applied here to simulate and generate the 3D model of 4 major LFAs were involved in the modeling representing LFAs 1, LFAs 2, LFAs 3, and LFAs 4. Facies modeling of the formations indicates a gentle shallowing from zone K4 to zone K3. The connectivity of LFAs 3 is well observed in zone K4, whereas in zone K3 the connectivity of LFAs 2 is evident. Zone K2 is associated with dominant LFAs 3 and minor LFAs 4. The zone K1 is characterized by the dominance of LFAs 1.