فهرست مطالب رضا میرزایی محمودآبادی

The Campanian-Maastrichtian sequence in the Shiraz region of Inner Fars includes Gurpi and Tarbur formations. In order to study petrography and evaluate the evolution of the sedimentary environment and sequence stratigraphy of these sediments, two stratigraphic sections of Koh-e Qhale and Koh-e Shahrek Abarj in Marvdasht city of Fars province were selected and analyzed. Based on field studies, manual samples, and a detailed microscopic study of 250 thin sections prepared from the studied formations, it was identified that 14 facies (11 carbonate microfacies and three lithofacies) were deposited in a shelf carbonate platform. By studying about 1400 meters of Maastrichtian sediments, depending on the location of the sections under study, three third depositional sequences were identified and separated in terms of sequence stratigraphy. During the Campanian period and the formation of the LST systems tract towards the northeast of the studied area (Koh-e Qhale section), the clastic sediments of the lower part of the Tarbur formation and in the deeper parts of the sedimentary basin of the Gurpi formation were deposited equivalently. At the time of the highstand systems tract (HST facies) and high carbonate production rate in the steep part of the sedimentary environment, interlayered reef deposits (rudist packstone and rudist grainstone) were deposited between the limestones of the Tarbur Formation.

Today, hydrocarbon reservoir modeling methods used for optimal production, predicting reservoir behavior, and production management is very important. In this study, the geology of the Bangestan reservoir was analyzed along with the evaluation of a 3D geological model created by RMS software (structural and petrophysical models) of the Kaboud oil field. The petrographic study of the concerned samples indicates that the main lithology of Bangestan Reservoir in this field consists of limestone, shale, dolomite, and pelagic limestone. Using the merge of geological (paleologs), petrophysical, structural, and RMS output data, the Bangestan Reservoir was subdivided into 8 zones and 4 subzones. The results obtained by the geostatic models prepared by RMS showed that the most proper reservoir zone considering petrophysical features in Bangestan Reservoir is zone No. 4. The stratigraphic correlation of Bangistan Reservoir in Kabud oil field based on the studied wells showed that this zone has the highest thickness in well 1 and the least thickness in well 5. In the prepared cross-section prepared according to NTG, it is observed that the more the layers move towards the east of the field, the better the reservoir quality would be. Volumetric calculations verified that the volume in place of oil in normal conditions is 048/308/72 barrels which correspond to zone No. 4.

In the present study, for the first time, a three-dimensional geological model of Asmari/Shahbazan reservoir (structural, petrophysical, porosity and water saturation model) of Balarud oil field using geophysical, petrographic and structural information by 6 wells of this field RMS software was created. Petrographic study on sample (well number 1) shows that the main lithology of Asmari / Shahbazan reservoir in this field is limestone, dolomite and dolomitic limestone. Combining the available data, it was found that the Asmari / Shahbazan reservoir in Balarud oily field can be divided into 5 zones, with Zone 2 being divided into 3 sub-zones. Assessment of the maps extracted from the models shows that the best reservoir zone in terms of petrophysical characteristics is in Asmari / Shahbazan reservoir zone 1. Using the study of lateral and longitudinal sections prepared by the RMS software, changes in the thickness of the zones and how to expand the reservoir zones of the study area were determined. Examination of the petrophysical model of Asmari reservoir shows that the East and Northeast areas of the reservoir have better hydrocarbon potential compared to other areas of the reservoir and the more the layers extend to the Northeast of the field, the better the reservoir quality. In volumetric calculations, the volume in place of hydrocarbons in normal conditions has been calculated 658226013 barrels. Of this amount, the highest volume of oil is allocated to zone number 1 of the reservoir.

Paleocene-Eocene succession in the Shiraz region includes Sachun and Jahrom-Pabdeh formations. In order to study petrography, sedimentary environment, and sequential stratigraphy, 4 stratigraphic sections of Beiza, Sadra (auxiliary), Sarvestan, and Shahneshin were selected and analyzed. Based on field studies, manual samples, and detailed microscopic study, 800 thin sections prepared from the studied samples were identified as 23 microfacies and lithofacies deposited in a homoclinal carbonate ramp model. This model the time evolved to steepened ramp sedimentary environment model. By studying about 1700 meters of Paleocene-Eocene sediments, 9 depositional sequences were identified and separated depending on the location of the sections under study in sequence stratigraphy. During the Paleocene and FSST systems tract formation toward to southwest of the study area (Sarvestan section) evaporites sediments in the lower part of Sachun formation correlative deposited the equivalent of Pabdeh formation in the outer ramp. The evolution of steepened carbonate ramps in shallow parts of the carbonate platform of Jahrom Formation and in deeper parts of the Pabdeh formation was deposited in the Middle Paleocene to Middle Eocene period. In the HST systems tract and high carbonate production rate (Highstand Shedding) in the sloping part of the environment calciturbidite has been deposited as a layer between the Pabdeh Formation. Studies show that the facies of Sachun Formation in the study area gradually changes from west to evaporitic-marly facies to marl, limestone, dolomitic limestone, and purple shale facies.

In order to study petrography, sedimentary environment, sequence stratigraphy and reservoir potential of Asmari Formation in Kilurkarim oil field, 5 wells from this field were analyzed. Based on the study of 800 thin sections prepared from cutting and cores, 15 carbonate microfacies were identified, which were deposited in a homoclinal carbonate ramp. Major diagenetic processes that have affected the Asmari Formation include, micritization, dolomitization, dissolution, cementation, compaction, pyritization, hematitation, and fracture. The identified diagenetic processes are the product of shallow to deep marine and meteoric diagenesis. The sum of petrographic and petrophysical studies showed that Asmari reservoir can be divided into 5 reservoir zones in the study area. Among the reservoir zones introduced, only zones No. 1 and to some extent zone No. 4 show acceptable reservoir potential. According to lithological changes, gamma log changes, vertical changes of microfacies, sequence stratigraphy of Asmari reservoir in wells No. 1 and 5 of the field was evaluated and 5 third order depositional sequences were detected. In general, the TST systems tract in the studied sequence is characterized by a slight increase in the amount of gamma log in every 5 sequences. The HST systems tract is characterized by the reduction or persistence of gamma log values along the reservoir thickness in all five separated depositional sequences. The important thing about this systems tract is the equivalence of this systems tract with the increase of reservoir potential along the reservoir.

Yadavaran oil field is one of the oil fields in Iran which located 130 km west of Ahwaz, at a zero point border with Iraq and in the vicinity of the Hural Hoveyzah wetland, and is located in the Iraqi Majnoon field in a joint oil reservoir. The most important reservoir of this field is the Sarvak Formation (Upper Albian- Turonian) from the Bangestan Group which, together with the Ilam Formation, forms the second major reservoir of Zagros Basin after the Asmari Formation. In order to evaluate the reservoir characteristics of the Sarvak Formation based on petrophysical and petrographical data in Yadavaran oilfield, one well was selected and analyzed. Based on the petrophysical cross plots, Sarvak Formation with the thickness of 640 meters is conformed of limestone. Based on the study of 500 thin sections of the cutting samples and cores, 10 carbonate microfacies were identified that were deposited in a carbonate ramp. Major diagenetic processes affecting the Sarvak Formation include neomorphism, bioturbation, micritization, dissolution, cementation, compaction, piritization, hematitization, and fractures. The main types of porosities identified in Sarvak Formation are vuggy porosity, intercrystaline, molding, and microscopic fractures, which have higher permeabilities than the other porosities detected. The sum of petrographic and petrophysical studies showed that the Sarvak reservoir can be divided into 5 main reservoir zones and 4 sub-reservoir zones (9 in total) in the study area. Zone number 2, sub-zone 4-1, 4-3, and some parts of sub-zone 5-2 have good reservoir quality. Studies also showed that ...

Evaluation of water quality and bed load sediment contamination of Qareaqhaj River to heavy metals, Kahfr Watershed, Fars provinceIn order to determine the water quality and sediments contamination of Ghare-Aghaj River 10 sediment samples and 10 water samples (in 2 periods) were taken and analyzed. The analysis of physico-chemical diagrams shows that the water type of river is sulfate-calcific and river water settele in the C3S1 category. According to the concentration maps drawn by the GIS software, the mean concentration of most of elements increases from the upstream to the downstream, but this increase does not reach the level of pollution and is not alarming. Statistical studies on the physicochemical parameters of water samples and heavy metals show that EC values are strongly correlated with TDS, Hco3, chlorine and magnesium. Statistical studies showed that there is a high correlation between nickel, iron, zinc, copper, iron and cobalt elements, which shows the same stability of these metals in sediment samples studied.

Shaley Pabdeh Formation (Paleocene-Oligomiocene) expanded in Fars، Khozestan and Lorestan. Lower Lithostratigraphical limit with Gurpi Formation recognized by purple shale. Upper Lithostratigraphical limith with Asmari Formation is transitional. In order to study sedimentary environments and sequence stratigraphy of Pabdeh Formation two stratigraphic sections were chosen (Zanjiran and Shahneshin). Petrographic study indicated 9 pelagic and calciturbidite microfacies. These microfacies in deep marine deposited. Calciturbidite facies were formed during sea level highstand، when high rate of carbonate production result in transportation of carbonate sediment in deep sea. Sequence stratigraphy study shows that Pabdeh Formation consists of two depositional sequences. In Zanjiran section lower and upper contact of first sequence is type two and upper contact of second depositional sequence is conformity with unconformity. In Shahneshin section the lower contact is type two and upper contact is correlative conformity with unconformity.