The studied succession is deposited during late Berriasian-Aptian interval, which is represented by the Zubair, Ratawi, Yamama formations. The present study includes stratigraphic development and basin analysis for 21 boreholes (Rachi-1, 2; Rifaei-1, Diwan- 1; Ratawi-1, 2; Halfaia-5; West Qurna 12, 15; Nahr Umr-7,8; Zubair-47,49; North Rumaila- 72, 131, 158; Suba-7; Majnoon-2, 3 and Luhais-2, 12) distributed within 13 oil fields in the southern Iraq. The back-stripping process determined the original direction of basin depocenter for the studied succession. The Yamama basin in the study area stretches from southeast to southwest with single depocenters, it was located in the southeast of the study area near wells Mj-2, Mj-3.NR-8 and WQ-15 and stretched to the new position southwest near wells NR-7, RU-131, RU-158, ZB-47 and ZB-49. The Ratawi Formation is represented by one depocenter located in the southwest of the study area near wells Rc-1, Rc-2, Lu-12 and Ru-72. The Zubair basin in the study area has two depocenters, the first depocenter is located to the north of the study area near well Dn-1, while the second one is located at the northwest area near wellsSu-7, Lu-12, Rc-1, RC-2 and Rt-1.
The Paleocene-Early Eocene sequence is represented by Aliji and Umm Er Radhuma formations, while the Middle-Late Eocene sequence is represented by Jaddala and Dammam formations. The Rus Formation has been described and its basin was analyzed separately because it was deposited during the regression period (Middle Eocene), which is a transitional period between these two cycles.
This study includes analysis of the geohistory of this succession, interpretation of the changes of the accumulation, and calculation of subsidence rates. The results were compared with the space available to explain the basin development. The study site included the boreholes of Garraf-84 and 92, Halfaya-1, Nasirya-13 and 40, and Noor-5 at th
... Show MoreThe Carbonate-clastic succession in this study is represented by the Shuaiba and Nahr Umr Formations deposited during the Albian - Aptian Sequence. The present study includes petrography, microfacies analyses, and studying reservoir characterizations for 5 boreholes within West Qurna oil field in the study area. According to the type of study succession (clastic – Carbonate) there are two types of facies analyses:-Carbonate facies analysis, which showed five major microfacies were recognized in the succession of the Shuaiba Formation, bioclastic mudstones to wackstone, Orbitolina wackestone to packstone, Miliolids wackestone, Peloidal wackestone to packstone and mudstone to wackestone identified as an open shelf toward the deep basin.
... Show MoreThe study area is situated in the northern part of the Arabian Plate. The evolution of the Zagros Foreland basin is related to the compressional tectonic system at the beginning of the Tertiary Period.
This study gives an adequate nomenclature for the Oligocene – Early Miocene Sequence is Missan Group. The Buzurgan Oilfield was chosen to represent the stratigraphic column corresponding to that period. These sediments were subdivided into two cycles, where each one ends by a sequence boundary, equivalent to the lowstand siliciclastic residues in the basin center. The first cycle, Paleocene-Oligocene Epoch, was deposited marly limestone with planktonic foraminifera in the basin center during the transgressive and highst
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The Miocene succession of western and southern Iraq is represented by the
Euphrates, Ghar, Jeribe, Nfayil, Fatha, and Injana formations. The Euphrates
Formation (Early Miocene) consists mainly of shallow marine facies; it`s equivalent
the Ghar Formation (Early- Early Middle Miocene) is represented by continental
clastic facies. The Jeribe Formation (Early Middle Miocene) represents shallow
marine environment. The Nfayil Formation (Middle Miocene) also of shallow marine
environment, it`s equivalent the Fatha Formation is represented mainly by supratidal
marine environment. The Injana Formation (Late Miocene) represents the clastic
continental facies.
The studied succession was highly affected by many diagene
The present study is focused upon the sedimentology and basin development of the Jeribe and Fatha Formations by using the field observations and microfacies analysis. The area of study situated in the Zurbatiyah area to the south of the Shur sharin valley about 21 km northeast of Badrah city to the southeast of Baghdad. This area lies within the Zagros foreland basin, and located between the Zagros mountains at the northeastern and the Arabian shield at the southeastern.
The studied succession which including the Jeribe and Fatha Formations were deposited within four associated facies for the Jeribe Formation and three for the Fatha Formation, as shown below: -
Jeribe Formation
... Show MoreCarbonate-clastic succession which includes the Shu'aiba, Nahr Umr and Mauddud formations are representing a part of the Barremian-Aptian Sequence (Wasi'a Group). The present study includes three boreholes (Ba-1, 4 and 8) within the Balad Oil Field. The study area is located in central Iraq. This field represents a subsurface anticline with a northwest to southeast direction axis within the Mesopotamian Zone. Eight types of microfacies were recognized in the succession of the Mauddud and Shu’aiba formations. These microfacies represent shallow open marine, restricted and semi-restricted, reef - back reef, deep open marine and basinal depositional environments. While Nahr Umr Formation includes two successions, the first is the upp
... Show MoreIn this study, different oil fields in Mesopotamian basin, southern Iraq (Siba, Zubair, Nahr - Umr, Majnoon, Halfaya, Kumait, and Amara) were selected for studying burial history. PetroMod software 1D was used for basin constructing and to evaluate burial history of the basin. Results showed that in the upper Jurassic to the Recent, Mesopotamian Basin exhibited a complex subsidence history over a period of about 152 Ma.There are different periods of subsidence: high, moderate, and slow. High subsidence occurred at upper Jurassic- mid Cretaceous and at Miocene due to Tectonic subsidence. Slow subsidence occurred at upper Cretaceous and moderate subsidence at Paleogene. In the upper Jurassic, rapid subsidence is driven under the effect of
... Show MoreThe Late Maastrichtian–Danian phosphatic succession prevails as a deposit to the west of Rutbah region, Western Iraq. This is manifested through the lithostratigraphic sections of boreholes (K.H5\6 and K.H 5\8) drilled previously in the area. The succession is mainly composed of phosphate, shale, porcelanite, oyster and foraminiferal carbonate lithofacies belonging to Digma and Akashat formations. Three facies associations are distinguished during the study: the phosclast planktonic (FA1) that dominates the outer ramp, the phosclast foraminiferal (FA2) that dominates the mid ramp, and the quartz dolomitic phosclast (FA3) present in the inner ramp. These facies’ associations are differentiated into se
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