International Journal of Modeling and Optimization, 2012

Simulation in petroleum geology is an art to build the structure of the reservoir with the help of geological, seismic, well logs, and petrophysical data which are transferred digitally to the suitable computation software of the reservoir management system. Core analysis, and thin sections petrography are also applied to get more information. In any petroliferous area such as Zagros, reservoir simulation can be also used to predict the best position for drilling projects, and so the reservoir construction is an essential part of the process. The present study is an attempt to construct 3D-structural model using geostatistical method to access in situ oil volume and best position for oil production. The area considered as a case study is the Asmari reservoir of the Ramin oilfield located at Dezful Embayment in SW of Iran. In this oilfield the Asmari reservoir is divided into 4 zones. To make up the model several steps such as griding, kriging and experimental variogram were carried out for all available data. To increase the accuracy and variability of data, selected dimensions was 193×228×1m of each cell in grid model except for zone 4 that it was non reservoir. In this case, for the last zone, dimensions were changed to 193×228×5m. Simulated reservoir model revealed that zone 1 is the main pay zone since it contains about 97.9% of total oil volume in this field. Distribution of the porosity and water saturation indicated that zones 1 and 2 are good candidates for oil production since they have higher porosity% and lower water saturation% than other zones. The best situation for drilling program is in the western part.

Iraqi Journal of Chemical and Petroleum Engineering, 2018

Geologic modeling is the art of constructing a structural and stratigraphic model of a reservoir from analyses and interpretations of seismic data, log data, core data, etc. [1]. A static reservoir model typically involves four main stages, these stages are Structural modeling, Stratigraphic modeling, Lithological modeling and Petrophysical modeling [2]. Ismail field is exploration structure, located in the north Iraq, about 55 km northwest of Kirkuk city, to the northwest of the Bai Hassan field, the distance between the Bai Hassan field and Ismael field is about one kilometer [3]. Tertiary period reservoir sequences (Main Limestone), which comprise many economically important units particularly reservoir pay zone, in Ismail field are belong to middle Miocene age and Oligocene age, which includes six formations, Jeribe, Bajwan, Baba, Baba/palani and Palani formation. The information of Ismail field such as final well report, drill stem test, completion test and well logs data also previous studies and results of core data, indicated that hydrocarbons are accumulated in the Baba formation. The main purpose of this study is to make use of all the available sets of data acquired from Ismail field to build a static geological model for Baba formation in Ismail field to get full description for this reservoir. The most important phase of a reservoir study is probably the definition of a static model of the reservoir rock, given both the large number of activities involved, and its impact on the end results. As we know, the production capacity of a reservoir depends on its geometrical/structural and petrophysical characteristics. The availability of a representative static model is therefore an essential condition for the subsequent dynamic modeling phase. A static reservoir study typically involves four main stages, carried out by experts in the various disciplines, these stages are Structural modeling, Stratigraphic modeling, Lithological modeling and Petrophysical modeling [2]. 2-Model Design Petrel 2009 software was chosen to build geological model for exploration Ismail field. Petrel is a software application package for subsurface interpretation and modeling, allowing building and updating reliable subsurface models. It is a latest reservoirs modeling software recently deployed by schlumberger information solutions Inc. For the purpose of this study, a data base was created within petrel, clearly delineating the different information and data needed to complete the study. The geological, and petrophysical data were imported to petrel within the main data base. This made it possible to generate and visualize the imported data in 2D as well as 3D. The work flow design used for the study and wide range of functional tools in the petrel software include: 3D visualization, well correlation, 3D mapping, and 3D grid design for geology simulation, well log up scaling, petrophysical modeling, data analysis, and volume calculation. 3-Data Preparation Data preparation is the basis for geologic model. This geologic model building chiefly applies software of petrel. On the basis of software demand and research area characteristic, the data prepare for this 3D-geological model are well heads, well tops, well logs (Raw data and CPI), and core analysis.

The petroleum system of Jabal Kand Oil Field shows that the formations such as Tertiary Kolosh, Cretaceous Shiranish, and Jurassic Sargelu are immature and have not generated any oil Ro< 0.55%. They are neglected as compared to formations below them which are also source rocks. The Kurra Chine Formation is mature with Ro> 0.55%. Other formations such as Gele Khana and other Triassic formations are with high maturity with Ro≥ 1.3% and are within wet and dry gas window while older formations are either within dry gas zone or completely generated hydrocarbon and depleted after hydrocarbon was expelled and migrated to reservoir rock of structure traps.

Arabian Journal of Geosciences, 2016

Tertiary reservoir represented by Jeribe, Anah, Azkand, and Azkand/Ibrahim formations has been studied from reservoir characterization point of view in Khabbaz Oil Field/Northern Iraq. Examined thin sections prepared from core rock samples which are selected from the wells Kz-8 and Kz-9 revealed the existence of different microfacies in which are varies types of porosity such as interparticle, intraparticle, moldic, vuggy, and fractures have been noticed. In addition to these different types of diagenetic features are represented mainly by cementation, dolomitization, recrystallization, and dissolution. The available log data for the wells Kz-11, Kz-14, and Kz-16 have been used in characterizing the reservoir properties of the studied formations. The detected lithologies from porosity logs showed domination of limestone, dolomitic limestone, and dolomites in addition to few thin beds of anhydrites in Jeribe Formation and thin beds of sand dominated lithologies in Azkand Formation. Clay content has been calculated from gamma ray log along the studied sections and appeared to be mostly of dispersed clay type as shown from density-neutron porosity crossplot of Thomas-Stieber. Correction from the effect of clay content has been done for all the measured sonic, density, and neutron porosities. The available porosity and permeability values which are measured from core tests in the well Kz-9 for the formations of Jeribe, Anah, and Azkand have been adapted to formalize the best equation for calculating permeability in the other studied wells which have no core test measurements but only log data (Kz-11, Kz-14, and Kz-16 wells). Depending on porosity, permeability, and shale content, the studied sections have been subdivided into seven reservoir units in the wells Kz-11 and Kz-16, and for eight reservoir units in the well Kz-14.

Iraqi geological journal, 2024

Although the High Folded Zone in the Kurdistan Region of Iraq forms part of the Zagros-Taurus Folds and Thrust belt considered one of the potential hydrocarbon provinces, the oil fields within the zone are still lacking in geophysical exploration and scientific research. So, the rationale behind this study is the prospecting and evaluation of one of the Tertiary carbonate reservoirs at the "WN" oil field in the Duhok area by integrating the 3D seismic and well-log data. The methodology covered seismic interpretation, well logs and their relevant petrophysical analysis, attribute computation, and 3D static property modeling. The constructed reservoir maps revealed a double-plunging rollover anticlinal structure trending in the East-West direction parallel to the Taurus Mountain series. A total of nineteen minor reversal faults trending E-W to ENE-WSW dissecting the northern limb of the anticline were manually interpreted. The isopach map shows various thicknesses ranging from 160 to 330 m, averaging 245 m. The property models show the limited values of their parameters as the effective porosity is limited (0.97-23%), the secondary porosity (0.43-11.7%), permeability (0.00-238.8 mD), the water saturation (12.44-99.8%), and the clay volume (0.00-9.8%). The results of this research indicate that the horizon is a promising reservoir characteristic.

Iraqi Geological Journal, 2021

The paper generates a geological model of a giant Middle East oil reservoir, the model constructed based on the field data of 161 wells. The main aim of the paper was to recognize the value of the reservoir to investigate the feasibility of working on the reservoir modeling prior to the final decision of the investment for further development of this oilfield. Well log, deviation survey, 2D/3D interpreted seismic structural maps, facies, and core test were utilized to construct the developed geological model based on comprehensive interpretation and correlation processes using the PETREL platform. The geological model mainly aims to estimate stock-tank oil initially in place of the reservoir. In addition, three scenarios were applied based on sensitivity and uncertainty of five variables to determine an accurate estimation of stock-tank oil initially in place of the reservoir. The oil-water contact appeared to be the major uncertain parameter for stock-tank oil initially in place es...

Iraqi geological journal, 2022

The Zubair Formation is main prolific reservoirs in the Rumaila oilfield in southern Iraq. The petrophysical assessment of the Zubair Formation was carried out using a suite of openhole logs from eight wells along with the Rumaila North oil fields, in Basra. Based on THE neutron, density and Gamma Ray logs, the Upper Sand Member of the Zubair Formation is divided into the alternate units of the sand and shale and defining their boundaries. Based on the obtained results, the Upper Sand Member was divided into three main pay units: AB, DJ, and LN, separated by two insulating shale units designated C and K. The unit DJ was subdivided into four secondary reservoir units: D, F, G, H, and the LN unit, which is split into L, M, and N. High porosity, high oil saturation and a high net-to-gross ratio were found in the petrophysical investigation. The porosity types are good (from 15 to 20%), very good (20-25%) and excellent (more than 25%) except wells R-559 and R-256, which has medium permeability, all the wells have good to excellent permeability. The net pay for the reservoir unit thickness ranges from 5 to 59m in all wells, resulting in significant hydrocarbon productivity due to strong hydrocarbon saturation, good effective porosity, and low shale volume.

ARTICLE INFO ABSTRACT The purpose of this study was to decipher some petro physical properties of studied wells in Halewah Oilfield, block-5, Marib-Shabwa basin, Yemen. Reservoir characterization of hydrocarbon reservoirs using well logs have been carried out in order to evaluate the field's hydrocarbon prospectivity, delineate hydrocarbon and water bearing zones and petro physical properties of the Alif reservoir. Alif reservoir is mainly made up of sandstone sediments with bands of shale that contain a substantial amount of proven oil in the Halewah Oilfield. Data from four wells comprising of gamma ray, resistivity, neutron, density logs were used for the study. Gamma ray log was used for lithology differentiation, Resistivity log was used to identify form the response of resistivities of various zones. High resistivity denotes hydrocarbon bearing zone while low resistivity value indicates water bearing zone or shaley zones. The combined density and neutron logwas used for the identification and differentiation of the various fluids (Oli and Water) in the reservoir. Computer-assisted log analyses were used to evaluate the petro physical parameters such as shale volume, total porosity, effective porosity, water saturation, hydrocarbon saturation, flushed zone saturation and reservoir and pay flags. Cross-plots of the petro physical parameters versus depth were illustrated. The results from the study showed that the Alif reservoir is capable of yielding appreciable hydrocarbon. The Upper Jurassic Alif reservoir reflects that the matrix components are mainly quartz and shales. Moreover, the lithological-geologic model reflected that these shales are strongly affecting the porosity and, consequently, the fluid saturation in the Alif reservoir, especially in the lower part of reservoir. The results from the study showed that the maximum Net-Pay is 64.79 m recorded around Halewah-02 well whereas minimum is 3.78 m recorded around Halewah-09 well. The evaluated petrophysical parameter indicated that effective porosity (PHE) ranges between (13-34%), water saturation (SWE)range between (13-31%), hydrocarbon saturation SH range between (69-88%), and permeability (220-12250).The Alif reservoir reveals promising reservoir characteristics especially the upper reservoir unit. The northwestern area should be taken into consideration during future development of the oilfield area. Copyright©2017, Albaroot et al., This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Edelweiss Chemical Science Journal

Hamrin oil field is one of the important oil field in northern Iraq. The field represent an asymmetrical anticline that extend North West-South East for more than 101 km, with width (4-7) km. Hamrin oil field was located at the south western boundary of foothill zone of the unstable shelf area according to the tectonic division of Iraq. The Tertiary reservoir represented by Jeribe and Euphrates formations as main reservoirs and Dhiban formation as secondary reservoir that represent an attractive petroleum completion target in Hamrin oil field. The aim of this study is to determine the petrophysical properties of these formations, using log data, because these properties affect the estimate of reserves (porosity and saturation) and well deliverability (permeability). This study shows that the petro physical properties of these formations were controlled by depositional environment, diagenesis and tectonic activity. The evaluation of the petro physical for tertiary reservoir in Hamrin...

Modeling Earth Systems and Environment, 2016

One dimension petroleum system modeling was performed on selected wells located within four oil fields in Southern Iraq, these are: Rumila, Subba, Tuba and Ratawi. The geo history analysis was applied for the studied fields; and it shows that the stratigraphic section contains many periods which are different in the tectonic and sedimentary subsidence, burial history, sedimentary, and erosion rates. It was seen that the burial depth was greater in the Ratawi oil field than the other fields. There is a different period of subsidence, which ranges from high to moderate subsidence, occurred at upper Jurassic to Mid-Cretaceous. Also, special uplift occurred in the Miocene and moderate subsidence occurred during the Paleogene. Four unconformities took place during the geological history of the Mesopotamian basin. In general, there is similarity to the burial histories that indicates all formations were deposited in the same basin of the studied oil fields, which was effected by the tectonic and sedimentary subsidence. Heat flow is in range (27-70 mW/m 2) which influence in the thermal maturity.