scholarly journals 3D Geological Modeling for Yamama Reservoir in Subba, Luhias and Ratawi Oil Fields, South of Iraq

2019 ◽  
Vol 60 (5) ◽  
pp. 1023-1036
Author(s):  
Naseem Sh. ALhakeem ◽  
Medhat E. Nasser ◽  
Ghazi H. AL-Sharaa

3D geological model for each reservoir unit comprising the Yamama Formation revealed to that the formation is composed of alternating reservoirs and barriers. In Subba and Luhais fields the formation began with barrier YB-1 and four more barriers (YB-2, YB-3, YB-4, YB-5), separated five reservoirs (YR-A, YR-B, YR-C, YR-D, YR-E) ranging in thickness from 70 to 80 m for each of them deposited by five sedimentary cycles. In the Ratawi field the formation was divided into three reservoir units (YR-A, YR-B, and YR-C) separated by two barrier units (YB-2 and YB-3), the first cycle is missing in Ratawi field.   The study involves 1 well in Luhais field (Lu-12), 3 wells in Subba field (Su-7, Su-8, and Su-9), and 5 wells in Ratawi field (Rt-3, Rt-4, Rt-5, Rt-6 and Rt-7), the Luhais, Subba, and Ratawi fields located in the Mesopotamia zone (Zubair subzone). The reservoir units (YR-C and YR-D) in Subba oil field, and YR-B in Ratawi oil field represent the major reservoir units that characterized by the best Petrophysical properties (the highest porosity, the lowest water saturation, and the best Net Pay Thickness), Luhais oil field has poor to moderate Petrophysical properties and low oil bearing in YR-A, YR-B and YR-C units, and produce heavy oil and salt water from YR-D and YR-E as indicated by low resistivity log reading, and according to the Drill Steam Test (DST) with the description of cutting in final geological reports.

2021 ◽  
Vol 54 (1D) ◽  
pp. 29-42
Author(s):  
Rayan Ahmed

The Mauddud reservoir, Khabaz oil field which is considered one of the main carbonate reservoirs in the north of Iraq. Recognizing carbonate reservoirs represents challenges to engineers because reservoirs almost tend to be tight and overall heterogeneous. The current study concerns with geological modeling of the reservoir is an oil-bearing with the original gas cap. The geological model is establishing for the reservoir by identifying the facies and evaluating the petrophysical properties of this complex reservoir, and calculate the amount of hydrocarbon. When completed the processing of data by IP interactive petrophysics software, and the permeability of a reservoir was calculated using the concept of hydraulic units then, there are three basic steps to construct the geological model, starts with creating a structural, facies and property models. The reservoirs were divided into four zones depending on the variation of petrophysical properties (porosity and permeability). Nine wells that penetrate the Cretaceous Formation (Mauddud reservoir) are included to construct the geological model. Zone number three characterized as the most important due to it Is large thickness which is about 108 m and good petrophysical properties are about 13%, 55 md, 41% and 38% for porosity, permeability, water saturation and net to gross respectively. The initial oil and gas in place are evaluated to be about 981×106 STB and 400×109 SCF.


2021 ◽  
Vol 54 (1C) ◽  
pp. 66-86
Author(s):  
Mahdi Menshed

Geological modeling is very important in reservoir study, where it is described the framework of the structure and provided a distribution of petrophysical properties, the geological model helps to comprehend the fluid flow behavior affected by the heterogeneity of reservoir, also it is used to calculate oil initially in place and to choose the new well location in reservoir management. In this study, a geological model is built for Nahr Umr Formation based on data of 11 wells (SU-2, SU-3, SU-4, SU-5, SU-6, SU-7, SU-9, SU-10, SU-11, SU-13, and SU-14), including the location of wells, well tops, also contour map of the Nahr Umr Formation in Subba oil field is utilized. The structural model is constructed for the Nahr Umr Formation, which consists of two domes. The formation is composed of sandstone mainly interbedded with shale. The formation is divided into four units (B1, B2, C1, and C2) depending on well log data, each unit is divided into layers for getting better distribution of petrophysical properties, where unit B2 is divided to the number of layers is higher than other units due to its heterogeneity. The variogram is used as a geostatistical method to predict the petrophysical properties at unsampled locations, experimental variogram is calculated from well log data in a horizontal and vertical direction. The spherical variogram model shows a good fitting with the experimental variogram. Sequential Gaussian algorithm is used in distribution of petrophysical properties in a geological model which shows good petrophysical properties in unit B2 and unit B1, while units C1 and C2 are highly saturated with water.


2020 ◽  
Vol 10 (2) ◽  
pp. 54-75
Author(s):  
Yousif N. Abdul Majeed ◽  
Dr. Ahmad A. Ramadhan ◽  
Dr. Ahmed J. Mahmood

3D Geological model for tertiary reservoir in khabaz oil field had been constructed byusing petrel software. Seven wells have been selected in this study in order to designPetrophysical properties (porosity, water saturation, and permeability). Structural modelcan be clarified tertiary reservoir in term of geological structures is a symmetrical smallanticline fold with four faults. Tertiary reservoir consist of six units are (Jeribe, UnitA,UnitA', UnitB, UnitBE, and UnitE). According to Petrophysical properties, layering hadbeen constructed for each tertiary units. Petrophysical model has been designed using thesequential Gaussian simulation algorithm as a geostatistical method. The results illustratesthat Unit B and Unit BE have the best petrophysical properties and the big amount of oil.


2021 ◽  
pp. 4810-4818
Author(s):  
Marwah H. Khudhair

     Shuaiba Formation is a carbonate succession deposited within Aptian Sequences. This research deals with the petrophysical and reservoir characterizations characteristics of the interval of interest in five wells of the Nasiriyah oil field. The petrophysical properties were determined by using different types of well logs, such as electric logs (LLS, LLD, MFSL), porosity logs (neutron, density, sonic), as well as gamma ray log. The studied sequence was mostly affected by dolomitization, which changed the lithology of the formation to dolostone and enhanced the secondary porosity that replaced the primary porosity. Depending on gamma ray log response and the shale volume, the formation is classified into three zones. These zones are A, B, and C, each can be split into three rock intervals in respect to the bulk porosity measurements. The resulted porosity intervals are: (I) High to medium effective porosity, (II) High to medium inactive porosity, and (III) Low or non-porosity intervals. In relevance to porosity, resistivity, and water saturation points of view, there are two main reservoir horizon intervals within Shuaiba Formation. Both horizons appear in the middle part of the formation, being located within the wells Ns-1, 2, and 3. These intervals are attributed to high to medium effective porosity, low shale content, and high values of the deep resistivity logs. The second horizon appears clearly in Ns-2 well only.


2021 ◽  
pp. 3570-3586
Author(s):  
Mohanad M. Al-Ghuribawi ◽  
Rasha F. Faisal

     The Yamama Formation includes important carbonates reservoir that belongs to the Lower Cretaceous sequence in Southern Iraq. This study covers two oil fields (Sindbad and Siba) that are distributed Southeastern Basrah Governorate, South of Iraq. Yamama reservoir units were determined based on the study of cores, well logs, and petrographic examination of thin sections that required a detailed integration of geological data and petrophysical properties. These parameters were integrated in order to divide the Yamama Formation into six reservoir units (YA0, YA1, YA2, YB1, YB2 and YC), located between five cap rock units. The best facies association and petrophysical properties were found in the shoal environment, where the most common porosity types were the primary (interparticle) and secondary (moldic and vugs) . The main diagenetic process that occurred in YA0, YA2, and YB1 is cementation, which led to the filling of pore spaces by cement and subsequently decreased the reservoir quality (porosity and permeability). Based on the results of the final digital  computer interpretation and processing (CPI) performed by using the Techlog software, the units YA1 and YB2 have the best reservoir properties. The unit YB2 is characterized by a good effective porosity average, low water saturation, good permeability, and large thickness that distinguish it from other reservoir units.


2019 ◽  
Vol 10 (2) ◽  
pp. 371-393
Author(s):  
Mohamed F. Abu-Hashish ◽  
Hamdalla A. Wanas ◽  
Emad Madian

Abstract This study aims to construct 3D geological model using the integration of seismic data with well log data for reservoir characterization and development of the hydrocarbon potentialities of the Upper Cretaceous reservoirs of GPT oil field. 2D seismic data were used to construct the input interpreted horizon grids and fault polygons. The horizon which cut across the wells was used to perform a comprehensive petrophysical analysis. Structural and property modeling was distributed within the constructed 3D grid using different algorithms. The workflow of the 3D geological model comprises mainly the structural and property modeling. The structural model includes fault framework, pillar girding, skeleton girding, horizon modeling and zonation and layering modeling processes. It shows system of different oriented major and minor faults trending in NE–SW direction. The property modeling process was performed to populate the reservoir facies and petrophysical properties (volume of shale (Vsh), fluid saturations (Sw and Sh), total and effective porosities (Φt and Φe), net to gross thickness and permeability) as extracted from the available petrophysical analysis of wells inside the structural model. The model represents a detailed zonation and layering configuration for the Khoman, Abu Roash and Bahariya formations. The 3D geological model helps in the field development and evaluates the hydrocarbon potentialities and optimizes production of the study area. It can be also used to predict reservoir shape and size, lateral continuity and degree of interconnectivity of the reservoir, as well as its internal heterogeneity.


2019 ◽  
Vol 9 (4) ◽  
pp. 89-106
Author(s):  
Ali Duair Jaafar ◽  
Dr. Medhat E. Nasser

Buzurgan field in the most cases regards important Iraqi oilfield, and Mishrif Formation is the main producing reservoir in this field, the necessary of so modern geophysical studies is necessity for description and interpret the petrophysical properties in this field. Formation evaluation has been carried out for Mishrif Formation of the Buzurgan oilfield depending on logs data. The available logs data were digitized by using Neuralog software. A computer processed interpretation (CPI) was done for each one of the studied wells from south and north domes using Techlog software V2015.3 in which the porosity, water saturation, and shale content were calculated. And they show that MB21 reservoir unit has the highest thickness, which ranges between (69) m in north dome to (83) m in south dome, and the highest porosity, between (0.06 - 0.16) in the north dome to (0.05 -0.21) in the south dome. The water saturation of this unit ranges between (25% -60%) in MB21 of north dome. It also appeared that the water saturation in the unit MB21 of south dome has the low value, which is between (16% - 25%). From correlation, the thickness of reservoir unit MB21 increases towards the south dome, while the thickness of the uppermost barrier of Mishrif Formation increases towards the north dome. The reservoir unit MB21 was divided into 9 layers due to its large thickness and its important petrophysical characterization. The distribution of petro physical properties (porosity and water saturation) has shown that MB 21 has good reservoir properties.


2020 ◽  
Vol 26 (6) ◽  
pp. 18-34
Author(s):  
Yousif Najeeb Abdul-majeed ◽  
Ahmad Abdullah Ramadhan ◽  
Ahmed Jubiar Mahmood

The aim of this study is interpretation well logs to determine Petrophysical properties of tertiary reservoir in Khabaz oil field using IP software (V.3.5). The study consisted of seven wells which distributed in Khabaz oilfield. Tertiary reservoir composed from mainly several reservoir units. These units are : Jeribe, Unit (A), Unit (A'), Unit (B), Unit (BE), Unit (E),the Unit (B) considers best reservoir unit because it has good Petrophysical properties (low water saturation and high porous media ) with high existence of hydrocarbon in this unit. Several well logging tools such as Neutron, Density, and Sonic log were used to identify total porosity, secondary porosity, and effective porosity in tertiary reservoir. For Lithological identification for tertiary reservoir units using (NPHI-RHOB) cross plot composed of dolomitic-limestone and mineralogical identification using (M/N) cross plot consist of calcite and dolomite. Shale content was estimated less than (8%) for all wells in Khabaz field. CPI results were applied for all wells in Khabaz field which be clarified movable oil concentration in specific units are: Unit (B), Unit (A') , small interval of Jeribe formation , and upper part of Unit (EB).


2020 ◽  
pp. 2979-2990
Author(s):  
Buraq Adnan Al-Baldawi

The present study includes the evaluation of petrophysical properties and lithological examination in two wells of Asmari Formation in Abu Ghirab oil field (AG-32 and AG-36), Missan governorate, southeastern Iraq. The petrophysical assessment was performed utilizing well logs information to characterize Asmari Formation. The well logs available, such as sonic, density, neutron, gamma ray, SP, and resistivity logs, were converted into computerized data using Neuralog programming. Using Interactive petrophysics software, the environmental corrections and reservoir parameters such as porosity, water saturation, hydrocarbon saturation, volume of bulk water, etc. were analyzed and interpreted. Lithological, mineralogical, and matrix recognition studies were performed using porosity combination cross plots. Petrophysical characteristics were determined and plotted as computer processing interpretation (CPI) using Interactive Petrophysics program. Based on petrophysical properties, Asmari Reservoir in Abu Ghirab oil field is classified into three sub formations: Jeribe/ Euphrates and Kirkuk group which is divided into two zones: upper Kirkuk zone, and Middle-Lower Kirkuk zone. Interpretation of well logs of Asmari Formation indicated a commercial Asmari Formation production with medium oil evidence in some ranges of the formation, especially in the upper Kirkuk zone at well X-1. However, well X-2, especially in the lower part of Jeribe/ Euphrates and Middle-Lower Kirkuk zone indicated low to medium oil evidence. Lithology of Asmari Formation demonstrated a range from massive dolomite in Jeribe/ Euphrates zone to limestone in upper Kirkuk zone and limestone and sandstone in middle-lower Kirkuk zone, whereas mineralogy of the reservoir showed calcite and dolomite with few amounts of anhydrite.


2020 ◽  
pp. 1362-1369
Author(s):  
Gheed Chaseb ◽  
Thamer A. Mahdi

This study aims to evaluate reservoir characteristics of Hartha Formation in Majnoon oil field based on well logs data for three wells (Mj-1, Mj-3 and Mj-11). Log interpretation was carried out by using a full set of logs to calculate main petrophysical properties such as effective porosity and water saturation, as well as to find the volume of shale. The evaluation of the formation included computer processes interpretation (CPI) using Interactive Petrophysics (IP) software.  Based on the results of CPI, Hartha Formation is divided into five reservoir units (A1, A2, A3, B1, B2), deposited in a ramp setting. Facies associations is added to well logs interpretation of Hartha Formation, and was inferred by a microfacies analysis of thin sections from core and cutting samples. The CPI shows that the A2 is the main oil- bearing unit, which is characterized by good reservoir properties, as indicated by high effective porosity, low water saturation, and low shale volume. Less important units include A1 and A3, because they have low petrophysical properties compared to the unit A2.


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