Characterization of Mishrif Formation Reservoir in Amara Oil Field, Southeast Iraq, Using Geophysical Well-logging

Reservoir characterization requires reliable knowledge of certain fundamental properties of the reservoir. These properties can be defined or at least inferred by log measurements, including porosity, resistivity, volume of shale, lithology, water saturation, and permeability of oil or gas. The current research is an estimate of the reservoir characteristics of Mishrif Formation in Amara Oil Field, particularly well AM-1, in south eastern Iraq. Mishrif Formation (Cenomanin-Early Touronin) is considered as the prime reservoir in Amara Oil Field. The Formation is divided into three reservoir units (MA, MB, MC). The unit MB is divided into two secondary units (MB1, MB2) while the unit MC is also divided into two secondary units (MC1, MC2). Using Geoframe software, the available well log images (sonic, density, neutron, gamma ray, spontaneous potential, and resistivity logs) were digitized and updated. Petrophysical properties, such as porosity, saturation of water, saturation of hydrocarbon, etc. were calculated and explained. The total porosity was measured using the density and neutron log, and then corrected to measure the effective porosity by the volume content of clay. Neutron -density cross-plot showed that Mishrif Formation lithology consists predominantly of limestone. The reservoir water resistivity (Rw) values of the Formation were calculated using Pickett-Plot method.

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Petrophysical Properties and Digenetic Evolution of Shuaiba Formation in Nasiriyah Oil Field, Southern Iraq

Iraqi Journal of Science ◽

10.24996/ijs.2021.62.12.19 ◽

2021 ◽

pp. 4810-4818

Author(s):

Marwah H. Khudhair

Keyword(s):

Gamma Ray ◽

Water Saturation ◽

Middle Part ◽

Effective Porosity ◽

Oil Field ◽

Neutron Density ◽

Petrophysical Properties ◽

Secondary Porosity ◽

Primary Porosity ◽

Gamma Ray Log

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.

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Petrophysical Properties and Well Log Interpretations of Tertiary Reservoir in Khabaz Oil Field / Northern Iraq

Journal of Engineering ◽

10.31026/j.eng.2020.06.02 ◽

2020 ◽

Vol 26 (6) ◽

pp. 18-34

Author(s):

Yousif Najeeb Abdul-majeed ◽

Ahmad Abdullah Ramadhan ◽

Ahmed Jubiar Mahmood

Keyword(s):

Water Saturation ◽

Total Porosity ◽

Effective Porosity ◽

Oil Field ◽

Neutron Density ◽

Petrophysical Properties ◽

Secondary Porosity ◽

Northern Iraq ◽

Sonic Log ◽

Oil Concentration

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).

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Hydrocarbon Reservoir Characterization of ‘Khume’ Field, Offshore Niger Delta, Nigeria

Journal of Geography Environment and Earth Science International ◽

10.9734/jgeesi/2021/v25i1030314 ◽

2021 ◽

pp. 47-60

Author(s):

K. A. Obakhume ◽

O. M. Ekeng ◽

C. Atuanya

Keyword(s):

Niger Delta ◽

Reservoir Characterization ◽

Gamma Ray ◽

Water Saturation ◽

Seismic Interpretation ◽

Effective Porosity ◽

Well Logs ◽

Integrative Approach ◽

Neutron Density ◽

Hydrocarbon Reservoir

The integrative approach of well log correlation and seismic interpretation was adopted in this study to adequately characterize and evaluate the hydrocarbon potentials of Khume field, offshore Niger Delta, Nigeria. 3-D seismic data and well logs data from ten (10) wells were utilized to delineate the geometry of the reservoirs in Khume field, and as well as to estimate the hydrocarbon reserves. Three hydrocarbon-bearing reservoirs of interest (D-04, D-06, and E-09A) were delineated using an array of gamma-ray logs, resistivity log, and neutron/density log suites. Stratigraphic interpretation of the lithologies in Khume field showed considerable uniform gross thickness across all three sand bodies. Results of petrophysical evaluations conducted on the three reservoirs correlated across the field showed that; shale volume ranged from 7-14%, total and effective porosity ranged from 19-26% and 17-23% respectively, NTG from 42 to 100%, water saturation from 40%-100% and permeability from 1265-2102 mD. Seismic interpretation established the presence of both synthetic and antithetic faults. A total of six synthetic and four antithetic faults were interpreted from the study area. Horizons interpretation was done both in the strike and dip directions. Time and depth structure maps revealed reservoir closures to be anticlinal and fault supported in the field. Hydrocarbon volumes were calculated using the deterministic (map-based) approach. Stock tank oil initially in place (STOIIP) for the proven oil column estimated for the D-04 reservoir was 11.13 MMSTB, 0.54 MMSTB for D-06, and 2.16 MMSTB for E-09A reservoir. For the possible oil reserves, a STOIIP value of 7.28 MMSTB was estimated for D-06 and 6.30 MMSTB for E-09A reservoir, while a hydrocarbon initially in place (HIIP) of 4.13 MMSTB of oil equivalents was derived for the undefined fluid (oil/gas) in D-06 reservoir. A proven gas reserve of 1.07 MMSCF was derived for the D-06 reservoir. This study demonstrated the effectiveness of 3-D seismic and well logs data in delineating reservoir structural architecture and in estimating hydrocarbon volumes

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Petrophysical Properties of Nahr Umar Formation in Nasiriya Oil Field

Iraqi Journal of Chemical and Petroleum Engineering ◽

10.31699/ijcpe.2020.3.2 ◽

2020 ◽

Vol 21 (3) ◽

pp. 9-18

Author(s):

Ahmed Abdulwahhab Suhail ◽

Mohammed H. Hafiz ◽

Fadhil S. Kadhim

Keyword(s):

Gamma Ray ◽

Water Saturation ◽

Oil Field ◽

Well Logs ◽

High Porosity ◽

Reservoir Properties ◽

Petrophysical Parameters ◽

Resistivity Logs ◽

Lithology Prediction ◽

Porosity And Permeability

Petrophysical characterization is the most important stage in reservoir management. The main purpose of this study is to evaluate reservoir properties and lithological identification of Nahr Umar Formation in Nasiriya oil field. The available well logs are (sonic, density, neutron, gamma-ray, SP, and resistivity logs). The petrophysical parameters such as the volume of clay, porosity, permeability, water saturation, were computed and interpreted using IP4.4 software. The lithology prediction of Nahr Umar formation was carried out by sonic -density cross plot technique. Nahr Umar Formation was divided into five units based on well logs interpretation and petrophysical Analysis: Nu-1 to Nu-5. The formation lithology is mainly composed of sandstone interlaminated with shale according to the interpretation of density, sonic, and gamma-ray logs. Interpretation of formation lithology and petrophysical parameters shows that Nu-1 is characterized by low shale content with high porosity and low water saturation whereas Nu-2 and Nu-4 consist mainly of high laminated shale with low porosity and permeability. Nu-3 is high porosity and water saturation and Nu-5 consists mainly of limestone layer that represents the water zone.

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Joint petrophysical interpretation of multidetector nuclear measurements in the presence of invasion, shoulder-bed, and well-deviation effects

Geophysics ◽

10.1190/geo2016-0037.1 ◽

2017 ◽

Vol 82 (1) ◽

pp. D13-D30 ◽

Cited By ~ 5

Author(s):

Edwin Ortega ◽

Mathilde Luycx ◽

Carlos Torres-Verdín ◽

William E. Preeg

Keyword(s):

Gamma Ray ◽

Water Saturation ◽

Total Porosity ◽

Neutron Density ◽

Layer By Layer ◽

Fluid Type ◽

Fluid Properties ◽

Radial Length ◽

Neutron Porosity ◽

Porosity Logs

Recent advances in logging-while-drilling sigma measurements include three-detector thermal-neutron and gamma-ray decay measurements with different radial sensitivities to assess the presence of invasion. We have developed an inversion-based work flow for the joint interpretation of multidetector neutron, density, and sigma logs to reduce invasion, shoulder-bed, and well-deviation effects in the estimation of porosity, water saturation, and hydrocarbon type, whenever the invasion is shallow. The procedure begins with a correction for matrix and fluid effects on neutron and density-porosity logs to estimate porosity. Multidetector time decays are then used to assess the radial length of the invasion and estimate the virgin-zone sigma while simultaneously reducing shoulder-bed and well-deviation effects. Density and neutron porosity logs are corrected for invasion and shoulder-bed effects using two-detector density and neutron measurements with the output from the time-decay (sigma) inversion. The final step invokes a nuclear solver in which corrected sigma, inverse of migration length, and density in the virgin zone are used to estimate water saturation and fluid type. The fluid type is assessed with a flash calculation and Schlumberger’s Nuclear Parameter calculation code to account for the nuclear properties of different types of hydrocarbon and water as a function of pressure, temperature, and salinity. Results indicate that accounting for invasion effects is necessary when using density and neutron logs for petrophysical interpretation beyond the calculation of total porosity. Synthetic and field examples indicate that the mitigation of invasion effects becomes important in the case of salty mud filtrate invading gas-bearing formations. The advantage of the developed inversion-based interpretation method is its ability to estimate layer-by-layer petrophysical, compositional, and fluid properties that honor multiple nuclear measurements, their tool physics, and their associated borehole geometrical and environmental effects.

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Petrophysical Analysis of Well Logs for Asmari Reservoir in Abu Ghirab Oil Field, South Eastern Iraq

Iraqi Journal of Science ◽

10.24996/ijs.2020.61.11.20 ◽

2020 ◽

pp. 2979-2990

Author(s):

Buraq Adnan Al-Baldawi

Keyword(s):

Gamma Ray ◽

Water Saturation ◽

Bulk Water ◽

Computer Processing ◽

Oil Field ◽

Well Logs ◽

Asmari Formation ◽

Petrophysical Properties ◽

Resistivity Logs ◽

Environmental Corrections

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.

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Evaluation of Mishrif Reservoir in Abu Amood Oil Field, Southern Iraq

Iraqi Journal of Science ◽

10.24996/ijs.2021.62.12.14 ◽

2021 ◽

pp. 4758-4768

Author(s):

Ahmed Hussain ◽

Medhat E. Nasser ◽

Ghazi Hassan

Keyword(s):

Total Porosity ◽

Effective Porosity ◽

Oil Field ◽

Well Logs ◽

Neutron Density ◽

High Porosity ◽

Petrophysical Properties ◽

Density Method ◽

Southern Iraq

The main goal of this study is to evaluate Mishrif Reservoir in Abu Amood oil field, southern Iraq, using the available well logs. The sets of logs were acquired for wells AAm-1, AAm-2, AAm-3, AAm-4, and AAm-5. The evaluation included the identification of the reservoir units and the calculation of their petrophysical properties using the Techlog software. Total porosity was calculated using the neutron-density method and the values were corrected from the volume of shale in order to calculate the effective porosity. Computer processed interpretation (CPI) was accomplished for the five wells. The results show that Mishrif Formation in Abu Amood field consists of three reservoir units with various percentages of hydrocarbons that were concentrated in all of the three units, but in different wells. All of the units have high porosity, especially unit two, although it is saturated with water.

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Reservoir Characterization of Sand Intervals of Lower Goru Formation Using Petrophysical Studies; A Case Study of Zaur-03 Well, Badin Block, Pakistan

International Journal of Economic and Environmental Geology ◽

10.46660/ojs.v10i3.320 ◽

2019 ◽

Vol 10 (3) ◽

pp. 118-124

Author(s):

Mustafa Yar ◽

Syed Waqas Haider ◽

Ghulam Nabi ◽

Muhammad Tufail ◽

Sajid Rahman

Keyword(s):

Reservoir Characterization ◽

Water Saturation ◽

Effective Porosity ◽

Indus Basin ◽

Reservoir Properties ◽

Drilling Parameters ◽

Resistivity Logs ◽

Prime Objective ◽

Lower Goru Formation

Present study deals with petrophysical interpretation of Zaur-03 well for reservoir characterization of sandintervals of Lower Goru Formation in Badin Block, Southern Indus Basin, Pakistan. Early Cretaceous Lower GoruFormation is the distinct reservoir that is producing hydrocarbons for two decades. Complete suite of wireline logsincluding GR log, Caliper log, SP log, Resistivity logs (MSFL, LLS, LLD), Neutron log and Density log along withwell tops and complete drilling parameters were analyzed in this study. The prime objective of this study was to markzones of interest that could act as reservoir and to evaluate reservoir properties including shale volume (Vsh), porosity(ϕ), water saturation (Sw), hydrocarbon saturation (Sh) and net pay thickness. Based on Petrophysical evaluation threezones have been marked in Lower Goru Formation, A Sand (1890m to 1930m), B-sand (1935m to 2010) and C-sand(2015m to 2100m). The average calculated parameters for evaluation of reservoir properties of Zaur-03 well depicts anaverage porosity of 8.92% and effective porosity of 4.81%. Water Saturation is calculated as 28.54% and HydrocarbonsSaturation is 71.46%. Analysis shows that Sh in Zaur-03 well is high so the production of hydrocarbons iseconomically feasible.

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Seismic Data Interpretation and Petrophysical Analysis of Kabirwala Area Tola (01) Well, Central Indus Basin, Pakistan

Applied Sciences ◽

10.3390/app11072911 ◽

2021 ◽

Vol 11 (7) ◽

pp. 2911

Author(s):

Naveed Ahmad ◽

Sikandar Khan ◽

Abdullatif Al-Shuhail

Keyword(s):

Gamma Ray ◽

Water Saturation ◽

Research Work ◽

Total Porosity ◽

Effective Porosity ◽

Indus Basin ◽

Drilling Process ◽

Reservoir Properties ◽

Log Data ◽

Petrophysical Analysis

Well logging is a significant procedure that assists geophysicists and geologists with making predictions regarding boreholes and efficiently utilizing and optimizing the drilling process. The current study area is positioned in the Punjab Territory of Pakistan, and the geographic coordinates are 30020′10 N and 70043′30 E. The objective of the current research work was to interpret the subsurface structure and reservoir characteristics of the Kabirwala area Tola (01) well, which is located in the Punjab platform, Central Indus Basin, utilizing 2D seismic and well log data. Formation evaluation for hydrocarbon potential using the reservoir properties is performed in this study. For the marked zone of interest, the study also focuses on evaluating the average water saturation, average total porosity, average effective porosity, and net pay thickness. The results of the study show a spotted horizon stone with respect to time and depth as follows: Dunghan formation, 0.9 s and 1080.46 m; Cretaceous Samana Suk formation, 0.96 s and 1174.05 m; Datta formation, 1.08 s and 1400 m; and Warcha formation, 1.24 s and 1810 m. Based on the interpretation of well logs, the purpose of petrophysical analysis was to identify hydrocarbon-bearing zones in the study area. Gamma ray, spontaneous potential, resistivity, neutron, and density log data were utilized. The high zone present in the east–west part of the contour maps may be a possible location of hydrocarbon entrapment, which is further confirmed by the presence of the Tola-01 well.

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