scholarly journals Characteristics of the Oil Water Contact Zone of Nhar Umr and Mishrif Reservoirs in Kumait and Dujaila Oil Fields, Southern Iraq, Using Vp/Vs Ratio and Porosity Logs Data

2020 ◽  
pp. 2998-3005
Author(s):  
Nowfal A. Nassir ◽  
Ahmed S. Al-Banna ◽  
Ghazi H. Al-Sharaa
Keyword(s):  
Contact Zone ◽  
Water Saturation ◽  
Oil Fields ◽  
P Wave ◽  
Water Contact ◽  
Clastic Rocks ◽  
Rock Formations ◽  
Oil Water ◽  
Porosity Logs ◽  
Southern Iraq

The detailed data of the Vp/Vs ratio and porosity logs were used to detect the Oil-Water Contact Zone (OWCZ) of Nahr Umr sandstone and Mishrif limestone reservoir formations in Kumiat (Kt) and Dujaila (Du) oil fields, southeastern Iraq. The results of OWC were confirmed using P-wave, Resistivity, and Water Saturation (Sw) logs of Kt-1 and Du-1 wells. It was found that the values of the oil-water contact zone thickness in Nahr Umr sandstone and Mishrif limestone were approximately one meter and eight meters, respectively. These results suggest that the OWCZ is possibly thicker in the carbonate rock than clastic rock formations. The thickness of OWCZ in the clastic rocks changed from one part to another, depending on several factors including mineral composition, grain size, porosity, pore shape, and fluid type.

Real-Time EM Look-Ahead Resistivity for Mapping of Oil/Water Contact While Drilling at Low Deviated Well, New Perspective for Mature Oil Fields Development: A Case Study Of Umm Gudair Field, Kuwait

2021 ◽  
Author(s):  
Nasser Faisal Al-Khalifa ◽  
Mohammed Farouk Hassan ◽  
Deepak Joshi ◽  
Asheshwar Tiwary ◽  
Ihsan Taufik Pasaribu ◽  
...  
Keyword(s):  
Water Saturation ◽  
High Water ◽  
Carbonate Reservoir ◽  
Water Contact ◽  
Saturation Zone ◽  
Look Ahead ◽  
Production History ◽  
Oil Water ◽  
High Water Cut ◽  
Water Cut

Abstract The Umm Gudair (UG) Field is a carbonate reservoir of West Kuwait with more than 57 years of production history. The average water cut of the field reached closed to 60 percent due to a long history of production and regulating drawdown in a different part of the field, consequentially undulating the current oil/water contact (COWC). As a result, there is high uncertainty of the current oil/water contact (COWC) that impacts the drilling strategy in the field. The typical approach used to develop the field in the lower part of carbonate is to drill deviated wells to original oil/water contact (OOWC) to know the saturation profile and later cement back up to above the high-water saturation zone and then perforate with standoff. This method has not shown encouraging results, and a high water cut presence remains. An innovative solution is required with a technology that can give a proactive approach while drilling to indicate approaching current oil/water contact and geo-stop drilling to give optimal standoff between the bit and the detected water contact (COWC). Recent development of electromagnetic (EM) look-ahead resistivity technology was considered and first implemented in the Umm Gudair (UG) Field. It is an electromagnetic-based signal that can detect the resistivity features ahead of the bit while drilling and enables proactive decisions to reduce drilling and geological or reservoir risks related to the well placement challenges.

scholarly journals The Use of Seismic Reflection Data Inversion Technique to Evaluate the Petro- Physical Properties of Nahr Umr Formation at Kumait and Dujaila Oil Fields – Southern Iraq

2021 ◽  
pp. 565-577
Author(s):  
Nowfal A. Nassir ◽  
Ahmed S. AL- Banna ◽  
Ghazi H. Al-Sharaa
Keyword(s):  
Seismic Data ◽  
Acoustic Impedance ◽  
Water Saturation ◽  
Water Reservoir ◽  
Effective Porosity ◽  
Oil Fields ◽  
Seismic Reflection Data ◽  
Data Inversion ◽  
Reflection Data ◽  
Southern Iraq

The estimation of rock petrophysical parameters is an essential matter to characterize any reservoir. This research deals with the evaluation of  effective porosity (Pe), shale volume (Vsh) and water saturation (Sw) of reservoirs at Kumait and Dujalia fields, which were analyzed from well log and seismic data. The absolute acoustic impedance (AI) and relative acoustic impedance (RAI) were derived from a model which is based on the inversion of seismic 3-D post-stack data. NahrUmr formation’s sand reservoirs are identified by the RAI section of the study area. Nahr Umr sand-2 unit in Kumait field is the main reservoir; its delineation depends on the available well logs and AI sections information. The results of well logging interpretation showed a decrease of Sw and Vsh and an increase of effective porosity in the oil reservoir area, which coincides with the decrease of AI values. The existence of the water reservoir in Du-2 well revealed a convergence of the results of AI and effective porosity with those of Kumait wells , along with and some differential results of Sw and Vsh values that may be related to changes in lithology and fluid density.

THE YAMMADERRY, COWLE AND ROLLER DISCOVERIES IN THE BARROW SUB-BASIN, WESTERN AUSTRALIA

1991 ◽  
Vol 31 (1) ◽  
pp. 32
Author(s):  
M.K. McLerie ◽  
A.M. Tait ◽  
M.J. Sayers
Keyword(s):  
Early Cretaceous ◽  
Western Australia ◽  
Oil Fields ◽  
Seismic Survey ◽  
Seismic Profiles ◽  
Water Contact ◽  
Vertical Seismic Profiles ◽  
Fluid Saturation ◽  
Oil Water ◽  
Thickness Variable

The TP/3 Part I permit in the Barrow Sub-basin has been held by WAPET since 1952. Improvements in seismic quality and oilfield economics in the early 1980s resulted in the 1985 Saladin oil discovery, which subsequently led to the Yammaderry, Cowle and Roller discoveries.Yammaderry-1, drilled in 1988, encountered 16.5 m of gas capping a nine metre oil column. In 1989, Cowle-1 penetrated a 14 m oil column and tested at 1016 m3 (6390 BBL) of oil per day. Roller-1, drilled in 1990, encountered six metres of gas capping nine metres of oil and tested at 866 m3 (5450 BBL) of oil per day. Roller-2, deviated downdip to find the oil/water contact, proved an 18 m oil column, confirmed later by Roller-4.Early Cretaceous Barrow Group deltaic sandstones are the reservoirs for the Saladin, Yammaderry, Cowle and Roller oil fields. The Barrow Group is overlain by the Mar- die Greensand, the basal unit of the Muderong Shale which forms the regional seal. The transitional acoustic character of the Mardie Greensand and its thickness, variable fluid saturation and lithology, cause problems in picking a top Barrow Group event. Vertical Seismic Profiles acquired in the Yammaderry, Cowle and Roller wells have helped tie the wells to the seismic data.With Saladin on stream, and Yammaderry and Cowle under development, a major seismic survey was completed in late 1990 to delineate Roller and to detail prospects for future drilling in the revitalised TP / 3 Part 1 permit.

Comparative Analysis of the Composition of Carbon-Rich Rocks from Domanik Deposits and the Oil–Water Contact Zone Exemplified by Tatarstan’s Bavly Oilfield

2020 ◽  
Vol 60 (6) ◽  
pp. 659-667
Author(s):  
Yu. M. Ganeeva ◽  
T. N. Yusupova ◽  
E. E. Barskaya ◽  
E. S. Okhotnikova ◽  
G. V. Romanov
Keyword(s):  
Comparative Analysis ◽  
Contact Zone ◽  
Water Contact ◽  
Oil Water

scholarly journals A Comparison of Mishrif Formation Characteristics in Kumait and Dujaila Oil Fields, Southern Iraq, Using Seismic Inversion Method and Petrophysical Properties Analysis

2020 ◽  
pp. 3294-3307
Author(s):  
Ahmed S. Al-Banna ◽  
Nowfal A. Nassir ◽  
Ghazi H. Al-Sharaa
Keyword(s):  
Acoustic Impedance ◽  
Water Saturation ◽  
Water Reservoir ◽  
Seismic Inversion ◽  
Effective Porosity ◽  
Oil Fields ◽  
Inversion Method ◽  
Oil Reservoir ◽  
Petrophysical Properties ◽  
Southern Iraq

A comparison was conducted between two wells, Kt-1and Kt-2, in Kumait and two wells, Du-1and Du-2, in Dujaila oil fields that belong to Mishrif formation, southern Iraq.  Seismic inversion method was employed to detect oil and water reservoirs. The comparison included the behavior of acoustic impedance (AI) of fluids and the lithology with related petrophysical properties. The values of water saturation, Shale volume (Vsh), and effective porosity were compared between the AI,  two fluid reservoirs. It was found that the AI value for the oil reservoir unit is relatively low to medium, whereas it was relatively medium for the water reservoir. Effective porosity value showed, in general, an increase in the oil reservoir and a slightly decrease in the water reservoir. The Vsh and water saturation (Sw) values of the oil reservoir unit were in general lower than those in the water reservoir, which indicates the presence of hydrocarbons accumulation. The lithology and porosity are the main factors affecting the acoustic impedance values. Despite the small difference in density between oil and water, these two fluids still show perceptible variation in their properties.  

DISCOVERY OF THE WANAEA AND COSSACK OIL FIELDS

1991 ◽  
Vol 31 (1) ◽  
pp. 22
Author(s):  
A.N. Bint
Keyword(s):  
Upper Jurassic ◽  
Oil Field ◽  
Oil Fields ◽  
Seismic Survey ◽  
Gas Oil ◽  
Water Contact ◽  
North West ◽  
The North ◽  
Reservoir Development ◽  
Oil Water

Exploration of the Dampier Sub-basin on the North West Shelf of Australia commenced with a reconnaissance seismic survey in 1965. In 1969 Madeleine-1, the first well drilled on the Madeleine Trend, encountered water bearing Upper Jurassic sandstones. Following acquisition of a regional grid of modern seismic in 1985 and 1986, and comprehensive hydrocarbon habitat studies, the Wanaea and Cossack prospects were matured updip from Madeleine 1. They were proposed to have improved reservoir development and an oil charge.The Wanaea Oil Field was discovered in 1989 when Wanaea-1 encountered a gross oil column of 103 m in the Upper Jurassic Angel Formation. The well flowed 49° API oil at 5856 BPD (931 kL/d) with a gas-oil ratio of 1036 SCF/STB. Two appraisal wells were drilled in the field in 1990.The Cossack Oil Field was discovered in 1990 when Cossack-1 encountered a gross oil column of 54 m also in the Angel Formation. The oil-water contact is 18 m deeper than in Wanaea-1. Cossack-1 flowed 49° API oil at 7200 BPD (1145 kL/d) with a gas-oil ratio of 98 SCF/STB.The Angel Formation reservoir consists of mass flow sandstones interbedded with bioturbated siltstones. Sandstone porosities average 16 to 17 per cent for both the Wanaea and Cossack Fields. Permeabilities average about 300 mD at Wanaea and about 500 mD at Cossack.An extensive 3-D seismic survey was conducted over the Wanaea and Cossack Fields in 1990. Final reserves calculations await interpretation of this survey, but it is clear that the combined Wanaea and Cossack oil reserve is the largest outside Bass Strait.

scholarly journals Reservoir modeling and petrophysical evaluation of kanga field onshore Niger delta.

2021 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Niger Delta ◽  
Water Saturation ◽  
Hydrocarbon Exploration ◽  
Reservoir Modeling ◽  
High Porosity ◽  
Water Contact ◽  
Bulk Volume ◽  
Oil Water ◽  
Structural Closure ◽  
Petrophysical Evaluation

Reservoir sands from seven wells in Kanga Field in the Onshore Niger Delta was subjected to both petrophysical evaluation and reservoir modeling. Methodologies used are standard methods used in reservoir modeling and petrophysical evaluation. Results from reservoir modeling, shows that six synthetics and four antithetic faults have been identified and these faults are the main structural closure for hydrocarbon accumulation in Kanga Field. Petrophysical analysis showed porosity ranging from (25-27%), (16-27%) and (11-17%) for J100, K100 and L100 respectively. Modeled porosity showed high porosity in J100 and the central part of K100 reservoir. While, low porosity/; is recorded in L100. Water saturation ranges from 20 to 90% in the J100 reservoir, the lowest water saturation value was at the NE, NW and central part of the reservoir. Oil water contact reveals pockets of hydrocarbon in J100 and L100 reservoir. The bulk volume of hydrocarbon saturation closure is (21,954.37) arceft, (209,613.7) acreft and 46,025.51) acreft for J100, K100, and L100 reservoirs respectively. The estimated volumetric for P90 are (4,648,755.06) STB, (16,545,452.38) STB and (9,976,551.38) STB respectively. This study de that the field is viable for hydrocarbon exploration.

scholarly journals ANALISIS PETROFISIKA UNTUK MENENTUKAN OIL-WATER CONTACT PADA FORMASI TALANGAKAR, LAPANGAN “FBT”, CEKUNGAN SUMATRA SELATAN

2020 ◽  
Vol 5 (1) ◽  
pp. 15-29
Author(s):  
Febrina Bunga Tarigan ◽  
Ordas Dewanto ◽  
Karyanto Karyanto ◽  
Rahmat Catur Wibowo ◽  
Andika Widyasari
Keyword(s):  
Gamma Ray ◽  
Water Saturation ◽  
Effective Porosity ◽  
Neutron Density ◽  
Water Contact ◽  
Core Data ◽  
Petrophysical Property ◽  
Reservoir Conditions ◽  
Oil Water ◽  
Well Data

In conducting petrophysics analysis, there are many methods on each property. Therefore, it is necessary to determine the exact method on each petrophysical property suitable for application in the field of research in order to avoid irregularities at the time of interpretation. The petrophysical property consists of volume shale, porosity, water saturation, etc. This research used six well data named FBT01, FBT02, FBT03, FBT04, FBT05, and FBT06 and also assisted with core data contained in FBT03. Core data used as a reference in petrophysical analysis because it was considered to have represented or closed to the actual reservoir conditions in the field. The area in this research was in Talangakar Formation, "FBT" Field, South Sumatra Basin. The most suited volume shale method for “FBT” field condition was gamma ray-neutron-density method by seeing its photo core and lithology. As for the effective porosity, the most suited method for the field was neutron-density-sonic method by its core. Oil-water contact was useful to determine the hydrocarbon reserves. Oil-water contact was obtained at a depth of 2277.5 feet on FBT01, 2226.5 feet on FBT02, 2312.5 feet on FBT03, 2331 feet on FBT04, 2296 feet on FBT05, and 2283.5 feet on FBT06. The oil-water contact depth differences at Talangakar formation in FBT field caused by structure in subsurface.

scholarly journals High Resistivity Reservoirs (Causes And Effects): Sahara Field, Murzuq Basin, Libya

Warta Geologi ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 230-234
Author(s):  
Abubaker Alansari ◽  
◽  
Ahmed Salim ◽  
Abdul Hadi Abd Rahman ◽  
Nuri Fello ◽  
...  
Keyword(s):  
Capillary Pressure ◽  
Water Saturation ◽  
Oil Field ◽  
High Resistivity ◽  
Geological Time ◽  
Water Contact ◽  
Data Set ◽  
Low Resistivity ◽  
Resistant Medium ◽  
Oil Water

High and low resistivity values is an alarming phenomenon that is usually associated with a very complicated reservoir history and worth looking into. Ordovician sandstone reservoirs are the primary oil producers in the Murzuq basin oil fields that is characterized with an average porosity of 14%, permeability range 410-10,760 md and clean quartz aranite composition. More than fifty wells were drilled in Sahara oil field, but only four of them were announced to have high resistivity values more than 100k ohm-m and ten others to be considered as low resistivity wells (below 50 ohm-m). Therefore, average deep resistivity was mapped in both water and oil legs using all available data set, and the top reservoir was employed as a trend map. They showed distinctive trends for low resistivity readings in oil-leg and confirmed the extreme deep resistivity nature for the wells (W7, W8, W9, and W10). Height above oil water contact and capillary pressure was also calculated for all the wells and revealed a high pressure (400 psi) at the location of the high resistivity wells. As a result, of higher capillary pressure in thicker reservoir area oil might have been able to displace water through geological time by benefitting of more considerable height above oil-water contact, higher connate pressure, and buoyancy forces support, which resulted in occupying all the larger pores and pushed the water into minor scattered pores leading to gradual alteration of reservoir wettability from water to oil-wet. Hence, the brine fluids will no longer be connected to each other inside the pore system. Therefore, they will lose their contribution to resistivity readings, and the resistivity tool will encounter a more resistant medium, which in turn will lead to underestimation of water saturation.

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