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العنوان
INTEGRATED PETROPHYSICAL AND GEOMECHANICAL EARTH MODLING FOR THE CRETACEOUS TIGHT SAND RESERVOIRS AND ITS IMPACT ON THE PRODUCTION OPTIMIZATION IN TUT FIELD, WESTERN DESERT, EGYPT /
المؤلف
Youssef, Amr Abd El Raouf.
هيئة الاعداد
باحث / Amr Abd El Raouf Youssef
مشرف / Nasser Hassan Abu-Ashour
مشرف / Abdullah Mahmoud El-Sayed
مناقش / Awad Abdel Khaliq Omran
تاريخ النشر
2019.
عدد الصفحات
219 P. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
الجيوفيزياء
تاريخ الإجازة
1/1/2019
مكان الإجازة
جامعة عين شمس - كلية العلوم - قسم الجيوفيزياء
الفهرس
Only 14 pages are availabe for public view

from 219

from 219

Abstract

TUT field locates 4-5 km north and northwest of Salam field at the northern edge of Safir-TUT ridge at Khalda concession in the northwestern part of the Western Desert. The field is discovered in 1986 producing from many horizons; Upper Bahariya, Lower Bahariya, Alam El Bueib Units (AEB-1, AEB-2, AEB-3) and Jurassic reservoirs (Khatatba-2B middle, 2F upper and 2F lower).
The study focused on the Petrophysical, Geomechanical earth modeling characteristics of the Cretaceous tight sand reservoirs, in the TUT field, North of Western Desert, Egypt to build Geomechanical earth modeling to evaluate the hydrocarbon potentialities and the impact on the production optimization in the Cretaceous reservoirs (Bahariya and Alam Al Bueib).
The data provided is comprised of 6 wells (TUT19, TUT 23, TUT 30, TUT 40, TUT 45, &TUT 79), all of them are vertical except TUT 45 which is deviated to the SW direction with maximum angle of 19º.
The studied oil field was investigated using available data in 6 wells for the purpose of evaluating the Cretaceous reservoirs (Bahariya and Alam Al Bueib formations).
TUT 19, TUT 23, TUT 30, TUT 40, TUT 45 and TUT 79
The available well logging data are density, neutron, gamma ray, resistivity, caliper, uni-axial sonic, mud logs obtained from Khalda Petroleum Company.
Exploration history and Geological setting have been touched for the western desert and the cretaceous time zone.
Regional tectonics and structural setting of Western Desert have been touched.
Geothermal gradient of Western Desert and TUT field have been summarized.
Due to lack of some data, the researcher tried to extract and validate the information not only from the available well data from the hosting company but also from external sources and practical field experiences in different locations worldwide.
In both Petrophysical and Geomechanical chapters, brief theoretical backgrounds have been offered (Formation Evaluation Data, different methods of density calculating, wellbore instability, shale properties, reservoir production system, critical state concept, MEM and stability analysis, pore pressure, unconfined compressive strength).
Petrophysical analysis was run by Techlog software version 2013 to perform a comprehensive analytical formation evaluation system to establish and interpret the basic advanced logging data; determination and interpretation of the main petrophysical parameters; Vshale (shale volume, Sw (water saturation) and porosity.
Formation temperature, correction of the Mud Resistivity (Rmf), fluid and hydrocarbon Saturations and Rw validation were required and calculated.
A number of maps were made for Petrophysical parameters obtained by log analysis Using Surfer software
Seismic maps, seismic lines and cross plots have been created and interpreted to define the field structures and their directions and lateral variation characters of the formations, then getting close to the hydrocarbon accumulations.
Since TUT 45 is the only well having sonic and Density logs, in addition to check shot, a synthetic Seismogram can be created.

Litho-saturation logs and Density-Neutron cross plots have been created for each formation in each well
Summary of the weighted average values of the petrophysical parameters for the studied wells have been calculated.
As the wells are old and the acoustic logs were usually for Compressional waves only, no shear waves available, the Sonic was not a powerful interpreting tool to measure the elastic moduli. The researcher used P-wave with the lithology to predict S-wave.
WBS logs and mechanical earth models have been created indicating the Geomechanical parameters, mud weight windows and touched the effect of the well trajectory to some extent due to lack of deviated wells with high angles and azimuths.
As a routine reservoir management data, Khalda consider that Bahariya reservoir cutoff as 12% porosity, 55-65% water saturation and 40% Vsh
Some cross plots have been created between the UCS and the Young’s modulus with high regression rate making them reliable using the Gamma ray as a discriminator.
As the wells are old and the acoustic logs were usually for Compressional waves only, no shear waves available, the Sonic was not a powerful interpreting tool to measure the elastic moduli. The researcher used P-wave with the lithology to predict S-wave using Castagna relationship between Vp and Vs. The regression rate is 99% meaning best fit and when employed in Techlog it showed good matching with the other Geomechanical parameters and Seismic profiles as well, consequently interpretation significance accepted the empirical log.

5.2 Conclusions
After applying the workflow of the supporting software (Techlog, Surfer and Petrel) in Petrophysics and Geomechanics and from the field experience in Oil & Gas industry and the discussions with the hosting oil company and the reasonable awareness of the related reports, technical papers and articles, the researcher has found some conclusions:
Petrophysical parameters:
• Vsh derived from the gamma-ray is better-defined than density-neutron method especially after applying clavier correction on gamma-ray log. That is confirmed by comparison between different methods.
• from the logs, the relative difference between total and effective porosity can be observed indicating the Vd or the volume of the dispersed clay or the clay-bound water which in turn shows the higher shaly sand in BAH formations, so applying the effective porosity is more accurate.