3D GEOSTATISTICAL MODELING OF FACIES AND PETROPHYSICAL PROPERTIES OF THE UPPER KHARTAM OUTCROP OF KHUFF FORMATION, CENTRAL SAUDI ARABIA

3D GEOSTATISTICAL MODELING OF FACIES AND PETROPHYSICAL PROPERTIES OF THE UPPER KHARTAM OUTCROP OF KHUFF FORMATION, CENTRAL SAUDI ARABIA. Masters thesis, King Fahd University of Petroleum and Minerals.

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Abstract

Oolitic grainstones can contain significant hydrocarbon reserves. The heterogeneity in carbonate reservoir ascribes to the depositional and digenetic processes. Within the studied interval, facies were analyzed and grouped into four depositional sub-environment which stacked in five cycle sets (4th order sequences). The porosity and permeability were measured from core plug of outcrop samples. However, the measured porosity and permeability values showed patterns of distributions when statistically analyzed based on the rock typing and stratigraphic intervals. Based on the outcrop observations, the 3D framework was constructed which comprises of five zones separated by six surfaces. In the context of depositional environment, these zones are; foreshoal and shoal (zones 1 and 2), shoal and backshoal (zones 3 and 4) and tidal flat deposits (zone 5). The sea level within these zones was relatively high, fluctuated and dropped within deposits of zones 1 and 2, zones 3 and 4 and zone 5, respectively. In the context of 3D modelling, lithofacies within each zone was populated separately by using different geostatistical algorithm. Based on the relative sea level, the dominated lithofacies and the presence or absence of marine fauna, the studied interval was subdivided into three broad intervals. These intervals are; lower (zones 1 and 2), middle (zones 3 and 4) and the upper interval (zone 5). The porosity evolution was investigated within each zone and incorporated within the 3D outcrop model. The results showed how the incorporation of the porosity scenarios within the 3D framework can provide a realistic and to some extent the exact vertical stacking of reservoir units. This approach could be applied to predict and enhance the reservoir quality in the analogous oolitic reservoir.

Arabic Abstract

صخور الكربونات الاوليتية تحتوي علي معظم الاحتياطي النفطي في العالم. وكما تتميز بتعدد انواع المسامية نتيجة للعمليات الرسوبية و اللاحقة. في هذه الدراسة تم تحديد وحدات طبقية قابلة ان تكون مكامن نفطية جيدة بواسطة بناء نمذجة صخور الترياسي السفلي في تكوين الخف. وكما تم استنتاج عدد من السيناريوهات للمسامية التي قد تنتج من العمليات اللاحقة المختلفة, والتي استفيد منها في فهم المكامن المماثلة في المناطق المختلفة. لعمل النموذج الجيولوجي لمنطقة الدراسة, تم استخدام العينات الحقلية للمكشف الصخري. حيث تم عمل ست مجموعات من اسطح او فواصل والتي بدورها تحدد خمسة نطاقات صخرية. كل نطاق يمثل بيئة ترسيبية معينة, حيث النطاق الاول والثاني يشتملان علي رسوبيات المقدمة والمياه الضحلة, والنطاق الثالث والرابع يحتويان علي رسوبيات المياه الضحلة و خلف الحاجز الرسوبي, والنطاق الخامس يحتوي علي رسوبيات المد والجزر. توزيع السحنات الرسوبية داخل النطاقات تم باستخدام خوارزمية جيواحصائية لكل نطاق. كما تم تقسيم النموزج الصخري الثلاثي الابعاد لثلاث وحدات ريئسية. الوحدة السفلي (النطاق الاول والثاني) والتي ترسبت على الحد الفاصل بين رسوبيات البيرمي والترياسي وتميزت بترسيب وحدات اوليتية عندما كان سطح البحر في ازدياد سريع وغياب تام للكائنات الحية, الوسطى (النطاق الثالث والرابع) ترسبت عندما كان سطح البحر في تذبذب وظهور نسبي للكائنات الحية وتميزتا بمسامية قالبية وبين حبيبية, العليا (النطاق الخامس) وكان سطح البحر في تقهقر ونتيجة لذلك ترسبت صخور كربونات دولمتية زات مسامات بين بلورية و بين حبيبة. تم تطوير السيناريوهات المتعددة للمسامية في نموذج ثلاثي الابعاد لكل نطاق على حدة. ومن خلالها يمكن فهم انواع المسامية الممكنة في المكامن الصخرية الشبيهة. وكما بواسطة هذه الدراسة يمكن فهم وتحسين استكشاف واستغلال الموارد النفطية المخزونة داخل تلك المكامن

English Abstract

Oolitic grainstones can contain significant hydrocarbon reserves. The heterogeneity in carbonate reservoir ascribes to the depositional and digenetic processes. Within the studied interval, facies were analyzed and grouped into four depositional sub-environment which stacked in five cycle sets (4th order sequences). The porosity and permeability were measured from core plug of outcrop samples. However, the measured porosity and permeability values showed patterns of distributions when statistically analyzed based on the rock typing and stratigraphic intervals. Based on the outcrop observations, the 3D framework was constructed which comprises of five zones separated by six surfaces. In the context of depositional environment, these zones are; foreshoal and shoal (zones 1 and 2), shoal and backshoal (zones 3 and 4) and tidal flat deposits (zone 5). The sea level within these zones was relatively high, fluctuated and dropped within deposits of zones 1 and 2, zones 3 and 4 and zone 5, respectively. In the context of 3D modelling, lithofacies within each zone was populated separately by using different geostatistical algorithm. Based on the relative sea level, the dominated lithofacies and the presence or absence of marine fauna, the studied interval was subdivided into three broad intervals. These intervals are; lower (zones 1 and 2), middle (zones 3 and 4) and the upper interval (zone 5). The porosity evolution was investigated within each zone and incorporated within the 3D outcrop model. The results showed how the incorporation of the porosity scenarios within the 3D framework can provide a realistic and to some extent the exact vertical stacking of reservoir units. This approach could be applied to predict and enhance the reservoir quality in the analogous oolitic reservoir.

Item Type: Thesis (Masters)
Subjects: Earth Sciences
Department: College of Petroleum Engineering and Geosciences > Geosciences
Committee Advisor: Makkawi, Mohammad
Committee Members: Korvin, Gabor and Abdulraheem, Abdulaziz and Babalola, Lamidi
Depositing User: ABDASEED KUBUR BOKHARI KUBUR (g201304290)
Date Deposited: 13 Nov 2016 10:08
Last Modified: 01 Nov 2019 16:35
URI: http://eprints.kfupm.edu.sa/id/eprint/140123