Document

Mechanical stratigraphy for hydraulic fracturing model : a case study from South Oman Athel Formation.

Source
Master's thesis
Other titles
توصيف الطبقات الميكانيكية لنموذج الكسر الهيدروليكي : تشكيلة آثيل في سلطنة عمان
Country
Oman
City
Muscat
Publisher
Sultan Qaboos University
Gregorian
2023
Language
English
Thesis Type
Master's thesis
English abstract
The petroleum industry profoundly influences hydrocarbon reservoir production and the economy. Al Shomou Field, situated in the southern part of Oman, is associated with a crude oil of low gravity of approximately 48◦American Petroleum Institute gravity (API) The primary reservoir, Athel Silicilyte, is located at a depth of 4Km and comprises 90% silica. Athel Silicilyte known as a tight reservoir featuring a porosity of 40% and a permeability of 0.02mD. Hydraulic fracturing is employed as a development technique to enhance field production. This study aims to developed a mechanical stratigraphy of the Athel Formation with using of existing logs, such as porosity, resistivity, density, gamma-ray and permeability. As well as, to create a rock physics model for identifying the pore aspect ratio, create a facies log based on core data, and characterize the Athel reservoir by examining geomechanical properties such as Poisson’s ratio and Young’s modulus. The main data sources for this project include wireline logs, drilling parameters, natural fracture interpretation, radioactive tracer data, and information on perforation intervals. The project comprises three distinct workflows. The first workflow involves constructing a rock physics model and generating plots using the Xu-Payne 2009 methodology and is categorized into three sections. A rock physics log has been developed, and subsequently, the pore aspect ratio model has been refined. In the second workflow, three core wells were analyzed to identify different facies, which were then used to create log facies using six Machine Learning algorithms known as Support Vector Machine (SVM), Gaussian Process Classification (GPC), Random Forest Classifier (RFC), Neural Network Classifier (NNC), K-Nearest- Neighbors (KNN) and Decision Tree Classifier (DT). The pore aspect ratio process provided a more comprehensive understanding of the reservoir’s pore spaces system. The vi rock physics model of eight drilling wells used in the study indicates a porosity range of 0.05% to 0.30%, with velocity values ranging from 3km/s to 5km/s. The pores within the formation exhibit cracked shapes, as observed in the rock physics model. In contrast, the rock physics model derived from tracer data shows a narrower porosity range of 0.15% to 0.25%. The pore aspect ratio log provides further insights into the Athel formation, dividing it into five distinct units. Utilizing the facies log and geomechanics log, which includes Poisson’s ratio and Young’s modulus, eight different facies have been identified within the formation. These facies categorize and characterize the different lithological variations and properties observed within the Athel reservoir.
Arabic abstract
تؤثر صناعة النفط بشكل كبير في إنتاج مكامن الهيدروكربون والاقتصاد. ويرتبط حقل الشموع الواقع في الجزء الجنوبي من سلطنة عمان بهيدروكربون 480 درجة لزوويقع الخزان الرئيسي أثيل سيليسليت ، على عمق 4 كم ويتكون من 90٪ من السيليكا. يُعرف أثيل سيليسليت يتميز بمسامية 40٪ ومسامية 0.02 ملي دارسي.
Category
Theses and Dissertations