Petroleum Engineering Commons^™

Reasons Why Oil Reserves Remain Unproductive-A Case Study, Mohamed Al-Saho

Journal of the Arab American University مجلة الجامعة العربية الامريكية للبحوث

By studying the production plans of some wells of Al Furat Petroleum Company, the researcher noticed that the rate of production increases to reach a peak and then falls back sharply. The deformation of the area around the well due to the decrease in the formation pressure (after production for a certain period) may have caused a change in the storage properties (porosity, permeability) and thus lower production rate. However, from the point of view of the geomechanics of the oil formation, which includes the study of the stress situation and its effect on the rock tissue, we will notice …

Fluid-Driven Fracture Initiation From Oil And Gas Wells Considering Lifetime Stresses, Andreas Michael

LSU Doctoral Dissertations

Fluid-driven fracture initiation from oil and gas wells is examined in detail. The dissertation covers three subtopics: drilling, completion (stimulations), and post-blowout capping-induced fracture initiation.

Drilling-induced tensile fractures (DITFs) are located in an azimuth orthogonal to wellbore breakouts and are observed from image logs obtained during drilling operations. Fully analytical criteria for the orientation of DITFs initiating from wells in porous, permeable media are derived considering fluid infiltration from a pressurized wellbore. DITF orientation (longitudinal or transverse-to-the-wellbore) is used to constrain the magnitude of the local maximum horizontal principal stress. The range of the possible stress states is indicated on …

Modeling Of Leakage Through Fault-Zone Structures In Co2 Geological Storage, Dayna Rodriguez Zambrano

LSU Master's Theses

Faults intersecting target geological CO₂ storage zones have important implications for storage integrity. Potential leakage pathways due to fluid over-pressurization are investigated in this project to ensure long-term containment of injected CO₂. Numerical flow simulations coupled with a geomechanical module are presented in this work with the purpose of determining the extent of CO₂ up-fault migration, the driving mechanisms of leakage and the corresponding response of quantified pore pressure and stress variations.

This study uses dual-continuum models performed by using CMG (2017) to correctly account of flow through fractures in a fault damage zone. Numerical simulations …

Impact Of Natural Fracture Induced Elastic Anisotropy On Completion And Hydraulic Fracturing Designs, Emre Can Dundar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Shale has been usually recognized as a transverse isotropic (TI) medium in conventional geomechanical log interpretation due to its laminated nature. However, when natural fractures (NFs) exist in the rock body, additional elastic anisotropy can be introduced, converting Shale to an orthorhombic (OB) medium. Previous study illustrates that treating the naturally fractured shale rock as a TI medium by ignoring the NF-induced anisotropy can cause the erroneous estimation of the geomechanical properties (i.e. Young’s modulus, Poisson’s ratio, brittleness index, and etc.) and in-situ stress. In this paper, the study is extended to quantify the impact of NF-induced elastic anisotropy on …

Application Of The Variational Fracture Model To Hydraulic Fracturing In Poroelastic Media, Chukwudi Chukwudozie

LSU Doctoral Dissertations

Hydraulic fracturing has persisted through the use of simple numerical models to describe fracture geometry and propagation. Field tests provide evidence of interaction and merging of multiple fractures, complex fracture geometry and propagation paths. These complicated behaviors suggest that the simple models are incapable of serving as predictive tools for treatment designs. In addition, other commonly used models are designed without considering poroelastic effects even though a propagating hydraulic fracture induces deformation of the surrounding porous media. A rigorous hydraulic fracturing model capable of reproducing realistic fracture behaviors should couple rock deformation, fracture propagation and fluid flow in the both …

Application Of The Finite Element Method To Solve Coupled Multiphysics Problems For Subsurface Energy Extraction, Milad Ahmadi

LSU Doctoral Dissertations

Fractures are a source of extra compliance in the rock mass. Fracture compliance can estimate the fracture roughness and the type of fluid filling the fracture. The focus of this research study in chapter 2 is to illustrate how the compliance ratio of rough fractures can diverge from the compliance ratio of smooth fractures. The imperfect interface of the fracture is modeled with saw-tooth-like structures. The defined saw-tooth-like structures of contact asperities impose an in-plane asymmetry in the shear direction. The compliance ratio of the rough fracture is larger than the compliance ratio of the smooth fracture. Interlocking and riding …

Poroelastic Inhomogeneities: Applications In Reservoir Geomechanics, Houman Bedayat

LSU Doctoral Dissertations

The scarce amount of conventional hydrocarbon reservoirs and increase of fuel consumption in the world have made production from unconventional hydrocarbon resources inevitable. Because of the low permeability of unconventional formations, fractures are the main paths for the fluid to flow. Therefore, detailed knowledge of the size, orientation, and permeability of the fracture systems are essential for reservoir engineers. Permeability of the fractures is function of their volume and opening, and stress and fluid pore pressure distribution in the formation. Since reservoir pressure may change over the production life of the reservoir, studying stress redistribution and mechanical behavior of the …

Investigation Of Wellbore Stability In A North Sea Field Development, Steven Austin Hilgedick

Doctoral Dissertations

"Planning drilling operations is key to the development of oil and natural gas fields. As part of well design, wellbore stability and pore pressure analysis are main factors in determining the safe operating window for selecting mud density. The motivation for this research was to conduct wellbore stability based on exploration wells as basis for planning new offshore field developments with deviated and horizontal wells. A second objective was to investigate the use of a probabilistic approach to wellbore stability, and compare it to the conventional deterministic methods, in order to evaluate the value of including a probabilistic approach to …