Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 12 of 12 for “"Wellbore stability"”.
-
Wellbore stability in water-sensitive shales
<p>Wellbore instability is a widespread problem, especially when drilling in deep, low strength shale formations at high temperature and pressure. The instability can be caused by the high compressive effective stress or tensile stress due to the stress concentration and pore pressure increase …
-
Investigation of wellbore stability in a North Sea field development
… 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 …
-
Development and evaluation of a coaxial cable sensing system for CO₂ sequestration wellbore integrity monitoring
… sensing system for monitoring and evaluation of wellbore stability during CO<sub>2</sub> injection.</p> <p>The real-time distributed sensing system is composed of Fabry-Perot interferometer based coaxial cable temperature and strain sensors. A high pressure high temperature (HPHT) sensor testing …
-
Wellbore instability mechanisms in clays
This dissertation investigates the stability of wellbores drilled in Ko-consolidated clays using non-linear finite element method (FEM) and effective stress soil models to characterize the behavior of clay and unconsolidated shale formations. Two constitutive models are used: Modified Cam Clay …
-
Low oil-water ratio invert emulsion mud for unconventional shale reservoirs
… is beneficial to low fluid loss for enhanced wellbore stability. The focus of this study is to achieve a novel low oil-water ratio invert emulsion using Jatropha oil and egg yolk as an emulsifier. Shale-fluid interaction and the economic viability of the mud were also evaluated. The findings …
-
Geomechanics and elastic anisotropy of the Bakken Formation, Williston Basin
… in geomechanical modeling. I will analyze wellbore stability and predict wellbore behavior under stress alteration caused by drilling. Elastic anisotropy of the formation will be included in the 3 D numerical models. In addition the effects of local geological features on the mode of …
-
Unconfined compressive strength prediction using drilling parameters and analyzing feature importance through principal components analysis
… and estimation of UCS is vital to avoid wellbore stability problems that are inversely correlated with the pace of drilling operations. Furthermore, UCS is an essential input to ensure the success of completion operations such as acidizing and fracturing. Different methods are available …
-
Coupled geomechanics and transient multiphase flow at fracture-matrix interface in tight reservoirs.
… naturally-fractured tight reservoirs - such as wellbore stability, CO2 sequestration and improved hydrocarbon recovery - are relative permeability and capillary pressure. Although the effects of geomechanical parameters on single-phase fluid flow in naturally-fractured tight reservoirs are well …
-
Thermal modeling for calculation of formation temperatures for deep water wells with chemical heat source
… zonal isolation. Artificially strengthening the wellbore is of crucial importance in order to achieve successful drilling as well as cementing for deep water wells. Altering the thermal stresses results in increased tangential stresses in the vicinity of the wellbore and therefore increases the …
-
Characterization of anisotropy in organic-rich shales: shear and tensile failure, wave velocity, matrix and fracture permeability
… The shear fracture pattern can impact wellbore stability and hydraulic fracture analyses. A planar tensile fracture is expected perpendicular to minimum horizontal stress based on the assumption of isotropic mechanical properties. However, complex fracture network can be created in …
-
Geomechanical characterizations and correlations to reduce uncertainties of carbonate reservoir analysis
… that examines the uncertainty of carbonate wellbore integrity.</p><p>The results present a new engineering classification to evaluate the carbonate drillability and deformability. Additional developments regarding the relationships between the carbonate compressive strength and confining …
-
Exploring anisotropy in rock fluid flow and elastic behavior
… and the Amadei solution to stress around a wellbore to demonstrate the importance of the incorporation of anisotropic elastic rock properties in geomechanical modeling of shale formations (Kirsch, 1898; Amadei, 1983). This is done through a case study of a horizontal well in the Lower …