Interpretation of elastic – strain – recovery measurements near Elliot Lake, Ontario

1970 ◽  
Vol 7 (2) ◽  
pp. 576-578
Author(s):  
G. H. Elsbacher ◽  
H. U. Bielenstein
Keyword(s):  
Stress Field ◽  
Elastic Strain ◽  
Sedimentary Rocks ◽  
Lake Ontario ◽  
Strain Recovery ◽  
Tectonic Deformation ◽  
In Situ Stresses ◽  
Stress Environments ◽  
Mine Openings

In situ stresses obtained by measurements of elastic – strain – recovery in quartzose sedimentary rocks near Elliot Lake are interpreted in terms of two stress environments: one stress field induced by mining close to the mine openings and a remanent stress field preserved in the rocks from a time of tectonic deformation in the area.

What the Shale are We Talking About!

2021 ◽  
Author(s):  
Besmir Buranaj Hoxha ◽  
Claudio Rabe
Keyword(s):  
Failure Mechanism ◽  
Sedimentary Rocks ◽  
Formation Damage ◽  
Low Permeability ◽  
Wellbore Instability ◽  
The Past ◽  
In Situ Stresses ◽  
Different Types ◽  
Drilling Cost

Abstract Shale ‘stability’ has been extensively studied the past few decades in an attempt to understand wellbore instability problems encountered while drilling. Drilling through shale is almost inevitable, it makes up 75 percent of sedimentary rocks. Shale tends to be characterized as having high in-situ stresses, fissile, laminated, with low permeability. However, not all shale are the same, and the problem herein lies where they are all treated as such, in which most cases, has shown to be ineffective. Ironically, shale is predominantly generalized as being "reactive/swelling". Even though this can be true, it is not always the case because not all shale is reactive! In reality, there are many different types of shale: ductile, brittle, carbonaceous, argillaceous, flysch, dispersive, kaolinitic, micro-fractured etc. This study aims to clear many misconceptions and define different types of shale (global case scenarios) and their failing mechanisms that lead to wellbore instability, formation damage and high drilling cost. Afterwards, solutions will be offered, from a filed operation perspective, which will provide guidelines for stabilizing various shale based on their failure mechanism. Furthermore, we will define the symptoms for shale instability and propose industry accepted remedies.

scholarly journals 3-D geomechanical modelling of a gas reservoir in the North German Basin: workflow for model building and calibration

2013 ◽  
Vol 5 (1) ◽  
pp. 767-788 ◽  
Author(s):  
K. Fischer ◽  
A. Henk
Keyword(s):  
Stress Field ◽  
Fractured Reservoirs ◽  
Wellbore Stability ◽  
Fe Model ◽  
North German Basin ◽  
Gas Reservoir ◽  
The North ◽  
In Situ Stresses ◽  
German Basin

Abstract. The optimal use of conventional and unconventional hydrocarbon reservoirs depends, amongst others, on the local tectonic stress field. For example, wellbore stability, orientation of hydraulically induced fractures and – especially in fractured reservoirs – permeability anisotropies are controlled by the recent in situ stresses. Faults and lithological changes can lead to stress perturbations and produce local stresses that can significantly deviate from the regional stress field. Geomechanical reservoir models aim for a robust, ideally "pre-drilling" prediction of the local variations in stress magnitude and orientation. This requires a~numerical modelling approach that is capable to incorporate the specific geometry and mechanical properties of the subsurface reservoir. The workflow presented in this paper can be used to build 3-D geomechanical models based on the Finite Element Method (FEM) and ranging from field-scale models to smaller, detailed submodels of individual fault blocks. The approach is successfully applied to an intensively faulted gas reservoir in the North German Basin. The in situ stresses predicted by the geomechanical FE model were calibrated against stress data actually observed, e.g. borehole breakouts and extended leak-off tests. Such a validated model can provide insights into the stress perturbations in the inter-well space and undrilled parts of the reservoir. In addition, the tendency of the existing fault network to slip or dilate in the present-day stress regime can be addressed.

scholarly journals A workflow for building and calibrating 3-D geomechanical models &ndash a case study for a gas reservoir in the North German Basin

Solid Earth ◽  
2013 ◽  
Vol 4 (2) ◽  
pp. 347-355 ◽  
Author(s):  
K. Fischer ◽  
A. Henk
Keyword(s):  
Stress Field ◽  
Fractured Reservoirs ◽  
Wellbore Stability ◽  
Fe Model ◽  
North German Basin ◽  
Gas Reservoir ◽  
The North ◽  
In Situ Stresses ◽  
German Basin

Abstract. The optimal use of conventional and unconventional hydrocarbon reservoirs depends, amongst other things, on the local tectonic stress field. For example, wellbore stability, orientation of hydraulically induced fractures and – especially in fractured reservoirs – permeability anisotropies are controlled by the present-day in situ stresses. Faults and lithological changes can lead to stress perturbations and produce local stresses that can significantly deviate from the regional stress field. Geomechanical reservoir models aim for a robust, ideally "pre-drilling" prediction of the local variations in stress magnitude and orientation. This requires a numerical modelling approach that is capable to incorporate the specific geometry and mechanical properties of the subsurface reservoir. The workflow presented in this paper can be used to build 3-D geomechanical models based on the finite element (FE) method and ranging from field-scale models to smaller, detailed submodels of individual fault blocks. The approach is successfully applied to an intensively faulted gas reservoir in the North German Basin. The in situ stresses predicted by the geomechanical FE model were calibrated against stress data actually observed, e.g. borehole breakouts and extended leak-off tests. Such a validated model can provide insights into the stress perturbations in the inter-well space and undrilled parts of the reservoir. In addition, the tendency of the existing fault network to slip or dilate in the present-day stress regime can be addressed.

Sign in / Sign up

Export Citation Format

Share Document