Gas Drilling Wellbore Stability Analysis in Igneous Rock Carboniferous System of Dzungaria Basin

2013 ◽  
Author(s):  
Laiju Han ◽  
Hongshan Zhao ◽  
Zonggang Wang ◽  
Guangtong Feng
Keyword(s):  
Stability Analysis ◽  
Igneous Rock ◽  
Wellbore Stability ◽  
Gas Drilling

scholarly journals Geomechanical model and wellbore stability analysis utilizing acoustic impedance and reflection coefficient in a carbonate reservoir

2021 ◽  
Author(s):  
Hassan Bagheri ◽  
Abbas Ayatizadeh Tanha ◽  
Faramarz Doulati Ardejani ◽  
Mojtaba Heydari-Tajareh ◽  
Ehsan Larki
Keyword(s):  
Stability Analysis ◽  
Reflection Coefficient ◽  
Acoustic Impedance ◽  
Shear Failure ◽  
Normal Fault ◽  
Carbonate Reservoir ◽  
Wellbore Stability ◽  
Tensile Failure ◽  
Geomechanical Model ◽  
Gas Drilling

AbstractOne of the most important oil and gas drilling studies is wellbore stability analysis. The purpose of this research is to investigate wellbore stability from a different perspective. To begin, vertical stress and pore pressure were calculated. The lowest and maximum horizontal stress were calculated using poroelastic equations. The strike-slip to normal fault regime was shown by calculated in situ stress values. The 1-D geomechanical model was utilized to investigate the failure mechanisms and safe mud window estimation using the Mohr–Coulomb failure criterion. Using density and sonic (compressional and shear slowness) logs, the acoustic impedance (AI) and reflection coefficient (RC) logs were determined subsequently. The combination of layers with different AI indicates positive and negative values for the RC, zones prone to shear failure or breakout, and the mud weight in these zones should be increased, according to the interpretation of the AI and RC readings and the results of the geomechanical model. Furthermore, the zones with almost constant values of AI log and values close to zero for RC log are stable as homogeneously lithologically, but have a lower tensile failure threshold than the intervals that are sensitive to shear failure, and if the mud weight increases, these zones are susceptible to tensile failure or breakdown. Increased porosity values, which directly correspond with the shear failure threshold and inversely with the tensile failure threshold, cause AI values to decrease in homogenous zones, but have no effect on the behavior of the RC log. This approach can determine the potential zones to kick, loss, shear failure, and tensile failure in a short time.

scholarly journals Wellbore stability analysis based on the stress model around boreholes

2018 ◽  
Vol 1 (T5) ◽  
pp. 290-301
Author(s):  
Khanh Quang Do ◽  
Nam Nguyen Hai Le ◽  
Quang Trong Hoang ◽  
Huy Xuan Nguyen
Keyword(s):  
Stability Analysis ◽  
Oil And Gas ◽  
Wellbore Stability ◽  
Rock Properties ◽  
Stress Model ◽  
Gas Drilling ◽  
Wellbore Pressure ◽  
Tensile Fractures ◽  
Matlab Programming

Wellbore stability analysis plays an important role in the oil and gas drilling. Instability problems during the drilling phase are often the results of a combination of both mechanical and chemical effects. This study aims to assess the mechanical wellbore stability based on the stress model around boreholes. The development of the stress model around boreholes, which is associated with the in-situ stresses, rock properties as well as the wellbore pressure and configuration, are presented. It could visualize the stress distribution around an arbitratily orientated wellbore. Next, lower hemisphere diagrams are presented to demonstrate the wellbore pressure required to initiate borehole tensile and compressive failures. A program for the risk analysis of wellbore (RAoWB) is designed and developed by the Matlab programming language to describe and analyse the risk diagrams of the drilling induced tensile fractures (DITFs) and breakouts (BOs). They help to choice the optimum wellbore trajectories for well planning, as well as to predict the wellbore instabilities caused by inappropriate wellbore pressures.

Wellbore Geomechanics of Extended Drilling Margin and Engineered Lost-Circulation Solutions

SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1178-1188 ◽  
Author(s):  
Amin Mehrabian ◽  
Younane Abousleiman
Keyword(s):  
Mechanical Properties ◽  
Stability Analysis ◽  
Analytical Approach ◽  
Wellbore Stability ◽  
Tensile Failure ◽  
Mechanical Interaction ◽  
Lost Circulation ◽  
Drilling Operations ◽  
Secondary Fractures ◽  
Lost Circulation Materials

Summary Wellbore tensile failure is a known consequence of drilling with excessive mud weight, which can cause costly events of lost circulation. Despite the successful use of lost-circulation materials (LCMs) in treating lost-circulation events of the drilling operations, extensions of wellbore-stability models to the case of a fractured and LCM-treated wellbore have not been published. This paper presents an extension of the conventional wellbore-stability analysis to such circumstances. The proposed wellbore geomechanics solution revisits the criteria for breakdown of a fractured wellbore to identify an extended margin for the equivalent circulation density (ECD) of drilling. An analytical approach is taken to solve for the related multiscale and nonlinear problem of the three-way mechanical interaction between the wellbore, fracture wings, and LCM aggregate. The criteria for unstable propagation of existing near-wellbore fractures, together with those for initiating secondary fractures from the wellbore, are obtained. Results suggest that, in many circumstances, the occurrence of both incidents can be prevented, if the LCM blend is properly engineered to recover certain depositional and mechanical properties at downhole conditions. Under such optimal design conditions, the maximum ECD to which the breakdown limit of a permeable formation could be enhanced is predicted.

3-D Geomechanical Modeling and Wellbore Stability Analysis in Abu Butabul Field

2012 ◽  
Author(s):  
Qiuguo Li ◽  
Xing Zhang ◽  
Khalid Salim Al-Ghammari ◽  
Labib Mohsin
Keyword(s):  
Stability Analysis ◽  
Wellbore Stability
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