A NEW APPROACHING METHOD TO ESTIMATE FRACTURE GRADIENT BY CORRECTING MATTHEW-KELLY AND EATON’S STRESS RATIO

• Main Author: Noor Corina, Anisa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/64178
• Institution: Institut Teknologi Bandung

Prior to drilling, wellbore stability is performed to obtain a successful drilling project and minimize the possibility of hole problems by analyzing wellbore behavior. The most important parameters for performing wellbore stability are overburden pressure, pore pressure, and fracture pressure. From those parameters, mud weight profile, casing setting depth, and cementing operation could be determined. An incorrect design will cause a great damage during drilling or post-drilling operation. Formerly, the fundamental theory of fracture gradient was developed by Hubbert-Willis in 1957. Afterwards, there have been a lot of studies in predicting fracture gradient, such as Matthew-Kelly and Eaton?s equation. But, mostly those studies concerned on fracture gradient prediction in selected area which resulting improper prediction in other drilling areas. However, the best results in approaching the actual fracture gradient could be obtained by analyzing the area characteristic previously. This study is performed due to improper approximation methods to predict fracture gradients which mostly limited with area characteristics. To generate more accurate prediction, it is necessary to correct the calculation methods, especially Matthew-Kelly and Eaton?s equation as the main focus on this study. This study concerns on developing new empirical equations of each constant, such as stress ratio of Matthew-Kelly and Eaton equation, and Poisson?s Ratio (?) from Eaton?s calculation. The constraint of this study is the minimum available experimental data, such as leak-off test and formation integrity test. Therefore, this study also proposed a methodology to develop fracture gradient model to approach those available data.