EVALUASI GRADIEN REKAH HANYA BEDASARKAN DATA LOT DAN FIT PADA FORMASI KARBONAT BERGEROWONG DI LAPANGAN X

• Main Author: Vincent Soelaiman, Andrew
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/56045
• Institution: Institut Teknologi Bandung

One of the most important parameters in wellbore stability is fracture pressure. Fracture pressure shows the abillity of rock to hold vertical stress before it starts to fracture. The application of fracture gradient (FG) affects the well design, such as casing setting depth, cementing operation, and mud weight profile. Fracture gradient could be determined directly by using leak-off test (LOT) and formation integrity test (FIT), and calculation from logging data. There have been a lot of studies in predicting fracture gradient after the fundamental theory of fracture pressure was developed by Hubbert and Willis in 1957. However, most of these studies were performed without considering the geological characteristic, such as precipitation environment, geology structure, and stratigraphy. (Marbun et al., 2015). A new methodology to predict fracture pressure from former calculations, Matthew-Kelly and Eaton, is proposed. The methodology characterized the formation lithology from Poisson’s ratio and stress ratio value which is corrected and analysed by two correcting constants, a and b. As a result, a new value of Poisson’s and stress ratio of the formation was generated and the accuracy of fracture gradient was improved. In addition, the flexibility of this methodology indicates that this methodology could be applied in various drilling area. (Marbun et al., 2015).