Evaluate the Smear Effect of Casing while Drilling in South Rumaila Oil Field Using Finite Element Model

Authors

  • Sajjad Mezher Mutar, Ayad A. Alhaleem, Ghanim M. Farman, Nazik Nouman Mahmood

Abstract

The concept of casing while drilling (CwD) is drilling and isolating the formations in one process. This done by replacing drill pipe with casing during drilling, which eliminate both of operational and financial challenges encounter conventional drilling. Lost circulation is the most problem accompany drilling processes in South Rumaila oil field. CwD proposed as one of the solutions in South Rumaila to mitigate lost circulation problem and improve wellbore stability in Dammam formation by the smearing effect. This research focuses on modeling smear effect of CwD in Shuaiba formation, one of the most formations severe from losses in this field. The model is based on finite element method by using ABAQUS/CAE software to simulate the fracture in CwD and study the smearing mechanism into the wellbore wall. In addition determine the effects of parameters on hoop stress distributions while drilling. The results of this finite element model (FEM) showed that smear effect increased the hoop stress in the wellbore wall at fracture mouth by 5000 psi and at the bridge location within the fracture by 43500 psi. All the other results are included in this paper. The aim of this study is predicting the achievable smear effect during CwD in the wellbore wall and in the fracture surface and examining the smear effect ability to heal the fracture by using FEM depending on decreasing the fracture width beyond seal location. In addition, give an idea of the suitable cuttings size crashed into the wellbore wall to create the bridge in the fracture. In conclusion, CwD can enhance hoop stresses significantly around the wellbores of the most lost circulation zones in South Rumaila and minimize the loses problem. FEM is considered as a basic tool to give an idea of the smearing mechanism in depleted formation.

Published

2020-10-14

Issue

Section

Articles