Numerical simulation & risk analysis of well kick

Islam, MD Rakibul (2017) Numerical simulation & risk analysis of well kick. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (2MB)

Abstract

Oil and gas development is moving into harsh and remote locations where the highest level of safety is required. A blowout is one of the most feared accidents in oil and gas developments projects, which is the result of uncontrolled flow of influx into the wellbore. Limited insights about the rapidly changing physical parameters during a blowout necessitates the exhaustive analysis of kick detection parameters. The risk of blowout consequences can be minimized by appropriate kick detection and well control techniques. This work presents a dynamic numerical simulation of kick detection and experimental studies to analyze hydrodynamic properties of drilling fluid to detect a kick. The experimental results are used to verify dynamic numerical simulation results. A three dimensional CFD simulation of a pressure cell which is a mimic of a scaled down version of a wellbore is performed using commercial CFD package ANSYS Fluent-15. The main objective of this simulation model is to analyze the pressure gradient, rising speed of a gas kick and volumetric behaviour of the gas kick with respect to time. Simulation results exhibit a sudden increase of pressure while the kick enters and volumetric expansion of gas as it flows upward. This improved understanding helps to develop effective well control strategies. The proposed numerical simulation model is validated by comparison with experimentally obtained downhole pressure during an influx into the pressure cell. This study confirms the feasibility and usability of an intelligent drill pipe as a tool to monitor well condition and develop blowout risk management strategies. Furthermore, to quantify the risk of blowout consequences, this work aims to test and validate a blowout risk assessment model using uniquely developed experimental results. Kick detection is a major part of the blowout risk assessment model. The accuracy and timeliness of kick detection are dependent on the monitoring of multiple downhole parameters such as downhole pressure, fluid density, fluid conductivity and mass flow rate. In the present study these four parameters are considered in different logical combinations to assess the occurrence of kick and associated blowout risk. The assessed results are compared against the experimental observations. It is observed that simultaneous monitoring of mass flow rate combined with any one the three parameters provides most reliable detection of kick and potential blowout likelihood. This work confirms that a blowout risk model integrated with real time monitoring is a reliable and effective way of managing blowout risk. Upon success testing of this approach at the pilot and field levels, this approach could provide a paradigm shift in drilling safety.

Actions (login required)

View Item