Multiphase Flow in Oil and Gas Well Drilling

Baojiang Sun

• Publisher: Wiley
• Year: 2016
• Print ISBN: 9781118720257
• eBook ISBN: 9781118720356
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Mechanics

A major contribution to the state-of-the-art for those interested in multiphase flow in well-bore, drilling cutting, hydrate and/or acid gas involvements

• The author is a leading researcher on the topics presented, and his development of gas-liquid flow pattern transition mechanism and multiphase flow models are major contributions to the multi-phase flow in wellbore
• Focuses on acid gas and hydrate involvements, offering the latest results from drilling engineering computation research
• Presents an emerging hot spot in petroleum engineering, with more multi-phase flow methodologies developed and adopted to improve the engineering process for gas & oil drilling and production

Chapter 1
Introduction

Abstract

Most of the fluid flows in the petroleum engineering are multiphase flows. For instance, the drilling fluid, during the common drilling of oil and gas wells, is a gas-solid phase. There are various macroscopic models for multiphase, such as the homogeneous flow model, the separated flow model, the drift-flux model and the statistical average model. These models are all based on the conservation laws of mass, momentum and energy. The basic parameters to describe a single phase flow are velocity, mass flow rate, and volumetric flow rate. Besides, in wellbore multiphase flow, the mass flow rate, volumetric fraction and velocity of each phase are also the important parameters. Although the mass proportion of gas-liquid phase is the same, the fluid behaviors change with the different gas-liquid distribution. Recognition of these characteristics is of great significance in multiphase flow study.

Keywords: drift-flux model; flow parameters; flow patterns; gas well drilling; homogeneous flow model; multiphase flow models; oil well drilling; separated flow model; statistical average model

A multiphase flow is a fluid flow that comprises more than one phase of matter. The phase defines the different chemical and physical properties of the matter, and the interface between different phases should be physically distinguished for multiphase flow. The same matter in different states, such as gas, liquid and solid, is considered as different phases. Insoluble chemicals with the same state are also considered as different phases. For instance, the fluid flow of ice and water, or vapor and water, is a multiphase flow. The fluid flow of oil and water is also a multiphase flow. However, the fluid flow of salt and water solution is not, because this solution is a homogeneous fluid without any physical interface between the two components.

The study of multiphase flow started at the beginning of the 20th century. Multiphase flow is widely applied in industry, such as in power generation, nuclear reactor technology, food production, chemical process, aerospace, automotive industries and petroleum engineering. From the 1970s, multiphase flows in the oil and gas wells especially became more and more important, because of the increasing dependence of world economy on petroleum, and the development of drilling and production engineering.

1.1 Multiphase flow in the well

Basically, most of the fluid flows in the petroleum engineering are multiphase flows. For instance, the drilling fluid, during the common drilling of oil and gas wells, is a gas-solid phase. Crude oil, during the production, is normally a gas-oil-water mixture. However, there are well-established methods to solve these fluid problems for conventional processing in petroleum engineering. In this book, we focus on the multiphase flow for unconventional processing, especially in drilling. These problems include underbalanced drilling, well control for kicking, well control for the acidic gas well, and the well control for deepwater drilling.

Underbalanced drilling uses low-density drilling fluid to keep the wellbore pressure lower than formation pore pressure, which protects the formation during the drilling. This demands very precise pressure control of the drilling fluid, otherwise disasters such as kicking and well collapse will easily happen. Injecting air to the drilling fluid is the most popular approach to lighten the drilling fluid. The prediction for this gas-liquid system in the complicated pressure and temperature conditions of the wellbore is challenging.

Safety is of key importance for the petroleum industry. Kicking and blowing are disasters that can damage the drilling facilities, and even kill the crews in many cases. These lead to serious social and economic losses. The early prediction of kicking, and well control when kicking or blowing happens, could efficiently prevent these losses.

In the 21st century, oil fields have been extended to offshore, where efficient lifting and multiphase transfer techniques are the common means for oil and gas development. How to increase the pumping efficiency and metering accuracy is related to multiphase flow theory. Therefore, the development of multiphase flow theory has a close relationship with petroleum engineering.

Due to the complexity of the multiphase flow, there are still many theoretical problems that have not been solved so far – such as flow regime transition,...

Table of contents

• Cover
• Title Page
• Table of Contents
• Preface
• Chapter 1: Introduction
• Chapter 2: The Void Fraction Wave and Flow Regime Transition
• Chapter 3: Multiphase Flow Model for Well Drilling
• Chapter 4: Multiphase Flow During Underbalanced Drilling
• Chapter 5: Multiphase Flow During Kicking and Killing
• Chapter 6: Multiphase Flow During Kicking and Killing with Acid Gas
• Chapter 7: Multiphase Flow During Kicking and Killing in Deepwater Drilling
• References
• Author Index
• Subject Index
• End User License Agreement