Fundamentals of horizontal wellbore cleanout / Основы очистки горизонтального ствола скважины

Sand transport in wellbores occurs during various phases of a well’s life. During horizontal well drilling, fracturing, and production processes, cuttings, proppant, and formation sand are often encountered, and a solids bed is easily formed at the bottom of the horizontal wellbore.Poor hole cleaning may result in lost circulation, hinder running the casing into the selected position, excessive bit wear, and pipe sticking. The conventional horizontal well cleanout technique is to increase the surface pump flow rate; however, the maximum flow rate is restricted to the surface pump capability and wellbore stability.

Horizontal solids cleanout by the rotary jet is a high-efficiency, low-cost technology. In this book,we attempt to address the theory and applications of rotary jetting for sand cleanout in horizontal wells. The annular helical flow of the rotary jetting greatly improves the transport efficiency of sand in horizontal wells. The book includes nine chapters: Chapter 1 introduces the fundamentals of rotary jetting;Chapter 2 experimentally investigates the drag coefficient and settling velocity of sand in cleanout fluids; Chapter 3 analyzes the cuttings transport efficiency during horizontal well drilling; Chapter 4 presents the sliding friction between coiled tubing and solids bed in cleanout operations; Chapter 5 investigates the characteristics of helical flow field in horizontal annulus; Chapter 6 presents the behavior of solids transport in annular helical flow field; Chapter 7 describes the cleanout model development and hydraulic parameters calculation; Chapter 8 provides some field cases of sand cleanout by the rotary jetting;Chapter 9 presents the sand cleanout by the supercritical CO2.

As a novel technology in recent years, sand cleanout by rotary jetting has not yet been investigated thoroughly or completely. The purpose of this book is not intended to solve all the sand cleanout problems in horizontal wells. It describes the main ideas of the subject with the purpose of providing the reader with tools to tackle other problems; some of these contents have been published previously in papers written by the authors; and this book aims to serve graduate students, advanced seniors, and field engineers. The authors gratefully acknowledge the financial support from theMajor <...>