Field of Swabbing

Field

of

Swabbing

Khosrow M. Hadipour

Copyright © 2018 by Khosrow M. Hadipour. 777499

Library of Congress Control Number:   2018905340

ISBN:   Softcover     978-1-9845-2468-3

             Hardcover   978-1-9845-2469-0

             EBook         978-1-9845-2467-6

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the copyright owner.

Rev. date: 06/26/2018

Xlibris

1-888-795-4274

www.Xlibris.com

The subject material contained herein is based on forty-one years of oil field experience working offshore and onshore in Mississippi, Louisiana, Texas, New Mexico, the Gulf of Mexico, and Venezuela.

It is not the purpose of this book to be used as final procedure and/or definite guidelines. This book is prepared to act as a basic reference to swab tools, equipment, and their application based on my experience only.

Definition of Swabbing in Oil and Gas Operations

Swabbing is the artificial pulling of a well fluid by mechanical tools.

Swabbing is the artificial removal of water, oil, and gas from a well, using mechanical tools, which is quicker and cheaper (fluid can refer to oil, water, and/or gas).

Components of Mechanical Swabbing Tools

• Steel wire line cable referred as swab cable, the swab line, or sand line

• Hydraulic oil saver

• Swab lubricator

• Swab mandrels

• Rubber or steel swab cups of various sizes

Artificial swabbing begins when an oil or gas well cease to flow naturally. Once an oil or gas well stops flowing fluid, a swab process will begin to remove heavy fluid out of the wellbore and to prolong the natural flow as long as economically practical.

Artificial swabbing will reduce the hydrostatic head and help a well to flow.

Hydrostatic head is defined as the pressure exerted by a column of fluid.

Hydrostatic pressure = 0.052 × fluid density × fluid height.

Effective well swabbing begins when the reservoir pressure depletes down, preventing a well from flowing. When the reservoir pressure declines below the hydrostatic column of fluid in the wellbore, then the well will stop flowing.

Methods of Swabbing in Oil and Gas Operations

• Through tubing string swabbing requires a good tubing string, packer, and seating nipple.

• Through casing string swabbing requires fully open perforations and a good casing string.

Only through tubing swabbing are the swab tools made up or screwed at the end of ⁹/16 in. wire line cable (swab line) and lowered in the hole to a predetermined depth to artificially pull fluid out of oil and gas wells.

Artificial Fluid-Lifting Methods in Oil and Gas Wells

• Artificial lifting fluid by mechanical swab tools

• Artificial lifting fluid by beam pumping and sucker rods

• Artificial lifting fluid using gas-lifting tools

• Artificial lift using electric submersible pump

• Artificial lift by jet pump and hydraulic lifts

• Artificial lift using plunger lift

This book will examine the most common swabbing method, which is swabbing by using mechanical swab tools.

Tubing Swabbing

Through tubing swabbing is a method of artificially removing oil, gas, and water fluid from a predetermined swabbing depth out of a wellbore.

Tubing swabbing is used on different stages in oil and gas operations:

• Swabbing before perforating an oil or gas well, which is referred as underbalance perforating

• Swabbing after perforating with the intention of pulling water and making the well flow naturally (referred to as bringing the well in)

• Swabbing after an acid treatment (to pull acid and solids out of the wellbore before fracturing treatment or running an artificial pump in the well)

• Swabbing the water block in oil and gas wells to remove the hydrostatic head to make the well flowing again

Tubing Swabbing Preparation

• Check location, and remove all hazardous objects.

• Check and record well pressure. Don’t swab in any well with flowing pressure of more than 10 psi.

• Move in and rig up the swabbing unit

• Rig up a swab tank and flow line from the well to the rig tank. The swab tank must be located 150 ft. away from the wellhead, behind guy lines.

Swabbing High H2S Wells

Hydrogen sulfide (H2S) is a