BAKER HUGHES INCORPORATED
`AND
`BAKER HUGHES OILFIELD
`OPERATIONS, INC.
`Exhibit 1019
`
`Page 1 of 25
`
`

`
`7 l
`
`AFFIDAVIT OF DEBBIE CAPLES
`
`1.
`
`My name is Debbie Caples.
`
`I am the Senior Graphics Designer for the
`
`Petroleum Extension Service (“PETEX”) at the University of Texas at Austin in
`
`Austin, Texas. I have worked at PETEX since 1978, and have been a graphic
`
`designer at PETEX since 1980. I have worked on the graphic design and layout of
`
`every book published by PETEX since 1981, including coordinating with printers
`
`to generate the physical books. Based on my experience performing my ordinary
`
`job duties at PETEX, as well as records PETEX maintains in the ordinary course of
`
`its business that I am personally familiar with via my ordinary job duties, I have
`
`personal knowledge of the below statements.
`
`2.
`
`PETEX publishes books relevant to the petroleum industry. Prior to
`
`publication, these books are sent to subject matter experts in the petroleum industry
`
`to review and edit the text. My duties include working with authors to develop the
`
`graphics and layout of the books published by PETEX. Once a book is reviewed
`
`and the layout is completed, the book is sent to a printer. My duties also include
`
`working with printers to ensure that books are printed correctly. Once printed,
`
`PETEX ships copies of the book to libraries, book stores, companies in the
`
`petroleum industry, and individuals who order it. One example of such a book is
`
`entitled A PRIMER OF OILWELL DRILLING, of which PETEX has published multiple
`
`editions since 1951 and has sold as many as 5,000-10,000 copies per year.
`
`Another example of such a book is entitled FUNDAMENTALS OF PETROLEUM, of
`
`Page 1 of 25
`Page l of 25
`
`

`
`which PETEX has published multiple editions since 1979 and has sold as many as
`
`1,500 copies per year. Both of these books have been required by college
`
`professors for certain classes, and purchased by companies in the petroleum
`
`industry for training.
`
`3.
`
`I have been asked to confirm when the following book was published by
`
`PETEX: Kate Van Dyke, FUNDAMENTALS OF PETROLEUM ENGINEERING (4th ed.
`
`1997) (“Van Dyke”). A true and correct copy of certain pages of the first printing
`
`or “Impression” of Van Dyke is attached as Appendix A. Beginning in 1997,
`
`PETEX made Van Dyke available to any person interested in purchasing a copy.
`
`Because three editions of FUNDAMENTALS OF PETROLEUM had previously been
`
`published, there was demand for Van Dyke as soon as it was available. In the first
`
`year it was available, PETEX printed and shipped approximately l,5OO copies of
`
`Van Dyke to libraries, book stores, companies in the petroleum industry, and
`
`individuals. PETEX has also printed a number of subsequent batches or
`
`“impressions” of Van Dyke since the first printing in 1997. For example, a true
`
`and correct copy of certain pages of the eighth printing or “Eighth Impression” of
`
`Van Dyke reprinted in 2007, is attached as Appendix B. The only differences
`
`between reprintings or impressions are typographical and formatting corrections.
`
`For example, some sentences on pages 23, l08, and 162-164 of Appendix B break
`
`between lines in slightly different places than the same sentences on pages 23, 108,
`
`Page 2 of 25
`Page 2 of 25
`
`

`
`and 162-164 of Appendix A. However, as is seen from a comparison of Appendix
`
`B to Appendix A, the text and figures on pages 23, 108, and 162~164 are the same.
`
`4.
`
`I have also been asked to confirm when the following book vi/as published
`
`by PETEX: Ron Baker, A PRIMER OF OIL WELL DRILLING (5th ed. (rev.) 1996)
`
`(“Baker”). A true and correct copy of certain pages of the first printing of Baker is
`
`attached as Appendix C. Beginning in 1996, PETEX made Baker available to any
`
`person interested in purchasing a copy. Because five editions of A PRIMER OF OIL
`
`WELL DRILLING had previously been published, there was demand for Baker as
`
`soon as it was available. In the first year it was available, PETEX printed and
`
`shipped approximately 5,000 copies of Baker to libraries, book stores, companies
`
`in the petroleum industry, and individuals. PETEX has also printed a number of
`
`subsequent batches or “impressions” of Baker since the first printing in 1996. For
`
`example, a true and correct copy of certain pages of the third printing or “Third
`
`Impression” of Baker reprinted in 1998, is attached as Appendix D. As is seen
`
`from a comparison of Appendix D to Appendix C, the text and figures on pages
`
`147 and 148 are the same.
`
`5.
`
`I declare under penalty of perjury that the foregoing is true and correct.
`
`
`
`By: ®,cui;L >4
`
`Print: Debbie Caples
`
`Page 3 of 25
`Page 3 of 25
`
`

`
`
`APPENDIX A
`
`‘APPENDIX A
`
`Fundamentals
`of Petroleum
`
`FOURTH EDITION
`
`9??
`
`by Kate Van Dyke
`
`Published by
`
`PETROLEUM EXTENSION SERVICE
`
`Division of Continuing Education
`
`The University of Texas at Austin
`Austin, Texas
`
`in cooperation with
`ASSOCIATION OF DESK AND DERRICK CLUBS
`
`Tulsa, Oklahoma
`
`1997
`
`
`
`Page 4 of 25
`Page 4 of 25
`
`

`
`
`
`Library of Congress Cataloging-in-Publication Data
`
`Van Dyke, Kate, 1951-
`Fundamentals of petroleum / by Kate Van Dyke. —-— 4th ed.
`p.
`cm.
`ISBN 0-88698~162—X (pbl<.)
`1. Petroleuin engineering.
`TN870.V28
`1997
`665.5-—dc21
`
`1. Title.
`
`97-10098
`CIP
`
`© 1997 by The University of Texas at Austin
`All rights reserved
`First Edition published 1979. Fourth Edition 1997
`Printed in the United States of America
`
`pg
`
`This book or parts thereof may not be reproduced in any form without per-
`mission of Petroleuin Extension Service, The University of Texas at Austin.
`
`Brand names, company names, trademarks, or other identifying symbols
`appearing in illustrations or text are used for educational purposes only
`and do not constitute an endorsement by the author or publisher.
`
`Catalog No. 100040
`ISBN 0-88698-162—X
`
`Page 5 of 25
`Page 5 of 25
`
`
`

`
`/~ supplied
`mg oil out
`as general
`th oil and
`
`free gas in
`
`nperature,
`(fig. 1.36).
`gas comes
`amove the
`: allow for
`
`
`
`ll reservoir fluids are under pressure. The weight of the fluid itself
`creates a normal pressure. Abnormal pressure occurs when the weight
`of the formations on top of the reservoir is added to the fluid pressure.
`
`RESERVOIR
`
`PRESSURE
`
`Normal Pressure
`
`Fluid pressure exists in a reservoir for the same reason that pressure exists
`at the bottom of the ocean. Imagine a swimmer in a large swimming pool
`who decides to see Whether he or she can touch bottom. Everything is going
`well except that the swimmer’s ears begin to hurt. The deeper the dive, the
`more the ears hurt. The reason for the pain is that the pressure of the water
`is pressing against the eardrums. The deeper the swimmer goes, the greater
`the pressure.
`
`Just as water creates pressure in a swimming pool, fluids in a reservoir
`create pressure. When the reservoir has a connection to the surface (fig. 1.38),
`usually the only pressure in it is the pressure caused by fluid in and above it.
`As long as this connection to the surface exists, rocks that overlie a reservoir
`do not create any extra pressure in the reservoir. Even though their weight
`bears down on the formation, fluids can rise to the surface and escape. Imag-
`ine again the swimming pool full of water. Dump a huge load of rocks into
`it. The rocks do not increase the water pressure; instead the water sloshes
`over the sides.
`‘
`The same thing happens in a reservoir. Unlike a swimming pool, how-
`ever, a reservoir’s connection to the surface is usually circuitous. It may
`outcrop at the surface many miles away, or it may be connected to the sur-
`face through other porous beds that overlie it. In most cases, though, as long
`as the reservoir has some outlet to the surface, the pressure in it is caused
`only by the fluids and is considered to be normal pressure.
`
`SURFACE
`
`OUTGROP
`
`0.52 PSI/FT
`
`. MUD
`PRESSURE
`
`l\\‘l\\\\Wl\il\WllN‘‘
`5,200 PSI\l\\\\\\\\‘l\\.\\\\\\\§\\\\\\\\\\\‘
`
`/
`
`I.
`
`10,000 FT
`
`FORMATION
`PRESSURE
`4,550 PSI
`
`MUD SHEATH
`
`\A/hen the petroleum reservoir has a connection to the surface, the
`Figure 1.38
`pressure is considered normal.
`
`
`
`Petroleum Geology
`
`23
`
`Page 6 of 25
`Page 6 of 25
`
`

`
`
`
`
`
`n‘<%‘.-—m«ieg_g\_
`
`'
`
`int, the driller picks them up
`up tightly to the jo
`ousehole to the rotary table. The crew stabs the
`and moves them from the m
`e top of the joint of pipe coming out of
`bottom of the new joint of pipe into th
`make up the joints.
`the borehole and again uses the kelly spinner to
`d the driller lowers
`With the new joint made up, they pull the slips, an
`nears the bottom. Then he or she starts the pumps,
`the pipe until the bit
`lies weight to the bit, and drills another 40 feet (12
`begins rotation, app
`depending on the length of the kelly. The crew
`metres) or so of hole,
`the kelly is drilled down.
`repeats this process each time
`the crew foll
`When the rig uses a top drive,
`often making up two,
`procedures to make up the drill string,
`-up joints, called a stand,
`tead of one. The multiple made
`joints at a time ins
`sit in a rack on the rig floor to the side of the mast or derrick.
`e from hundreds of feet (metres)
`Eventually, at a depth that could rang
`to a few thousand feet (metres), drilling comes to a temporary halt, and the
`crew pulls the drill stem from thehole. This firstpart 0
`the surface hole. Even though the formation that contains the hydrocarbons
`may lie many thousands of feet (metres) below this po
`1 off the formations
`stops drilling temporarily to take steps to protect and sea
`e zones
`example, drilling mud could contaminat
`close to the surface. For at nearby towns use for drinking. To protect such
`containing fresh water th
`zones, the crew runs specialpipe called casinginto thehole and cements itin
`
`f the hole is known as
`
`place.
`
`ing is to pull the dril
`d the bit out of the
`
`Tripping Out
`1 stem and the bit out of the
`The first step in running cas
`hole in order to run casing,
`hole. Pulling the drill stem an
`change bits, or perform some other operation in the borehole is c
`ler stops rotation and circulation. Then, using con-
`ping out.
`To trip out, the dril
`trols on the drawworks, he or she raises the drill stem off thebottom of the
`hole until the top joint of drillpipe clears the rotary table andholds it there.
`Then, the rotary helpers set the slips around the drill pipe to suspend it in
`the rotary helpers break the kelly out of the
`athole (fig. 4.45). Since they leave the kelly
`lly when placing it in the
`op of the drill string protrudes
`tary where the t
`ck hangs above the drill pipe
`e hole is clear. Only the traveling blo
`sus ended in the hole.
`L
`Attached to the traveling block are a set of drill pipe lifting devices
`hed to the traveling block L
`called elevators. The elevators usually remain attac en the crew removes the T
`at all times and swing downward into position wh
`swivelfromthehook. Elevators are clamps that canlatch onto the tooljoints
`"
`of the drill pipe (fig. 4.46). The crew latches the elevators around the drill
`pipe,andthe drillerraisesthetravelingblocktopullthepipeupward.When
`the third joint of pipe clears the rotary table, the rotary helpers set the slip5
`and use the tongs to break out the pipe. The pipe is usually removed from
`the hole in stands of three joints. The crew guides the stand to the rack 011
`the rig floor.
`Once the bottom of the stand of pipe is set dow
`nto action. Standing on a small platform called
`L
`the derrickhand goes i
`bout 90 feet (metres) high in the mast or derrick, is
`
`,
`
`
`
`108
`
`VND
`ENTALSOF PETROLEUM
`Page 7 of 25
`age
`of 25
`
`
`

`
`
`he termwell stimulation encompasses severaltechniquesusedto en-
`largeoldchannelsortocreatenewonesintheproducingformation,
`Sinceoilusuallyexistsintheporesofsandstoneorthecracksoflimestone
`formations,enlargingorcreatingnewchannelscausestheoilorgastomove
`morereadilytoawell.Sometimestheproblemislowpermeability.lnthis
`case,thewellwillbestimulatedimmediatelyaftercompletion.lnothercases,
`thenaturalpermeability ofthe rockmaybe adequate,butthe formation
`nearthewellboremaybedamagedinawaythatrestrictstheflowchanne1s
`inporousrock Formationdamagecanoccurduringdrilling,
`'
`workover,production,orinjection.
`Therearethreewaystodothis.Thefirstandoldestme
`explosivefracturing. During the 19305, acid stimulation, or aci
`ailable.Hydraulicfracturing,thethirdstimula
`
`commercially av
`was introduced in 1948.
`
`
`
`Awed
`
`intoa
`andit
`fractu;
`thant]
`]
`illgne
`nelsfa
`I‘ef'ra(;1
`over1:
`fracu]
`Prop}Durin
`
`
`
`Explosives
`
`s exploded nitroglycerin ins
`nitro charge int
`
`Hydra
`
`ulicfracturingis allaboutpressure.Severalpowerfulpumps(fig.
`Hydraulic Fracturing
`into the well at a fast rate. Theroe
`inject a liquid, the fracturing fluid,
`gh pressure that actu
`develops a hi
`visualize this, imagine splitting alo
`
`Figure 5.
`mounted pumps are
`well site for a fracturing job.
`
`raeéu'sr5§‘ "
`
`Page 8 of 25
`
`

`
`m
`
`Awedge first cuts a tiny crack in the lo
`into a wider cut until the log splits. In
`and its high pressure is the force tha
`fracturing splits the rock instead of the
`than the rock.
`
`g that the force of the blow enlarges
`fracturing, the fluid acts as a wedge
`t pushes it into the rock. Hydraulic
`casing because the casing is stronger
`Hydraulicfracturingimprovestheproductivityofawellbyeithercreat-
`ing new fractures that act as flow channels or extending existing flow chan-
`nels farther into the formation. Fracturin
`g is a usual part of completion, and
`refracturing to restore productivity ofan old wellis a regularprocedure. Work-
`over people commonly shorten the word fracturing tofiac, as in frac job and
`frac unit. Hydraulic fracturing works well in sandstone reservoirs.
`
`Proppants
`During early experimental work, engineers discovered that a hydraulically
`formed fracture tends to heal, or lose its fluid-carrying capacity, after the
`
`~ manner. Proppzmts, or propping agents, hold the fractures open. Sand, nut-
`shells, and beads of aluminum,
`glass, and plastic may be used as proppants
`(fig. 5.27). Spacer materials are used between the particles of the proppant
`to ensure its optimum distribution.
`
`fig;Eafg:
`.
`formation
`v
`Channels
`Hnplefionl
`
`d is to use
`zg, became
`n method,
`
`;
`
`_
`0 lmprove
`enhole?“
`m shooting
`lic fractur-
`iuclear ex-
`
`ed to en
`Eormafion
`
`limestone
`§
`as to move
`1‘
`. I
`‘
`
`3
`L.
`
`
`
`
`
`Page 9 of 25
`Page 9 of19;5
`
`H
`
`'
`
`increased
`
`.
`
`'
`
`be fracturing fluid may be either oil based or wat
`er based. In reality, the
`is nearly always brine because it is safe, available, and cheap. Some
`
`
`
`the walls of the tubing. Al-
`y not sound as if it would be a factor, any slowing of the fluid
`quires larger pumps to keep the injection rate high enough.
`additives reduce fluid loss into the formation.
`
`
`

`
`
`
`Acidizing
`In acid stimulation, or acidizing, an acid reacts chemically with the rock to
`dissolve it (fig. 5.28). As in hydraulic fracturing, this enlarges existing flow
`channels and opens new ones to the wellbore. Well servicing crews stimu-
`late both new and old wells with acid. Reservoir rocks most commonly
`acidized are limestone (calcium carbonate) and dolomite (a mixture of ca}
`cium and magnesium carbonates), or carbonate reservoirs.
`
`
`
`Types of Acids
`Acids that are strong enough to dissolve rock are often strong enough to eat
`away the metal of the pipes and equipment in the well. Acidizing, therefore,
`always involves a compromise between acid strength and additives to prevent
`damage to the equipment. Oilfield acids must create reaction products that are
`soluble; otherwise, solids would precipitate and plug the pore spacesjust opened
`up. Since acidizing uses large volumes of acid, it must be fairly inexpensive.
`Workers on acidizing jobs must be trained to handle the acids they use,
`many of which have dangerous fumes and can burn the skin. Acidizing con-
`tractors choose the type of acid based on the formation and the conditions in
`the well. The choices include hydrochloric, hydrofluoric, acetic, and formic
`acids.
`
`Additives
`Additives are used with oilfield acids for many reasons, but one of the most
`important is to prevent or delay corrosion——that is, to inhibit the acid from
`attacking the steel tubing or casing in the well. A surfactant, or surface active
`agent, is another type of additive. It is mixed in small amounts with an acid
`to make it easier to pump the mixture into the rock formation and to prevent
`spent acid and oil from forming emulsions. An emulsion is a thick mixture
`like mayonnaise.
`Other common additives are sequestering agents, which prevent the pre-
`cipitation of ferric iron during acidizing, and antisludge agents, which pre-
`vent an acid from reacting with certain types of crude and forming an
`insoluble sludge that blocks channels or reduces permeability.
`
`Types of Acidizing Treatments
`There are two basic kinds of acid stimulation treatments: acid fracturing and
`matrix acidizing.
`Acidfracturing, orfracture acidizing, is similar to hydraulic fracturing,with
`acid as the fluid. Acid fracturing does not require proppants, however, because
`it does not just force the rock apart, but also eats it away. It is the more widely
`59.-9(D E’:9- 9-0
`used treatment for well stimulation with acid. Since most lime
`V
`mite formations have very low permeabilities, injecting acid into these formaf
`tions, even at a moderate pumping rate, usually results in fracturing.
`,
`Matrix acidizing can be subdivided into two types. The first is wellbof
`"U E? 2(‘D‘§9. §.
`cleanup, or wellbore soak. In wellbore soak, the crew fills u
`acid without any pressure and allows it to react merely by soaking. It is a I9 ,
`tively slow process because little acid actually comes in contact with the form
`tion. The second matrix acidizing method is a low~pressure treatment thatC109.
`not fracture the formation, but allows the acid to work through the nah“ i
`pores (fig. 5.29). This second process is what people in the oil patch are 11511
`referring towhenthey speakofmatrix acidizing. Operators generallyusema l.
`acidizing when the formation is damaged or when a Water zone or gas Ca?
`nearby and fracturing might result in excessive Water or gas production-
`
`Figure 5.28 Acid enlarges existing
`channels or makes new ones.
`
`
`
`Figure 5.29 Acid is injected down the
`tubing and into the formation through
`perforations to remove formation damage
`without fracturing the formation.
`
`164
`
`FUNDAMENTALS or PETROLEUM
`Page 10 of 25
`Page 10 of 25
`
`
`

`
`APPENDIX B
`
`APPENDIX B
`
`Fundamentals
`
`
`
`Page 11 of 25
`Page 11 of 25
`
`of Petroleum
`
`FOURTH EDITION
`
`5??
`
`by Kate Van Dyke
`
`Published by
`
`PETROLEUM EXTENSION SERVICE
`
`Division of Continuing Education
`
`The University of Texas at Austin
`
`in cooperation with
`ASSOCIATION OF DESK AND DERRICK CLUBS
`
`Tulsa, Oklahoma
`
`1997
`
`Austin, Texas
`
`

`
`Library of Congress Cataloging-in-Publication Data
`
`Van Dyke, Kate, 1951-
`Fundamentals of petroleum / by Kate Van Dyke. —— 4th ed.
`p.
`cm.
`
`ISBN 0-88698-162-X (pbk.)
`1. Petroleum engineering.
`TN 8705/28
`1997
`665.5-—dc21
`
`I. Title.
`
`97-10098
`CIP
`
`© 1997 by The University of Texas at Austin
`All rights reserved
`First Edition published 1979. Fourth Edition 199?
`Eighth Impression 2007
`Printed in the United States of America
`
`This book or parts thereof may not be reproduced in any form without
`permission of Petroleum Extension Service, The University of Texas at
`Austin.
`
`Brand names, company names, trademarks, or other identifying symbols
`appearing in illustrations or text are used for educational purposes only and
`do not constitute an endorsement by the author or publisher.
`
`Catalog No. 1.00040
`ISBN 0-88698-162—X
`
`":'‘!a:* UN iversity ofTr:.tas at Austin is an equal opportunity employer. No statefunds
`win-:> risen‘ to pmdnrr this mammal.
`
`Page 12 of 25
`Page 12 of 25
`
`

`
`All reservoir fluids are under pressure. The weight of the Fluid itself
`creates a normal pressure. Abnormal pressure occurs when the weight
`of the formations on top of the reservoir is added to the fluid pressure.
`
`Normal Pressure
`
`Fluid pressu re exists in a reservoir for the same reason that pressure exists
`at the bottom of the ocean. Imagine a swimmer in a large swimming pool
`who decides to see whether he or she can touch bottom. Everything is go-
`ing well except that the swirnmer’s ears begin to hurt. The deeper the dive,
`the more the ears hurt. The reason for the pain is that the pressure of the
`water is pressing against the eardrums. The deeper the swimmer goes, the
`greater the pressure.
`I
`Just as water creates pressure in a swimming pool, fluids in a reservoir
`create pressure. When the reservoir has a connection to the surface (fig.
`1.38), usually the only pressure in it is the pressure caused by fluid in and
`above it. As long as this connection to the surface exists, rocks that overlie
`a reservoir do not create any extra pressure in the reservoir. Even though
`their weight bears down on the formation, fluids can rise to the surface and
`escape. imagine again the swimming pool full of water. Dump :1 huge load
`of rocks into it. The rocks do not increase the water pressure; instead the
`water sloshes over the sides.
`
`The same thing happens in a reservoir. Unlike a swimming pool,
`however, a reservoir’:-I connection to ll1e surface is usually circuitous. It may
`outcrop at the surface many miles away, or it may be connected to the surface
`through other porous beds that overlie it. In most cases, though, as long as
`the reservoir has some outlet to the surface, the pressure in it is caused only
`by the fluids and is considered to be normal pressure.
`
`SURFACE
`
`10-PPG
`DRILLING-FLUID
`COLUMN
`
`10,00 FT
`
`I152 PSI,-’FT
`
`MUD
`PRESSURE
`5,2tJtI PS!
`
`FORMATION
`PRESSURE
`4,650 PSI
`
`MUD SHEATH
`
`\/Vhen the petroleum reservoir has a connection to the surface, the
`Figure 1.38
`pressure is considered normal.
`
`Petroleum Geology
`
`23
`Page 13 of 25
`Page 13 of 25
`
`

`
`,
`'
`
`I
`j
`
`,’
`
`.
`.
`'
`
`Once the kelly is made up tightly to the joint, the driller picks them
`up and moves them from the mousehole to the rotary table. The crew stabs
`the bottom of the new joint of pipe into the top of the joint of pipe coming
`out of the borehole and again uses the kelly spinner to make up the joints.
`With the new joint made up, they pull the slips, and the driller lowers the
`pipe until the bit nears the bottom. Then he or she starts the pumps, begins
`rotation, applies weight to the bit, and drills another 40 feet (I2 metres) or so
`of hole, depending on the length of the kelly. The crew repeats this process
`each time the kelly is drilled down.
`When the rig uses a top drive, the crew follows essentially the same
`procedures to make up the drill string, often making up two, three, or tour
`joints at a time instead of one. The multiple rnade-up joints, called a stmnl,
`sit in a rack on the rig floor to the side of the mast or derrick.
`Eventually, at a depth that could range from hundreds of feet (metres)
`to a few thousand feet (metres), drilling comes to a temporary halt, and the
`crew pulls the drill stem from the hole. This first part of the hole is known as
`the .-mrfece halt’. Even though the formation that contains the hydrocarbons
`may lie many thousands of feet (metres) below this point, the toolpusher
`stops drilling temporarily to take steps to protect and seal off the formations
`close to the surface. For example, drilling mud could contaminate zones
`containing fresh water that nearby towns use for driiikiiig. To protect such
`zones, the crew runs special pipe called casing into the hole and cements it
`in place.
`
`Tripping Out
`
`The first step in running casing is to pull the drill stem and the bit out of the
`hole. Pulling the drill stem and the bit out of the hole in order to run cas—
`ing, change bits, or perform some other operation in the borehole is called
`tripping am‘.
`To trip out, the driller stops rotation and circulation. Then, using con-
`trols on the drawworks, he or she raises the drill stem off the bottom of the
`
`hole until the topjoint of drill pipe clears the rotary table and holds it there.
`Then, the rotary helpers set the slips around the drill pipe to suspend it in
`the hole. Next, using the tongs, the rotary helpers break the kell y out of the
`drill string and put it into the rathole (fig. 4.45). Since they leave the kelly
`bushing, the swivel, and the rotary hose on the kelly when placing it in the
`rathole, the area above the rotary where the top of the drill string protrudes
`from the hole is clear. Only the traveling block hangs above the drill pipe
`suspended in the hole.
`Attached to the traveling block are a set of drill pipe lifting devices
`called elevators. The elevators usually remain attached to the traveling block
`at all times and swing downward into position when the crew removes the
`swivel from the hook. Elevators are clamps that can latch onto the tool joints
`of the drill pipe (fig. 4.46). The crew latches the elevators around the drill
`pipe, and the driller raises the traveling block to pull the pipe upward.
`When the third joint of pipe clears the rotary table, the rotary helpers set
`the slips and use the tongs to break out the pipe. The pipe is usually re-
`moved from the hole in stands of three joints. The crew guides the stand
`to the rack on the rig floor.
`Once the bottom of the stand of pipe is set down on the rig floor;
`the derriekhand goes into action. Standing on a small platform called the
`mtmkcyliosrd that is about 90 feet (metres) high in the mast or -.ierriL‘l"~«
`
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`WELL
`
`STIMULATION
`
`Several powerful, truck-
`Figure 5.20
`inounled pumps are arranged at the
`well site for a fracturing job.
`
`162
`
`he term well stiumtotion encompasses several techniques used to en-
`large old channels or to create new ones in the producing formation.
`Since oil usually exists in the pores of sandstone or the cracks of limestone
`formations, enlarging or creating new channels causes the oil or gas to move
`more readily to a well. Sometimes Lhe problem is low permeability. In this
`case, the well will be stimulated immediately after completion. in other cases,
`the natural permeability of the rock may be adequate, but the formation
`near the we] lbore may be damaged in a way that restricts the flow channels
`in porous rock. Formation damage can occur during drilling, completion,
`workover, production, or injection.
`There are three ways to do this. The first and oldest method is to use
`explosive fracturing. During the 19303, acid stimulation, or ocidizing, became
`commercially available. Hydrauiicfr'er.'turiug, the third stimulation method,
`was introduced in 1948.
`
`Explosives
`
`As early as the 18608, crews exploded nitroglycerin inside wells to improve
`their productivity. They simply lowered a nitro charge into the open hole
`on a conductor line and detonated it to fracture the formation. Nitro shooting
`became fairly routine until the advent of acidizing and hydraulic fracturing.
`For a time in the 1960s, lease operators experimented with nuclear explosives
`in a limited number of gas wells. While this method increased production
`somewhat, the cost was prohibitive.
`Oil companies are still interested in explosive techniques because
`certain kinds of tight formations do not respond readily to either acidizing
`or hydraulic fracturing. Research continues today to find other techniques
`that might increase production, but currently fracturing and acidizing are
`the most effective well stimulation methods.
`
`Hydraulic Fracturing
`
`Hydraulic fracturing is all about pressure. Several powerful pumps (fig.
`5.26) inject a liquid, the fracturing fluid, into the well at a fast rate. The fluid
`develops a high pressure that actually splits, or fractures, the rock. To
`visualize this, imagine splitting a log with an axe. The axe head is a wedge.
`
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`Page 15 of 25
`FUNoAMER1’:¥g§3ol: 5’9tfic?L§UM
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`A wedge first cuts a tiny crack in the log that the force of the blow enlarges
`into a wider cut until the log splits. In fracturing, the fluid acts as a wedge
`and its high pressure is the force that pushes it into the rock. Hydraulic
`fract1.1r-ing splits the rock instead of the casing because the casing is stronger
`than the rock.
`
`Hydraulic Eracturing improves the productivity of a well by either
`creating new fractures that act as flow channels or extending existing flow
`channels farther into the formation. Fracturing is a usual part of com pletion,
`and refracturing to restore productivity of an old well is a regular procedure.
`Workover people commonly shorten the word fracturing tofree, as in frac job
`and frac unit. Hydraulic fracturing works well in sandstone reservoirs.
`
`Proppants
`
`During early (.’X|I>€'l'll"t‘|E!l'llEil work, engineers discovered that a hydraulically
`formed fractu re tends to heal, or lose its fluid-carrying capacity, after the part-
`ing pressure is released unless the fracture is propped open in some manner.
`Propprmls, or propping agents, hold the fractures open. Sand, nutshells, and
`beads of alunfrnum, glass, and plastic may he used as proppants (fig. 5.27).
`Spacer materials are used between the particles of the proppant to ensure
`its optimum distribution.
`
`Figure 5.27
`
`Sand is one proppant used to hold fractures open.
`
`Fracturing Fluid
`
`The fracturing fluid may be either oil based or water based. in reality, the
`fluid is nearly always brine because it is safe, available, and cheap. Some
`fracturing fluids are gels, which suspend the proppants better. Polymer add i-
`tives reduce friction between the fluid and the walls of the tubing. Although
`this may not sound as if it would bea Factor, any slowing of the fluid due to
`friction requi res larger pumps to keep the injection rate high enough. Finally,
`additives reduce fluid loss into the formation.
`
`Production
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`Page 16 of 25
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`Acidizing
`
`in acid stimulation, or aciclizing, an acid reacts chemically with the rock to
`dissolve it (fig. 5.28}. As in hydraulic fracturing, this enlarges existing flow
`chan nels and opens new ones to the wel lbore. Well servicing crews stirnulate
`both new and old wells with acid. Reservoir rocks most com munly acidized
`are limestone (calcium carbonate) and dolomite (a mixture of calcium and
`
`magnesium carbonates), or carbonate reservoirs.
`
`Types of Acids
`
`Acids that are strong enough to dissolve rock are often strong enough to eat away
`the metal of |'.he pipes and equipment in the well. Acidizting, therefore, always
`involves a compromise between acid strength and additives to prevent damage
`to the equipment. Oilfield acids must create reaction products that are soluble;
`otherwise, solids would precipitate and plug the pore spaces just opened up.
`Since acidizing uses large volumes of acid, it must be fairly inexpensive.
`Workers on acidizing jobs must be trained to handle the acids they
`use, many of which have dangerous fumes and can burn the skin. Acidizing
`contractors choose the type of acid based on the formation and the condi-
`tions in the well. The choices include hyd rochloric, hydrofluoric, acetic, and
`formic acids.
`
`Additives
`
`Additives are used with oilfield acids for many reasons, but one of the most
`important is to prevent or delay corrosion——that is, to inhibit the acid from
`attacking the steel tubing or casing in the well. A surfactant, or surface ac-
`tive agent, is another type of additive. it is mixed in small amounts with an
`acid to make it easier to pump the mixture into the rock formation and to
`prevent spent acid and oil from forming emulsions. An emulsion is a thick
`mixture like mayonnaise.
`Other common additives are sequesteriirg agents, which prevent the
`precipitation of ferric iron during acidizing, and mifisludge ageiits, which
`prevent an acid from reacting with certain types of crude and forming an
`insoluble sludge that blocks channels or reduces permeability.
`
`Types of Acidizing Treatments
`
`There are two basic kinds of acid stimulation treatments: acid fracturing
`and matrix acidizing.
`/lt‘i{lfi‘fiBft£fil!g, orfiricmre aciiiiziirg, is similar to hydraulic Fracturing, with
`acid as the fluid. Acid fracturing does not require proppants, however, because
`it does not just force the rock apart, but also eats it away. It is the more widely
`used treatment for well stimulation with acid. Since most limestone and dolomite
`
`formations have very low perrneabilities, injecting acid into these formations,
`even at a moderate pumping rate, usually results in fracturing.
`Matrix acidizing can be subdivided into two types. The first is wellbore
`clcmiup, or wcllbore soak. I n wellbore soak, the crew fills up the wellbore with acid
`without any pressure and allows it to react merely by soaking. It is a relatively
`slow process because little acid actually comes in contact with the formation.
`The second matrix acidizing method is a low-pressure treatment that does not
`fracture the forrnation, but allows the acid to work through the natural pores (fig.
`5.29). This second process is what people in the oil patch are usually referring to
`when they speak of matrix acidizing