W H E R E V E R T H E D R I L L G O E S — S C H L U M B E R G E R G O E S

I N T E R C O M AUGUST, 1960

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intercom august 1960 number 82

I N T E R C O M is publ ished for be t te r liaison b e t w e e n

f ie ld engineers and m a n a g e m e n t of S c h l u m b e r g e r

O v e r s e a s , S c h l u m b e r g e r S u r e n c o , S o c i é t é de

P r o s p e c t i o n E l e c t r i q u e , a n d t h e i r s u b s i d i a r i e s .

EDITORIAL

WHY CARACAS AT PLAY

CARACAS AT PLAY

photographs and text

by Mike Grosmangin 6

PERSONNEL NEWS 38

THE SCHLUMBERGER BOOKSHELF 4 ^

by Nancy Lenkeith

TECHNIQUE

Back-Off Operations

"Where Goes The Neutral Point?" jê

by Jan Doekes

schiumberger's decision to create joint ly with D o w Chemical C o m p a n y the Dowel ! Schlum-

berger Corpo ra t i on , has been announced to the companies of our

Group . As president of this new Corpo ra t i on , and a faithful reader

of INTERCOM, I wou ld like to explain here what was behind that

decision.

through the purchase of welex, S'chlumberger's main compet i tor , Hall iburton cou ld attack

our logging and perforat ing f rom a position of s t reng th -

resting secure on his income from pump services wh ich con-

stitute the backbone of his business. W e lost several bases

to competi t ion through package doals. W e w e r e not in a

posit ion to counterattack.

the creation of the new Corpo ra t i on radical ly alters our posit ion. The purpose of Dowe l l Schlum-

berger Co rpo ra t i on is expressly to get the cementing, stimulation (acidizing, fracking)

and testing markets wherever open, and to gain the business from the competi tors

wherever established.

it should be dear to everybody that Dowe l l Schlumberger is not go ing this race a lone . Every

engineer has to become D.S. minded. Do the wells in your territory need high

pressure pumps for cementing? Do the logs war rant—and they nearly always

do — examination of logs and cores for possible stimulation of product ion?

Cou ld the testing be improved? Are these services del ivered to the satisfaction

of the client? This informat ion passed a long the line wi l l be vital in our develop-

ment. W h e n you help D.S. you replace adverse p ropaganda in your neighbor-

h o o d by friendly operat ions.

schlumberger has taken a decisive step and a gamble on the future. It should mean for all of us

more jobs, more promotions, more responsibilities.

G u y Baboin

editorial Guy Baboin, President

DOWELL SCHLUMBERGER CORP.

WSW MW

We hear it from all sides

Enough pictures of trucks stuck in the

mud and of people stuck behind their desks! We want

cheesecake; a joke contest; a man-of-the-year contest; a Miss Shaped

Charge contes t . . . !

This is one reason for the Caracas at Play story. Another is to show some of the

hobbies of our Caracas staff. People are known by the company they keep

and the hobbies they like. In a well-organized corporation, com-

posed of orthodox status-seekers, the hobby should even go with

the job. It is a proven fact that accountants are bowlers and soft-ball

players while the Personnel Department is made up of Sunday golfers. At

Commercial you go for outdoor sports and at F.O. you are too busy to have a

hobby. Presidents play tennis and vice-presidents play the

violin or the organ.

There is also the touchstone of companyman-

ship: playing poker with the boss without winning

too much.

Objections to "Caracas at Play" were raised im-

mediately in some quarters. A story like that

would ruin our corporate image. If a cus-

tomer got hold of that issue, would he trust

a poker-playing, horse-betting Schlumberger en-

gineer not to take chances in his oil well? What of

the trainee who would imagine Life with Schlum-

berger as an endless round of parties and

games? So it was decided to run

also a counterpoison

story, "Caracas at

Work" and the only point to be

settled was the order of appearance.

What comes first, work or play, the

chicken or the egg? Leave them laughing

or leave them with a message?

Well, one of the stories happened to be ready for

the press so here is Caracas at Play" but there is a mes-

sage too: we need our readers' help. We should not have to resort to

-heap tricks like printing a picture right side left in order to elicit a response.

It is a proven fact that, among Schlumberger engineers, there are more shut-

terbugs than you can shake a stick at. So please start the cameras

clicking and send us the results.

INTERCOM

5

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ntercom/August, I 9 6 0

7

S Y L V I E E N S E L M E .

The difficult art of wafer-skiing is pract iced mostly at the Puerto Azul

Club, about 25 miles from the Maiquetia Airport. Puerto Azul is prob-

ably the largest club of its type. It has close to 6000 members and

enough palm-tree shaded Ä e s to give each one a reasonable meas-

ure of privacy. It has three swimming pools, two beaches, oir-con-

dit ioned bowling alleys, tennis courts, movie house, restaijrants, night

club, half a dy^zen snack bars, three 14-story ^ a r t m e n t buildings

and a locker-room as big as a cathedral.

Promoters claim that Puerto Azul sho\ i^ the shape of things to come

and do not seem to be aware of its disturbing Orwellian overtones.

One can visualize a different 1984 when the working week wil l have

been reduced to 20 hours, and the main concern of the government

will be to organize the "LOISIRS DIRIGES" of the people. Dozens

of Super-Puertos-Azules will run on an ass^b ly - l i ne basis: ^mul tane-

ous application of sun-tan oil to your r ight -hand^eighbor , half-an-

hour of mass calisthenics, ha l f -an -^u r or group swimming, fifteen

minutes of water ski parade and the crowning touch to a gloroius

day, ten thousand happy slaves taking' ten thousand showers in ten

adjoining stalls and singing the praises of Big Brother.

M I K E G R O S M A N G I N B R E A K I N G T H E W A K E .

I n t e r c o m / A u g u s t , I 9 6 0

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P I E R R E A G A I N .

M I K E A G A I N

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B E L O W . A V I E W O F T H E Y A C H T B A S I N

Confinued from previous page

In the meantime we enjoy our water-skiing. In c^fder to

be al lowed to drive his 14-J;pot launch, "Caroline,"

Pierre Enselme had to pass a stiff t es t . ^amp le question:

DEMOSTRAR QUE SABE ENTAUNGAR Y ARM^é UNA

ANCLA DE ŒPO) and is now^^APITAN DE BARCO

for boats up to 10 tons. W e have a wonds^u l collection

of gadgets: special skis for jumping, mono-ski for slalom

races, "banana peels" for skiing backwards, a Flying

Saucer (science fiction is all around us) for Sylvie Enselme.

•^©r. Roberto Fontain#'^ails hi^i'S-egatta-wlnning sloop, PSIQUE (o Rhodes prototype

bui f t in Long Islanâf with an a lmos i^^ch lun^rger crew. First mate Rene Delmont

used to r e f ^ r galvanometers in E[ Tigre but left us in 1940 for a profitabi© venture

in the watch rep f f r and jewelry business. Crewman Floris is Jean Thibou's brother-

in-law and a successful painter and decorator. Dr. Fontaine himself has been

the unofficial company doctor since he started setting bones in Caicora near

Jusepin twelve years ago.

G E R M A I N E G R O S M A N G I N W I T H L I T T L E P A T R I C I O A N D M I C H E L L E .

Vil?

Intercom/August, 19SO 11

I n t e r c o m / A u g u s t , I 9 6 0

J u e g o d e g o l f ^ ^ continued

mLagunita Country Club

T H E P E R S O N N E L D E P A R T M E N T I S M A D E U P O F S U N D A Y G O L F E R S .

j u n k o g o l f club

A B O V E . N E N A S O U C H O N A N D T O T H E R I G H T , E D U A R D O

^te.

presentacion de m ö d e l o s

iultamira tennis club

Mery now and then tennis players need o rest from

energe t i c pursuits, and the up-to-date tennis club

finds the perfect answer: o fashion show. Or is the

stv 'jk show intended to give the girls some entertain-

®fnt while the boys are on the courts.

16

Intercom/August, 19SO

W E T H O U G H T T H I S O N E W A S W O R T H R E P E A T I N G F R O M P A G E 6

c inco y se is la rinconada

Cinco y Seis is a truly indigenous pastime of Venezuela. It origi-

nated in 1945 and the rules of the game are childishly simple.

On Saturday, for one Bolivar, you buy a Formulario at one of

the 200-odd open air booths scattered around the city. Six of

the twelve races to be run the fol lowing day are VALIDAS for

the Cinco y Seis. In each one you select one or more horses

and list them on your formulario. You pay according to the

number of horses, with o minimum of 4 bolivares. If you have

selected one horse in the first, second and third, two horses in

the fourth and fifth and three horses in the sixth, you pay

twelve bolivares.

Deadline is 2 A M Sunday and, around midnight, anxious

aFicionados pondering the chances of a BATACAZO (long

shot) are a familiar sight on the sidewalks of Caracas. They

very seldom go to the beautiful hipodromo, LA R INCONADA,

and a lot of them probably have never seen a horse at close

quarters although they can tell you exactly the weight

TAQUIMETRO is carrying in the third and how jockey BUSTA-

MENTE led him to victory in ZSYs" last week.

Usually you watch the races on television and curse your luck

if it starts raining. If you have picked five or six winners you

collect your share of the total money bet. Close to a million

dollars ore bet on some week-ends and if you are the only

lucky guesser with six horses, your share may work out to more

than 300,000 dollars.

The Cinco y Seis folk lore is rich in wonderful and improbable

tales like the old story of the fellow who played horses No. 5

and No . 6 in each race for a total investment of 65 bolivares and

sure enough all the horses came in fifth or sixth.

Several Schlumberger engineers are known to have picked six

winners (Jean-Louis Droulers, Maurice de Verteuil, Luciano

Baccovich) but they claim it did not pay because it was a

MERCADO LIBRE that is several thousand other people had

CUADROS with six winners too. Only Brian Miller felt rich

enough to quit Schlumberger after winningi the Cinco y Seis.

T O T H E L E F T , G I S E L L E A N D R O L A N D M I L L E T W I T H G E R M A I N E G R O S M A N G I N .

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beîstool (êmmm m pi/ÎIÏÏ

Spanish basebal l vocabulary is not very glamorous. A hit is a hit, a foul is a foul, a catcher is a catcher. Some people try to use LANZADOR for pitcher and CARRERA for run, without much success. Occasionally, a n amusing spelling is found like JONRON for home run or AMPAYER for umpire.

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EL JON

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E L S C H L U M B E R G E R L I N E U P I N C L U D I N G F R O M L E F T , G E R A L D M C K E N Z I E , B I L L N I L E S , A L

W I L S O N , C H U C K R I L E Y A N D C R U Z B O L I V A R . ( A L A N D C R U Z A R E F R O M P R I C E - W A T E R H O U S E . )

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F R O M L E F T . C H U C K R I L E Y , G E R A L D M C K E N Z I E A N D B I L L N I L E S .

RON DE CHUCK RILEY 'iL?

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R A U L A L E M A N B I L L N I L E S .

beistool continued T H E A M P A Y E R I S A L W A Y S R I G H T . F R O M L E F T , B I L L N I L E S , A N D R A M O N B O R G E S ,

F R O M B È F T , C H U C K R I L E Y , M A N U E l I A T E O S , R A U L A L E M A N A N D G E R A L D M C K E N Z I E .

G E R A L D M C K E N Z I E

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ALTAMI RA f EN NI S CLUB

Caracas is something of o tennis c e n t e r ^ n d year the tournaments attract

internationally-known players. Thl^^photograph below shows the finals doubles

match between Australians Fraser and Emerson and Gimeno and Arilla. A B O V E , R O L A N D M I L L E T .

c a r a c a s » c o uji t r y club -M'a

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'presidents... play tennis"

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A R N O L D H E B E R T A N D M A R I E - A N T O I N E T T E M A L G O Y :

A B O V E , M A R I A E S T E R B U E N O , T H E N O . 1 G I R L I N T H E W O R L D .

C A R L O S N A V A R R O .

H A R R Y B R O W N , O N E M E M B E R O F C O M M E R C I A L W H O G O E S F O R I N D O O R S P O R T S

A N D R E S P A R R A .

3 2

I n t e r c o m / A u g u s t , 1 9 S O

IM Piaïï

juego de bolos casablanca club

juego de poker The little gar^Ö of chance shown below was conduced by the boys in Caracas, chez Demoustier.

While Mike Grosmangin right, was ^ ^ o k i n g orcRwd looking over everybody s shoulders under the

pretense of taking photographs. Marc, our secret agent, gûught him with o trusty Polaroid.

m

H E A T H E R R U S H T O N M A R C D E M O U S T I E R J E A N R A U X

A L A N R U S H T O N G E R M A I N E D E M O U S T I E R

J E A N - L O U I S Q t R O U L E R S

I n t e r c o m / A u g u s t , 1 9 6 0

LIFE IN CARACAS

Many adjectives have been used to describe life in Caracas

but the on ly really apt one iS; expensive. It is certainly no t

a t ropical paradise. In fact, the tempo in Caracas is more

N o r t h than South American. Other Latin American

countries enjoy such niceties as a 3-hour break for lunch

or start the work ing day at 11 ;00 A M or end it at 3:00 PM.

Caracas runs a businesslike 8 to 5 schedule.

Neither can Caracas rival the dance halls of Buenos Aires,

the bull-flghts of Mexico or the night clubs of Copacabana .

Venezuelans are stay-at-homes and love large fami ly

affairs, expensive weddings, lavish b i r thday pinatas. The

fact that the most popu lar performer at the most durable

cabaret is a cow and not an ecdysiast must have a deep

psycho-social meaning.

W h a t do foreigners do? They crank their own little

merry-go-round of cocktai l parties but mostly they center

their social activity on their favorite c lub. Go l f clubs,

tennis clubs, br idge clubs, yacht clubs, they provide a

wonder fu l haven a w a y from the oi l -drum-beating.

It is refreshing to meet peop le who do not care what y o u

do and w h o d o not know what Schlumberger is anyway .

One of our dearest friends still believes that we sell w ine

because in his native Austr ia, Schlumberger is the leading

wine-maker. Our friend himself manufactures brassieres.

Mike Grosmangîn

37

Personnel News

in Caracas

Bob Ford flew down to Argentina on a business trip and on his return left for Paris with Barbara, daughters Vicky and Janet, and son Robbie.

Bill Niles also took off for Argentina to meet with Marc Demoustier who was already there.

Maurice Bonnet of our Commercial Department left for Guiria to lend Luciano Baccovich a hand.

Georges Grimaud returned from long leave with his family and is in Caracas temporarily — refreshing in Interpretation. Welcome to Surenco's

Head Office, Georges!

Glenn Gamble, Bernard Besneux and Neal Moseley are now on long leave. Neal paid a fleet-ing visit to the Caracas staff before taking off on what he hoped would be a wonderful vacation.

done in the summertime as in the winter, more visiting firemen and more people on vacation are seen during June, July, and August than during the rest of the year. This to the Paris editor has always appeared a bit mysterious.

Bernard Delannoy was one of them. Tanned, and wearing glasses and a crew-cut, Bernard is pre-paring to move out of Lue (France) in the next few months . . . There was also Paolo Reynard

f rom Parma ( I ta ly) , Daniel Barbaut from Han-nover (Germany) , as well as Jean Boucau in a dashing army Lieutenant's uniform on a 15-day furlough from Algeria . . . Pierre Giraud, with one foot in SPE and one foot in DS (Dowell Schlumberger), a real African sun tan and his usual load of energy and good humor . . . Harry True and Marcel Delessert . . . Pierre Joubin,

who is preparing to leave France for Argentina . . . Bruno Massenti, who combined tourism, medical care and Engineer's examination in one visit to Paris, was successful in all three ventures.

Another returnee from a three-month holiday, Robert Claret, spent part of his vacation on the French Riviera and the rest of the time on the links of the Lagunita Country Club. (See photos in Caracas At Play. ) Robert is nursing a sore back at the present time, and is temporarily off golf. Better hurry and get in shape, Rober t—we hear that Clement Lepak has ordered some extra

long clubs . . .

Gerald McKenzie very proudly announced that the Schlumberger Softball Team tied for first place with the University Team, each team having won five matches. Next month we will announce the results of the play-off that took place in mid-July.

in Paris

In Paris we say; "What favorable breeze has blown you into this office?" Somehow, and not-withstanding the fact that there is as much drilling

Most pipe-smokers derive a great deal of pleasure from smoking a pipe but, according to Denys Pine des Granges, it is much more agreeable to smoke your pipe in Paris than in Edjeleh, and it's not a question of tobacco either! At present, Denys is enjoying a well-earned vacation in France before going back to his favorite Saharian

resort.

Bob Ford and Marc Demoust ier were also seen around the office and brought some good news f rom Surenco as well as a whisper of a South

American breeze!

Charlie "Tower's Cap" Bonnet de la T o u r

stopped in for a few days to have a closer look at

the Sonic.

Michel Fiquet who is enjoying his vacation will interrupt his holidays to follow Mr. Palustran's

next course starting August L

38

Roy Dudman came to Paris for the second time in his Ufe, but did not look at the city with a tourist's eye this time. He was seriously consider-ing the possibility of settling down to work for Dowell Schlumberger.

Lester Heath, well known to SWSC friends hav-ing spent thirteen years with them, crossed Paris on his way to Hannover (Germany) where he will relieve Harry True. Harry will take up his new post as Manager of the East Mediterranean Area the middle of August.

Bernard Douet came by before taking olf for Trinidad, his new assignment, and other places south.

Old friends met or missed each other by a few hours . . . Georges Gourp f rom Nigeria, Fernan-do Rios from Indonesia who came to pass his exam . . . Christian Dubant f rom Kuwait . . . Jean Visage and Gerhard Clauss f rom the Sahara.

movements

John Moore spent a few days in Oasis I (Libya) before going to Syrte where Xavier de Peyronnet

is in charge. John turned over O A l to Jacques Leveaux who is there on a new assignment.

Formerly in Benghazi, Jeremy Farrow is now in charge of N B H (Libya) center.

After an enjoyable leave in his homeland, Ger-many, Hans Hager flew to Libya to take over the C F A center f rom John Johannessen. John went one step further to Amoseas center to pinch-hit for Bruno Massenti during his local leave.

Pierre Lehmann left New Zealand for Brisbane (East Australia) where he is now in charge. This liberated friend Gerard Metenier who took off for Papua where he reopened the base.

Claude Abadie arrived in Sidi Kacem (Morocco) f rom Pau (France) to allow Daniel Cuisinier

to go on leave.

No longe r in M o r o c c o , Phi l ippe L e n g r a n d

opened a new base on July 1 at Ghanet (Sahara) .

Norbert Paierait said goodbye to his homeland, Germany, and flew off to Istanbul (Turkey) where Roger Conrad was expecting him. Roger then went to Diyarbakir where Gilbert D o m p s

gave him the reins of the center so he could go on leave.

Rene Treyvaud's home leave is over and he can be found in Nigeria where he took over from Jean-Claude Pijeaud. Jean-Claude visited Paris, and anybody who thinks the grub is no good in Nigeria should take a look at Jean-Claude's waistline!

Roland Joly left Mogadiscio to go to Troyes (France) where he replaced Alain Berthe.

Alain is now on leave but thinking more and more seriously about his next assignment in the Sahara.

Walter Shoquist is now enjoying a well-earned holiday in Canada, while Max Wrany f rom West Bengal, took over his center in East Pakistan.

All good things come to an end, and Claude Ducomte, after visiting the Paris office during his leave, once more returned to the Iran District. This allowed Gunter Wawrzenitz to take over from John Taylor in Arabia, and John to go on leave.

Aimery de Saint Mars has been very busy lately in view of the new Rio de Oro District he opened on July 10. He was seen in Paris very briefly.

Jose de Leizaola is staying in the Paris area after attending the Training School. Argenteuil center has taken him on and will help him train for his Junior Engineer's exam.

Omar Halawa also attended the school and is now back in the land of the pyramids in Ras Gharib. Iskander Tadros left Ras Gharib, and after a month's leave is now back on the job in Sinai.

39

Henry Briend finished school and headed for Pescara on the sunny Adriatic to train for his Junior Engineer's exam.

Armin Dokter f rom the Hannover (Germany) District, passed his Engineer's exam in Paris and returned to N E A to train for the job of Division Engineer. In the meantime, Hans Korn moved up f rom Karlsruhe to Hannover.

Christian Dubant turned over his job in IDC Kuwait to Lionel Stiles, who will look after every,-thing during Christian's absence on local leave.

After a course with Professor Palustran, Carl Alberto Costa took off for the Neutral Zone (Kuwait ) where James Dunlap will help him train for his Junior Engineer's exam.

Raymond James finally made it to Libya f rom Egypt where he has been very busy for several weeks due to an increase in activity there.

Jean-Jacques Renault is busy on local leave replacements and is now in Qum (Iran) during Juan Hurtado's absence.

Jean de Labachelerie interrupted his vacation to give a helping hand to the new South West Europe Division Manager, Bob Gaymard.

Jean Burtin is packing his bags in Pau and pre-paring to give a helping hand in Head Office with Sales and Client Relations.

Jean-Claude Kayser, back from the Ivory Coast, is now contemplating a new assignment in Argentina.

Denis Meunier is skipping around doing local leave replacements in Indonesia. At present Denis is in Djambi where Emmanuel Moreau left him in charge while he takes a month's enjoyable leave.

Alan Rushton spent two weeks in Ecuador when Colin Guthrie was laid up with the flu in June. Since then, Colin has recovered, is back at work, and Alan took off with Heather and sons Ian and Simon Anthony for long leave in England.

Curtis Samples and Mike Grosmangin were slightly delayed in Houston when they were advised their Venezuelan reentry permits and visas were cancelled during their Stateside visit last month. This gave them a little more shop-ping time, but all good things come to an end and Mike and Curtis arrived back at their posts none-the-worse for their extended trip.

Arnold Hebert took off for Jamaica for one week's local leave with the family before their departure for the States in late July. "Polly" visited SL offices with Arnold, Jr., and daughter Pat after picking up a brand new Sky-mist blue, air-conditioned Thunderbird. They will visit Polly's relatives in Mississippi and then return to Houston in time for school.

Other Surenco vacationers are Pierre Latulippe

who is in Canada . . . Willard Kyrk in the States . . . Hector Mayorga in Columbia . . . and Guy de Schoulepnikow in Europe on local leave. Rumors are flying that Guy's wedding to Miss Francine Maylan will take place in her home-town, Vevey (Switzerland). We hope to receive details for next issue's Wedding Bells.

Recently returned from long leave, Rene Jouanin

spent a few days in his wife's native country, Peru, before settling down to hard work in Argentina.

Jean Gartner has taken up his new assignment as Manager, North Africa Area with headquarters in Algiers.

After fifteen years with SWSC, Bill Bowen,

former Manager of Louisiana Coast Division, will take over the Middle East Area on August 15, and Bill Goode will return to SWSC.

Bob Leleu accompanied Pemex representatives Ing. Armando Moran, Chief Petroleum Engi-neer; Ing. Ignacio Garcia de la Torre, Chief Schlumberger Pemex Division; and Ing. Carlos Salgado, Schlumberger Pemex Engineer in Rey-nosa (Mexico) , on a tour of SWSC's Plant. From Houston they flew to Ridgefield (Connecticut) for a tour of the Research Plant before returning to Mexico City.

4 0

welcome mat sick bay news

From I'Escuela de Minas in Madrid, Antonio Ribalaygua who hails f rom Santander (Spain) , spent a few weeks at the Masterman Smith In-stitute to brush up on his Enghsh before going to the Sahara. Following this period of training Antonio will attend Professor Palustran's school.

Also from I'Escuela de Minas and his hometown, Madrid, Manuel Rodriguez started his training in Karlsruhe (Germany) , after a short while at the Masterman Smith Institute.

Surenco's Colombia Division recently welcomed Harold Bibb, formerly with SWSC in Victoria (Texas). Harold became a familiar, figure around the Caracas offide during an airport shutdown which detained his flight to Colombia.

Another new arrival f rom SWSC, Midland (Texas), Adam Geisel, has also been assigned to Colombia and is now in Barranquilla.

A third arrival in Colombia, Ostap Hawaleshka

who graduated f rom McGill University, Montreal (Canada), is on his first assignment in El Centro.

A hearty welcome to all the new-comers.

seniority pins

Mike Gahan, Bill Mountjoy and Otto Schroder

all reached five years seniority in July.

Angola's Portuguese chauffeur, Pedro Antunes,

received his five-year pin.

In Gabon, two local employees, Michel K o u m b a

and Jean-Bernard Mihindou got ten-year pins.

George Nadal in Pau and Francois Borges in Lue are also wearing ten-year pins.

Hannover (Germany) proudly announce the 25th anniversary of oldtimer Mr. Heinrich Hartlage.

Rober t van Deusen, of Canadon Seco (Argen-t ina ) , was recently on Surenco's sick list. We are glad to report Robert had a speedy recovery and is now back on the job.

Leo Constantino who was involved in quite a serious automobile accident not so long ago, was seen roaming around the Caracas office looking very bruised. An operation was scheduled for him and we are sure all Intercom readers will join in sending him best wishes for a prompt recovery.

Brian Greenland successfully underwent an ap-pendectomy in Tripoli just in time to avoid peri-tonitis. This kept Brian away f rom work for a couple of weeks.

Rodrigue Caron who suffered a bout of dysentery was hospitalized for a couple of days for observa-tion. Three weeks away from work put him back on his feet and back on the job, this time in Benghazi (Libya).

Jacques Savy had a most unfortunate accident while enjoying time off at the beach with his family. Jacques sustained a fracture of the spine diving through a wave. He is hospitalized under excellent medical care but it will be some time before he is back on his feet.

Af ter his truck broke down in the desert, exces-sive heat and over-exposure put Marcel Dutheil

under medical care for two weeks. He is now in France on a well-earned vacation.

SAVINGS AGENCY

At June 30 the value of

thé unit was reported to be $15.52

41

promotions

Armin Dokter (Hannover) , Bruno Massenti and Fernando Rios (both on leave), are promoted

to Engineer.

The following promotions in SPE have been announced: Joe Bricaucl — Vice-President — Technique; Denis Tanguy—Manager—Research and Development; Louis Al laud — Manager — Technical Services — Operations; R. Rouss in —

Assistant to the Vice-President—Manufacturing; Jean Simon-Suisse — Department Head — Me-chanical Engineering. Denis Tanguy was formerly SWSC's Electrical Engineering Department Head

in Houston.

wedding bells

Jean-Pierre Etter and Miss Pierrette Gros were

wed in Cairo last March 23rd.

Terezinha de Jesus Lisboa dos Santos became the bride of Juvenal Gonzalez on May 26, in Salvador

(Brazil).

The wedding of Georges Oilier and Miss Berna-dette d'Heilly took place on August 4th in Saint-Waast de Rousies (France) .

Wedding bells have also been pealing in several

Surenco locations:

On June 15, Hermes Ronzoni and Matilde Quiroga Duarte were married in Colombia.

Miss Linda Darlene Brown became Mrs. Fiorino Fiorini on June 1, in Porvenir, Tierra del Fuego

(Argentina).

Best wishes to the happy newly-weds.

stork news

Eileen and Charlie McElrue proudly announce the birth of their first child, John Clive, on July 1. Little John was born in the Clinica Orsini (El Tigre) and weighed 8 pounds.

Also in El Tigre, the Rene Ferrieres welcomed Alain on July 6—much to brother Pierre's delight.

Marc and Beatrix Periers are happy to announce the arrival of their new brother, Guy, on July 12,

in Pau (France) .

Bryan and Pamela Jones now have four hand-some children. The latest arrival, a daughter, was born in Milford (England) on Bastille Day.

Congratulations to the proud new parents and all

good wishes to the new arrivals.

4 2

JUL 1 S i9o0

" S C H L U M B E R G E R " SURENCO, S. A . I N T E R O F F I C E C O R R E S P O N D E N C E

TO: INTERCOM DATE; July 15, 1900

FROM: Solalog FILE:

S U B J E C T :

For those who pant and complain over the current Houston

weather, we submit the following quotation from a report

of J. Bonsergent in Dhofar:

"Miscellaneous :

The use of the maximum bottom hole thermometer Is

somewhat perturbed by the fact that the surface

temperature is higher than the bottom temperature

in shallow holeg: from 90°F in the coolest (?)

night up to 122 under shadow".

The above datum may not cool off the poor Houstonians, but

it provides an interesting point of comparison. Apparently,

Dhofar is almost as hot as Wichita Falls, Texas.

LP jm

the schlumberger The Torrents of Spring by Turgenev reappeared last month in a new and brilliant translation by

David Margashak (F.S.&C., $3 .75 ) . Written dur-

ing the Franco-Prussian war of 1870, the novel was an immediate success despite the fact that it had none of the political or social interest to be expected of a Russian author. It is indeed, as

Flaubert was quick to see, one of thé most pe r -ceptive and least sentimental love-stories in Euro-

pean literature. "Ah, that is a love-story if ever

bookshelf

by ISancy Lenkeith

4 3

there was one!"—Flaubert wrote to Turgenev on

August 2, 1873. "You know everything there is to know about life and you know how to put it

into words, which is an even rarer accomplish-ment! Quel homme que mon ami Tourguéneff!

Quel homme!"

"So immoral, I have never been." This is how Turgenev himself felt about The Torrents of

Spring because his hero Sanin, who could appre-

ciate stainless beauty, betrayed it by yielding to lust. Or, in the words of Turgenev's friend Annen-kov, because Sanin was capable of "savoring divine ambrosia and devouring raw meat like a kalmuck with equal relish."

How is the modern reader expected to feel about

this moral dualism which was the central problem of Turgenev's life and fiction? The publisher's blurb on the dust-jacket of the new book reveals the inquisitive tone of our post-Freudian ortho-doxy: "What is it that makes Sanin, the hero of The Torrents of Spring, treacherously abandon

the young girl with whom he is genuinely in love and to whom he becomes engaged? What is it that makes him follow a woman who is con-fessedly amoral and whose only aim in life is freedom to satisfy her own selfish desires irre-spective of the ruined lives she leaves in her wake?"

What was it that made Turgenev himself fall in love with a beautiful young Jewess when, like

Sanin, he was 22, in Frankfor t , and returning from Italy? What was it that made him leave her only to pursue so fatuously the famous singer

Pauline Viardot, daughter of a Spanish gypsy? There was, no doubt, a motive which may well have been subconscious and hidden, an incest bar

perhaps, as the post-Freudian reader is only too quick to suspect and detect.

The unsuspecting Turgenev, however, wrote for unsuspicious readers. "Truth ," he says in a letter dated January 1869, "is the air without which we cannot breathe; but art is a plant, sometimes even a rather fantastic one, which grows and develops in this air." And five years later: "Real-ism by itself is fatal—truth, however powerful, is not art." To paraphrase Flaubert , Turgenev knew about life everything he was given to know—the

tragic element of love, the obsession leading to ruin.

H o w he put his own painful experience into words—the plant that grew into our own present

t ime—is at its most fantastic in his introductory description of the 52-year-old Sanin's fear of

death: "Life did not seem to him to be like a storm-tossed sea, as the poets describe it. No.

H e imagined that sea to be smooth and unruffled, calm as a mill pond and transparent to its darkest bottom; he himself sat in a small, unsteady boat, and down below on that dark, slimy bottom, he could just make out the shapes of hideous mon-sters, looking like huge fishes: all the maladies and infirmities of life—grief, madness, poverty,

blindness . . . Even while he looked, one of the monsters detached itself from the darkness, rose

higher and higher, became more and more dis-tinct, more and more horribly distinct . . . An-

other moment and the boat that bore him would be overturned. But then it seemed to grow indis-tinct again, it withdrew further and further, it

sank to the bottom, and there it lay stirring the water round it faintly . . . But the appointed hour would come and it would overturn the boat."

James Agee's A Death in the Family, one of our

paperbacks for this month, is also a fantastic plant grown in an air of truth. Below the surface of consciousness, it uncovers another of those

forgotten, rejected moments when human feelings are most tender—the death of a father. And in prose which is in the full sense poetry, it makes this anguish—the sense of the father: the place he filled and the emptiness he left—immediately and universally live. The reality we could only

forget is made here both present and meaningful by the magic of art. James Agee, who died sud-denly of a heart attack five years ago at the age of forty-five, was indeed an American Turgenev: he knew everything about life there was to know, and he knew how to put it into words.

During the past few years, as more and more journalists have taken up writing fiction to capi-talize on their experience—such royalties are subject only to a 25% capital gains tax—we have been confronted with an increasing number of reportage-novels. Some of these are trash. F o r instance, the sensational The Chapman Re-

port (Simon & Schuster, $4.50) which is a fic-tional exposure of a famous nationwide survey

of American female sex habits. The aim is to

question the sincerity of the thousands ques-tioned and to show the obvious hmitations of

statistical sex. So we get a rehash of the whole dreary business about frequency of intercourse, length of orgasm, and infidelity; we gef a plot complete with nymphomaniacs, murder and rape; and we get a morality play on the importance of

kindness vs. science, of love vs. sex. The author, Irving Wallace, can thus satisfy those who like

their pornography plain as well as those who like it moral—and he can even please the public

censors as D. H. Lawrence could not.

The reportage-novel can be absorbing, however,

particularly when the observer is both honest and shrewd and also talented as a story-teller. Such is Theodore H. White's The View from the

Fortieth Floor (Sloane, $4.95) which describes

the communications world of New York's "Mira-cle Mile"; "Right here, Nat, you put the point of a compass down where this building is and swing a mile around it. All the radio nets and

all the T V nets are in the circle. All the syndi-cates and all the press agencies. Every advertising agency and word packager is here. The Cardinal sits here. They decide what movies Hollywood is going to make from here. They publish 9 0 % of

the books in the country here. The magazines are all here, or almost all of us. And we're all

guessing, guessing what makes them angry, what makes them cry, what makes them laugh. We

sell dreams, and ideas, and news."

The view is from the office of a news magazine in Rockefeller Center. But the guessing-game does not pay off, even though Mr. White is a former bureau chief for Time and a former staff-

writer for the now defunct Collier's. His view takes in all magazines that have to pay their way. He shows the moral cost: "Truth and dreams," says the editor of Trumpet, "get paid for these days by breakfast foods, by patent medicines, by cranberries, by deodorants. And advertisers want

an audience, first, not the truth."

But this anyone can see just by looking at one of these magazines. More instructive is Mr.

White's lively account of the actual financing. Despite costly circulation drives, frantic editing, and advertising, the magazines on the fortieth floor are not paying their way. So what does the

editor do? Make the bankruptcy of the magazines

profitable to the other divisions of the corpora-tion—text-books, trade-magazines, and radio-stations? He decides to save the magazines— why? And how does he go after the cash? The

View from the Fortieth Floor had to be fiction

in order to be true. Mr. White has performed a public service in bringing the cold facts to life

and to light.

The Way West by A. B. Guthrie, our second

monthly paperback, is the story of an emigrant

trek from Independence, Missouri, to Oregon in the 1840's. It is a fictional report like The Big

Sky, Guthrie's earlier novel and one of our earlier

paperbacks, which tells how a Kentucky boy was made into a mountain man. In fact, Dick

Summers, one of the leading characters of The

Big Sky, reappears in this book.

Here again, Guthrie is a master of time and place, but not a master of the novel. The Western

talk and stride come through with warmth and vitality, despite the pseudo-poetic descriptions. And if the plot—earth-mother-woman and pretty-

young-thing—lacks originality, this is of no im-portance. A John Ford movie- will show you what westerners did; Guthrie shows you how each one thought and felt, adding freshness and

vigor to the d rama of Western passage. The Way

West is that rarity; an adult Western.

There is one current book which this reader might be tempted to call a classic: Born Free

(Pantheon, $4.95) by Joy Adamson, the wife

of a game warden in Kenya, who writes about her pet lioness much as Colette wrote about her

cats—without a trace of that sentimentality which can betray the dignity of m a n and beast.

Four years ago, her husband went out to stalk a man-eating lion, was charged by a lioness whom he had to shoot, found her three cubs nearby, and decided to keep one as a pet. This was Elsa

who slept in their tent with her paw on her master's shoulder; who, when she was nervous, sucked her mistress's thumb; who rode on the

roof of their Land Rover until it caved in and had to be reinforced; who hated cameras and

typewriters, but tolerated visitors at camp, even

those who were really scared . . .

4 5

But how the Adamsons prepared to release her when she was grown—that is the truly extraor-

dinary story. First, she must learn to kill when hungry. So they taught her to hunt and, when she got her first buck, she insisted on pulling the kill into the car herself. Then she must mate. So they took her to the bush and waited for her

to come into season: "For two days and nights she kept away, except for one short visit during which she rushed up to us, rubbed her head

against our knees, and dashed off again, only to come back a few moments later, indulge in some more rubbings, then make off a second time and as quickly return, as through to tell us: " I am very happy, but please understand I must go. I just came to tell you not to worry." Then she was off again. When she finally returned, for

good, she was badly scratched and bleeding f rom several claw marks and was very irritable when I tried to dress her wounds. It needed much patience to make her jump into the truck."

Realizing how long it would take before Elsa could go wild, the Adamsons gave up their home leave to give her more time. They took her to the bush, left her for a week, then came back

for her—and still she slept in their tent, in their bed. They did this again and again until she was ready for the final break, until she had found her mate. The temptation to quote from this book is irresistible, perhaps because it is a classic, because style and subject are so superbly matched. Here, then, is the dénouement in Joy Adamson's own words:

"On the 29th of August George was obliged to go to Elsa's area for Game control and arrived at 6 :00 PM at her camp to spend the night there. He fired off two thunder flashes to attract her attention. At about 8:00 P M he heard a lion down river and let off another thunder flash. The lion continued to call throughout the night, but there was no sign of Elsa. Next morning George found the pugmarks of a young lion or lioness close to camp. He had to leave immediately af ter-

ward but returned at 4:00 P M . An hour later Elsa came across the river, looking very fit and full of affection. Although she was not hungry,

she ate a little of the buck which George had brought her and then dragged the carcass into the tent. Soon after dark a lion began to call. Much to George's surprise, she completely ignored the invitation, which continued throughout most

of the night. Early next morning she made a hearty meal and then without any show of hurry

disappeared in the direction from which the lion had called. Shortly afterward George heard her voice and saw her sitting on a big rock and

heard her making deep grunts. As soon as she spotted him, she came down and met him but, although pleased to see him, made it obvious

that she wanted to be alone and after a briet head-rubbing disappeared into the bush. Guessing the direction she had taken, George followed and found her running tracks heading for the river. Presently he saw her sitting on a rock

almost hidden by bush. He watched her for some time. She seemed very restless and kept on looking intently downstream. First she miaowed,

then with a starüed "whuff-whuff" dashed down the rock and streaked past George into the bush. Next moment a young lion appeared, evidently in hot pursuit, and not sensing George came

straight toward him. When the lion was less than twenty yards away George thought it time to act and waved his arms and shouted. Startled, the beast spun around and made off the way he had come. A few seconds later, Elsa reappeared, squatted nervously close to George for a few

moments, and then followed the lion. George withdrew and moved camp.

" T w o days later he had to revisit the same area. A few hundred yards before reaching Elsa's camp one of the men in the car saw her under

a bush close to the track, apparently hiding: most unusual behavior, for normally she would rush out to meet the car and greet everyone. Thinking the man might have mistaken a wild lioness for Elsa, George turned the car and drove back. There she was sitting under the bush. At

first she made no movement; then, realizing that she had been caught out, she came forward and was courtesy itself, making a great fuss of George

and pretending to be as pleased as ever at seeing him, and she condescended to eat some of the meat he had brought her. WhUe she was eating, George walked up the track to look for spoor. He found her pugmarks together with those of

another lion. Then he saw the lion himself peeping

at h im from behind a bush. It appeared to be the same one he had seen with Elsa a few days earlier. Presently there was an uproar from a troop of baboons by the river, which heralded the approach of the lion. Hearing this, Elsa hurriedly finished her meal and went off to find her lord and master ."

4 6

Drawing by F. 5« Modell

© 1959 The New Yorker Magazine, Inc.

This was the end of August and the end of Joy Adamson's story. At the end of December, the publisher received the following cable: CUBS BORN 20TH—ADAMSON. The Adamsons had achieved their aim. Elsa had lived for more than a year the natural, independent life of a wild

lioness and still, she retained her affection for

them. Whatever her ultimate fate might be, Joy Adamson's story of her upbringing and release,

documented by mor© than a hundred photographs, shows how deeply civilized a man and a woman

must be to befriend the wild without harm being done to any nature, human or not .

4.7

S C H L U M B E R G E R S U R E N C O , S. A. C A P I T A L ; U. S. t 7 . 0 0 0 . 0 0 0 , 0 0

Apartado 430

Maraoalbo - Zulla

V«n«xu*la

F l a u « Forward to

Laa Meroohaa

The Ed i to r Intercom

\r Apartado 1608 Caracas

Dear S i r :

In your June I s s u e on Las Morocbas, I sun i n complété

agreement w i t h you on "the d i s t r i c t a t Las Morochas i s a b l y

run "by Miguel Feldman who above surveys h i e domain".

However, on t h e ques t ion of t h a t domain as i l l u s t r a t e d ,

I am qu i t e a t a l o s s . Could i t be t h a t INTERCOM h a s i t s

tongue in t h e cheek and b e l i e v e s t h a t Mike runs t h i n g s b a c k -

s i d e f o r e m o s t , or i s e v e r y t h i n g r e a l l y a l l r i g h t and the

shrewd Mike i s mere ly t h i n k i n g of t a k i n g up an o p t i o n on t h a t

p o t e n t i a l l y l u c r a t i v e po r t ion of l ä s t e r n Lake Maracaibo?.

Yoxirs f a i t h f u l l y ,

J . C . Bennet

JCB/ei

Of course, there is a third possibility: that Intercom runs things

backside foremost. We will try to avoid this unflattering posture

in the future.-Ed.

Las Morochas 2 0 t h June I960

PRES LEO

PER

CON 1

FO

TER

2? JUN1960 TRE

AC"

COM

si îUWU: : r i o

48

TECHNIQUE

BACK-OFF OPERATIONS

"Where Goes The Neutral Point?"

4 9

1) Introduction.

When backing off drill pipe, drillers usually

apply rules of thumb for calculating the neces-

sary data such as Weight on Hook, Amount of Torque, a.s.o. Regarding the Weight on Hook,

it has been noticed that the amount of weight as applied by drillers is usually less (and sel-dom more) than the nominal value required to obtain optimum back-off conditions i.e., the

neutral point at the joint to be backed off.

The reduction in weight (when consciously applied) appears to be based on, f rom the driller's point of view, practical reasons. Some

of those reasons are:

1) The threads of the joint being backed off are required to remain engaged in case one wants for some reason to screw back in again; the weight is reduced in order to prevent the loosened joint from jumping out of the stuck one (according to current

opinion).

2) Violent movement of drill pipe at rotary table observed during successful backing off creates fear in the minds of some drill-ing people that similar movement occurs down-hole, damaging the thread of the stuck drill pipe, thus making it difficult or impossible to screw back in after washing-over. Leaving a certain weight on the joint to be backed off is believed to reduce the violence and the risk of damaging the

thread.

3) When backing off in Drill Collars, the extra weight necessary to overcome the hydrostatic pressure on the shoulder causes great stress on the drill pipe, risking to

break the pipe.

The following study is meant to investigate

whether above arguments are theoretically cor-rect and deserve consideration, or not. The outcome might help field engineers in antici-pating objections against the recommended back-off procedure and in being ready to deal

with them.

2 ) Static Pos i t ions of Drill P i p e before a n d

after Back-Off .

To simplify the problem, only a homogeneous string of drill pipe is taken into consideration (no drill collars, jars or subs). Further is dealt with movements in vertical direction only,

because the rotational movement of the drill pipe is not likely to have any influence on the raised problems. Assumed is that the drill pipe cannot move up or down at the rotary table.

The distribution of the tension in the drill pipe before and after back-off depends on the weight on hook and on the hydrostatic pres-sure of the mud. Referring to fig. 1, it will be clear that in the ideal situation (the neutral point at back-off depth "A") the tension in the drill pipe before backing off increases

upward from "A" and decreases downward (i.e. increasing compression). The tension at a certain depth is proportional to the distance from point "A", reaching its maximum at the

rotary table.

After backing off the loosened pipe will jump upward, show a damped longitudinal oscilla-

tion and finally reach a stable position as indi-cated in fig. 2. In this stable position there is a gap "a" between the loosened and stuck

pipe. This gap exists because the length of drill pipe "L" has been compressed by the

hydrostatic pressure "p" which has, since the back-off, free access to the bottom of the

loosened pipe.

The distribution of the tension in the drill pipe

after the back-off has been represented in the diagram of fig. 2. It will be clear that this

diagram has been derived from that in fig. 1 by moving the tension-line to the left over a distance = p (the hydrostatic pressure). The

neutral point has moved upward over a dis-tance r= b. The ratio b / L is equal to the rat io: density of mud/density of drill pipe material.

b /L has a value of 1/6 to 1 /7 for average mud

densities.

The value of the gap "a" can be easily calcu-lated from the hydrostatic pressure and f rom the elastic deformation of the drill pipe accord-ing to Hooke's law; see Appendix 1. "a" proves to be proportional to the square of the back-off depth "L", and can be expressed in a practical

formula as;

50

where: a = gap between pipes at B.O. point, in inches

D = mud density in Lbs./gal. (water: 8.3 Lbs./gal.)

L = back-off depth in feet.

From formula (1) it is clear that we cannot influence the value of "a" greatly without en-dangering the success of the back-off operation.

As soon as we should reduce the weight on the hook prior to backing off, in attempting to obtain a smaller gap "a" after unscrewing, we would have considerable weight pressing on

the joint to be backed off.

Whether the threads of the drill pipe remain engaged after backing off, depends therefore

mainly on the depth and on the length of the male thread on the drill pipe ("c" in fig. 3) . As an example, we take "a" equal to "c" and find that for 4 1 /2" API drill pipe (where c = 4") "L" would be 4900' in case of a light mud, and L = 4000' for a heavier mud with

density 12.5.

The conclusion can be that, when we back

off with the neutral point at the back-off depth,

the drill pipes will remain engaged in any case-if the back-off depth is less than 4000', and the drill pipes will never remain engaged for back-off depths more than 5000'. For smaller drill pipe "c" will be smaller and therefore

also the above values of "L".

Referring to question (1) of the "Introduce

tion" it is clear that one should never be tempted into varying the place of the neutral

point because even a great displacement of the n.p. results in a very small change of the value

of "a" only.

3 ) Energy Released During Back-Off.

As soon as the drill pipe unscrews, the mud rushes in ät the gap and pushes the loosened pipe upward. The energy released during the

process is equal to:

En = p.F.a

where: En = energy p = hydrostatic pressure at depth L

F = cross area of drill pipe a r= gap between pipes in position of equi-

librium after back-off.

"p" is proportional to the depth L, " a " is proportional to L^ so the energy is proportional

to the third power of the depth.

The potential energy incorporated in the sys-tem of free drill pipe is different f rom the energy in the system before backing off. The

difference is due to:

a) compression of drill pipe by the hydro-

static force p.F b) vertical displacement of the mass of drill

pipe in the gravitational field.

The total increase of potential energy of the system during backing-off amounts to 1 /2 p.F.a (Appendix 2). As the total energy re-leased* by the mud amounts to En = p.F.a.,

half of this energy is extra and must be de-stroyed by other means. This extra energy is

large enough to do serious damage to the threads as suggested in the second question of paragraph 1. Whether a situation can arise enabling to do this damage is discussed in the

next paragraph.

4 ) Movement of Drill P ipe in Vertical Direc-

tion after unscrewing.

It could be suggested that the extra energy initiates a shock-wave when the in-rushing mud hits the bottom of the backed-off drill pipe.

However, at the moment of unscrewing, the gap

between the pipes widens very slowly in com-parison with the speed of the mud which enters the gap at high pressure. There is no real col-lision and therefore no shock. All (or practi-cally all) the energy is used to push the pipe higher than its final position of equilibrium, thus initiating a (longitudinal) oscillation. This

oscillation is damped by the viscosity of the mud and the friction between the drill pipe and the wall of the bore-hole. The frequency of this

oscillation is low because of the great mass of the drilling string. The frequency is inversely proportional to the length of the free string and amounts to about 25 cycles per minute for a length L = 10,000'. (Formula in Appendix 3) .

51

The question of interest is whether the ampli-tude "e" of the oscillation is so great that the free pipe might approach the stuck pipe too close at the end of its downward travel and actually damage the thread (see fig. 4 ) . The study (Appendix 4) reveals that this situation does not arise: the ratio of amplitude to gap between pipes e/a proves to be less than 1 /5 and independent of the depth L. Only close to the surface the distance (a-e) is small enough to enable contact between the pipes ; in this case however the energy available to cause damage is very small (the energy being proportional to the third power of the depth.)

5 ) Backing Off in Drill Collars.

Due to the extra hydraulic pressure on top of the drill collars, the " jump" while backing off

and also the amplitude of oscillation will be greater. As far as the problems discussed in this article are concerned, backing off in drill collars does not bring a change in the con-clusions which have been found.

The problem which deals exclusively with drill

collars is the last one mentioned in the "intro-duction": counteraction of the hydrostatic pres-sure on top of the drill collars causing a too high tension in the drill pipe. Not much can be said about this problem except that the situation is not likely to arise when the drill collar diameter is less than 1 1 /2 times the drill pipe diameter and the depth is less than

10,000'. When in doubt, a simple calculation of the weight must be made and the value com-pared with the yield strength of the pipe (cor-recting for age of pipe, if necessary) to conclude whether the neutral point can be positioned safely at the back-off depth or not.

6 ) Conclusions.

The objections mentioned in paragraph 1 against increasing the pull on the drill pipe sufficiently to bring the neutral point down to the back-off depth are incorrect. On the con-trary, to ensure optimum conditions for a successful back-off operation the rule remains valid that the neutral point must be brought as close as possible to the back-off depth.

J. G. Doekes

APPENDIX 1

Gap between drill pipes af ter back-off ( s ee f ig. 2 ) .

PL Apply Hooke's law: a =

EF

a = gap in meters

P = force on bottom of loosened drill pipe, in kg L = back-off depth in meters

E = coefficient of elasticity of d.p. material, in kg/cm" F = cross area of d.p. in cm"

The force P = p.F, where p is the hydrostatic pressure at depth L. p. can be expressed as:

DL P = ^ ( T

If D (density of mud) is expressed in kg/dm^ and L in meters. Substitution in Hooke's law gives:

DL=

" lOE

The value of E is for steel: E = 2.1 x 10° kg/cm'' so

DL^'

21 x 10°

When a is wanted in inches, L is given in feet and D in Lbs./gallon, the formula (1) on page 2 is valid, which formula has been derived from the one above.

5 2

APPENDIX 2

Energy Balance of system of drill pipe.

Note: the units used in the computations of Appendix 2 and the following ones are;

Unit of length: 1 meter mass : 1 kilogram

force; 1 Newton Time; 1 second

1 ) Energy in system after back-off .

The nominal length of d.p. "L" refers to the length without any forces present from gravitation or otherwise. Please refer to fig. 5. The section dx undergoes the

influence of two forces, the weight of the bottom section-^, mg and the upward

hydrostatic force P = p.F. ("g" is the acceleration of gravity, equal to 9.8

m/sec^).

a) Stretch due to own weight less influence of force P.

Apply Hooke's law on section dx: Stretch de» = ( t «•= - ï " )

EF

L

f ( r ~ Displacement of section dx; ox — X EF

^ {U - x^) - P (L - x) or Cx = 2L

EF

Elongation for total pipe-length at bottom (x L) ;

mgL PL

~ W F ~ ËF (2)

b) Energy from elastic deformation due to own weight less influence of hydrostatic

force P.

Energy required for compressing section dx an amount d(ei) :

mg - P)^

dx ~ 2 EF

Energy in whole system:

L x' , 2 2mgP „2 L - 2 m g X —p X "1 ^ nisP

2 E F 2EF V. 3L L 0 0

m^gT mgPL P' L

" 6 Ë F ~ ^ Ë F 2EF {31

c) Potential energy from gravitational field.

Downward travel of section dx: = e«.

Energy in section dx; mg e«. X j

„ r 1 1 ( mg 1 rn 'g^L mgPL Energy ot whole system: I ex dx = — ^ 2 E F

0

d) Total energy after backing off absorbed in system: Formula (3) - Formula (4 ) :

^ ^ g T ^

"2 6EF 2EF

2 ) Energy in system before back-off .

The energy in the system before backing off can be derived from the formulae

for the energy after back-off by making the force P equal to zero. The total energy from formula (5) becomes

P _ m°g'L "1 ~ 6EF

3 ) The energy-increase due to the hydrostatic pressure is equal to

E„2 - (6)

The hydrostatic force P is constant, so the energy developed by the mud is equal

to P (Cj — e^), being the stretch of drill pipe before backing off:

^ D X . PL P=L Energy P X ^ ^

equal to twice the energy-increase in the system.

APPENDIX 3

Oscillation of Drill Pipe

Assumptions made:

1) No damping action present.

2) Oscillation of all particles of system are in phase.

3) All particles of the system oscillate with the same frequency.

In fig. 6 the forces are indicated which control the movement of section dx. These forces are:

1) constant forces viz. the weight ^ mg, a downward force ^ mg and an upward L L/

. X 4" dx force j- mg.

2) the varying forces of inertia Kx and Kx + <ix. In the computations the difference of those two forces, the resultant dKx will be used instead.

5 4

The deflection of dx from its position of equilibrium will be called "y" and the maximum deflection (the amplitude) e c. Assuming the oscillation to be harmonic

the following function is valid:

y =: ex sin«t

where <d = angular frequency of the oscillation t = time (in sec.)

Differentiating above formula gives

dy —;— — CxQ) COSa)t dt

d^y 2 .

and , „ = — enü) sinwt dt '

The law: "Force equal to mass times acceleration" applied on section dx is

dx d'y

TT ^

dx 2 and thus: dK m etm' sinwt -— — (7)

" L

To solve the relationships = f (x) and e^ = f (x) we consider the values of K* and ei at maximum deflection only. Therefore sinrnt = 1.

This is allowed as t is independent of x. We can therefore write formula (7) as follows:

(8) m«' dx

and the derivative is: ^ (9) dx mo) dx'

Hooke's law applied on section dx can be written as: de* = or

(10) dex Kx

dx " EF

Eliminating from equations (9) and (10) gives the equation: dx

I J l _ ^ - 0 EF m<ü' dx'

which equation can be solved by substituting Kx = K sinax (and = — a'Kx) dx

in which K is a constant (in fact K is the maximum value of Kx, occurring at the surface (x = L) . The Substitution gives the equation

I • = ^ J K smax = Ü VEF mm

r 1 lua' \ To satisfy this equation at all times, ( ==r : ) = 0 (11)

v-Lf mil) y

We assumed Kx to be equal to K for x = L as Kx is maximum at the surface. There-

fore sinax = 1 for x = L or sinaL = 1. This means aL = - ^ o r a The function

Kx = f (x) is found and proves to be:

Kx = K sin X . sinwt — — — — — (12)

The solution for function e« = f(x) can be found by substituting the derivative of equation (12) ;

dKn t tK TT —,— = cos X . smoit dx 2L 2L

in equation(8), giving the general equation:

t t K t t ei = — r; 5 c o s xï" X . sino)t

zmw 2L

If we call the maximum amplitude "e" (existing at x = 0 ) , obviously

7r ei = e cos x . smcut.

From the last two equations the relationship between e and K can be derived:

t t K

2m«,'

2KL or by elimination from eq. (11) and (13) : e =:

TTEF

(13)

Substitution of the value a — ~ in equation (11) provides a formula for the

frequency of the oscillation:

f — - ^ - 1 = 0 V EF 4mL«V

the angular frequency is w = ~ times the normal frequency.

1 A / E F ' Oscillation frequency: —r\ — c y c l e s / s e c o n d

4 V mL

where :

E = coefficient of elasticity 2.1 lo' Newton/cm" for steel.

F cross area of drill pipe in cm^.

m = mass of drill pipe L meters long, in kgs.

L = length of drill pipe.

APPENDIX 4

Computation of Ampl i tude "e".

Method of computation:

The potential energy incorporated in the system of drill pipes while at maximum

deflection is compared with the energy being in the system while in position of

equilibrium (that is, the final position after the oscillation has been damped). The

difference between those two energies must be equal to the extra energy available P T

at the moment of backing off = — ^ (equation 6) . 2LF

1) Forces in cross section at dx are (fig. 6) :

a) Hydrostatic force F

b) Weight mg

c) Force f rom inertia: Kx = K sin ^ x. (sinwt = 1 at max. deflection)

5 6

Considering the section dx to be deflected upward with the maximum amplitude,

the resultant of the forces stretching section dx is equal to

X T, i r • - mg - P - K sm ^ X

2) Movement of section dx. x _ „ . tt ^ mg — P — K s i n ^ X

Hooke's law for dx: d(ex) =; g p dx

L

— e f ( Movement e^ = / d(ei) = (L'' — x'') — P ( L — x) —— cos ^

x

3) Energy from elastic deformation due to resultant force.

Energy for stretching section dx:

dEn =

mg - P - K s i n ^ x)= dx

2EF

Energy for whole system: En = J dE» 0

_ 1 f f m ' g ~ 2EFJ\ r

o

g* 2 2mgP 2 r>i • . IT x — Ï X + P PK X — — X sm

O

1 r mY

2EF L 3L''

L

L

mgP

+ i

, , „PKL TT , mgK 2L X + P X — 2 cos X —J X cos

TT ZL> I j TT ZLi

L

. ) | +

0

+ i è r / ( - ^ 2mgK TT , K

e o s ^ - x + - - i ^ - c o s - ^ x I d x 0

1 m ' g ' L , 2 4 m g K L . tt = - w i t I 1 + P T + P K L ^ sm X

2EF V 3 t t 77 2L + X +

0 0

K ' L . ,r

^ X " ) =

o 1 ^

2EF V 3 e - r P L K

4mgKL K'L 9. J '

4) Potential energy from gravitational field.

dx Energy of dx:dE..

L,

mg ex. Total energy for whole system En = j dEn =

0

mg

EFL • G l r " ' 0

m^g^L mgPL

3EF 2EF

x=) — p (L — x)

4mgKL

tt' EF •

2KL cos ^ x ) dx =

57

5) Total energy in top position: (3) — (4) :

m V L 2 m g K L P=L P K L K=L

6 E F + t t ' E F + 2 E F + TTEF 4 E F "

6) Energy in system in position of equilibrium (eq. 5) amounts to

„ m ^ g ' L , ?'L = +

6EF ' 2EF

7) The energy-increase when pipe moves from zero to maximum deflection is:

2mgKL , PKL , K T , . , , , P T , ^^EF + ^ ^ E F + " 4 Ê F " 2ËF

therefore:

K — 2P' z=z 0 V t t TT y

Because the equation is quadratic, two values are found for K. The bigger one

of the two has no practical meaning as far as this problem is concerned. The smaller of the two values is equal to :

The value of the amplitude at the lowest point of the drill pipe is found bv eliminating K from the above formula and the one found on page 8:

— 2KL ® ~ ttEF •

To simplify the formula further, the following substitutions are made:

P = gDFL and m = SFL where

g is expressed in m/sec^ (and has a numerical value of 9.812)

D (mud density) is expressed in kg /m' (for water D = 1000)

F expressed in m ,

L expressed in m

S is the density of the drill pipe material, including a correction factor for the extra volume of the tool joints. Therefore S = 8700 kg/m".

The formula for the value of "e" becomes:

" = + ? ) -

N.B.: The same values for "K" and "e" would have been found if the computa-

tions had been carried out for the system of drill pipe being in its lowest

position while oscillating.

8) The relationship between amplitude of oscillation and gap between stuck and

backed-off drill pipe emerges when the last equation of paragraph 7 is compared with the one for the gap: a = gDLVE (values expressed in the same dimensions as mentioned in paragraph 7 ).

e 4 8S , ^ 8S ^ + ^ r +

a t t ' D V V w' TT'D

For mud density D = 1000 kg/m' (clean water), eja = .17 For mud density D = 1500 kg/m'' e / a = .20

58

i J J un

t a/I

FIG. 1 : Tension in pipe before back-off

FIG. 2: Tension in pipe

after back-off

FIG. 3

/ / / / / / / /

~n

/ / / / / m g

dx

^ m g /

Constant Variable

Forces Forces

X -|- dx

FIG. 4 FIG. 5 FIG. 6: Forces on a small

section dx.

5 9

i

INTERCOM INDEX

A

ABADIE, 43

ADAMSON, 49-51

B

BABOIN, 6-7

BACCOVICH, 22, 42

BARBAUT, 42

BENNET, 52

BERGER, 9

BERNARD, 42-43

BONSERGENT, 47

BOTH, 48-49

BOUCAU, 42

BURTIN, 44

C

CLARET, 42

CLAUSS, 43

COLIN, 44

CONRAD, 43

D

DANIEL, 42-43

DAVID, 47

DAY, 12, 22, 41-42

DE LABACHELERIE, 44

DE PEYRONNET, 43

DE VERTEUIL, 22

DELANNOY, 42

DELESSERT, 42

DEMOUSTIER, 38, 42

DENIS, 44

DOEKES, 5, 56

DOUET, 43

ii

INTERCOM INDEX

DROULERS, 22

DUCOMTE, 43

DUDMAN, 43

DUNLAP, 44

E

ENSELME, 15

F

FARROW, 43

FELDMAN, 52

FIQUET, 42

FORD, 42, 49

FRASER, 29

G

GARCIA, 44

GARTNER, 44

GAYMARD, 44

GEORGE, 50

GIRAUD, 42

GOOD, 42-44, 50

GOURP, 43

GRIMAUD, 42

GROSMANGIN, 5, 38, 44

H

HEAD, 42, 44, 50

HEATH, 43

HENRY, 44

HOUSTON, 44, 47

HUNT, 50

HUSBAND, 49

I

IRVING, 49

J

JAMES, 44, 48

JAN, 5

JOB, 8, 43-44

JOUANIN, 44

K

KORN, 44

iii

INTERCOM INDEX

L

LAW, 15, 54, 56

LEHMANN, 43

LELEU, 44

LESTER, 43

LEVEAUX, 43

LO, 60

LONG, 6, 15, 22, 42, 44, 50, 60

M

MASSENTI, 42-43

MEUNIER, 44

MICHEL, 42

MILLER, 22

MOORE, 43

MOREAU, 44

MOSELEY, 42

N

NEWTON, 60

NILES, 42

NORTH, 44

P

PIJEAUD, 43

PINE DES GRANGES, 42

R

RAT, 54

RENAULT, 44

REYNARD, 42

ROGER, 43

ROLAND, 43

ROSE, 48

ROUND, 9, 41, 48

ROY, 43

S

SIMON, 44, 48

SPEED, 55

STEEL, 56, 60

T

TAN, 12, 42

TAYLOR, 43

TONGUE, 52

TONS, 15

TRUE, 42-43, 49

iv

INTERCOM INDEX

V

VISAGE, 43

W

WAWRZENITZ, 43

WAY, 43, 49-50

WHITE, 49