The Corrosive Well Waters 

of Egypt's Western Desert

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1757-O

Prepared in cooperation with the 

Arab Republic of Egypt under the 

auspices of the United States 

Agency for International Development
The Corrosive Well Waters 

of Egypt's Western Desert

By FRANK E. CLARKE

CONTRIBUTIONS TO THE HYDROLOGY OF 

AFRICA AND THE MEDITERRANEAN REGION

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1757-O

Prepared in Cooperation with the 

Arab Republic of Egypt under the 

auspices of the United States 

Agency for International Development

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1979
UNITED STATES DEPARTMENT OF THE INTERIOR 

CECIL D. ANDRUS, Secretary

GEOLOGICAL SURVEY 

H. William Menard, Director

Library of Congress Cataloging in Publication Data

Clarke, Frank Eldridge, 1913 

The corrosive well waters of Egypt's western desert.

(Contributions to the hydrology of Africa and the Mediterranean region) 

(Geological Survey water-supply paper; 1757-0)

"Prepared in cooperation with the Arab Republic of Egypt, under the auspices of the United States Agency for International Development."

Bibliography: p.

Includes index

Supt. of Docs. no. : I 19.16 : 1757-0

1. Corrosion resistant materials. 2. Water, Underground Egypt. 3. Water

quality Egypt. 4. Wells Egypt Corrosion. 5. Pumping machinery Corrosion. I. United States. Agency for International Development. II. 

Title. III. Series. IV. Series:

United States. Geological Survey. Water-supply

paper; 1757-0.

TA418.75.C58 627'.52 79-607011

For sale by Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402

Stock Number 024-OOL-03234-1
CONTENTS

Page

Abstract ___________________________________ Ol

Introduction _______________________________________________ 3

Acknowledgments ________________________________ 3

Environmental setting __________________________ 5

Evolution and design characteristics of Western Desert wells _____ 9

Corrosion observations and investigations ____________________ 10

Quality characteristics of New Valley well waters ___________ 33

Causes of corrosion _______________________________________ 41

Control of corrosion ________________________________________ 47

Pumps and their problems ________________________________ 50

Opportunities for further study ________________________ 53

Summary ______________________________________ 53

References _____________________________________________ 54

ILLUSTRATIONS

FRONTISPIECE. Flowing well, Kharga Oasis, 1961 ___________ VI

FIGURE 1. Map showing principal features of Egypt's Western

Desert and the boundary of the New Valley Project __ O2

2. Site and well location map, New Valley area, Egypt's

Western Desert __________________________ ____ 5

3. Macrograph of Nubian sandstone showing loosely cemented angular grains, X 34 ___________ _ __ 6

4. Sketch of native well drilling equipment ____ ____ 8

5. Photograph of Acacia wood casing from native well,

Kharga Oasis ____________________ _______ 9

6. Photograph of perforated elbow, Mut well 1, Dakhla

Oasis ______________________________________ 14

7. Photograph of severed screen bridge, Kharga well 1A,

Kharga Oasis, X 4.6 _______________________ _ 16

8. Photograph of corroded discharge line, Kharga well 1A,

Kharga Oasis _____________________ _ ___ _ 17

in
IV CONTENTS

Page

FIGURE 9. Photograph of surface line corrosion specimen?, Kharga

well 1A, Kharga Oasis ___________________ 017

10. Sketch of stainless steel stress corrosion specimen used

in Kharga well 1A __________________ ____ 18

11. Photograph of subsurface pitting, Kharga well 1A, x 5 19

12. Photograph of white corrosion tubercles, aluminum specimen, Kharga well 1A, x 1 --- ____________ 20

13. Photograph of corroded bridge-slotted screen, after 2-

year exposure, Kharga well 1A ___________--- 21

14. Photograph of downhole corrosion specimen string, Mut

well 2, Dakhla Oasis _____________________ 22

15. Photograph of deep, deposit-free corrosion, steel specimen,

Mut well 1, Dakhla Oasis, x 7 _______________ 23

16. Photograph of severely corroded bridge-slotted steel specimen from down-hole string, Mut well 2 ___________ 24

17. Photograph of corroded aluminum specimen from downhole string, Mut well 2 _________-_______- 25

18. Photograph of undamaged stainless steel screen specimen,

surface line, Mut well 1, X 5 _.________________ 26

19. Photograph of slightly corroded Monel Metal specimen

down-hole string, Mut well 2 _______-______ 27

20. Photograph of Mohammed Shaaban, Egyptiar General 

Desert Development Organization, operating a corrosometer, Kharga well 1 _____________________________ 28

21. Photograph of corrosion probe and shield ____________ 29

22. Photograph of corroded steel probe wire, Baris well 11,

Kharga Oasis, x 12 ____________________ 30

23. Corrosion rate curves, Kharga Oasis wells ___________ 32

24. Corrosion rate curves, Dakhla Oasis wells ____________ 33

25. Photograph of etched aluminum probe, Kharga well 1A,

X 10 _________________________________ __- 34

26. Photograph of corroded aluminum probe, Nass^r well 1,

X 11 -_-_______________________________ 35

27. Photograph of Hassan Mostafa, Egyptian General Desert 

Development Organization, and the late Paul Bieber, 

U.S. Geological Survey, measuring bicarbonate ion in 

water from a Kharga Oasis well, 1962 _________ 36

28. Photograph of flow cell for measuring Eh ___________ 37

29. Trilinear diagram showing ionic balances of New Valley

well waters __________________________ 41

30. Graph showing relation of sulfochloride concentration to

corrosion rate ________________________________ 44

31. Stability field diagram, ferric and ferrous species, assuming 2 X 10~7 molal activity of iron and based on 

Fe(OH) 3 _________________________________ 45

32. Graph showing relation of calcium carbonate equilibrium

to corrosion rate ____________________________ 46

33. Photograph of key-lock joint, fiberglass well pipe ______ 49

34. Photograph of Kanat at nonflowing well, Kharpa Oasis__ 51
r.

FRONTISPIECE. Flowing well, Kharga Oasis, 1961.
CONTENTS

TABLES

	Page

TABLE 1. Well obstruction and self-potential data _________ 012

2. Redox potential (Eh) and geotrode data, Kharga Wells 13

3. Long-line current data, Kharga wells ___________- 14

4. Water-quality data, selected New Valley wells ____ 38

5. Gas composition, selected New Valley wells -___-__ 40

6. New Valley wells being pumped, 1976 ____________ 52

CONVERSION FACTORS

Factors for converting from International System of Units (SI) to Inchpound units are given below to three or four significant figures. However, 

in actual conversions, inch-pound equivalents should be determined only to 

the number of significant figures consistent with the SI counterparts.

SI UNIT MULTIPLY BY

millimeter (mm) 0.03937

centimeter (cm) 0.3937

meter (m) 3.281

square kilomter (km 2) 0.3861

million cubic meters (Mm s) 810.80

cubic meters per day (m Yd) 35.30

centimeter per second (cm/s) 0.0328

degree Celsius ( ° C) 9/5 ( ° C)+32

metric ton (t) 1.10

= INCH-POUND

inch (in)

inch (in)

foot (ft)

square mile (mi 2)

acre-feet (acre-ft)

cubic feet per day (ft s/d)

foot per second (ft/s)

degree Fahrenheit ( ° F)

short ton, (2,000 Ib)
CONTRIBUTIONS TO THE HYDROLOGY OF AFRICA AND 

THE MEDITERRANEAN REGION

THE CORROSIVE WELL WATERS OF 

EGYPT'S WESTERN DESERT

By FRANK E. CLARKE

ABSTRACT

The discovery that ground waters of Egypt's Western Desert are highly 

corrosive is lost in antiquity. Inhabitants of the oases have been aware of 

the troublesome property for many decades and early investigators mention 

it in their reports concerning the area. Introduction of modern well-drilling 

techniques and replacements of native wood casing with steel during the 20th 

century increased corrosion problems and, in what is called the New Valley 

Project, led to an intense search for causes and corrective treatments. This 

revealed that extreme corrosiveness results from combined effects of relatively acidic waters with significant concentrations of destructive sulfide 

ion; unfavorable ratios of sulfate and chloride to less aggressive ions; 

mineral equilibria and electrode potential which hinder formation of protective films; relative high chemical reaction rates because of abnormal temperatures, and high surface velocities related to well design.

There is general agreement among investigators that conventional corrosion control methods such as coating metal surfaces, chemical treatment 

of the water, and electrolytic protection with impressed current and sacrificial electrodes are ineffective or impracticable for wells in the Western 

Desert's New Valley. Thus, control must be sought through the use of materials more resistant to corrosion than plain carbon steel wherever well 

screens and casings are necessary. Of the alternatives considered, stainless 

steel appears to be the most promising where high strength and long-term 

services are required and the alloy's relatively high cost is acceptable. Epoxy 

resin-bonded fiberglass and wood appear to be practicable, relatively inexpensive alternatives for installations which do not exceed their strength 

limitations. Other materials such as high strength aluminum and Monel 

Metal have shown sufficient promise to merit their consideration in particular locations and uses. The limited experience with pumping in these 

desert wells leaves uncertainties concerning the durability of conventional 

pump designs.

Egypt's New Valley Project provides an excellent opportunity for continuing study of the corrosion problems that concern ground-water developers in many parts of the world.

01
02 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

25° 30° 35°

MEDITERRANEAN SEA

SaHum 

(AsSalturn)

Mersa Matruh 

(Matruh)

Siwa Oasis 

(Wabat Siwa) Qattara Depression

unkhafa^ al QaJJarah)

Beni Suef 

(Ban! Suwayf)

Bahariya Oasis 

(Al Wabat al Bahriyah)

Farafra Oasis 

(Wahat al Farafirah)

Dakhla Oasis 

(Al Wahat al 

Dakhilah)

Kharga Oasis

(Al Wabat al

Khariiah)

Boundary of area 

under investigation

100 100 200 KILOMETERS

100 0 100

I 

200 MILES

Names and boundary representation are not necessartty* authoritative. Asterisk (*) preceding name, name is not verified by BGN. Dagger (t) 

preceding name, name is conventional name form; name following in 

parentheses is native name form.

FIGURE 1. Map showing principal features of Egypt's Western Desert and 

the boundary of the New York Valley Project, Modified from Ezzat (1969).
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 03

INTRODUCTION

Ground-water development in the New Valley Project of 

Egypt's Western Desert, like that in many other parts of the 

world, has been troubled by serious corrosion of metal casings, 

screens, pumps, pipes, and fittings. Over the years there have 

been numerous observations and investigations of this problem 

and various theories and remedies have been proposed in rdministrative documents, open-file reports, and other communications. 

This report summarizes such work to 1977, including that of the 

author during the period 1962-64. It discusses corrosion control 

in the light of theory and operational experience with the objective of providing useful background information for all who may 

have such problems. Although the observations were confned to 

wells in Kharga and Dakhla Oases depressions, corrosiveness is 

likely to be a problem in other parts of the Nubian aquifer underlying the Western Desert.

The site and well location maps (figs. 1 and 2) provide official 

translations from Arabic to English terms, as approved by the 

U.S. Board on Geographic Names (BGN). The official (BGN) 

name is shown in parenthesis. Names have been obtained from a 

variety of sources. Only the English terms are used elsewhere in 

the text, tables and illustrations, consistent with recent practice 

in U.S. Geological Survey publications dealing with Egypt. Names 

preceded by an asterisk (*) have not been verified by the Board 

on Geographic Names.

ACKNOWLEDGMENTS

The well-water studies discussed in this report were made in 

cooperation with the Egyptian General Desert Development Organization (EGDDO) under the auspices of the United States 

Agency for International Development (USAID). The references 

contain the names of many individuals of both organizations who 

provided valuable background information and assistance. General H. Sobieh, Hussein Idris, Mohammed Ezzat, Moussa Seddik, 

Hassan Mostafa, Mohammed Shaaban, and George Fal:my of 

EGDDO, and Herbert A. Waite, Raymond W. Sundstrom, the late 

Paul Bieber, Robert V. Cushman, and Joseph S. Gates of USGS/ 

USAID, in particular, spent much time in field work or related 

discussions.

Valuable assistance in analysis of samples or data also was 

received from my associates William Back, Ivan Barnes, Edward 

J. Dwornik, Herman R. Feltz, Blair F. Jones, and James R. Jones 

all of the U.S. Geological Survey.
O4 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

ENVIRONMENTAL SETTING

The Western Desert of Egypt extends from the northern margin of Qattara Depression and Siwa Oasis to the border of the 

Sudan and from the western edge of the Nile Valley to the Libyan 

border. Its area is approximately 685,000 square kilometers (km2 ) 

or about 68.5 percent of Egypt's total area. As shown in figure 1, 

a series of topographic depressions, thought to be tlis combined 

effect of wind and water erosion, extend diagonally southeastward 

from Siwa Oasis just north of latitude 29°, through the Oasis of 

Bahariya, Farafra, Dakhla, and Kharga to near where the Nile 

River crosses the northern boundary of Sudan. The heads and 

flanks of these lows are bounded by escarpments which rise to 

300 or 400 meters (m) above sea level. Their floors slope gently 

southeastward with subdepressions as low as 0.8 m above the sea. 

According to Ezzat (1974) mean daily temperatures in this 

southern part of the desert, known as the New Valley and covered 

by this study range, from 13°C in January to 31°C in July and 

temperatures may reach 49 °C or more. Rainfall averages only 1 

millimeter (mm) per year according to official records although 

infrequent intense storms are known to occur. Despite the arid 

climate, villages and supporting wells are scattered throughout 

the New Valley area as shown in figure 2.

The entire Western Desert is thought to be underlain by a 

thick sequence of waterbearing strata (aquifers) consisting of 

sand and sandstone, interbedded at places with shale, mudstone, 

and chalk. Loosely cemented angular sands like those of figure 3 

constitute part of the sandstone. This series, collectively called the 

Nubian aquifer (Jones, 1967), rests on a Precambrian basement 

of granite and gneiss which outcrops on the east flank of the Ennedi, Erdi, and Tibesti Mountains at the southwest extreme of 

the desert, outside of Egypt. The Nubian aquifer slopes at a 

gradient of 1/2,000 to the northeast and is capped, except in the 

depressions, by shales, chalks, and limestones of upper Cretaceous, 

Paleocene, and Miocene ages. The sand and sandstone components, 

which constitute about 30 percent of the reservoir are nonfossiliferous and thus undated, but are thought to range from upper 

Cretaceous at the top to Cambrian at the bottom.

Thickness of the Nubian aquifers varies throughout the desert. 

It averages about 300 m in North Kharga Oasis and is as thick as 

1,500 m in South Dakhla Oasis. The upper surface ranges from 

50 m to several hundred meters below land surface, and artesian 

pressures as great as 157 m above sea level and 50 m land surface have been reported (Cushman and Gates, 1967). Numerous
26°2 29° 30°

25°

Mahariq 

Al Mahariq;

Rashda 

(Ar Rashidah)

Masara 

Al Ma'$arah) Mahariq 2\ *Hepus 

Temple

Kharga 1A

Kharga 1 B Gidda [Gedidah] (Al Jadldah)

Rashda 2 

Mut 2 

Mut 1

Garmashm 1 

('Ayn Jarmashfn) Dakhla Oasis UA1 Wahat al Dakhilah)

(Al Wahat al Kharijah)

Rase from U.S. Geological Survey

Series 1301, Scale 1:1000000, I960, and

Series 1401, Scale 1:500000,1960

EXPLANATION

Well with name and number

Form line, ticks indicate depression. 

Number is altitude in meters 

above mean sea level

11111111111111

Escarpment or cliff

Road, hard surface, all weather, two 

lanes

Road, loose surface, all weather

Mut 

,(Mut)

Populated area, with name. Name in 

parenthesis is BGN name

Spot elevation above mean sea level, in 

meters

Names preceded by asterisk 

are not verified by BGN.

FIGURE 2. Site and well location map, New Valley area, Egypt's Western Desert. O en
06 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 3. Macrograph of Nubian sandstone showing loosely cemented

angular grains, x 34.

opinions exist concerning the source and extent of recharge to 

this subsurface reservoir. However, it is generally agreed that, 

whatever the source, there is a vast amount of water. Hellstrom 

(1940) estimated water movement under Kharga and Dakhla at 

15 m per year and concluded that at that rate it took 50,000 years 

to traverse the distance between the nearest rainfall areas and the 

oases, a period later confirmed reasonably well by carbon dating 

that indicated 25,000 years "travel time" for Dakhla Oasis and 

50,000 years for Siwa Oasis. Ezzat (1974) calculated the rate of 

water movement to be 156 m per year and concluded that the 

storage beneath Kharga and Dakhla Oases is sufficient to provide 

1,280 million cubic meters (Mm3 ) of water annually for 200
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O7

years. He also concluded that the rate of movement through the 

entire Nubian section is 27 m per year. Burdon and Pavlov (1959) 

estimated the annual infiltration rate and practicable yield at 

17,000 Mm3 , a virtually inexhaustible supply in the kinds of development likely to be undertaken the Western Desert. Even if 

recharge and natural movement are insignificant there obviously 

is a great amount of water available in such a large amount of 

water-bearing earth material. The latest estimate is that 2,500 

MmVyr can be withdrawn at practicable pumplift (Ezzat, 1978). 

There is evidence that humans have inhabited the desert depressions and utilized water from the Nubian aquifer and other 

sources over a great period of time. Waite (1962) discussed sedimentary evidence of a post-Pleistocene lake which covered some 

of the Kharga Oasis depression and may have stood at 65 to 70 

m above sea level when Darius II revised Hepus Temple about 

423 B.C. near the present village of Kharga. Ball (1900) mentioned a spring of perched water which still exists 260 m above 

sea level on the scarp to the east and 180 m above the village 

of Baris in South Kharga Oasis. Inscriptions nearby suggested 

that this spring was used by the Coptic Christians who migrated 

to the desert during the fifth century A.D. Nubian ground water 

probably discharged at occasional natural springs coincident with 

geologic faults; perhaps the flow amounted to the several tens of 

thousands of ms/d suggested by Cushman and Gates (1967). Although there is no longer any physical evidence of such natural 

leaks, it is clear that desert cultures expanded around them. The 

Roman Admiral Scylox is reported by LaMoreaux (1962) to have 

developed extensive irrigation in Kharga Oasis including underground transfer systems (kanats) some 2,500 years ago near 

Hepus "city of the plow." Ball (1900) states that Bishop Nestorius practiced irrigation in the Christian settlement in Kharga 

Oasis in the early 400's A.D.

The exact manner of constructing the earliest Western Desert 

wells is unknown but it seems likely that the ancient method described by Beadnell (1901), and others was used from the time 

of the Roman occupation to the appearance of relatively modern 

percussion drilling machinery in the desert about 1860. This consisted of a palm log frame 2 m square sunk by hand 50 m or more 

to the bottom of the surface clay and a central acacia wood casing 

of similar depth and 35 centimeter (cm) inside diameter. The 

two members were separated by a tightly packed filling of earth 

material. In later years the depth of the frame and upper casing 

were reduced to about 30 m and a smaller water conducting pipe
O8 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

made of hemicylindrical sections of palm or acacia was sunk to 

the base of the surface clay. How the deeper drilling was accomplished in the early days is unknown; however, Beadnell's report 

illustrates drilling equipment which must have been quite similar 

to that used. (fig. 4). The same kind of native drilling rigs and 

casings of unknown age (fig. 5) were observed by the writer in 

1962.

Parts of boring-plant used in Dakhla Oasis

1. Heavy timber framework with pulley wheel

2. Windlass

3. Beam for lifting and dropping whole length 

of rod during boring

4. Rods. 4 a. Enlarged junction of 

two (not to scale.) 4 b. Cutter

5. Auger

FIGURE 4. Sketch of native well drilling equipment. From Beadnell (1901).

Improvements in drilling techniques ineviably led to construction of more wells, sometimes to well interference and the loss of 

some flowing wells and productive land. Early investigators of 

these problems (for example, Ball and Beadnell) correctly surmised that deeper wells might tap other, perhaps more productive 

aquifers. Such studies eventually led to modern drilling, steel well 

components, and an increasingly troublesome problem corrosion.
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O9

FIGURE 5. Acacia wood casing from native well, Kharga Oasis.

EVOLUTION AND DESIGN CHARACTERISTICS OF 

WESTERN DESERT WELLS

Although Beadnell (1901) mentioned 162 new wells in Dakhla 

Oasis, his report, like that of Ball (1900), indicates little improvement during the 19th century in either boring equipment or well 

design over primitive practice. More advanced percussion drilling 

equipment and metal well components, in lieu of wood, were introduced during the first half of the 20th century. Little and 

Attia (1942), mentioned the reported presence of a rig in Kharga 

Oasis capable of drilling to 750 meter depths, presumably in 

search of deeper water. The same report expressed views on the 

increasing use of steel casing and the corrosion problems likely 

to follow.

It would appear from a discussion of well collapse by Paver 

and Pretorius (1954) that early steel-cased wells were constructed 

without external cementing. More recent deep wells in the desert 

have casings which are cemented above the water-bearing formation and a down-hole construction sequence which includes 15 m 

of 12% to 143/4 in. (31-36 cm) diameter surface casing, 8% to 9% 

in. (21-23.6 cm) intermediate casing to screen height and 6% 

in. (16.25 cm) screen (filter pipe). Boreholes are sufficiently large 

to provide annul! of 2.5-7.5 cm for cementing around the cas-
O10 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

ing. Of the 255 screened wells studied by Cushman and Gates in 

. 1967, 131 had screens of mild steel, 56 of aluminum, 36 of stainless steel, 12 of wood, 5 of fiberglass, 3 of unreinforced plastic; 

and 30 were operating with no screens at all. Screen pattern and 

openings included horizontal-slotted wood, fiberglass and plastic, 

drilled and bridge-slotted mild steel and aluminum, and both wirewrapped and louvered stainless steel. It is common practice to use 

christmas-tree well heads, like those employed in the oil industry, 

together with concrete sumps and weirs.

Although some of the desert wells initially yielded more than 

14,000 m3 /d and flowed considerably above ground level, it is 

generally agreed that their relatively small diameters are not ideal 

for optimal production. In fact, Cushman and Gates (1967) found 

that efficiencies ranged from 20 to 50 percent of that theoretically 

obtainable. Small diameters increase linear velocity in the casing 

and screens with attendant adverse effects discussed later in the 

report.

Over the years there have been recurrent reports of declining 

pressure and yields in the desert wells as drilling progressed and 

these effects have been more pronounced since intensive development started in 1959.

CORROSION-OBSERVATIONS AND INVESTIGATIONS

The general corrosiveness of Western Desert well waters has 

been known for a very long time and reported either directly or 

indirectly by virtually everyone who studied the oases since the 

turn of the century. There is consistent reporting of iron stains 

in discharge channels and of the odor of hydrogen sulfide even in 

ancient wells. Both indicate anaerobic water and suggests its capacity for converting iron components of aquifer materials to 

soluble form. The reports of Beadnell (1901), Little (1926 and 

1931) and Little and Attia (1942) indicate that inhabitants of 

the desert have been aware of the water's corrosiveness since 

ancient times. The following account by an unidentified investigator, Buckley (1908), in the report by Little and Attia (1942) 

would appear to indicate that this knowledge stems in part from 

experience with early well maintenance problems:

It seems to be doubtful whether the employment of metallic 

tubes as casings would be advisable. The natives declare that 

any piece of iron used in the wells invariably becomes corroded 

in a very short time. At one period they began to strengthen 

their casings by binding them with hoop irons such as those 

used in making up cotton bales but they had to abandon this on
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT Oil

account of the excessive oxidation of the iron. They declare 

that rods which have been left in a well for a few months have 

become corroded; that any iron nails driven into the casings 

perish almost immediately and that it is for this reason that 

they are obliged to fix the two halves together by means of 

timber dowels. (See fig. 5.)

In the report which contained the quotation cited above, the 

view was expressed that corrosion problems would be encountered in using ordinary steel casings.

Paver and Pretorius (1954), who appear to have been the first 

to study desert well corrosion in any detail, mention serious metal 

loss in the upper casings of Gina well 2 of Kharga Oasis after 

only 6 months of operation and stated that significant attach was 

apparent in a pipe used for cleaning Qara well 1 in Dakhla Oasis 

after only one week of immersion. They described the mode of 

attack on steel accurately as the formation of a black film on the 

metal surface and development of a deposit which gradually eats 

into the metal, flakes it off, and yields serious pitting. These same 

effects were observed by the author and pictured in his repcrt of 

1963 (fig. 11). Paver and Pretorius attributed the collapse and 

obstruction of certain desert wells to perforation of metal casings 

and resulting intrusion of formation materials or erosion of the 

casings by high pressure leakage. They apparently made no measurements to determine how much corrosion and obstruction contributed to the observed reductions in flow. They did, however, 

make self-potential logging measurements on a number of obstructed and unobstructed wells, including some cased in whole 

or in part with wood, by observing the difference in electrical 

potential between a nonpolarizing electrode in "a fixed ground 

position" and a movable electrode within the well. The resulting 

data in table 1 show values above what they termed ncrmal 

ground potential of 140 millivolts (mV) for all but the wood-cased 

holes. From this they concluded that the steel tubes were corroding over their entire lengths. Although such measurement between a nonpolarizing electrode near the well and a sliding electrode within the casing is primarily an indication of external 

corrosion potential, their conclusion that serious corrosion was in 

progress was sound.

Fahmi (1956), who approached the problem primarily from 

theoretical considerations based on knowledge of water quality, also concluded that plain mild steel would corrode rapidly. 

He .accurately predicted that aluminum, stainless steel and Monel 

Metal would be significantly more resistant. On the basis of this 

assessment he recommended aluminum and galvanized steel as
012 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

TABLE I. Well obstruction and self-potential data

[Modified from Paver and Pretorius, 1954. J

Well 

designation

Deep wells:

Kharga Oasis

(steel casing)

Ginah 2

Bustan

Faruqiya

Qara

Borg

El Mahariq

Dakhla Oasis

(steel casing)

Budkhulu

Qara 1

Qara 2

Gedidah

Qalamun

Faruqiya

Ismant 1

Completion 

date

1952

1950

1939

1939

1940

1947

1941

1947

1943

1940

1940

1940

1951

Percentage 

decline 

in flow *

Nil

62

69

77

41

40

100

58

64

66

84

69

Nil

Depth to 

obstruction, 

(m)

No

obstruction

248

350

412

348

432

42

2

2

110

118

Collapsed

No 

obstruction

Casing 

depth 

(m)

200

457

470

507

497

492

240

Unknown

221

259

249

233

20?

Selfpotential 

(mVi

740

850

910

770

800

760

800

___

___

800

820

___

830

Shallow wells:

Dakhla Oasis

El Adion

(wood casing) _ __ _ _--

Abdl Latif

(wood casing) _ _ _ __- ---

Abdl Latif

(steel casing) ____ ___ ---

80

35

125

140"

140"

600

* Combined effects of corrosion and other hydrologic factors. 

" Normal ground potential.

practicable alternative construction materials. Burdon and Pavlov 

(1959) also were aware of the waters' serious corrosiveness and 

stated that a solution to the problem must be found1 before largescale well development began in the oases.

Sudrabin (1962), an American corrosion consultant to the New 

Valley Project, examined a number of wells in Kharga Oasis and 

reported after examination of corroded steel screen parts and 

discharge pipes that damage is more severe on internal surfaces 

and that hydrogen sulfide and carbon dioxide are the principal 

corrosive agents, the latter's effect possibly being increased by gas 

release due to pressure drop across the screen openings. Sudrabin
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O13

TABLE 2,. Redox potential (Eh) and geotrode data, Kharga zvells

[From Sudrabin, 1962. J

Well 

designation

El Kharga 1

El Kharga 1A

Baris 2

Eh

(mV)

+ 16

+ 12

+ 76

Potential of discharge pipe 

against copper sulfate 

electrode, ( mV )

-811

___

- 774

stated, on the basis of water data compiled by the Desert Institute, particularly for the carbon dioxide, iron, and calcium carbonate saturation values, that more corrosion might be expected 

in Dakhla than in Kharga Oasis, a view also expressed by Paver 

and Pretorius (1Q54). Tests performed during the Sudrabin survey by Dr. Gregory Jann, Fulbright professor at Ein Shams University, showed no evidence that hydrogen sulfide was resulting 

from active bacterial sulfate reduction within the wells.

Sudrabin measured electrical potentials between an inert platinum electrode and a copper sulfate reference electrode immersed 

in certain Kharga Oasis well discharges and between the same 

copper sulfate electrode and a probe (geotrode) contacting the 

submerged internal surfaces of the discharge pipes. The first measurement, when corrected for reference-electrode potential, indicates voltage differentials in terms of the standard hydrogen electrode and is commonly referred to as the Eh value. The second, 

which is read directly without reference-electrode correction, also 

indicates oxidizing or reducing environment and therewith a probability for either retention or destruction of protective oxide 

films. The data in table 2 indicate reducing conditions which 

would promote metal loss.

As final checks, Sudrabin measured long-line potentials produced 

by coupling both nearby and remote buried copper sulfate reference-electrodes with the well heads. He also performed well-casing 

polarization tests by applying a series of increasing currents (that 

is, amperage) to well heads and measuring residual potential 

against a copper sulfate electrode after interruption of each successive current application.

From the long-line current data (table 3), he concluded that 

aluminum screen as well as iron casing was udergoing corrosion, 

the former because of direct coupling to the iron. He interpreted 

the polarization data as indicating more than one transition in 

electro-chemical process within the casing. This study, like earlier 

ones, pointed to the need for better construction materials.
O14 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

TABLE 3. Long-line current data, Kharga wells

[From Sudrabin, 1962.]

Well 

designation

El Kharga 1

El Kharga 1A

Baris 9

(150 m depth)

Baris 9

(600 m depth)

Baris 2

Potential against 

nearby copper sulfate 

electrode ( m V )

-700

___

-860

-777

-752

Potential against 

remote (160 m) copper sulfate 

electrode (mV)

-717

-650

___

-861*

-827

 

* This value in excess of 850 said to indicate galvanic attack at junction of steel casing 

and aluminum screen.

During 1962, 1963, 1964 the author continued the field studies 

of corrosion started by Sudrabin and extended them to Dakhla 

Oasis, using corrosion monitoring equipment and special field testFIGURE 6. Perforated elbow, Mut well 1, Dakhla Oasis.
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O15

ing for unstable water-quality parameters likely to influence the 

corrosion process. His first examination of Kharga and Dakhla 

wells in June of 1962 confirmed the observation of Sudrabin concerning serious internal corrosion of well screens and well head 

equipment and' provided additional information concerning the 

sulfide-bearing black corrosion deposits which are common to many 

of the steel-cased wells. He concluded that perforation of a Dakhla 

well head elbow (fig. 6) on its outer curve indicated the combined 

effect of high linear velocity and corrosive water and suggested 

that observed separation of relatively thick bridge pieces from 

the steel screens (fig. 7) was the result of preferential attack at 

stress points. The photograph of a corroded discharge line (fig. 8) 

from a Kharga Oasis well is evidence of the aggressiveness of the 

water.

The first corrosion test specimens installed in March 1962 in 

Kharga well 1A on the recommendation of Sudrabin and examined 

by the author in late June of the same year are shown in figure 9. 

They consisted of wood-slat insulated 30 cm screen lengths of 

bitumastic-coated bridge-slotted steel, mild steel casing drilled 

with 1.5 cm holes, bridge-slotted 61SW aluminum, and wirewrapped Type 304 stainless steel. After the three months exposure, these four large specimens were covered with the thick 

slimy black deposit characteristic of desert well interiors. The 

organic coating had disappeared from much of the bridge-slotted 

steel specimen, and the mild-steel drilled specimen was heavily 

etched. Both of these steel sections contained numerous pits ranging from 0.25 to 0.75 mm deep, the deepest on the coated specimen. Neither the aluminum nor the stainless steel specimens 

showed evidence of attack after this short exposure, even when 

examined with a low power microscope.

Following this initial inspection, the same four specimens were 

returned to the discharge line of Kharga well 1A along with a 

sample of fiberglass tubing and a Type 347 stainless steel stress 

corrosion test specimen of the type shown in figure 10. The fiberglass was drilled with 2 mm holes to simulate well-screen openings 

and to serve as indicators of swelling or delamination in such 

critical passages. All six specimens were examined again by the 

author and by USAID and EGDDO personnel in May 1963, 14 

months after the original installation, and again in March 1964 

after the four older specimens had been exposed for two years.

The later examination substantiated the corrosive effect of 

Kharga Oasis well water on mild steel. Both the bridge-slotted and 

the drilled steel specimens had severe general etching and local-
O16 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 7. Severed screen bridge, Kharga well 1A, Kharga Oasis, x 4.6.
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 017

FIGURE 8. Corroded discharge line, Kharga well 1A, Kharga Oasis.

FIGURE 9. Surface line corrosion specimens, Kharga well 1A, Kharga Oasis.
018 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

Point of cracking

A. BEFORE EXPOSURE B. AFTER EXPOSURE 

FIGURE 10. Stainless steel stress corrosion specimen used in Kharga well 1A.

ized pits to 1.5 mm depth. On casual examination, however, the 

damage was difficult to detect. But surfaces which retained original mill marks and saw scratches flaked away to reveal deep subsurface penetration of the type described by Paver and Pretorius 

and illustrated in figure 11. The corrosion deposit was heavy and 

relatively brittle. The aluminum specimen had developed white 

corrosion tubercles but had only insignificant etching on cut edges 

(fig. 12). The stainless steel screen specimen retained original 

mill marks and there was no evidence of corrosion.

The final inspection showed that two years of exposure had 

increased the overall metal loss in both mild steel specimens although the maximum depth of pitting was still about 1.5 mm. 

Damage of the type shown in figure 13 was concentrated on the 

convex surfaces of the slot bridge as evidence that stress from 

cold working was contributing to local attack. Analysis of the 

brittle black corrosion deposit showed it to contain iron sulfide 

(Fe9S8 ), in addition to the more common black hydrated iron 

oxide. The aluminum and stainless steel specimens endured the 

two-year exposure with no significant damage. Except for a superficial coating of iron corrosion products, small white tubercules
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O19

FIGURE 11. Subsurface pitting, Kharga well 1A, X 5.

of hydrated aluminum oxide (A12O3 .3H2O), and slight etching on 

cut ends of aluminum pieces, both types of specimens appeared to 

be in original condition. There was no evidence of corrosion attack 

on the wire-wrapped stainless steel and no intergranular attack 

on the stressed specimen of stainless steel. The fiberglass tubing 

also appeared to be in essentially original condition after 22 

months of exposure, with no swelling and no seperation of 

laminates except in one small area of a sawed edge.
O20 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 12. White corrosion tubercles, aluminum specimen, Kharga

well 1A, X 7.

Similar surface line specimens of mild steel, aluminum, and 

stainless steel were installed in Mut well 1 of Dakhla Oasis in 

December 1962 and examined in May 1963, replaced with new 

specimens and examined again in March 1964. In April 1963 

down-hole specimens consisting of weighted, rubber-insulated 

cylinders or flattened screen sections made variously from mild 

steel, aluminum, stainless steel, Monel Metal and Incoloy 800, also 

were suspended together on stainless steel cable in Mut well 2 

just above screen height and 340 m below the surface. This specimen string was examined during the final inspection. The assembly is shown in figure 14.

As reported by early observers, the deep well water of Dakhla 

Oasis proved to be more destructive to steel than that of Kharga 

Oasis. After only 4 months' exposure, steel specimens were 

severely damaged on slot bridges and on the peripheries of holes
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O21

FIGURE 13. Corroded bridge-slotted screen, after 2-year exposure, Kharga

well 1A.
O22 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 14. Downhole corrosion specimen string, Mut well 2, Dakhla Oasis.

drilled in the specimens. Many bridge pieces had been completely 

penetrated by pitting. The drilled casing- appeared to have lost 

about 25 percent of its average wall thickness and its 6 mm wall 

had been perforated in some places. All corroded areas were 

relatively clean with only superficial films of nonadherent deposits 

as shown in the macrograph (fig. 15). Final inspection in March 

1964 showed similar severe damage on mild steel surface line 

specimens installed one year earlier and on the down-hole specimens mentioned above. In the latter exposure, the bridge-slotted 

specimen has been reduced to approximately 50 percent thickness
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O23

FIGURE 15. Deep, deposit-free corrosion, steel specimen, Mut well 1, Dakhla

Oasis X 7.

overall and had lost its bottom half entirely, dropping the drilled 

casing specimen and the tension weight (fig. 16).

As in the Kharga Oasis test, the resistance of aluminum specimens to Dakhla Oasis well water was much better than that of 

steel specimens, but there was evidence of significant attack. 

After four months' exposure in Mut well 1, the bridge-slotted 

aluminum specimen was speckled with scattered white corrosion 

tubercles covering shallow corrosion pits up to about 0.125 mm
024 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 16. Severely corroded bridge-slotted steel specimen from down-hole

string, Mut well 2.
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O25

in depth. Effects on down-hole wire-wrapped and bridge-slotted 

specimens were even more pronounced after a year's exposure 

in Mut well 2. White corrosion tubercles of the type shown in 

figure 17 covered 25 percent of their surfaces and underlying 

these were pits which penetrated up to 10 percent of the total 

wall thicknesses. Surfaces between the tubercles were covered 

with thick deposits of black iron oxide.

FIGURE 17. Corroded, aluminum specimen from down-hole string, Mut well 2.

The Type 304 stainless steel specimens installed in Dakhla 

Oasis wells showed no evidence of corrosion except for superficial brown films of iron oxides on the surface line specimen 

(fig. 18) and somewhat heavier films on the down-hole specimens. 

This alloy was in original condition as far as could be determined 

by microscope inspection at the end of the test period. The same 

was true of the specimen made from a special chromium-nickel 

steel alloy (Incoloy 800) that was suspended in Mut well 2. The 

performance of a down-hole specimen of 27-68 copper nickel
026 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 18. Undamaged stainless steel screen specimen, surface line, Mut

well 1, X 5.

(Monel Metal) also was good. Although its surface was mottled 

blue, gold, and brown as evidence of selective nickel solution and 

there was overall etching and minor uniform metal loss (fig. 19), 

there was no localized pitting of the sort that occurred on mild 

steel.

In addition to these corrosion tests with relatively massive 

metallic specimens, the authors, with the help of USAID and 

E'GDDO personnel, made a series of corrosion probe studies in 

Kharga and Dakhla Oases well waters, using the corrosometer 

shown in figure 20. These corrosometer probes consisted of loops 

of 1-mm diameter wire that were installed through the surface 

casing above ground level by means of suitable bushing-shield 

assemblies (fig. 21). A portion of the wire loop representing1 one 

leg- of a Kelvin resistance bridge is protected with water proof 

coating- so that it senses and compensates for water temperature
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 027

FIGURE 19. Slightly corroded Monel Metal specimen, down-hole string, Mut

well 2.

but is not affected by corrosion. A battery powered meter is used 

to compare electrical resistances in the exposed to that in the 

reference leg of the resistance bridge. Resistance change due to
028 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 20. Mohammed Shaaban, Egyptian General Desert Development Organization, operating a corresometer, Kharga well 1.

metal loss of the exposed leg is converted to average metal penetration by the equation:

D_

mm PY=TxO.Q927l 

where: mm PY = millimeter penetration per year

D = change in instrument dial reading (electrical resistance change) between data points 

T = exposure time in days between data points 

0.09271 = a factor for converting diameter change of the 

W 40 probe wire to millimeters penetration per 

year (mm p/yr), using a probe multiplier of 10.

Such readings average corrosion rate over the entire specimen. 

The relative severity of attack is judged by these criteria:

Extent of damage Penetration (mm/yr)

Insignificant (mild)

Moderate

Severe

Extreme

Less than 0.05 

0.05 to 0.5 

0.5 to 1.25 

Greater than 1.25
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 029

FIGURE 21. Corrosion probe and shield.
O30 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 22. Corroded steel probe wire, Baris well 11, Kharga Oasis, x 12.

Data obtained in corrosion probe studies of Kharga and Dakhla 

Oases wells were in general agreement with those obtained on
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 031

actual well-screen specimens exposed in the corresponding well 

discharged lines. Except for the test in Nasser well 3, all steel 

probes exposed in Kharga Oasis wells corroded rapidly during a 

large part, if not all, of the test periods and developed heavy corrosion products and occasional deep localized pitting as in the 

more massive specimens (fig. 22). Steel probes in Dakhla Oasis 

wells corroded more rapidly and exhibited the same clean, uniformly wasted surfaces as in the counterpart screen specimens. 

Figures 23 and 24 show corrosion rate curves for Kharga and 

Dakhla respectively. In each figure, the shaded area indicates 

severe attack in terms of the aforementioned accepted engineering 

criteria. The erratic corrosion rate curves obtained for steel in 

Kharga well 1A and Nasser well 1, and the exceptionally low 

corrosion rate for the steel probe in Nasser well 3 are evidence 

that great care must be taken in interpreting data obtained on 

the mixed discharges from a multizone aquifer system.

The data obtained with aluminum probes also were generally 

consistent with the behavior of actual screen specimens exposed 

in flowing water of Kharga and Dakhla Oasis wells. Except for 

Masara well 1 in Dakhla Oasis where the aluminum probe corroded almost as rapidly as steel, aluminum corrosion rates 

(0.0005-0.05 mm/yr) were well within the engineering limits for 

long-term performance. Despite this generally favorable quantitative performance, there were significant qualitative differences 

and evidences of local effects which did not appear in corrosion 

rate curves. Some aluminum probes, like that exposed in Kharga 

well 1A (fig. 25), developed uniform light etching under the black 

surface deposits of iron corrosion products. Others, like that exposed in Nasser well 1 (fig. 26), exhibited scattered white tubercles covering pits up to 20 percent of the probe wire diameter. 

This variation in mode and extent of attack on aluminum again 

points to probable differences attributable to qualitative variation 

in the water-bearing zones or to differences in hydraulic characteristics of the wells.

The effects of Monel Metal probes exposed in the two oases 

were essentially identical to those on specimens of Monel tubing 

suspended just above the screen in Mut well 2 of Dakhla Oasis. 

Both the probes and the tubing were mottled blue, gold, and 

brown in color as evidence of nickel loss and corrosion on both 

types of specimens consisted of separation of extremely thin concentric layers of metal. The performance of the alloy from a
O32 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

0 20 40 60 80 100 120 140 160 180 200 22Q 240 260 280 300 

TIME, IN DAYS

1. Steel,

2. Steel,

3. Steel,

4. Steel,

5. Steel,

Baris 11 

Kharga 1A 

Nasser 1* 

Bulaq 4A 

Nasser 3*

6. Aluminum rate 

spectrum, 

Kharga 1A 

Nasser 1* 

Nasser 3* 

Baris 11

7. Stainless steel, 

Kharga 1A and 

Nasser 1* 

Monel Metal, 

Baris 11

FIGURE 23. Corrosion rate curves, Kharga Oasis wells.

quantitative standpoint was excellent. Corrosion rated ranged 

from 0.005 to 0.032 mm/yr. Such performance equals that of 

the best aluminum probes and approaches the superior performance of stainless steel.

Both the Type 304 stainless steel and the Incoloy 800 probes 

proved to be almost completely resistant to corrosion in both 

Kharga and Dakhla Oasis well waters. This corresponds to the 

similar excellent performance of surface-line and bottom-hole 

specimens of the same materials discussed earlier in this report.

Although some differences in corrosion effects between these
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 033

1000

a

MILD

0 20 40 60 80 100 120 

TIME, IN DAYS

Steel, Masara 1 

Steel, Balat 6 

Aluminum, 

Masara 1

4. Aluminum, 

Balat 6

5. Aluminum, 

Rashda 2

6. Incoloy, Masara 1 

Stainless steel, 

Balat 6

FIGURE 24. Corrosion rate curves, Dakhla Oasis wells.

small probe wires and actual well parts could be expected because 

of differences in geometry, surface velocities, residual stresses, 

resistance to fatigue and other contributing factors, the probe 

data appear to distinguish durable materials from those which are 

questionable or a poor risk.

QUALITY CHARACTERISTICS OF NEW VALLEY 

WELL WATERS

Pertinent water-quality observations concerning wells in 

Kharga and Dakhla Oases extend back at least to the turn of the
034 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 25. Etched aluminum probe, Kharga well 1A, x 10.

Century. Ball (1900), Beadnell (1901), Little (1926, 1931), Little 

and Attia (1942), and Paver and Pretorius (1954) all reported 

iron stains in discharge channels, including those in wood-cased 

wells, in addition to the odor of sulfide, effervescing gas, and 

relatively high temperatures. Beadnell concluded that most of the 

well-water temperatures in Dakhla Oasis are higher than would
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 035

*

FIGURE 26. Corroded aluminum probe, Nasser well 1, x 11.

otherwise be expected from well depth and average ambient conditions and attributed this to deep circulation of the water before 

it reaches the wells. Little and Attia mentioned a pH of 6.6 

in Bir Faruqya near Mut in Dakhla Oasis, but did not state how 

it was measured.
O36 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

FIGURE 27. Hassan Mostafa (right), Egyptian General Desert Development 

Organization, and the late Paul Bieber, U.S. Geological Survey, measuring 

bicarbonate ion in water from a Kharga Oasis well, 1962.

Later investigators, including those of the Nasr Oil Company, 

the Egyption Desert Institute, and the EGDDO extended waterquality information with gas analysis and mineral analyses made 

of samples transported to laboratories in Cairo and other locations. Unfortunately, analyses at distant laboratories did not permit accurate measurement of unstable constituents and characteristics such as pH, oxidation potential (Eh) bicarbonate ion, and 

dissolved gases. To overcome this problem, both field tests for 

unstable parameters and laboratory analyses for the stable ones 

were included in the author's investigation reported here. Field 

tests were made for pH and bicarbonate ions by the methods of 

Barnes (1964), using an electronic pH meter with a glass-calomel 

electrode system both for measuring pH and for detecting the 

equivalence point in the bicarbonate titration (see fig. 27). Electrode potential was measured by the method of Back and Barnes 

(1961), using the pH meter as a potentiometer and a platinumcalomel electrode system in the flow cell shown in figure 28. Iron 

and sulfide ion were determined in the laboratory on samples
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O37

FIGURE 28. Flow cell for measuring Eh.

treated at the wells with acid and zinc acetate, respectively. All 

other analyses were made in the laboratory using untreated 

samples.

Because it is difficult to make reliable field tests under desert 

conditions, a relatively small number of such analyses have been 

made and not all of them included every measurement of interest. 

However, the resulting data contained in tables 4 and 5 are con-
O38 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

"5

~2

I

?^

"Ss

§

3

^

1

II

*S)

-S

J

?

s

r

3g:

( ^jH

w

PC

H

1

.a

J*"a

C9

'c

o

to

o'£

eg

U

 T3 "to

E

-wddo^ g

0

UBJ\[ ^

UO.IJ OJ fe

uinuiiuniv 2

tunissBioj ^

iunipoS .*

iunisdu&Hp^[ 1^4

CO

0

(A/iuiu) sd^BJ uoiso.1.103

uinuiiuiui iy uinuiixB]^

K

a

^

'**'

X

H

1/8ui

COOH ujojj) roO

OcO

c 

_o

'tA 

01 a

o o -* o o

>H « Q « i,

N NO N N

t- -* I- CO O

° « ^ ° fc

o o o ON

f -HE- CO O

oj in oj oj ,-1

£ 2 P

S

"~l ""I <u Z O O N N

in ,-H oo c- TJI

OJ CO CM <N OJ

OC t O OJ IT03 00

OJ C- * OO'

1-" CO 1-H

in co 1-1 * C3

0, COCO ^ ^

O t- *! O O

CM 1-1 O r oj --I r

O O3 CO

' ' ^ ^ **

"*.

i it-i co in

1 1 "}" OJ

'7 i +

 *}< oo in

1 1 t-H CO 00

in

CO "^ CO O3 OO

CO CO CO CC CO

^3 01

0

« - c £ 'H

s o) - ^H ^^ ^ -Ji ?co XJ

0 « s i SI c, T ^ £ x* bt CO 3 co 

b 03 03 C W W CO

XM

P

OJ

00

d

OJ

"

d

oo

CO

CO 

CO

00

OJ

^CO

0 «*

CM O

ITCO

00

r^

OJ

1

^CO

cc

cc

Nasser 1

o 

d

CO

d

^oi

o

e*

fOJ

LCM

f_H

^H

OC~

in

0

o

O3 co'

 *oo'

OJ

1

in

OJ

00

CO

01

: oj 1O CA

to rt

01

Q

o 

d

co 

d

00

in

p

OJ

CO

CO 

OJ

COoo'

.

CO

^

CO

1

1

1

o

CO

cco

CO

"5

03

CO 

0

d

00

OJ

d

O3

in

p

z

CO

in

CO 

<N

tC3

in

OJ

oi -*'

CO

CO

1

1

1

OJ

CO

CO

CO

Masara 1

p 

8

00

OJ

d

OJ

d

zero

COoo"

in

OJ

IO

fj

o

CM

'

CO

CO

CO

t-03'

+

cc 

oi

CO

-tJ

g 

%

-4< O

dS

in c-

-* 0

d d

00 00

ui in

2 2

OJ OJ

in 1-1

co m

in oo

OJ OJ

oo in

06 oi

CO O3

OJ OJ

1 '

oo

CO CO

CO CO

!>;

 ^ I

CO 1

+

co oi

CO CO

T* CO

CO CO

Rashda 1Rashda 2
39.4 64 70 0.1 0.34 

_______. 

** Field Determination

Ionic analysis (mg/L)

Anions

Well +>

designation a

o

0)

O

CO.i

Kharga Oasis 

Baris 11

Bulaq 4 A

Garmashin 1

El Kharga 1A

El Mahariq 2

N asser 1

N asser 3

Dakhla Oasis

Balat 6

Masara 1

Mut 1

Rashda 1

Rashda 2

a

O Bicarbonate

___

104.5

104

205.5

89.5

110

27

24.5

55.5

53

39.4

"3

03

SOi

52

133

31

12

27

111

11

49

56

47

53

64

S Chlorine

102

225

117

34

65

116

59

42

62

45

62

70

NO:*

zero

zero

0.1

0.3

0.2

0.1

zero

zero

0.1

zero

0.1

0.1

0.85

1.36

1.36

2.2

1.36

1.7

0.9

2.39

0.17

zero

0.34

0.34
040 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

TABLE 5. Gas composition, selected New Valley wells

[Data from Mostafa Salem, Nasr Oil Co.]

Well 

designation

El Kharga 1 

El Kharga 1A 

El Mahriq 2 

Nasser 1

Mut 1

Percentage

Hydrogen sulfide 

HaS

Trace 

0.1 

Trace 

Trace

Trace

of gaseous components

Carbon dioxide 

CO*

3.1

1.4 

4.0 

1.5

2.9

Nitrogen 

Na

96.9 

98.5 

96.6 

98.5

97.1

sidered to be generally reliable. Together with computer analyses 

of pertinent geochemical factors by the method of Flummer and 

others (1976), these data form the basis for generalizations concerning water-quality characteristics and their contributions to 

metallic corrosion. The data agree with earlier conclusions that 

well waters of Kharga and Dakhla Oasis are abnormally high in 

temperature and relatively high in iron, sulfide ion, and dissolved 

gas. Reliable temperatures range from 33° to 39°C in the test wells 

and are up to 6°C above expected values for some of the shallow 

wells according to Cushman and Gates (1967), although they 

found the thermal gradient with depth to be less than expected.

Despite the significant variation in water quality from well to 

well and from Dakhla Oasis to Kharga Oasis, as judged from 

samples taken at the surface, all waters tested fall into a category 

characterized by relatively low dissolved solids content, low pH 

and Eh values, and relatively high temperatures and gas contents, particularly nitrogen and carbon dioxide. The pH values 

are significantly lower and the Eh values significantly higher in 

Dakhla Oasis than in Kharga Oasis. The trilinear diagrams in 

figure 29 also show significant differences between waters of the 

two oases. In these percentage plots of principal ions and ionic 

combinations, Dakhla Oasis waters are consistently sulfochloride 

types and except for Balat well 6, have more alkaline earth (Ca 

and Mg) than alkali species (Na and K). The Kharga Oasis 

waters do not group as consistently. Garmashin well 1 and Nasser 

well 1, like the Dakhla Oasis wells, are sulfochloride types relatively high in alkaline earths, and Nasser well 3 is a marginal 

sulfochloride type, whereas Kharga well 1 and Mahariq well 2 

are alkaline bicarbonate types.

There is little doubt and some analytical evidence that quality 

varies appreciably between certain ground-water horizons and 

that bottom-hole qualities are different from those measured in
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 041

Kharga Oasis

1. Garmashin 1

2. Kharga ^f

3. Mahariq 2

4. Nasser 1 *

5. Nasser 3*

Dakhla Oasis

6. Balat 6

7. Masara 1

8. Mut 1

9. Rashda 1 

10. Rashda 2

PERCENTAGE REACTING VALUES ANIONS

FIGURE 29. Trilinear diagram showing ionic balances of New Valley well

waters.

the mixed waters at the well heads. There also is evidence that 

dissolved gas content varies with depth. Cushman and Gates 

(1967) conducted borehole pressure tests which indicated gas separation starting above the screened sections in certain deep wells. 

Considerably more work would be required to relate quality characteristics to the various geographic locations and water-bearing 

zones.

CAUSES OF CORROSION

Corrosion of iron and steel in aqueous media is an electrolytic 

process involving innumerable anodic and cathodic areas on the 

metal surfaces that are caused by differences in stress (for example, from cold working), surface films, metallic inclusions, and 

other nonuniformities. Long-line electrolytic currents resulting
042 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

from differences in solute concentrations, temperature, flow rates, 

or other characteristics from one part of the metallic system to 

another (for example, top to bottom of a well casing) may be 

superimposed upon and markedly influence local corrosive action. 

Direct coupling of dissimilar metals such as steel ard aluminum 

can cause local electrolytic (galvanic) attack.

In its simplest form the electrolytic corrosion of steel involves 

solution of iron in anodic areas to form ferrous ion and release 

electrons which pass through the metal to cathodic areas where 

they react with hydrogen ions in the water and cause atomic 

hydrogen to form upon and protect (polarize) metal surfaces. 

Loss of protective hydrogen through combination with dissolved 

oxygen, lowering of pH or involvement in bacterial reduction 

processes depolarizes the cathode and allows corrosion to 

proceed.

In natural waters a variety of quality characteristics tend to 

influence electrolytic reactions. If the water contains sufficient 

calcium bicarbonate, calcium ion attracted to the cathodic areas 

will react with hydroxyl ion to form concentrated calcium hydroxide which, in turn, will react with bicarbonate ion to precipitate 

protective calcium carbonate scale on the metal surface. Sodium 

chloride, on the other hand, yields nonscaling sodium hydroxide 

at the cathode which increases pH of the cathode in relation to 

that of the anode thereby increasing reaction rate (corrosion). 

Chloride ion attracted to anodic areas has no corrosion-inhibiting 

power and actually tends to increase solubility of the metal. If 

dissolved oxygen is present, the resulting iron solution will convert to ferric chloride and this will hydrolize to hydrcchloric acid, 

a very corrosive agent.

Water of particularly low pH reacts as acid solution by dissolving metal and liberating a chemically equivalent amount of 

hydrogen gas. For a weak acid, such as a solution of carbon 

dioxide in water (carbonic acid), this attack may b^ significant 

at a pH value of 6 or more and it is markedly influenced by temperature, doubling in rate for each 10°C temperature increase.

Interaction of these factors is expressed by the Langlier and 

Ryznar indices. The Langlier which equals the actual pH minus 

the pH of calcium carbonate saturation (pHs), yields either positive or negative values as evidence of the water's ability or lack 

of ability, respectively, to form protective carbonate deposit. 

The Rynar index, which equals 2pHs-pH, yields cnly positive 

numbers and there is some agreement that values below 7 indicate increasing tendency to deposit calcium carbonate, whereas
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESEFT 043

higher numbers indicate increasing tendency to corrode. It is 

significant that New Valley waters appear to be nonpntective 

(corrosive) by these criteria. See table 4.

Solubility of metal and related protective films also is influenced 

by the pH-Eh relationship which determines stability of mineral 

species and by the concentrations (degree of saturation) of various solutes in the aqueous solution. The nature and rate of water 

movement across metal surfaces can be important factors in 

corrosion, depending upon the type of metal and corrosion process 

involved. Whatever the process, increasing electrical conductivity 

in the solution (for example, by increasing dissolved mineral) 

tends to intensify its effects. In most natural waters, chemical 

interactions are so complex that it is difficult to determine which 

of the several contributing factors is primarily responsible for 

the damage observed.

Data collected on the well waters of Kharga and Dakhla Oases 

show that they combine a number of characteristics which could 

be expected to cause corrosion. The trilinear diagrams in figure 

29 indicate that none of the predominantly sulfochloride waters 

has a calcium carbonate content high enough to precipitate protective calcium carbonate scale, a fact confirmed by EGDDO's 

saturation index studies. Such waters could be expected to promote the corrosive chloride electrode processes discussed above, 

with the resulting effects generally more pronounced in Dakhla 

Oasis than in Kharga Oasis. This has been confirmed by the 

limited number of corrosion observations made thus far and is 

consistent with the correlation of corrosion rate and combined 

percentage of sulfate and chloride ions in sulfochloride type 

waters (fig. 30).

The relatively high carbon dioxide and hydrogen sulfHe contents of certain wells and the high temperatures of all waters in 

both oases undoubtedly are contributing very significantly to corrosion processes. The nature of attack in Kharga well 1A (fig. 11) 

is evidence that sulfide ion is combining directly with the iron to 

generate relatively cathodic iron sulfide, which increases the corrosion potential, and hydrogen which penetrates and apparently 

embrittles the metal surface. Chloride and sulfate concentrations 

are known to increase and pH to decrease under such deposits, 

thus increasing corrosion (Baylis, 1926). Less than a part per 

million of sulfide ion can be very destructive in this process.

The pH values of Dakhla Oasis ground water collected at the 

well heads are in the range where direct attack of the metal by 

carbonic acid would be expected and it is likely that much lower
044 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION 

100

0 .5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 

MAXIMUM CORROSION RATE, IN MILLIMETERS PER YEAR

4.5

FIGURE 30. Relation of sulfochloride concentration to corrosion rate.

pH values exist in the carbonic-acid rich envelopes of carbon 

dioxide bubbles that contact the metal surfaces. Even in Kharga 

well 1A where the pH was significantly higher than in Dakhla 

Oasis wells, the deep relatively uniform corrosion noted in the 

discharge pipe is evidence of acid attack. These unfavorable reactions are being intensified both by the high temperatures that 

characterize all the well waters and by the relatively high surface velocities that result in part from well design. The temperature abnormalities observed by Cushman and Gates (1967) would 

be significant in corrosion reactions controlled by hydrogen liberation (for example, carbonic acid attack) where doubling of rate 

occurs with each 10°C rise in temperature. The maximum surface velocity of 335 cm, s which the author estimated for flow at 

Rashda well 2 in 1962 on the basis of the well's discharge of 

11,000 m:Vd is far above the 90 cnvs recommended limit for steel 

exposed to corrosive water.

Innate corrosiveness of the New Valley well waters also is indicated by the Eh-pH relationships shown in figure 31. In this 

stability field diagram, plotted according to Hem and Cropper 

(1959), the segmented central line separates oxidized species
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESEFT 045 

+ 1200

+ 1000

+800

+600

o

.c

LLJ

+400

+200

-200

-400

-600

Water oxidized

Water reduced

EXPLANATION

A Kharga Oasis 

 Dakhla Oasis Fe (OH)2c

10 12 14

DH

FIGURE 31. Stability field diagram, ferric and ferrous species, r.ssuming 

2 x 10~7 molal activity of iron and based on Fe(OH) a.

above from reduced species below. Vertical lines which separate 

the various species are determined from equilibrium constants. 

The Eh-pH values which intersect in reducing areas of the diagram, particularly in the ferrous ion (Fe+2 ) stability field, indicate waters capable of dissolving iron from either geologic formations or the steel in well components. Those which plot in 

areas of oxidation, particularly in the ferric hydroxide [Fe(OH) :! ]
046 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN PEGION

field, represent less aggressive solutions which may actually inhibit corrosion of steel.

All the well waters tested by the author plot in the ferrous 

ion field (fig. 31) as evidence of their abilities to take iron into 

solution. This is consistent with the fact that dissolved iron is 

common in native desert wells which contain no mete.l parts.

Additional information concerning tendency for corrosion to 

occur can be obtained by comparing the observed concentration of 

calcium carbonate, a protective mineral species, with its equilibrium concentrations in the same environment. Such comparisons 

made by the computer method of Plummer and others1 (1976) are 

plotted against corrosion rates in figure 32 where the dark horizontal line separates oversaturation (protection) above from undersaturation (lack of protection) below. The fact that all the 

well waters included in the plot are far below calcium carbonate 

saturation agrees with their observed high corrosion rates. The 

degree of undersaturation (that is, distance of point below the 

saturation line) correlates reasonably well with observed maximum corrosion rates despite the fact that other corrcsion control 

+ 1

Typical encrusting 

wells (W. Pakistan) k v

-2

-3

Saturation line Encrust

Corrode

Nasser 1* 

Kharga 1A

Masara 1

0 .5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 

MAXIMUM CORROSION RATE, IN MILLIMETERS PER Y*AR

FIGURE 32. Relation of calcium carbonate equilibrium to corrosion rate.

5.0
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 047

mechanisms are involved (for example, sulfide, chloride, and carbonic acid processes).

Taken together, the characteristics described in the preceding 

text show the New Valley well waters to be anaerobic media with 

considerable capacity for reduction (solution) of protective iron 

compounds; with ionic ratios known to promote corrosion rather 

than inhibit it (for example, chloride to bicarbonate), and with 

minor solutes, such as carbon dioxide and sulfide ion, whicl are 

particularly destructive to steel. Sudrabin's long-line potential 

data (table 3), which range from -700 to -861 mV and suggest 

corrosion of steel in an anaerobic environment, agree with these 

conclusions. Concentration of damage in certain parts of the system can be attributed to cold-work stresses, such as those in the 

formed bridge slots of screen sections, and to velocity effects, 

like those evident in the elbow from Mut well 1 (fig. 6), or other 

pecularities of construction or operation which intensify effects 

of the basically corrosive waters.

CONTROL OF CORROSION

A variety of treatments are commonly used for controlling corrosion of steel in aggressive aqueous solutions, including surface 

coatings, soluble inhibitors, impressed electrical currents and 

sacrificial electrodes of more active metals. Unfortunately, none 

of these treatments is practicable for use in water wells of the 

New Valley. Even the best surface coating provides little protection at sharp edges like those in screen slots, and coating? are 

liable to damage in transit and installation with resulting severe 

corrosion in the damaged area. Similarly, down-hole chemical 

treatment with corrosion inhibitors is impracticable and in compatible with the intended water use. Cathodic treatment with impressed current requires precise control which cannot easily be 

achieved in remote desert locations and it protects only external 

surfaces, not the interiors of screen slots and casings where serious damage is known to occur. Proper positioning and maintenance of sacrificial electrodes also would be difficult and costly 

in these desert wells and even the best installations would not 

prevent corrosion of casing exteriors and inner surfaces of screen 

openings.

Because of the limitations of conventional treatments, one must 

depend upon selection of materials and well design to minimize 

the kinds of corrosion damage discussed in this report. Several
048 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

investigators suggest operation with open-hole construction instead of conventional screen wherever the characteristics of the 

water-bearing formations favor such design since it would eliminate the problem of rapid deterioration of steel screens. Continuation of the present practice of externally cementing steel 

casing above filter (screen) sections should prevent formation 

erosion in case of casing failure and overcome the problem of well 

collapse described by Paver and Pretorious (1954). Using optimal 

screen lengths and openings and increasing diameters of well 

screens and casing to reduce surface velocities and accommodate 

larger pumps, where pumping is required, also should significantly reduce corrosion problems and increase hydraulic efficiency, 

but the cost-benefit aspects of such design changes obviously are 

an important consideration. Designing well-head equipment for 

long life or easy replacement, even if down-hole corrosion of steel 

parts occurs, is desirable.

Corrosion problems which cannot be handled practicably by 

design changes must be overcome through the use of alternative 

construction materials that are inherently more resistant to attack by the desert ground waters. The corrosion data already discussed show that high strength aluminum is significantly more 

resistant than steel in most Western Desert locations. However, 

because of aluminum's relatively high cost (about 2.5 times that 

of steel), and its unpromising behavior in certain tests, particularly down-hole exposure, it is a questionable substitute for 

steel in wells which are intended for long-term trouble-free service and when durability of down-hole metal parts (for example, 

screens) is an important consideration. The excellent performance 

of Type 304 stainless in all tests shows that it would be durable 

screen material for long-term service in any location which requires screening rather than open-hole operation. Such material 

could be used in conjunction with cemented mild steel casing 

with or without an electrically insulated joint, but such insulation would be an additional safeguard against possible galvanic 

attack. The relatively high cost of stainless steel (4 to 6 times 

that of mild steel, depending on design), is its only disadvantage. 

That cost must be weighted against the cost and practicability of 

replacing less durable screen materials' as well as the feasibility 

of open-hole operation.

In recent years considerable progress has been made in fabricating epoxy-bonded fiberglass and wood tubing for use as both 

casing and filter pipe (screen) for well construction. Modern 

fiberglass products, which are essentially corrosion proof, will
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 049

withstand tensile loads of 45 metric tons (t) or more; and the 

overall strength of fiberglass is approximately equal to that of 

red brass tubing of similar dimensions. Even where strength is 

reduced by saw-slotting, fiberglass filter pipe is considered to be 

strong enough for well depths to over 300 m. Great progress 

also has been made in quick coupling design for rapid assembly 

of fiberglass tubing. The key-lock joint shown in figure 33 proved

FIGURE 33. Key-lock joint, fiberglass well pipe.
O50 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

to be quite practicable and durable in well-field development in 

the Indo Gangetic plains (Indus Plains) of West Pakistan.

Although fiberglass tubing costs about 2.5 times as much as 

mild steel tubing of the same size, the lower cost of transporting 

and installing it makes it a close competitor from the standpoint 

of installed cost. For this reason it should be economically practicable to use fiberglass for either filter pipe or casing wherever 

its strength is adequate for the particular installation.

As with all new products, we currently have limited information concerning the long-term durability of laminated wood and 

fiberglass in water well service. Recent down-hole camera observations of fiberglass installations in West Pakistan wells showed no 

evidence of encrustation or deterioration after several years of 

service but well performance tests showed some evidence of sand 

clogging of filter pipe slots. Similar observations on fiberglass 

and modern wooden screen installations in the Western Desert 

would provide additional useful information on these alternative 

construction materials.

Tests with corrosion probes showed Monel Metal to be very 

resistant to waters of the Western Desert. Although this material, 

which as approximately as expensive as stainless steel, probably 

would not be as durable as stainless if used for well screens, it 

might be a practicable alternative for special components, such 

as well-head valves.

The need to lift or otherwise gain access to water which once 

flowed freely to the desert surface has been recognized for a very 

long time. Near the old village of Kharga there are remains of 

a kanat (ancient underground tunnel) once used to tap a declining well below the surface and convey its water to a lower part 

of the oasis (fig. 34). Beadnell (1901) mentioned the use of 

native water-lifting devices in Dakhla Oasis in 1896, and Ball 

suggested in 1900 that these saqiyas (waterwheels) and shadufs 

(sweeps) could be used to good advantage in revitalizing a number of desert wells which had ceased to flow because of expanded 

and indiscriminate drilling. Despite this growing need Paver and 

Pretorius reported only a small number of water-lifting devices 

in the Western Desert in 1954.

Rapid development of deep wells, starting with the New Valley 

Project in 1959, caused a relatively rapid decline in artesian pres-
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT O51

FIGURE 34. Kanat at nonflowing well, Kharga Oasis.

sures and increased the need for lifting water by mechanical devices. By 1967, according to Cushman and Gates, there were about 

200 saqiyas operating in Kharga and Dakhla Oases with a maximum unit discharge of 800 m3 /d and an average of 255 m3 /d.

The need for modern pumping and the possibility of troublesome pump maintenance problems were both recognized by those 

involved in New Valley Project planning and water-quality investigations. Pump experiments to assess corrosion problems 

were recommended by the author in 1962 and experimental pumps 

were obtained for this purpose the following year. According to 

Cushman and Gates, 60 pumps of approved design had been acquired for desert use by 1967 and some later were installed in 

Kharga Oasis.

Table 6 shows information provided by Idris and Ezzat (1976) 

concerning the pumps in use around Kharga Oasis. It is apparent 

from this summary that while modern pumping had not yet 

started in Dakhla Oasis, it is relatively common in the north and 

south of Kharga Oasis. The diesel-operated, shaft-driven pumps 

in use were obtained from the United States, India, and Denmark. All have cast-iron bowls, but shafts include water-lubricated mild steel, water-lubricated stainless steel, and oil-lubri-
052 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

cated mild steel. Impellers are made of either bronze or stainless steel and discharge lines and couplings of plain carbon steel.

TABLE 6. New Valley wells being pumped, 1976

GOVERNMENT WELLS, KHARGA OASIS

Sherka 1A

Sherka 3

Sherka 34

Sherka 2

El Mahariq 2

El Mahariq 7

El Kharga 1

El Kharga 1A

El Kharga 2

El Kharga 10

El Kharga 12

West Kharga

El Sajaha

Hepus

El Bustan 1C

El Bustan old

Genah 2A

Genah 1A

Genah 3A

Genah 3B

Garmashin 1

Garmashin 2

Garmashin 2A

Garmashin 6

Garmashin 16

Garmashin 2A

replacement

Garmashin 4

replacement

Baris 1

Baris 12

Baris 15

Baris 18

NATIVE AND VILLAGE WELLS, KHARGA OASIS, BARIS AREA

Baris Village and i>aris El Qasr Rajda El Oeum

El Maks Om Saeda El Gaba

Doush Salm and Fakhara Badran

OTHER LOCATIONS

Sherka Native Genah Village

NOTE: There are no pumping wells in Dakhla.

According to Idris and Ezzat (1976), corrosion occurs primarily in the plain steel shafts, couplings, and discharge lines, 

which is not surprising in view of the relatively high carbon 

dioxide contents and the change from velocity head to pressure 

head in passing through the relatively small diameter, high speed 

pumps. Significant corrosion of pump bowls is reported to occur 

in only 10 percent of the installations and average pump life is 

estimated by Idris and Ezzat to be 6 to 8 years. However, Parkinson and Worts (1977) mention failure of well parts, including 

pumps, in as little as 6 months of service. In such aggressive 

waters 6 to 8 years would be surprisingly good performance for 

iron pumps.

It seems likely that damage to discharge lines and couplings 

could be reduced significantly and perhaps economically through 

the selection of alternative materials. Relatively large pumps are 

known to be operating with plastic discharge lines in other corrosive well waters (for example, in Australia).
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 053

OPPORTUNITIES FOR FURTHER STUDY

To make the best of Western Desert experience in planning 

new wells for Egypt or well fields elsewhere in the world, it 

would be desirable to make additional observations when circumstances permit. Down-hole camera observations of the several 

kinds of metallic and non-metallic filter pipe materials installed 

since 1959 would provide positive evidence of their performance 

and allow better predictions in the future. Similar observations 

would show whether or not open-hole construction is practicable 

and shed some light on the relative merits of various filter pipe 

designs.

Ability to predict corrosiveness on the basis of water-quality 

data also could be improved by measuring the qualities of the 

individual water-bearing strata rather than by measuring their 

mixed discharges at the well heads. Such data would also aid in 

understanding the Nubian aquifer system. Advances in techniques 

for sampling and analysis since initiation of the New Valley 

Project should simplify these tasks. There is little doubt that the 

technical community would be eager to see the results of such 

studies.

SUMMARY

The observations and investigations reported here confirir the 

extreme corrosiveness of well waters in the New Valley area of 

Egypt's Western Desert. Relatively low pH and Eh values together with the relatively high water temperatures, high carbon 

dioxide contents, and high concentrations of sulfide, sulfate, and 

chloride ions account for the severity of the attack.

Use of corrosion-resisting metals such as stainless steel or high 

strength epoxy-resin bonded fiberglass or wood appears to be the 

most practicable solution to maintenance problems in deep v7 ells 

which require long-term service from screens and casings. However, high strength aluminum should provide significantly better 

service than plain steel in most locations.

Better information on the specific quality characteristics of the 

several water-bearing horizons and on the performance to date of 

the various kinds of well screen materials would simplify the 

choice among alternative construction materials.
O54 THE HYDROLOGY OF AFRICA & THE MEDITERRANEAN REGION

REFERENCES

Back, William, and Barnes, Ivan, 1961, Equipment for field measurement

of electrochemical potentials: U.S. Geol. Survey Prof. Paper 424-C,

p. C366-C368. 

Ball, J., 1900, Kharga Oasis, its topography and geology: Egypt. Survey

Dept. 116 pages, 19 maps, 16 figures. 

Barnes, Ivan, 1964, Field measurement of alkalinity and pH: U.S. Geol.

Survey Water-Supply Paper 1535-H, 17 p. 

Baylis, J. R., 1926, Factors other than dissolved oxygen influencing the

corrosion of iron pipes: Industrial and Engineering Chemistry 18, no.

4, p. 370. 

Beadnell, H. J. L., 1901, Dakhla Oasis, its topography and geology: Egypt.

Survey Dept. 104 pages, 9 maps, 7 figures.

 1908, Flowing wells and subsurface water in Kharga Oasis: Geol. 

Mag., v. 5, no. 524, p. 49-57; no. 525, p. 102-108.

Burdon, D. J., and Pavlov, M. I., 1959, Proposed pre-develo^ment investigations prior to large-scale groundwater development in the Western 

Desert of the Egyptian region, United Arab Republic: Rept. by United 

Nations to Dir. Gen., Desert Development Authority, U.A.R., Cairo, 

Egypt.

Clarke, F. E., 1962, Evaluation and control of well water corrosion problems 

in Kharga and Dakhla Oases, Western Desert, Egypt, United Arab 

Republic: U.S. Geol. Survey open-file rept., 61 p.

Clarke, Frank, E., 1963, Appraisal of corrosion characteristics of Western 

Desert well waters, Egypt: U.S. Geol. Survey open-file rept., 65 p.

 1964, Selection of metal components for long-term development of 

Egypt's corrosive ground waters: U.S. Geol. Survey open-file rept., 39 p.

Cushman, Robert L., and Gates, Joseph S., 1967, Private communication.

Ezzat, M. A., 1974, Exploitation of ground water in El Wadi El Gedid 

project area (New Valley); part II-Hydrologic conditions in DakhlaKharga area: Ministry of Agriculture and Land Reclamation, Executive Agency for Desert Projects, Cairo, Egypt.

 1978, Private communication.

Fahmi, Ali, 1956, Technical note on corrosion theory, corrosion resisting 

materials, and cathodic protection for new wells in Kharga and Dakhla 

Oases: Administrative Rept., Ministry of Public Works, Cairo.

Hellstrom, B., 1940, The subterranean water in the Libyan Desert: Sartryek 

ur Geografiska Annater, v. 34, p. 206-239.

Hem, J. D., and Cropper, W. H., 1959, Survey of ferrous-ferric equilibria 

and redox potentials: U.S. Geol. Survey Wate.r-Supply Paper 1459-A, 

30 p.

Idris, Hussein, and Ezzat, M. A., 1976, Status of ground-water pumping, 

New Valley area, private communication.

Jones, J. R., 1967, Nubian sandstone basin, exploratory mission for a possible regional hydrogeologic project: U.N. Educ., Sci. and Cultural Organization, Pub. No. 27/BMS.RD/AVS, 11 p.

LaMoreaux, Philip E., 1962, A review of the New Valley Project, Western 

Desert of Egypt: Consultant report to the Egyptian General Desert 

Development Organization, UAR. Egypt.
THE CORROSIVE WELL WATERS OF EGYPT'S WESTERN DESERT 055

Little, O. H., 1926, Investigations of the water-supply of Kharga and Dakhla 

Oases: Egypt. Survey Dept.

 1931, Preliminary report on the water-supply of Kharga and Dakhla 

Oases: Egypt. Survey Dept.

Little, O. H., and Attia, M. I., 1942, The deep bores in Kharga and Dakhla 

Oases and their effects on the future of the Oases: Egypt. Survey Dept.

Parkinson, H. L., and Worts, G. F., 1977, A brief evaluation of ground 

water and soils potential for agriculture, Western Desert of Egypt: 

U.S. Geol. Survey open-file rept., 51 p.

Paver, G. L., and Pretorius, D. A., 1954, Report on hydrogeological investigations in Kharga and Dakhla Oases: L'lnstitute du Desert D'Egypte, 

Publ. No. 4.

Plummer, L. N., Jones, B. F., and Truesdell, A. H., 1976, WATEQF A 

Fortran IV version of WATEQ, a computer program for calculating 

chemical equilibria of natural waters: Reston, Va., U.S. Geol. Survey 

Water Resources Inv. 76-13, 61 p.

Sudrabin, Leon P., 1962, Preliminary study of corrosion of deep well casings and screens, Kharga and Dakhla Oases, Western Desert, UAR, 

in cooperation with UAR and USAID/UAR, Cairo: Consultant Report 

to the Egyptian General Desert Development Organization.

Waite, Herbert A., 1962, Hydrogeologic exploration of Nubian aquifers in 

the Western Desert of Egypt: Proceedings, 838th meeting, Geol. Soc. 

of Washington, October 24, 1962.

 6U.S. GOVERNMENT PRINTING OFFICE: 1979 O 311-344/120