Houston Ship Channel Project

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K. C. Yost, Jr., P. E., MustangEngineering, Inc., Houston, Texas

An engineering/constructioncont ra ctor a llian ce is pr ovid-ing opera ting companies with

a u nique mean s of instal l ing pipe

lines via directiona l drilling u nderthe 50-mi Houston Ship Chan nel.

The a llian ce is comprised of Mus-ta ng E ngineer ing, Inc.; Troy Con-stru ction, Inc.; King F isher Mar ineService, Inc.; and Laney DirectionalDrilling Co. It ha s brought n ew andtra ditional inst allation t echniques t oth e pipe line r elocation pr oject.

Due t o depth a nd locat ion sp eci-fications, relocating the existing linescan not be cost -effectively a ccom-pl ished by lowering in place. The

relocat ed lines mu st be r eplaced withnew l ines by direct ional dr i l l ing.However, in man y cases, th ere isinsufficient workspace for directionaldrilling operations.

To meet th is cha l lenge, th e al -lian ce has been a ugment ing exist-i ng i s l ands i n t he channe l . Theislands ser ve as platforms for direc-tional drilling and tie-in opera tions.

These islands, or workpads , areb e i n g c r e a t e d w i t h a G e o t u b edevice filled with dr edged mat erial,s p oi l, or s a n d . T h i s m a r k e d t h e

indu str y’s f irs t use of th is estab-l ished t echnology for dir ect ionaldrill ing opera tions.

Ship channel. The $500-millionHouston-Galveston navigation chan-nel project is designed to allow today’sdeeper-draft vessels to safely accessth e Port of Houston from t he Gu lf of Mexico. The project is the sharedresponsibility of the U.S. Army Corpsof Engineers and its local partner,th e Port of Houston Aut hority.

As a principal pa rt of the pr oject,the 50-mi Hous ton Ship Chan nel(HSC) is being deepened from a 40to a 45-ft dept h. The sh ipping lan e

is being widened from 400 ft t o anexpanded minimum 530-ft and ma x-imum 780-ft bottom width .

Relocation. By itself, the cha nn elwidening an d deepening pr oject is acomplex task. It is further compli-cated by 96 existing lines that must

PIPE LINE & GAS INDUSTRY / JULY 2000

Augmented islands facilitate

directional drilling projectEngineering, contractor alliance creates man-made

work areas for large Houston Ship Channel project

Fig. 1. Due to the widening and deepening of the Houston Ship Channel, more than 96 pipelines must be removed, or re-installed via directional drilling, in five basic geographic areas.

Reprinted from: July 2000 issue, pg. 45-49. Used with permission.



be removed or relocated. The linesran ge from 3 to 30-in. diam eter.

Of the 96 crossings affected byt he chann e l p r o ject , i nd i ca t i ons

a r e t h a t o n l y 3 7 l i n e s w i l l b eremoved. Pr imari ly, only marineconst ru ction ser vices ar e requiredfor th ese lines.

Of th e 59 remaining l ines , theallian ce ha s been selected by 11opera tors t o per form services fora m i n i m u m o f 4 5 l i n e s . Wh i l eb ids and pr oposa ls a r e pen dingon some l ines , r e loca t ion work b e ga n l a s t s u m m e r . F in a l l in eremoval is scheduled for a May2002 complet ion.

Projects. Alliance projects alongthe HSC can be divided into fivegeographic locations (Fig. 1):

• Galveston Bay• Bet ween Sp il m an I sl and and

Hog Islan d• Between Alexander Is land and

Mitchell Point• Between Exxon Corr idor (La-

Porte) and St. Mar y’s Island• Crys ta l Bay area .At present, engineering is un der-

way for t he r elocation of one n at ur al

gas line in Galveston Bay. En gineer-ing design, permitting, procurement,an d cont ra ctor selection a re sched-uled for t his year.

Relocat ion an d const ru ction work is underway between Spilman Islandan d Hog Island. Her e, one l ine isbe ing removed and 12 oth ers a r ebe i ng r e l oca t ed . L i ne d i am e t e r sran ge from 8 to 30 in. Site prepar a-tion presented a unique challenge.Avai lab le work a rea on Spi lmanIsland was too confined for t he dir ec-

tional dr illing operat ions.To m a k e m a t t e r s m o r e p r o b -

lematic, many lines ha d been orig-inally installed in bundles. This

ma de th e option of ma rine t ie-insex t r emely d i fficu l t , dan gerous ,an d cost p rohibitive.

Island. As a solution, the allianceproposed to create an augmentedisland, a 10.5-acre work area to bebuilt between Spilman Island andthe HSC. This island extension wouldbe used a s a directiona l drilling plat-form and tie-in location.

In a ddition, th e alliance proposedto create appr opriate ecological h abi-t a t s on th ese augmented i s lands ,af ter t he pipe l ine relocat ions arecompleted.

Th e proposa l’s cost -effectivenes sappealed to the operat ing compa-n i e s . I t s env i r onm en t a l f ea t u r e sappea led to th e regulatory agencies.The fac t tha t th e enlarged is landwould n ot obs t r uc t chan nel com-merce appealed to all parties.

Mustang completed constructiondrawings, secured per mits, and pr o-cured ma terial for t he pr oject in fall1999. The art ificial island created here

would provide a m odel for other s.

Geotubes. King F isher, using 45-ftcircumferent ial Geotu bes and a bout83,000 cu yd of HSC spoil an d bar gedsand, finished creating the islandworkpa d in December 1999.

The Geotube is a geotextile fabricconstructed into an elliptical tube.It is appr oximately 7 to 8 ft t all and19 ft wide, with inlet port s spa ced on20-ft cent ers (Fig. 2). As th e portsar e filled with dredged mat erial, the

Geotu be expands t o its full dimen-sions similar to a sa usage casing.

Wa t e r f r o m t h e f i ll m a t e r i a ldra ins thr ough the porous fabric

membra ne, leaving a solid int er-na l core. To prevent un dercutt ingdue t o un dert ow or wave action,th e Geotu be was set on t op of a25- ft -wide geotex t i l e pad wi th“toes” th at f il l any h oles caus edby erosion.

This concept has been used exten-sively along the Gulf Coast by theCorps of En gineers to act as a brea k-water, or propagate creat ion of art i-ficial island s. The ship chan nel project, however, mar ked t he Geotu be’sfirst application for creating direc-tional drilling workpads .

Push ditch. On Hog Island, TroyCons t r u c t i on ’s s i t e p r epa r a t i onincluded creating pipe racks and a“push ditch” system into Tabbs Bay.

Push - d i t ch m e t hodo l ogy wasemployed by digging ditches, 10 ftwide by 4 to 5 ft deep , from t he H oggIsland work ar ea int o Tabbs Ba y. Aspipe was welded up, it wa s push edi n t o t h e wa t e r - fi ll ed d i t ch , andfloated into the bay. The process is

similar to that used on an offshorepipelay ba rge (Fig. 3).

The pr ocedur e is providing con-sidera ble cost savings, especially atlocations wh ere mu ltiple lines ar e tobe installed in th e sam e bore h ole.

In a ddi t ion t o keeping th e pipestr ing al igned, th e meth od el imi-na tes n eed for pipe rollers. It alsoexpedites welding, coating, an d pre-installation X-ray testing. These st a-tions rema in stationary at t he work-site as the pipe moves thr ough them


Fig. 2. The Houston Ship Channel project marks the pipe line con-struction industry’s first use of a Geotube to augment existing islandsfor directional drilling operations. Here, crews on a barge install theGeotube next to Spilman Island.

Fig. 3. Push-ditch methodology, similar to that used for offshorepipelay operations, was employed on the Hog Island/TabbsBay job. The procedure provided considerable cost savings,especially at locations where multiple lines were installed in thesame bore hole.



an d into the ditch.On th is job, Laney is un derta king

four d i rec t iona l d r i l l s fo r 12 newcrossings. Hole No. 1 conta ins t wo12-in., one 10-in., an d two 8-in. lines .Hole No. 2 ha s one 6 an d one 8-in.line, while hole No. 3 contain s a sin-gle 30-in. line. H ole No. 4 ha s four 8-in . l ines . Removal o f th e ex is t ingcrossings is scheduled t o be complete

by October 2000.Work between Alexan der Islan dan d M i t che ll Po in t i s i n va r i ousstages of completion. One operatorhas cont racted th e allian ce to assistin th e removal of eight lines and t here loca t ion an d re - ins t a l l a t ion of thr ee oth er lines.

A le x a n d e r I s l a n d h a s e n o u g hroom for s t r inging , weld ing , an dtesting th e th ree new 10-in. cross-ings. Entering an d exiting the islandhas been the only significant chal-lenge here.

Some of the exi s t ing l ines , 3th rough 10 in., were bundled duringoriginal constr uction. As a conse-quence, identification, segregation,lift in g, t ie-in, a nd lowerin g of th eth ree relocat ed lines would be expen-sive an d dangerous.

Adding to the h azard is the facttha t, in some areas, electric tran s-mission tower foun dat ions ar e only50 ft from the existing bundle. Thesetowers could be compromised byrem oval of existin g lines.

Ba se d on t h e se i ssu e s , a n d t h eadditional cost of bar ge operations, itwas determined that direct ional lydri l ling the n ew l ines from land t oland was the safest and most efficientinsta llation method. Drilling an d tie-in opera t ions wi l l t ake p lace onMitchell Point an d Alexander Islan d.Perm its have been obtained for th ework, a nd constru ction is expected tobegin soon.

M u s t a n g h a s b e e n h i r e d b yanother operator to perform engi-neer ing services for i ts t wo 30-in.

an d one 10-in. crossings betweenA le x a n d e r I s l a n d a n d M i t ch e l lPoint. En gineering design, permit-ting, procurement, and contractorselection ar e scheduled for th is year.Completion is expected before Octo-ber 2001.

Subsidence. Between the ExxonCorridor (LaPort e) an d St. Mar y’sIsland, 26 lines, 6 through 16-in.,will be replaced with 23 new lines.

Here, the lines had been bundled

dur i ng o r i g i na li n s t a l l a t i o n .Knowing th is, th eal l ian ce decidedto emp loy direc-t i ona l d r i l l i nghere too . Thisavoids th e d i f fi -cu l t and danger -ous ma rine t ie-in

procedure.Yet in t his ar ea,su b s id e n c e h a sbeen an especiallydiff icul t opera-t ional chal lenge.For exa mple, some 2,000 ft of prop-erty on the chan nel’s western ba nk,an area where the original lines wereinsta lled, is now un der wat er.

Also, when th e origina l lines wer econst ructed across the chann el, St.Mar y’s Isla nd was S t. Mar y’s P ointon Goat Is lan d. However, St . Mar y’s

I s l a n d i s n o w fo u r a c r e s i n s i z e ,bringing the sa me workspace prob-lem encounter ed on Spilman Islan d.The island was too small to support

drilling and tie-in opera tions.The a l l i ance sugges ted a p lan

similar to th e one implement ed onSpilman Is land. King Fisher wil luse a Geotube s t ructur e and spoilm a t e r i a l f r o m S c o t t B a y t oincrease St . Mar y’s Is lan d by 8.5acres. Th is will provide a plat form

for t he directiona l dril ling an d tie-in operat ions.

Tr o y Co n s t r u c t i o n w i l l s e t u pw e ldin g s t a t i on s on t h e Ba y to wn


Rig. Directional drill rig crews prepare for installation operations onaugmented island.

Contractor, engineering alliance offerscombined services, economies of scale

In order to facilitate the Houston Ship Channel pipe line relocation project, four Houston, Texas/Gulf Coast-based firms formed an alliance. Thealliance is providing operators with the full range of services required for relo-cating their lines.

Some operators have selected engineering work only, while others havecontracted for installation and construction work. Most have selected atotal turnkey package. The alliance members, and the services they areproviding on this project, are as follows:

• Mustang Engineering, Inc., is providing project management and admin-istrative controls. It is responsible for preliminary and detail engineeringdesign, survey, drafting, environmental and right-of-way permitting, pro-curement, construction inspection, and certification.

• Troy Construction, Inc., is serving as the primary contractor. It is providingland construction services, including site preparation, pipe stringing, weld-ing, coating, and testing. It is also providing support for other constructionactivities.

• King Fisher Marine Service, Inc., is providing equipment and person-nel for offshore services and support. This includes entry and exit to drill andtie-in locations, marine pipe line construction, dredging, and removal of exist-ing lines.

• Laney Directional Drilling Co. is responsible for all directional drilling.From a financial perspective, the economies of scale the alliance offers

enable operators to realize significant savings compared to bidding each jobto individual contractors.

Overall project controls and scheduling will reduce field costs, notably mobi-lization/demobilization expenses, site preparation, equipment, personnel, andconsumables. It also promises lower administrative costs. By one estimate,the alliance will bring some clients a 40% overall cost savings on the shipchannel pipe line relocation work.



s ide of Scot t Bay . As each l in e i swelded, crews will bottom t ow themout to the n ewly-en la r ged i s lan d .Lan ey will directiona lly drill each of t h e f o u r b o r e h o l e s r e q u i r e d t oinsta ll the new lines.

In th e Crystal Bay area, one oper-ating compan y has hired th e allianceto rem ove five crossin gs (two 16-in.,one 10-in., an d two 8-in. lines). These

lines will be rep laced with four lines(one 10, one 16, an d t wo 8-in. lines).The crossing’s right , descending

bank is on t he edge of San J acintoSta t e Pa rk . To pro tect t he pa rk’sintegrity, entr y an d exit to the dr illand tie-in a rea will be achieved usingmarine equipment.

Subsidence also has eroded theleft ban k, a miniscule remainder of Goat Is land. Because Goat Is landis now a fra ction of its former size,considera t ion was given to creat-ing a work -space s imi la r to tha t

p r o p o s e d f o r S p i l m a n a n d S t .Mar y’s islan ds.

However, a n um ber of factors d idnot m ak e th is a cost -effective option

a t th i s loca t ion . Most notably ,fill/spoil am ount requirem ent s wouldhave been m uch greater than for th eother ar eas.

For th is job, the sma ll number of and distance between lines furtherred uced an ar tificial islan d’s costeffectiveness. As a conseq uen ce, abar ge will be used as a work plat-form where Goat Islan d used t o be.

S i m i l a r t o ope r a t i ons on S t .Mar y’s Islan d, Troy Const ru ctionwill set up welding stations on theBaytown s ide of Crys t a l Ba y. Aseach line is welded, crews will bot-t o m t o w t h e m o u t t o t h e n e w l y-placed barge.

Laney will directionally drill theone hole required to install th e fournew lines. Tie-ins will be made insideth e park a nd off th e barge.

Conclusion. While pipe line r elo-cation activities are in the begin-

nin g phas es, the allian ce’s valueon th is project is a lready evident.One examp le is th e push -ditch sys-tem on Hog Island, which borr ows

from the offshore pipelay technique.Anoth er exam ple is the in dust ry’sinau gura l use of a Geotube to cre-a t e a n e x t e n d e d w o r k a r e a a tSpi lman Is land. The ul t imate useof th is same t echnique at St. Mar y’sIsland, and creation of appropri-a te ecologica l habi ta t s on theseaugmented i s lands a f te r re loca-tions ar e completed, provides a tan -

gible benefit for both operators a ndthe environment .

The author

K. C. Yost, Jr., is Mus- tang Engineering’s project manager on the Houston Ship Channel project. He has more than 24 years experience in management, design and construction of onshore

and offshore pipe lines, and regularly con- ducts industry seminars on these topics. Agraduate of West Virginia University, Yost

holds an MBA from the University of Houston,and is a registered professional engineer in 21states. He is the incoming president of the Houston Pipeliners’ Association.

Article copyright © 2000 by Gulf Publishing Company. All rights reserved. Printed in USA.

Houston Ship Channel Project

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