Overview • No contract type can protect you from a Contractor’s underperformance that results in claims and delays • Contractor’s issues with underperformance become a Client’s headache • Robust production estimates provide the best insurance against slipping budgets and schedules
Hig igh-Level In Introductio ion to Production in iJ redging Lim imiti ting Factors Solutions adding value • Cutting or jetting Conducting Bottleneck Assessments • Pick-up • Pumping Identify Bottleneck(s) • Operator or control system Establish Prevent/Analyse Consequences/ and Select Estimates Manage/Develop Alternatives Identifying bottlenecks is critical to j mproving and monitoring productivity
Introduction to Dredge Performance In Monit itoring • Why use performance monitoring? Vessel Speed Monitoring Optimise production Tra ck Plot .. ··· ·· -· ·-- ..... . .. . , - ·· ···· 7,612,500 - Track Plot ·····---- --------- .. ---------- 7,612,000 - Contour Plot Review permit compliancy ······ ....................... . 7,611,500 ... ---·····--····· .. ·-···-···· 7,611,000 7,610, SOO Administer contract ...... -------- ................................. . 7,610,000 ' ' ' ' ' ' ................................................. ' ' ' 7,609, 500 ' ' ' ' ' ' ' __ _ __ __ ___ . ' ' 7,609, 000 • • • • • • • • • • • • • • • .J. • • • • • • • • • L • • • • • • • • • .J. • • • • • • • • • ' ' ' Conduct engineering or scientific analyses ' ' ' ------- _ ___ __ __ ., _________ ., __ ____ __ _ _ ' ' ' 7, 608 , 500 ' ' ' ' ' ' ' ' ' ..... -:••·······!········•• :••·····••:---------- 7,608,000 ' ' ' ' ' ' ' ' ---:---------:--------- {---------:---------- . 7,607, 500 . • Monitoring system in a nutshell: ' ' ' ' ' ' -- -,------- -- ---- ------ --,---- --- -- ... ---- -- --- ' ' ' ' 7, 60 7, 000- ' ' ' ' ' ' ····"l··········r··· .... .., ..... ' ' ' ' ' ' ' ' ' ' Calibrated sensors 7, 605 ,000 - -- - . - - . ~. - - ... -- . , - - - .. --- .. - , ... -- . ' ' - - ..... ' - .. ' 7, 60 4, 500 ' ' ' ' ' ' ' ' ' ' ' ' .. ·········'······ ' .. ·········'·········· 7,604,000 ··-'·········· Manipulate data, if required ' ' ' ' ' ' ' ' ' ' .J .......... ' ' ' ' ' 7, 603 , 500 L. • •••••• L ••••••••• J ••••••••• •'- ••••••••• J •••••• ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ···········.J····················J·········· .. ·········J······ 7, 603 ,000 ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ••:••·····••:••······••: ••·····••:••······•·:••·····••:••···· 7,602,500 Verify data integrity ' ' ' ' ' ' ' ' ' ' ' ' ...... {·········:·········· : ·········:··········:········ 1 ..... 7, 602 ,000 - ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' 7, 60 1, 500 ·······r·········--,··········r·········,··········,-·········,······ ' ' ' ' ' ' ' ' ' ' ' ' ·······r·········,··········r·········,··········r·········,······ ' ' ' ' ' 7, 60 1,000 ' Visualise data ' ' ' ' ' ' ' ' ' ' ' ' ' ' · • •• · · ·r • · •• • · · · · -.· · • • · · · · · · r ·•• ' ' • • ·· • · -.· • • · · • · · · • r • · • ··• ' ' • ••-. ' · · · · • · · • • ·.- · • ·· ' · • •• • , .. · · · • 7, 600 , 500 ' ' ' ' ' ' ' ' 7, 600 ,000 ······r·········-.··········r·········-.··········r·········,··········.-·········,···••· ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ...... ' ............................................................... . ·~ ' ' ' ' ' ' ...... . ........ ' . ·• 7, 599 , 500 ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' 292,000 294,000 296,000 298,000 300,000 302,000 304,000 306,000 E astiig Evidence based decision making rationalises relationship between Client and Contractor
Dis isappointing Dis ischarge Producti tion • Dredging professionals can accurately estimate suction and discharge production with specialised tools such as Pumps ‘n Pipeline (PnP) • Define pumps and pipelines before committing or . ,. ... Pump Regression Curves .... <I0 .000 Ftowr.i e:~~J to . GOO u, _J :J i r -- -=- --~ f ~ l~ -~ ~ =•·= 03 ~ 3 ~ ,F ~ 2~ •~ ·1 = 6 . 00 = ~ l ~ • :n d~ : Fl ~ • ~ ·~ l~ .7 31 = :_ _ ~ '.:..._ ___ l mobilising. Required data includes: I ... : I Pump engine characteristics j Pump characteristics .. u, Pipeline configuration i 60 Cl • 37 .005,C2 • 0. 583 and C3 • 0.705 10oi :1 i- - L ___:_ . _ ___:_ __ . _IEI/III " • Provide enough definition on mixture properties Pump Range Diagram from geotechnical data. Required data includes: no-.u :1~1 0 Particle size distribution Shell content In-situ, lump and solid density Yield stress
~ Pumping Productio ion Lim imitations in in One Graph • Operating areas: Production Lim it ations (PrQ-Diagram) Green is “possible” Fl owrate (Q) [USG/min) 0 20 ,00 0 40, 000 60 , 000 80 , 000 100,000 120,000 140 ,000 Orange is “challenging” 16,000 20,000 Red is “impossible” 14,000 • Pump Production 12,000 ';:' 1 5,000 ~ :, 0 .c ,E_ Limitations: ,;;- ~ E "O >, 10,000 a a · ;;; · ;;; i i Pickup mixture density ~ 0. 0. 8,000 1 0,000 ~ C 0 0 'ti 'ti Pump’s limiting vacuum :, :, e "O e 6,000 0. 0. Engine’s characteristics 4,000 5, 000 Mixture’s critical velocity kg /m 1 2, 000 4 6 8 Flowrate (Q) [m 3 /sec)
~ ~ ~ ~ Ris isks of No Cla lay Ball l Degradatio ion • Hydraulically transporting clay balls is a major risk as its potential impact on discharge production is disastrous, if not expected • Clay balls are likely to remain intact when: Di sc h ar ge Pro duction Lim it ation (P r ld - Di agram) Dischar ge P ip e li ne Lengt h (Ldl [ ft ] 2, 500 5, 000 7,500 10 ,000 12, 5 00 15 ,0 00 17, 5 00 1, 600+----~---~---~---~-------~---~--~ ~ - -- ._. - 2, 000 Clay content > 50% ·- 1 ,4 00 +- + Clay Balls 1, 75 0 Undrained shear 41& ,,...~. _,. ·~ . 1.200 _--, Discharge P roduction Li mit ation (Prl d-Diagr am ) 1, 500 12001:1,1 / m' Dischar ge P ipeline Length (Ld} [ ft ] strength > 25 kPa "' 0 2,50 0 5,000 7,500 10 , 000 1 2, 50 0 15 ,000 17,500 __[ ,E 1, 000 l . 600 +- --- ~~ -- - --- ~ --- ~ --- ~ --- ~ - - - ~ --~ " e 1, 250 { 2,0 00 1 1,1/ m 1 12f0k .~ ___j. + .~ Situ density 1, 400 Slurrified + 800 1,0 00 [ 1, 750 ~ • • l 600 B B 75 0 J > 1,500 kg/m 3 1, 200 1, 500 "' ,E 1, 000 4-00 1 1, 250 { Liquid limit 1 1 800 l 0S0J: 1,1/ in' 250 1, 000 [ > 25% < 125% • § o+- ----~-- - -~----- ~ ----~----- ·~ 600 1so I o 1,000 2, 000 3, 000 4, 000 5, 000 Di sch arge Pi p el ine Le ngth ( ld l [m ] Plasticity Index + 4-00 500 > 25% + 200 o+- ---- ~ ---- ~ ----- ~ ---- ~ ----- o 1, 000 More physical modelling anp detailed field observations are required
Underestimating Cutting Production in iJ redging in Hard Rock in Solutions adding value • Large Contractors have gained invaluable expertise on cutting hard rock • Cutting hard rock is less known by remainder of dredging industry • The risk from the potential presence of rock is often underestimated or even ignored Cutter head aver-cutting SMPa rack. • The cutting of hard rock can be limited by: Arrows shaw teeth and resultant farces. Cutter Power Side Winches Spud Hold Force Ladder Weight
~ ~ ~ ~ ~ ~ ~ Underestimating Cutting Production in in Hard Rock (2 (2) • The cutting forces on each tooth allow calculation of the resultant force, a principle on which the Subsea Rock Cutting (SRC) estimation tool is based • The resultant force is Utili sa tion of In stalla t i on 1 600 counteracted by the cutting 14 00 installation 0-8 1200 + :i: cutter UC r2 0.6 + 1000 J_ side winch UC .§. i:1 2 ... s pud UC C: ... ladderUC 0 + /J!. ,; ,.. cutterOC ... 800 . ,, + -0 C: e side winch OC 0 + Q. "' spudOC 3 0.4 ..... ladderOC ";~ --- ~~ - r.:J-t~ - ;tA --- - ,.;JJL~ - tA ---- ~~ - - ,.;J'thith - 5 ! =:1 -::'~ . , ~ w ~ = w~ = ~ = ~ - ~ ~ w 600 " _ _ F ··~ ~ r= ~ w 1 ~ 1 ! .. .. I 400 ~:::.:>-- 1r~ ---- v~ --- 1r~ ----- u -- ~ ---- ~ ---- 1r~ ----- 11 - ~ --- ~ 0-2 I ii: - 'Y"'' -' 'V'r-¥~Vr\tifr,=y_ - Vr\t1frri=y. - -- - ---- - 200 !~j ~i~7 ~ J o_o L -L ---~---~----- • ====~=======~ 0 4 6 8 10 12 14 Unconfined Compressive Strength (UCS) [MPa] 3 4 S 6 Mm!Mtlllnb!M(...:J
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