Deep Panuke Project Description - Encana

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Table 2.10Centre Substructure Type AlternativesAlternativeNew buildjack upTechnical SuitabilityExisting proven designs are available forthe Deep Panuke site conditionsCost/Lease Commercial Risk Technically and ConceptEconomically Feasible DeliverabilitySafetyCapital cost slightlyLow Yes Best No specifichigher than jacketsconcernsEnvironmental ImpactLow/negligible similar toother alternativesLease availableRefit existingjackupExisting harsh environment drill rigs exist,although none presently identified asavailable.Capital cost higherthan new buildjackupLease not availableHigh cost & schedule overruns tobe expectedYes Poor Existing rig mayrequire significantupgrades to meetregulationsLow/negligible similar toother alternativesJackdeckRelatively new concept, no provenexperience in these environmentalconditionsCapital cost higherthan new build jackupMedium (new design could leadto overruns, potentially singlesource supplier)Yes Risk involved No specificconcernsLow/negligible similar toother alternativesTechnically acceptable , with riskJacket Proven for Deep Panuke site conditions Lease option notavailableLowTechnically feasible; noteconomically feasibleSteel Semi-SubmersibleHullTechnical concerns related to riser designand mooring, adjacent to other platformsand riser designLack of experience in shallow/harshconditionsOnly one semi in use for gas production(deeper water)Slightly higher thanjacket optionGreater than jacket NoConcrete GBS Gravity based system (GBS) widely used –six examples in water this shallowMost expensiveSingle source of supply couldlead to high costsNoInshore topside analysis avoids large cranerequirementDeep Panuke Volume 4 (Environmental Assessment Report)• November 2006 2-64
Jacket-type structures piled into the sea floor are the most common solution world-wide for theenvironmental conditions experienced at the Project site. This concept is currently in use in Nova Scotiaby SOEP. The concept has the advantage of offering the lowest cost, technically acceptable solutionwith acceptable commercial risk. However, the disadvantage is that fixed structures have little to noresidual value at the end of a project as they are unlikely to be reused on another project. Since thisoption does not fit with EnCana’s financing objectives for the projected life of the Deep Panuke Project,it was rejected based on commercial considerations.Mobile StructuresTwo types of mobile structures were investigated; a jack-deck structure and a jack-up type structure.Each of these configurations can be used to construct a MOPU. The MOPU concept provides a facilitythat is designed to self-install, produce oil or gas at a given location and then demobilize for reuse atanother location. This concept is in use world-wide for fields that have marginal reserves or are expectedto have a short production life. Also, contractors may offer these types of structures on a lease basis;therefore the capital cost can be amortized over more than one project.Both the jack-deck and the jack-up concept are quite similar, each employing a three-legged structuresupporting a production topsides. The MOPU is brought to the field centre where it self elevates byjacking up on location. Risers for production fluids and export pipeline are connected to the structure forconveying produced fluids on and off the structure. At the end of the field life, the risers aredisconnected from the flowlines and pipeline, legs are retracted and the platform jacked down forremoval from the field. The structure can potentially be relocated and reused at another field.The main difference between the jack-deck and the jack-up structure is in the design of the deck. Thejack-deck is a custom engineered lattice-type structure designed to house the specific productionequipment needed for the specific application. Because it is a lattice-type structure, it cannot float andtherefore is brought to and removed from location on a barge. The jack-up type structure incorporates afloating hull so it does not require a barge for transportation. The jack-up carries a purpose-built topsidesto provide the necessary production equipment. The jack-up hull design concept is used extensively formobile offshore drilling rigs.The jack-deck concept was investigated and deemed to be technically feasible. However, it had somedistinct disadvantages when compared to the jack-up concept. First, this concept requires a customdesign where the topsides are fully integrated into the supporting leg structure. Further, the legs andfoundations are custom engineered for the specific application. Thus, at the end of the Project life, thechance of reuse for this type of structure at another location is greatly reduced, thus affecting theresidual value of the MOPU. The majority of the cost must be amortized over one project. Also, thisstructure type must be transported on an installation barge. The on-site installation using a barge schemeDeep Panuke Volume 4 (Environmental Assessment Report) • November 2006 2-65
Page 1 and 2:
2 PROJECT DESCRIPTIONThis section p
Page 3 and 4:
Potential Radioactive Components: T
Page 5 and 6:
2.2.2 Subsea Wells and FlowlinesThe
Page 10 and 11:
2.2.3.1 M&NP OptionThe proposed pip
Page 12 and 13:
The onshore portion of the pipeline
Page 14 and 15: 2.3 Construction and Installation2.
Page 16 and 17: 2.3.2 Export PipelineA proposed pip
Page 18 and 19: A dedicated subsea umbilical will b
Page 20 and 21: Table 2.2 Construction MethodsCateg
Page 22 and 23: These subsea structures may be fast
Page 24 and 25: For the new production and injectio
Page 26 and 27: Figure 2.8Typical Production Well S
Page 28 and 29: 2.3.8.1 Drilling Fluid ProgramWater
Page 30 and 31: Table 2.4 Hydrostatic Fluid Dischar
Page 32 and 33: Acid GasInjectionFeed GasCompressio
Page 34 and 35: Although the M&NP Option is the onl
Page 36 and 37: Spent TEG has no measurable H 2 S a
Page 38 and 39: Table 2.7 Water CompositionComponen
Page 40 and 41: 2.4.2 Utilities2.4.2.1 Electrical P
Page 42 and 43: will be designed considering emerge
Page 44 and 45: zones over the pipeline although th
Page 46 and 47: 2.7 Emissions and DischargesEnCana
Page 48 and 49: Table 2.8 Routine Project Emissions
Page 50 and 51: 2.7.1.1 Air PollutantsThe following
Page 52 and 53: esult in eye irritation, respirator
Page 54 and 55: Typically, a re-entry and completio
Page 56 and 57: 2.7.5.3 Deck DrainageDuring constru
Page 58 and 59: 2.9.2 Pipeline Leak PreventionThe p
Page 60 and 61: 2.9.5 Subsea Protection StructuresT
Page 62 and 63: • consider concept alternatives f
Page 66 and 67: is much more weather-dependent than
Page 68 and 69: Table 2.11 Processing Location Alte
Page 70 and 71: After carefully considering the con
Page 72 and 73: Flaring acid gas consists of direct
Page 74 and 75: Table 2.13Produced Water Disposal A
Page 76 and 77: Therefore, injection into an annula
Page 78 and 79: Use of a dedicated condensate pipel
Page 80 and 81: is taken offshore on a special lay
Page 82: Table 2.15Acid Gas Injection Locati
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Deep Panuke Project Description - Encana

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