GWF-1 Development DrillWell

Transcription

1 GWF-1 Development DrillWell Gary Nettleship Completion Engineer 4 th September 2014 DRIMS#

2 Disclaimer and important notice This presentation contains forward looking statements that are subject to risk factors associated with oil and gas businesses. It is believed that the expectations reflected in these statements are reasonable but they may be affected by a variety of variables and changes in underlying assumptions which could cause actual results or trends to differ materially, including but not limited to: price fluctuations, actual demand, currency fluctuations, drilling and production results, reserve estimates, loss of market, industry competition, environmental risks, physical risks, legislative, fiscal and regulatory developments, economic and financial market conditions in various countries and regions, political risks, project delay or advancement, approvals and cost estimates. All references to dollars, cents or $ in this presentation are to Australian currency, unless otherwise stated. References to Woodside may be references to Woodside Petroleum Ltd. or its applicable subsidiaries. 2

3 Development Changes - NWS Previously: Platforms with multi-tcf* reservoirs Goodwyn, North Rankin and Perseus Now: Subsea tiebacks with smaller reservoirs 10 s to 100 s BCF** Perseus Over Goodwyn Persephone to NRA Echo Yodel GWF-2 to GWA GWF-1 to GWA 5 wells * TCF is Trillion Standard Cubic Feet ** BCF is Billion Standard Cubic Feet 3

4 Overview of GWF-1 Subsea tieback to GWA Wells Two SMART dual zone Frac Pack wells Three SMART dual zone ESS* wells Subsea & Topsides GDA02 16 pipeline with CRA** lining GDA01 Control umbilical from GWA platform Optical oil detection on GWA * ESS = Expandable Sand Screens ** CRA = Corrosion Resistant Alloy 4

5 Well Design Drivers Opportunity / Risk Wells intersect multiple reservoirs Some reservoirs have insufficient reserves to justify a well Oil production reduces condensate value Water production exceeds production system capacity High subsea well intervention costs Transient sand production likely in high rate subsea gas well Limited core material for sand control selection Impact Increase reserves per well by producing multiple zones Monitor un-produced zones for depletion Shut off oil or water production zone to produce gas from other zones Driver to use smart completion Subsea well requires sand control Select conservative sand control method Gravel pack Smart* subsea well with multiple zones & sand control *Smart = Real time acquisition of pressure and temperature data and remote control of zonal flow 5

6 Greater Western Flank 1 Development Five subsea wells tied back to Goodwyn Platform via 16 pipeline Three work phases: 1. Drilled five wells in Complete GDA01 & GDA02 in Complete three Tidepole wells GDA01 & GDA02: Two zone Frac Pack Two S shaped wells Monitoring zone with cable-less gauges SMART completion 6

7 GDA01 & GDA02 Completion Schematic 12 planned trips in hole New technology Install Upper Completion - 2m depth uncertainty over 3200m - 60 hours control line termination - Ensuring flat pack is not damaged 9-5/8 liner installed Small tubing & washpipe HDFAV Isolate Perforate Cure losses Upper Frac Pack Frac Pack Clean up x 2 Install GP completion Small debris intolerant components Cure losses Clean up x 2 Frac Pack high KH KH = Permeability * Formation Height 2.94 Isolation Ball Valve Isolate Perforate Lower Frac Pack Frac Pack Install GP completion Cable-less Gauge Perforate Complicated & high risk Install debris plug WBCU Monitoring Cure losses Zone Install sump packer / gauges

8 GDA01 Outcome GDA01 Installed dual zone cased hole Frac Pack completion Experienced challenges related to S shaped well increasing torque and drag Successful installation of SMART upper completion Successful execution of lower V3 interval gravel pack Compromised gravel pack of upper V5 interval Compromised V5 Gravel pack likely cause: Models predict high KH can be fractured V5 interval screened out early at 3ppg* Acetic Acid for clean up sub-optimal Insufficient proppant across top sand screen or Voids in the proppant pack * ppg = pounds per gallon Gas production erodes exposed sand screen 8

9 Frac Pack Application & KH GDA01 V5 interval looking to extend Frac Pack envelope 400, ,000 Frac and Pack Analogues Total Cameroon Analogue GDA01 V5 300, ,000 KH (md-ft) KH (md-ft) 200, ,000 GDA02 V2 100,000 50,000 GDA02 V Permeability (md) GDA02 V2 changed to High Rate Water Pack (HRWP) GDA02 V5 remained as Frac Pack 9

10 Learning implemented for GDA02 GDA02 Changes: Increased pump rate from 20 to 27 barrels per minute Pumped 15% HCl acid to clean up perforations Injectivity increased Committed to gravel pack integrity restress check on both zones V2 zone HRWP due to high KH V5 zone Frac Pack dependent on DataFrac, switch to HRWP if needed Result: V2 successful execution of HRWP 14,000 lb proppant placed V5 successful execution of Frac Pack 39,000 lb proppant placed up to 6 ppg Restress showed proppant above sand screens for both zones 10

11 Risk Balance Between Functions Learning: Increase Development focus on D&C risk Examples Subsea reducing scope / risk by centralising wells at manifolds resulting in S shaped wells Reservoir accessing more reserves with two zones versus single zone Accelerating D&C work to increase overall project value Subsea Well Constructability Risk 10 D&C 5 Central S-Shape Central Deviated GDA01 Res 0 SS Distributed Vertical Functional Complexity (GDA) Single Zone 2-zone SMART HRWP ESS 2-zone SMART F&P 11

12 Implementation for future projects DEVELOPMENT EXAMPLE Previous concept: Three SMART dual zone CHGP* After concept challenge: One SMART dual zone CHGP Two single zone OHGP** Central S-Shape Central Deviated Distributed Vertical Subsea Well Constructability Risk 3 Wells 2 Wells 1 Well * CHGP = Cased Hole Gravel Pack ** OHGP = Open Hole Gravel Pack Single Zone 2-zone SMART HRWP ESS 2-zone SMART F&P Key Learning: Increased challenge with other functions to balance project risk Preference for lower risk well types Increased Front End Loading for new complex well designs 12