DTI Perspective on Reservoir Surveillance

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DTI Perspective on Reservoir Surveillance
15 September 2004
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Quote from the late Laurie Dake Thorough data
acquisition is expensive (very expensive) and it
is the duty of practising reservoir engineers to
convince those who hold the purse strings of the
necessity of the exercise.
The Practice of Reservoir Engineering
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Overview

• DTI-LCU remit
• PILOT initiatives
• UKCS reserves
• Brown field growth
• Reservoir surveillance
• General issues
• Field observations
• Conclusions

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DTI-LCU aim

• Maximise economic recovery of UK oil gas
• while minimising environmental impact

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Reservoir surveillance is important throughout
field life

• Need to establish economic viability of
  reservoir, .e.g EWTs
• Gain reservoir understanding for effective
  management
• Establish that reservoir is uneconomic prior to
  abandonment

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PILOT targets

• Government industry partnership
• Striving to meet 2010 target

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PILOT targets

• Government industry partnership
• Striving to meet 2010 target
• Can only be achieved via
• New field development
• Brown field growth
• Exploration success

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UK production forecast (mmboe/d)
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DTI initiatives

• PILOT
• Fallow process
• Promote licences
• Access to data
• Infrastructure code of practice
• Brown field work group
• Plus
• Work with ITF on technology development
• IOR conferences, web sites, eNewsletter

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UKCS recovery factor distribution
Northern North Sea Oil Recovery 43 (upside 45)
Central North Sea Oil Recovery 46 (upside 49)
Gas Recovery 65 (upside 71)
Southern North Sea Gas Recovery 74 (upside 78)
Source DTI
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Improving brown field recovery
Source UK Oil Gas Commemorative Volumes
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Brown field growth

• Brown field WG addressing barriers
• Typical success factors
• Cost control
• Combining technologies
• Technological advances
• Drilling completion
• Geo-steering
• Sub-sea tie-back
• Improved reservoir understanding
• Integrated approach
• 3D/4D advances

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By-passed trapped oil

• Causes
• Reservoir compartmentalisation
• Fault shadows
• Heterogeneity
• Attics
• Opportunities
• Better utilise injection
• Infill / sidetrack locations
• Well work / re-perforation / water or gas shut-off

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1) Existing wells draining effectively?
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1) Existing wells draining effectively?
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2) Existing wells draining effectively?
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2) Existing wells draining effectively?
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3) Existing wells draining effectively?
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Typical surveillance approaches

• Routine
• RFT, LWD, logging
• Production performance
• Non-routine
• 3D/4D, geochem, geomech, SrRSA
• Permanent surveillance
• Difficulty in estimating value
• More advanced cost/benefit analysis?

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Andrew production 4D surveys
Water Rate
Maximising Brown field Recovery
OIL Rate
Baseline 3D
2001
2002
2004
3D/4D Survey acquisition
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Surveillance challenges past and present

• Compartmentalisation
• Impacted injection strategies
• Hydraulic fracturing
• Poorly controlled water injection
• Marginal / sub-sea developments
• Pre-drilled wells
• Based on static data
• Non-optimum well placement
• Defer injection wells?
• Inaccurate zonal allocation
• Inability to model reservoir

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UKCS reserves categorised by development type
UKCS reserves 20 billion boe
Platform Fields
Undeveloped
Subsea tiebacks
FPFs/FPSOs
Source DTI web page
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Way forward - reservoir surveillance

• Continue to refine and improve surveillance
• Down-hole flow- pressure-meters
• By zone
• Continue to integrate data observations
• More sophisticated analysis
• Tailor strategy to specific reservoir situation
• Address key uncertainties
• Develop case for thorough data acquisition

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For DTI oil gas information
Thank you for listening

• http//www.og.dti.gov.uk/

or contact

• colin.cranfield_at_dti.gsi.gov.uk
• 01224 254066