Page 50 - Practical Well Planning and Drilling Manual

Section 1 revised 11/00/bc 1/17/01 2:55 PM Page 26

[ ] Well Design
1.3.2

PBR Monobore Openhole Prepacked Cemented
Completion Screen Completion Completion

Fig. 1-3 Examples of Possible Monobore Completion Schemes

Advantages of slimhole, monobore wells.

1. Reduced well cost/enhanced project profitability.
2. Increased activity levels as cheaper wells make conventional, mar-
ginally economic prospects worthwhile.
3. The capabilities of existing installations can be extended.
4. Possibly reduced location size (purpose-designed slimhole drilling
rig), waste, and environmental impact.
5. Ideally suited to completions through several reservoirs where the
reservoirs are produced and abandoned from the bottom up or pro-
duction can be commingled.
6. Increased wellbore stability in some formations (e.g., fractured
shales).
7. Coiled tubing drilling—especially underbalanced—may provide
sidetracking opportunities from existing wells while minimizing
impairment.
8. More expensive drilling and completion fluids can be used to min-
imize impairment since the volumes required are much less.
9. Monobore completions allow fullbore access to the reservoir and
give more flexibility in managing the reservoir. Most or all well

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