Perforating through cemented 3½ tubing and cemented 9⅝″ casing

Hi folks

At a recent well-specific Risk Assessment that I was facilitating, we got round to discussing potential well-test scenarios.

The land-well has multiple targets, with the uppermost likely being encountered in 12¼" hole size, which will then be isolated with a cemented 9⅝" casing string.  The deeper target will be drilled in 8½ size and a 3½ cemented monobore installed. The TOC behind the 3½ string may or may not be brought above the upper zone; current thinking is not to.

Testing the deeper section is likely to be quite straightforward.

However, we got to talking about how the upper section might be tested.

It is likely we would be faced with having to perforate through our 3½ string, across a 3½ × 9⅝" annulus (mud-filled) and through a 9⅝" string cemented in 12¼" open-hole.

The perforating company's first-look suggested that this would not be practical.

It would be good to hear what experience that our members have in this regard; please be careful to separate fact from opinion.

Things like:

1. Have you faced a similar challenge ?
2. What did you do about it ?
3. If you did perforate as suggested above, what did you learn ?

With kind regards

Dave

1 Answer(s)

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