Page 241 - Well Control for Completions and Interventions

CHAPTER SEVEN

Well Kill, Kick Detection, and
Well Shut-In

7.1 INTRODUCTION
Killing a well prior to a workover or intervention is a necessary and
planned part of the operation. There is normally time to decide upon the
most appropriate kill method and design the operation, based on the best
use of available data. A pre-intervention risk assessment can be carried
out, and the kill procedure written into a detailed work program for use
at the well site. This chapter describes the methods most commonly used
to kill wells when preparing for a workover or intervention. It goes onto
describe how well control can be restored following an unplanned kick
during a completion, intervention, or workover on a dead well.
There are several important and distinct differences between drilling
well control and well control during completions, workovers, and inter-
1
ventions. With much of well control training focusing on drilling related
issues, i.e., managing a kick whilst drilling ahead or tripping pipe, some
of the well control complexities associated with completion and workover
operations are overlooked. It is important that staff engaged in completion
and workover understand, and can manage, these differences. The impor-
tant ones are:
• When drilling, one of the main well control concerns is the integrity
(fracture pressure) of the exposed formation at the previous casing shoe.
This is normally the weak point and defines pressure limitations and the
maximum allowable annulus surface pressure (MAASP). Exceeding the
fracture pressure of the exposed formation would cause fluid loss.
During completion and interventions, the weak point is almost always
the exposed production formation. MAASP during a workover is either
defined by the pressure limits on the production casing and wellhead,
or by the fracture pressure of exposed formations.
• During a drilling operation, allowing a gas kick to migrate toward the
surface without choke controlled expansion can be disastrous. Most

Well Control for Completions and Interventions. © 2018 Elsevier Ltd.
DOI: https://doi.org/10.1016/B978-0-08-100196-7.00007-5 All rights reserved. 235