American Oil and Gas Reporter - December 2019 - 77

The pre-kick signs sometimes do not
show with lateral wells. The drilling fluid
may be gas cut because of drilled gas, or
show minimal background gas, so crews
do not pay much attention to gas concentrations unless they change significantly. Cuttings remain generally the
same as the lateral is drilled because the
drilling program follows the formation.
Porosity changes are subtle if they happen
at all, so ROP may not be a reliable kick
indicator. With most lateral wells, pit
volume is the only accurate kick indicator
in the lateral portion.
This case history offers several lessons.
First, drillers need to be empowered to
shut the well in when they think the well
is kicking, even if there is no flow. As the
case study showed, a well may be kicking
to the point of serious consequences and
never present a positive flow check.
Second, when consolidated gas moves
into the vertical section of the well unnoticed, even if there is not the dramatic Utube effect of the drilling fluid seen in
the case history, the gas expands rapidly.
In fact, with every one-half of the distance

to surface, with uncontrolled expansion,
the gas doubles in size.
To put that rapid expansion in perspective, if a 2-barrel kick enters the
well's vertical section at a depth of 10,000
feet, at 5,000 feet, the gas volume will be
4 barrels. By 2,500 feet, it'll reach 8
barrels. At 1,250 feet, it'll be 16 barrels.
By 625 feet, the volume will be 32 barrels.
When gas reaches 625 feet, there are only
19 barrels of available annulus space with
a .0301 barrel/foot annulus capacity. At
that point, the gas poses a credible risk to
the crew and assets at the well site.
If the driller stops to do a flow check
early when gas is in the vertical, he may
see minimal or no flow because of the
formation's low permeability; any flow
seen would be gas expansion. In many
cases, the flow will look like ballooning
(see "Ballooning Perception May Be
Flawed," AOGR April 2019). Because
most of the other standard kick signs
may be difficult to detect, we need to
consider PVT gains the primary kick indicator, especially when drilling deep,
unconventional lateral wells.
❒

NRG Safe is dedicated to safety in the oil and gas
industry. Our solar powered LED safety markers
are the preferred option when electricity is not
available on your location. These markers also aid
in darkened roadway illumination, lane delineation
and as a wrong way driver deterrent to create a
safer environment on high-traf昀c roads.

No Batteries
10 + Year Life
No Wires
Grid Independent
100% Waterproof
Multiple Color Options
3 Year Warranty

STEVE L.
RICHERT

Steve L. Richert is manager of instructor and course development at
Wild Well Control in Houston, where he
leads education and development for
well control instructors, including
knowledge progression, certification,
and course creation and refinement. He
has 20 years of industry experience,
coupled with a 20-year adult education
background focusing on how humans
acquire knowledge. Richert joined Wild
Well Control in 2012 after serving as a
driller at Ensign Energy Services, and
as a financial specialist at U.S. Bank
and TD Ameritrade. He studied mechanical engineering at the University
of Oklahoma and holds a B.A. in history
and philosophy from Grace University.

YHYS

YHDD

405.558.1295 * www.nrgsafe.com * sales@nrgsafe.com
DECEMBER 2019 77

http://www.nrgsafe.com

American Oil and Gas Reporter - December 2019

Table of Contents for the Digital Edition of American Oil and Gas Reporter - December 2019