American Oil and Gas Reporter - September 2015 - 118

SpecialReport: Tubulars Technology
etration rates."
With WDP, all this required data can
be transmitted at high speeds and updated
as frequently as every five seconds, which
Van Burkleo says unlocks increased penetration rates. "In a North Sea case study,
average ROP gains of 50 percent were
achieved with WDP across 14 production
sections drilled on four rigs," he reports.
"These rig time savings alone will more
than pay for the incremental cost for
WDP."
Because WDP costs more than conventional pipe, Van Burkleo suggests
that the best applications are multiwell
drilling campaigns where the operator
can save multiple days per well, and
these savings provide a return on the
WDP purchase investment.
To expand the technology's application
window, NOV has introduced a second
generation designed to improve reliability
and reduce total cost of ownership, Van
Burkleo reports. The new generation includes major changes, he outlines:
* The IntelliCoilTM, an inductive coil
that goes on the pin and box end of each
joint to help data move from one joint to
the next, sits farther back on the pin
nose, so it is no longer the first point of
contact if a connection is stabbed poorly;
* The data links, which are repeater
subs placed along the drill string to
amplify and clean the signal, have upgraded electronics and battery controller
system; and
* The DataCableTM that runs along
the internal diameter of the pipe uses InconelTM armoring instead of stainless
steel for increased corrosion resistance.
"We also have a new surface network
controller system," he continues. "It is a

touch-screen display that is mounted in
the driller's cabin. By providing an easy
way to manage the telemetry system and
troubleshoot any issues that arise, it
enables measurement-while-drilling companies to operate the system rather than
needing a dedicated rig technician."
The improvements have paid off, Van
Burkleo says. "Since introducing the second generation system, we have seen
significant improvement in system uptime,
which now runs 90-100 percent, with
some U.S. land rigs achieving 99 percent
uptime," he reports.

Casing Guide
Running large-diameter casing through
the severe doglegs characteristic of deepwater
and onshore horizontal wells can be challenging, observes Sarah Mitchell, engineering
manager for drilling tools at WWT International. "Large-diameter casing is extremely
stiff, so when an operator wants it to curve,
it will try to remain straight and dig into
the side of the well," she says.
To address that problem, Mitchell says
WWT International developed the WWT
FlexShoeTM, a composite casing shoe that
is extremely flexible. In fact, testing has
shown that it has 5 percent the stiffness
of steel.
"When we looked at why casing gets
stuck, we came to the conclusion that the
problem is at the bottom of a string,
where the exposed portion of the casing
can hang on ledges or doglegs and dig
into the side of the well," she says. "By
putting a flexible member at the bottom
of the casing, we distribute the load on
the string more effectively, so that instead
of digging into the wellbore, the bottom
generates forces that guide the rest of the

WWT International says the WWT FlexShoe™ offers a reliable and economic way to help
casing navigate doglegs in horizontal and extended reach wells.

118 THE AMERICAN OIL & GAS REPORTER

string around obstructions."
Although developed for offshore wells,
Mitchell says the WWT FlexShoe has
proven successful in onshore horizontals.
"The casing in onshore applications is
less stiff, but the dogleg angles are more
severe, so the shoe can be extremely
helpful," she relates.
"Because the shoe is so flexible, if it
takes 5,000 pounds to flex a certain casing
grade through a dogleg, it should take
only 5 percent of that load to do so with
the flexible casing shoe," she says.
Noting that WWT International worked
with Shell to understand operators' needs
while developing the product, Mitchell
reports that the shoe has been tested thoroughly. "The main structural components
have been tested at 150-200 percent of
their rated compressive loads without
failure," she reveals. "In a large-diameter
application, we can put almost 250,000
pounds of weight on the components before they start failing."
As of mid-August, the technology had
performed successfully in all Gulf of
Mexico and onshore horizontal well applications to date, according to Mitchell.
"We have had multiple runs on land and
in deep water, and every run has gone
well," she says. "The casing has gotten
to target depth without significant problems, even in areas where there was
trouble in previous wells. The shoe has
proven to be easy to put in a well, easy
to run down, and easy to drill out."

Tough Pipe
After decades of using nylon in the
hot and chemically rich environment
under a car's hood, as well as in hockey
sticks and other equipment that must endure constant impacts, Koch Industries
subsidiary INVISTA saw an opportunity
to bring the material to the oil patch.
"Nylon has great temperature stability
and resistance to abrasion, impacts and
chemicals, so we thought it would be a
good fit for oil and gas pipe," recalls
Steve Easley, the business manager for
RaptorTM nylon pipe.
That theory has proven correct, Easley
says, noting that Raptor has been applied
in 50 projects to date. "The most common
application is flowlines, but it also has
been used to handle produced water and
gather gas," he details.
"One of our earliest uses of Raptor
nylon pipe was a surface line in a demanding gas gathering application. It has
seen strong fluctuations in pressure, from
American Oil and Gas Reporter - September 2015

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