StimGun sect 2 Intro 9/19/02 11:50 PM Page 8

Tools, components, and industry

usage
Brent Kirschner, Owen Oil Tools

T he StimGun family of products currently consists

of three unique tool configurations – the
StimGun™ assembly, the StimTube™ tool and the Well
The StimGun technology is best understood as an
engineered job design process that integrates the use
of the products with PulsFrac™ computer modeling and
Stimulation Tool (WST). These three products allow data acquisition using the high-speed gauge. Unlike
for maximum stimulation design flexibility for a wide approaches used by others, the StimGun technology
range of well configurations. With each of these prod- takes into account well fluids, well mechanicals, and
ucts, production/injection enhancement is accom- rock properties to select the optimum tool for each
plished through perforation breakdown and near- specific application.
wellbore stimulation.

StimGun family of products

StimGun™ assembly

StimTube™ tool

Well stimulation tool (WST) and hardware

High-speed/high-shock downhole memory gauge

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I n t r o d u c t i o n

StimGun™
The StimGun assembly
™
perforating gun systems from 2 ⁄8 in. (60.3 mm)
3

The StimGun™ assembly has two major compo- through 7 in. (177.8 mm) outer diameter (OD).
The StimGun™ assembly can be lowered into the
nents – a conventional hollow steel perforating gun
well on wireline, tubing or drill pipe, or with coiled
and a sleeve of special propellant material sur-
tubing.
rounding the gun. The perforating gun is fired in
the wellbore as normal, and as a result of the per- Industry Usage
forating process the sleeve is ignited. The sleeve, As of December 2001, over 30,000 ft (9140 m)
which is a proprietary oxidizer, and binder combi- of the StimGun™ assembly have been run. This rep-
nation burns quickly and produces a burst of high- resents thousands of successful completions. These
pressure gas. This high-pressure gas enters the per- include onshore-offshore oil, gas, and injector wells
foration and creates fractures resulting in an around the world. The StimGun™ assembly is a
improved flow path from the formation to the well- field-proven method of perforating and stimulating
bore. The sleeves are available for hollow carrier in one run.

StimGun™ assembly components

Propellant sleeve – Cast tube of a proprietary oxidizer/resin binder material, similar in appearance to plastic pipe, that
simply slides over the perforating guns. The “propellant-like” material (actually classified as an oxidizer) is ignited by the per-
forating events. Usually a minimum of four shots per foot is required to adequately ignite the sleeve. However, 6 spf (20 spm)
are generally recommended. Maximum temperature rating is 330°F (160°C). The sleeves are impervious to all current well
fluids.

Centralizing rings – Used to position and secure the sleeves to the outside of the perfo-
rating gun. In addition to securing the sleeves, the rings are available over-sized (typically
sleeve OD + 1⁄4"/6.4 mm) to protect the sleeves from contact with the casing.

Finned tandem/bull nose subs – Subs centralize

the assembly and protect the sleeves – while resulting
in minimum flow restriction. Typically gun OD + 1⁄2"
(12.7 mm)

Perforating guns – Typically hollow steel carrier guns are recommended. Sleeves are currently available for the follow-
ing gun OD sizes: 23⁄8", 21⁄2", 23⁄4", 27⁄8", 31⁄8", 33⁄8, 4", 41⁄2", 45⁄8", 51⁄8", & 7" (60.3 mm, 63.5 mm, 69.9 mm, 73 mm,
79.4 mm, 85.7 mm, 101.6 mm, 130.2 mm & 177.8 mm).

High-speed/high-shock downhole memory gauge – Data acquisition at rates up to 100,000 points per second
(user programmable for high, intermediate, and low speeds). Sensors available include pressure, temperature, acceleration –
high-G for shock measurement and acceleration, low-G for tool velocity calculation. Maximum memory = one million
data points. Sizes available (OD) = 111⁄16" & 2" (42.9 mm & 50.8 mm). Maximum temperature rate = 255°F (125°C).

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The StimTube™ tool cord is then initiated causing the oxidizer to ignite.
The StimTube™ tool consists of a molded cylinder of Similar to the StimGun™, the StimTube’s proprietary
propellant-like oxidizing material surrounding an propellant burns quickly and produces a burst of
internal steel support tube containing detonating high-pressure gas.
cord. The StimTube™ tool provides efficient, cost
Industry Usage
effective remediation to existing perforated or open-
hole intervals. The StimTube™ tool is available in a As of December 2001, over 12,000 ft (3660 m) of
variety of sizes including 11⁄2 in., 111⁄16 in., 2 in., 21⁄2 in., the StimTube™ assembly have been run. Applications
and 3 in. (38.1 mm, 42.9 mm, 50.8 mm, 63.5 mm are primarily through-tubing pre-hydraulic fracture
and 76.2 mm). The StimTube™ tool is run into the treatment and stimulation of damaged wells, where
wellbore, typically on wireline, and positioned across wellbore restrictions do not allow for the use of the
existing perforations. The conventional detonating StimGun™ assembly.

StimTube™ tool components

The StimTube™ – A cast cylindrical rod of proprietary oxidizer/resin material with an embedded steel support tube, ignited
with 40 grain detonating cord. Available sizes – Outside Diameters – 11⁄2", 111⁄16", 2", 21⁄2", and 3" (38.1 mm, 42.9 mm, 50.8
mm and 76.2 mm); lengths – 1', 2', 3', and 4' (.3 m, .6 m, .9 m and 1.2 m). Maximum temperature rating = 340°F (170°C).
Impervious to all well fluids.

Firing head – Used to connect the detonator to the detonating cord and to connect the tools to the wireline or coiled tubing.

Connecting subs – Used to assemble multiple StimTube™ tools and to minimize tool contact with the casing. Generally,
maximum recommended total length per run of StimTube™ tool for wireline applications is 15' (4.6 m). Longer lengths can be
run on continuous tubing.

Bull nose sub – Used to terminate the assembly and protect the propellant and detonating cord end seal.

High-speed/high-shock downhole memory gauge – Typically run just below the wireline cable head.

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I n t r o d u c t i o n

StimGun™
Well Stimulation Tool (WST) Industry Usage
The WST is a “stick” tool consisting of a cast cylin- As of December 2001, over 15,000 ft (4570 m)
drical rod of a proprietary oxidizer/resin material of the WST has been run. This product has an
with a central ignition system. It is primarily used in extremely reliable ignition system and a verified
perforated or open hole wells with no inner diame- burn repeatability. The WST is primarily used as a
ter restrictions. perforation breakdown tool and as a horizontal
well stimulation tool.

Well Stimulation Tool components

End view

WST available sizes – ODs 11⁄2", 111⁄16", 2 in., 21⁄2 in., and 3 in. (38.1 mm, 42.9 mm, 50.8 mm, 63.5 mm and
76.2 mm); lengths – 1', 2 ft, 3 ft, and 4 ft (.3 m, .6 m, .9 m and 1.2 m). It is ignited with 40, 60, or 80 grain detonat-
ing cord, however 40 is typically recommended. Maximum temperature rating – 250°F (120°C). Impervious to all well
fluids except methanol.

Steel carriers – Similar to a spent perforating gun except with typically 24-1" holes per foot. It is available in
several ODs depending the specific WST used.

Connecting subs – Used to assembly multiple WSTs. Generally, maximum recommended total length per run of WST
for wire line applications is 12 ft (3.7 m). Lengths of over 1000 ft (305 m) can run on tubing.

Bull nose sub – Used to terminate the assembly.

Firing head – Used to connect the detonator to the detonating cord, and to connect the tools to the wire line or tubing.

High-speed/high-shock downhole memory gauge – Typically connected below the bull nose sub.

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