This document discusses perforated joints, flow couplings, and blast joints used in downhole equipment. A perforated joint is installed above a no-go and provides flow bypass when gauges are installed. It must have a total cross-sectional area of holes equivalent to the tubing internal diameter. Flow couplings are installed where turbulence is expected, such as above and below crossovers or nipples, and have thicker walls to prevent early erosion failures. Blast joints are placed near perforations and have heavy, blast-resistant coatings to protect from extreme erosional forces opposite open perforations.

1. Perforated Joint
D o w n h o l e E q u i p m e n t
Eng. El Sayed Amer
03

2. El Sayed Amer
Bachelor's degree of Petroleum & Natural Gas Engineering
2012.
Sequence
of
well
drilling
and
completion
https://bit.ly/2UFSgpn
01065860658
Eng20072007@gmail.com
/elsayedameer
Current Senior Process and Production Engineer at Suez Oil
Co “SUCO” since 2014.
Worked for Weatherford drilling international for 2 years as
well drilling and completion engineer.
Instructor for Oil & Gas Upstream and downstream courses
at MTC Egypt, Egyptian syndicates of engineers, OGS & OPA.
Member of SPE, AAPG, AACE, NACE, Environmental
Geoscience.
IWCF , HYSYS process modeling, Eclipse certified.

3. Eng. El Sayed Amer
Page 38
03 Perforated Joint
Applications
• Installed above No-go to provide flow bypass
when gauges are installed.
• The design criteria for a Perforated Joint is
that the total cross-sectional area of the
holes should be at least equivalent to the
cross sectional area corresponding to
internal diameter of the tubing.

4. Flow Coupling, Blast Joint
D o w n h o l e E q u i p m e n t
Eng. El Sayed Amer
04

5. Eng. El Sayed Amer
04 Flow Coupling
applications
1. Flow couplings are short sections of thick walled pipe.
2. The additional wall thickness prevents early failures
due to erosion in the turbulent flow area.
3. Installed at points in the tubing string where excessive
turbulence is expected.
• above and below cross-overs,
• above and below a landing nipple, SSSV nipple,
etc.

6. Eng. El Sayed Amer
Flow Coupling

7. Eng. El Sayed Amer
05 Blast Joint
applications
1. Placed adjacent to perforations
2. Heavy Wall “blast resistant” coating.
• Ceramic
• Tungsten
• Rubber

8. Eng. El Sayed Amer
43
Flow Couplings and Blast Joints
Flow Couplings and Blast Joints are specialty
Tubulars designed to protect the tubing string from
excessive wear and premature failure.
Flow Couplings (at left) can be installed above and
below tubing nipples. During production turbulence
can exist above and below a nipple due to its
restriction. The Flow Coupling, having thicker walls
than the production tubing onto which it is made
up, accepts the turbulence as opposed to the
tubing.
Blast Joints can be situated in the tubing string
opposite open and flowing perforations. Here,
erosional forces can be extreme. And like the Flow
Coupling, the Blast Joint has thicker walls and
tolerates the erosion better than the tubing.