Production of hydrogen by steam reforming of methanol

Abstract

Binary Cu/ZnO catalysts (with a Cu/Zn atomic ratio of 50/50) prepared via a novel dry synthetic approach based on solid-state oxalate-precursor
synthesis were studied in regard to their performance in the steam reforming of methanol (SRM). The synthesis route involves facile solid-phase
mechanochemical activation of a physical mixture of simple copper/zinc salts and oxalic acid, followed by calcination of the as-ground oxalate
precursors at 350 ◦C. For comparison, their conventional analogues obtained by aqueous coprecipitation techniques were also examined. Structural
characterization of the samples was performed by means of N2 adsorption, X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform
spectroscopy (DRIFTS), thermal gravimetric and differential thermal analysis (TG/DTA), scanning electron microscopy (SEM), temperatureprogrammed
reduction (H2-TPR), N2O titration, and X-ray photoelectron spectroscopy (XPS). The results show that the grinding-derived Cu/ZnO
catalysts exhibit superior SRM performance to their conventional counterparts obtained by wet-chemical methods. The enhanced performance of
the grinding-derived catalysts can be attributed to a higher copper dispersion as well as the beneficial generation of highly strained Cu nanocrystals
in the working catalyst. It is proposed that the present soft reactive grinding route based on dry oxalate-precursor synthesis can allow the generation
of a new type of Cu/ZnO materials with favorable surface and structural properties, providing an attractive alternative for preparation of improved
heterogeneous catalysts.

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Completion Components lec ( 7 )

Introduction 

The selection of completion equipment and hardware is based on the reservoir,
field, wellbore and operational requirements that will achieve efficient, safe and
economic production.
There are many types of components available, each of which may be specified
in a number of service or dimensional variations, (e.g. H2S or normal service).
Principal completion components are categorized as follows:

•  Production packers
•  Gas lift equipment
• Safety valves
•  Tubing flow control equipment
•  Permanent
•  Retrievable
•  Completion accessories

Production Packers 

The packer is often considered the most important downhole tool in the
production string. Completion packer types vary greatly and are typically
designed to meet specific wellbore or reservoir conditions, (e.g., single or
tandem packer configurations, with single, dual and triple completion strings).
Production packers can have several functions. However, the principal function
of a packer is to provide a means of sealing the tubing string from the casing or
liner. This seal must provide a long-term barrier compatible with reservoir
fluids or gasses and the wellbore annular fluid.
The production packer must also enable efficient flow from the producing (or
injection) formation to the tubing string or production conduit.

Downhole Anchor

 A secondary, but nonetheless important function of most packers is to provide
a downhole anchor for the tubing string. However, cup or isolation packers do
not anchor the tubing stringcontinued next However cup or isolation packers,
do not anchor the tubing string.

Subsurface Safety Valve

These hydraulically operated tubing flow control valves are used offshore, in
critical locations (next to a school or home) and areas of concern of the
environment, the reservoir, the facilities and the personel.

Gas Lift

Sidepocket mandrels with dummy valves are run in new free flowing completions
where workover costs are high and the reservoir will require artificial lift to
deplete.

Tubing Flow Control Equipment

This equipment expands the value of the completion by introducing flexibility.
Nipples, sleeves, plugs, chokes, test tools, standing valves, bomb hangers,
etc. could be utilized.

Casing String
Protection Example

For Casing
String Protection.

In most wellbores, the casing string or liner is a permanent component of the
completion system. Since casing replacement or repair procedures are
complicated and expensive, systems are designed (using packers) to protect
the casing from pressure differentials and corrosive conditions. The packer
and tubing string is typically easier to repair and/or replace than the casing
system.

Formation Safety
Control Example

For Downhole Formation
Safety Control


High Pressure gas and fluids are generally encountered at some depth. In the
absence of heavy completion fluids, a packer provides an effective means of
isolation. The high pressure can then be controlled by subsurface safety
valves in the tubing string attached to the packer. This also enables some
control of pressure on the wellhead. By inserting a tubing plug in the packer,
creating a temporary bridge plug, workover work above the packer can be
carried out with a greater degree of safety.

Multiple Zone
Completion Examples

For Zone Separation

 In multiple zone completions, it is generally necessary to separate the producing
zones for the following reasons:

•  Legality - Government regulations monitor produced flow-rates as

allowable production. Often each production zone must be isolated,
which is more easily accomplished through the use of a packer.

•  Control of formation fluids - Frequently, high and low pressure

zones are encountered. Packers are used to prevent cross flow of
reservoir fluids.

Artificial Lift Example
To Facilitate
Artificial Lift

When using gas lift to enhance production, a packer is utilized to separate
the produced fluid pathway from the injected gas pathway down the
annulus. Packers are often used with ESP’s to facilitate control of well zones.
Tubing anchors are commonly used to increase the efficiency of rod pumps.
Anti-rotational anchors are commonly used with progressive cavity pumps.

Remedial and
Repair Examples

To Facilitate
Remedial / Repair Work


In situations where casing is damaged, two packers can be used to seal off and
bypass the damaged area. With the use of accessory completion equipment,
such as stingers and on-off attachments, tubing can be pulled for repair and/or
replacement without releasing the packer.

Completion course

Tubulars con't lec ( 6 )

High Strength
Tubing Failure

Failures of high-strength tubing are normally caused by:

•  Manufacturing defects
•  Handling/transportation damage
•  Hydrogen embrittlement

API Tubing
Connections

There are two standard API coupling tubing connections available:

The API EUE type of connection is available in 23/8”, 27/8”, 31/2” and 41/2”.

Extra Clearance

 It is occasionally necessary to provide extra clearance to enable tubing
installation. To accommodate this, API couplings can be turned down (to
specified tolerances) without loss of joint strength. Special clearance collars
are usually marked with a black ring in the center of the color band indicating
steel grade. Extra-clearance, coupling-type thread forms have been developed
for non-upset tubing which have 100% joint strength.
Integral-joint premium threads provide additional clearance and are available
in a number of configurations. Some can be turned down to provide even
greater clearance. This type of joint is more expensive and is generally used in
special situations (high-pressure or gas well application).

Premium Tubing
Connections

In addition to the standard API connections, there are a wide variety of specific
joint connections available usually referred to as premium connection. Most
premium connections use a metal-to-metal seal which requires that the mating
pin and box surfaces are forced together with sufficient stress to establish a
bearing pressure greater than the differential pressure across the connection.
The bearing pressure (Pb) is defined as the pressure exerted between the metal
surfaces created by the torque used at make-up.
Premium connections are available in a wide variety of types, weights and
materials

Connection Seals

 Round thread connections form several metal-to-metal seals between the tapered
portions of pin and box surfaces. The small void between the crest and root of
the mating threads must be filled with thread compound solids in order to
transmit adequate bearing pressure from one threaded surface to another.
Some connections (e.g., HYDRIL) have large smooth metal-to-metal
connections. The threads in this type of connection have a relatively large
clearance and do not act as seals. Threads like Armco Seal Lock have both a
sealing thread and a smooth metal scaling surface (Fig. 10). A Teflon ring is
used in some premium connections to provide a supplementary seal and provide
corrosion protection.
The stresses applied during make-up and subsequent service determine the
success of the connection seal. When compiling tubular make-up procedures
the minimum, optimum and maximum torque for each connection type must be
known.

Basic String Design
and Selection

When selecting completion components, consider the factors shown below.
This of course is in addition to the basic efficiency, safety and economic
requirements of all completions.

•  Facilitate installation
•  Optimize production
•  Simplify maintenance
•  Enable stimulation or workover
•  Provide for contingency

Tubular
Design Factors

The basic string design and selection process should take into
account the following guidelines before detailed planning is begun:

Drift Inspection

 Before running in the hole, drift the tubing with an API drift mandrel to ensure
the internal clearance is within tolerance.
Handle all tubing (new, used or reconditioned) with thread protectors in place.
Do not remove the thread protectors until the tubing is ready to be stabbed.
High-strength tubing is particularly susceptible to damage caused by improper
shipping and handling practices.

Measurement

 When running tubing and completion components, careful measurement of
each joint or item is essential. Each measurement is recorded in a tally book
against the joint number which should be clearly marked on each joint. The
tape used is divided into feet and decimal fractions, (e.g., the reading for 20 ft.,
6 in., would be read as 20.5 ft.).
Tubing joints (and other string components) are measured from the box end to
the beginning of the threads on the pin end (not the end). Record completion
components on a separate sheet of the tally book. The length, OD, grade and
ID are listed as appropriate for each component.
When the grade and size of pipe has been chosen, details of the following
points should be made known to field personnel:

•  Handling - Tubing, especially high grade tubing (P-105, etc.)

must be handled carefully without dropping, denting, or nicking.

•  Torque - Too loose or too tight make-up on a joint connection

can result in failure.

•  Record (Tally) keeping - Accurate measuring and recording of

tubulars and placement of downhole components is essential. A
packer accidentally placed below the perforated interval is a prime
example of mis-measuring or miscounting tubing joints.

Running the
Tubing String

NOTE: Use PPE equipment.