Hydrocarbon Processing - February 2021 - 33

Digital Transformation
have been deployed across various industries to enable customers to maximize
long-term production, optimize maintenance spend and improve reliability-as
shown in the following examples:
1. Identification, categorization,
summary and reporting of
production losses
Challenge: Process
manufacturers need to track and
categorize performance losses
to identify bad actors, justify
improvement projects, and
perform historical and global
benchmarking. Production
loss accounting for process
manufacturing is a tedious
activity that can cost days of work
for process engineers. It requires
identifying losses, performing
root cause investigations, and
documenting the events leading
up to the loss. To make this
information available to all
interested personnel, it needs
to be easily aggregated into
reports that convey overall
equipment effectiveness and
identify unreliable equipment.
Effective use of this data can
inform decision making on capital
project spending to remove
process bottlenecks and upgrade
unreliable equipment, with the
end goal of minimizing downtime,
maximizing production rates
and optimizing maintenance.
This categorization is hard to do
retroactively, and most accurate
performance loss coding is done
either programmatically or by
frontline personnel at the time
of, or shortly after, a performance
loss event.
Solution: Digital toolsa are used
to identify performance losses
by comparing an operation to
ideal situations and creating
conditions when the operation
is constrained compared to
target. Losses are categorized
using specific conditions, where
events can be placed in the
correct categorical buckets, either
manually or logically, based on
configured thresholds. Summary
visualizations are created in the
application to represent the losses
both graphically and tabularly.

These summary visualizations
are compiled into an organizerb,
where configurable live or
scheduled date ranges are used
to create automatically generated
periodic reports, complete
with collaboration and sharing
capabilities (FIG. 1).
Result: Automatically generated
monthly reports can save
1 d/mos-5 d/mos of valuable
process engineering time. This is
time that engineers can get back
to work on improvement projects
and other value-added activities.
Easily exportable historical
loss data enables engineers
to spend more time adding
value to improvement projects
and less time developing
cost justifications.
2. Production run length
optimization
Challenge: Many process
manufacturing units hit process
throughput constraints over the
course of a run, resulting in the
degradation of production rates
over time. These constraints
are often reversible, but at the
cost of shutting down to clean/
maintain equipment. Sometimes,
the decision to shut down and
clean equipment-regaining
the throughput rate upon
startup-enables a unit to meet
its production goals sooner.
This type of planned downtime
also reduces maintenance
spend, as opposed to spending
time reacting to equipment
failure. Meeting targets sooner
translates into more production
and increased profits over the
long term. Developing solutions
to these types of optimization
problems typically requires
complex calculus, along with
advanced modeling packages and
programming experience.
Solution: A calculation enginec
was used to calculate the number
of shutdowns that would
minimize the total time required
to produce a given order size.
After determining the optimal
number of shutdown/run cycles,
engineers were able to determine
the run length between

shutdowns and to create a golden
profile of these run cycles. The
forecasted profile was then used
to compare against the actual
production rate to understand
where the projected end-of-run
date stood compared to the
best-case order fulfillment date
(FIG. 2).
Result: A sold-out production
unit had been looking at ways
to increase capacity to meet
demand. By implementing this
proactive downtime strategy, they
were able to meet supply chain
targets on average 11% sooner
over the course of the year. This
allowed them to creep production
volumes for multiple products
by a proportional amount, thus
growing sales and market share.
Takeaway. Reporting, complex calculations, modeling and other tasks required
for analysis of time series process data
have traditionally been performed using spreadsheets. As data volumes grow,
along with pressures to increase personnel productivity, new solutions are needed to deal with these and other issues.
Advanced analytics applications that
are specifically designed to deal with
time-series process data provide a solution for large data volumes. As these use
cases demonstrate, utilizing the right tool
for the job saves hours or days of process
engineer time, freeing these valuable individuals to work on higher-value activities
that will optimize production, increase
reliability and optimize maintenance.
NOTES
Seeq Workbench
b
Seeq Organizer Topic
c
Seeq Formula
a

ALLISON BUENEMANN is a Senior
Analytics Engineer for Seeq Corp.
She has a process engineering
background, and spent her
early career with ExxonMobil,
working in petrochemical
and polymers manufacturing.
Ms. Buenemann has spent much of her time
completing improvement projects to debottleneck
constrained unit operations and making operational
decisions with the goal of maximizing production.
In her current role, she draws on that manufacturing
experience to provide advanced analytics solutions
to customers in all process industry verticals.
She earned a BS degree in chemical engineering
from Purdue University in Indiana, and an MBA
degree from Louisiana State University.
Hydrocarbon Processing | FEBRUARY 2021 33



Hydrocarbon Processing - February 2021

Table of Contents for the Digital Edition of Hydrocarbon Processing - February 2021

Contents
Hydrocarbon Processing - February 2021 - Cover1
Hydrocarbon Processing - February 2021 - Cover2
Hydrocarbon Processing - February 2021 - Contents
Hydrocarbon Processing - February 2021 - 4
Hydrocarbon Processing - February 2021 - 5
Hydrocarbon Processing - February 2021 - 6
Hydrocarbon Processing - February 2021 - 7
Hydrocarbon Processing - February 2021 - 8
Hydrocarbon Processing - February 2021 - 9
Hydrocarbon Processing - February 2021 - 10
Hydrocarbon Processing - February 2021 - 11
Hydrocarbon Processing - February 2021 - 12
Hydrocarbon Processing - February 2021 - 13
Hydrocarbon Processing - February 2021 - 14
Hydrocarbon Processing - February 2021 - 15
Hydrocarbon Processing - February 2021 - 16
Hydrocarbon Processing - February 2021 - 17
Hydrocarbon Processing - February 2021 - 18
Hydrocarbon Processing - February 2021 - 19
Hydrocarbon Processing - February 2021 - 20
Hydrocarbon Processing - February 2021 - 21
Hydrocarbon Processing - February 2021 - 22
Hydrocarbon Processing - February 2021 - 23
Hydrocarbon Processing - February 2021 - 24
Hydrocarbon Processing - February 2021 - 25
Hydrocarbon Processing - February 2021 - 26
Hydrocarbon Processing - February 2021 - 27
Hydrocarbon Processing - February 2021 - 28
Hydrocarbon Processing - February 2021 - 29
Hydrocarbon Processing - February 2021 - 30
Hydrocarbon Processing - February 2021 - 31
Hydrocarbon Processing - February 2021 - 32
Hydrocarbon Processing - February 2021 - 33
Hydrocarbon Processing - February 2021 - 34
Hydrocarbon Processing - February 2021 - 35
Hydrocarbon Processing - February 2021 - 36
Hydrocarbon Processing - February 2021 - 37
Hydrocarbon Processing - February 2021 - 38
Hydrocarbon Processing - February 2021 - 39
Hydrocarbon Processing - February 2021 - 40
Hydrocarbon Processing - February 2021 - 41
Hydrocarbon Processing - February 2021 - 42
Hydrocarbon Processing - February 2021 - 43
Hydrocarbon Processing - February 2021 - 44
Hydrocarbon Processing - February 2021 - 45
Hydrocarbon Processing - February 2021 - 46
Hydrocarbon Processing - February 2021 - 47
Hydrocarbon Processing - February 2021 - 48
Hydrocarbon Processing - February 2021 - 49
Hydrocarbon Processing - February 2021 - 50
Hydrocarbon Processing - February 2021 - 51
Hydrocarbon Processing - February 2021 - 52
Hydrocarbon Processing - February 2021 - 53
Hydrocarbon Processing - February 2021 - 54
Hydrocarbon Processing - February 2021 - 55
Hydrocarbon Processing - February 2021 - 56
Hydrocarbon Processing - February 2021 - 57
Hydrocarbon Processing - February 2021 - 58
Hydrocarbon Processing - February 2021 - 59
Hydrocarbon Processing - February 2021 - 60
Hydrocarbon Processing - February 2021 - 61
Hydrocarbon Processing - February 2021 - 62
Hydrocarbon Processing - February 2021 - 63
Hydrocarbon Processing - February 2021 - 64
Hydrocarbon Processing - February 2021 - 65
Hydrocarbon Processing - February 2021 - 66
Hydrocarbon Processing - February 2021 - 67
Hydrocarbon Processing - February 2021 - 68
Hydrocarbon Processing - February 2021 - 69
Hydrocarbon Processing - February 2021 - 70
Hydrocarbon Processing - February 2021 - 71
Hydrocarbon Processing - February 2021 - 72
Hydrocarbon Processing - February 2021 - 73
Hydrocarbon Processing - February 2021 - 74
Hydrocarbon Processing - February 2021 - 75
Hydrocarbon Processing - February 2021 - 76
Hydrocarbon Processing - February 2021 - 77
Hydrocarbon Processing - February 2021 - 78
Hydrocarbon Processing - February 2021 - 79
Hydrocarbon Processing - February 2021 - 80
Hydrocarbon Processing - February 2021 - 81
Hydrocarbon Processing - February 2021 - 82
Hydrocarbon Processing - February 2021 - 83
Hydrocarbon Processing - February 2021 - 84
Hydrocarbon Processing - February 2021 - GP-1
Hydrocarbon Processing - February 2021 - GP-2
Hydrocarbon Processing - February 2021 - GP-3
Hydrocarbon Processing - February 2021 - GP-4
Hydrocarbon Processing - February 2021 - GP-5
Hydrocarbon Processing - February 2021 - GP-6
Hydrocarbon Processing - February 2021 - GP-7
Hydrocarbon Processing - February 2021 - GP-8
Hydrocarbon Processing - February 2021 - GP-9
Hydrocarbon Processing - February 2021 - GP-10
Hydrocarbon Processing - February 2021 - GP-11
Hydrocarbon Processing - February 2021 - GP-12
Hydrocarbon Processing - February 2021 - GP-13
Hydrocarbon Processing - February 2021 - GP-14
Hydrocarbon Processing - February 2021 - GP-15
Hydrocarbon Processing - February 2021 - GP-16
Hydrocarbon Processing - February 2021 - GP-17
Hydrocarbon Processing - February 2021 - GP-18
Hydrocarbon Processing - February 2021 - GP-19
Hydrocarbon Processing - February 2021 - GP-20
Hydrocarbon Processing - February 2021 - GP-21
Hydrocarbon Processing - February 2021 - GP-22
Hydrocarbon Processing - February 2021 - GP-23
Hydrocarbon Processing - February 2021 - GP-24
Hydrocarbon Processing - February 2021 - GP-25
Hydrocarbon Processing - February 2021 - GP-26
Hydrocarbon Processing - February 2021 - GP-27
Hydrocarbon Processing - February 2021 - GP-28
Hydrocarbon Processing - February 2021 - GP-29
Hydrocarbon Processing - February 2021 - GP-30
Hydrocarbon Processing - February 2021 - GP-31
Hydrocarbon Processing - February 2021 - GP-32
Hydrocarbon Processing - February 2021 - GP-33
Hydrocarbon Processing - February 2021 - GP-34
Hydrocarbon Processing - February 2021 - GP-35
Hydrocarbon Processing - February 2021 - GP-36
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2024-v2
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2024
https://www.nxtbook.com/gulfenergyinfo/gulfpub/gas-processes-handbook-2022_v2
https://www.nxtbook.com/gulfenergyinfo/gulfpub/gas-processes-handbook-2022
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hp_202212
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2023-v2
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2023
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hp_202211
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202210
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202209
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202208
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202207_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202207
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202206_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202206
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202205_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202205
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202204_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202204
https://www.nxtbook.com/nxtbooks/gulfpub/hp_032022
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202203
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202202
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202201
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202112
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202111
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202110
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2022_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2022
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202109
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202108
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_processes_handbook_2021_v2
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_processes_handbook_2021
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202107
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202106
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202105
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202104
https://www.nxtbook.com/nxtbooks/gulfpub/hp_ebooks
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202103
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202102
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202101
https://www.nxtbook.com/nxtbooks/gulfpub/catalyst_handbook_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/catalyst_handbook_2020
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202012
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202011
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202010
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2021
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202009
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202008
https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020
https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202007
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202006
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202005
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202004
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202003
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202002
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202001
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201912
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201911
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2020
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201910
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201909
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201908
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201907
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201906
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201905
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201904
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201903
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201902
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201901
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018_v2
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201812
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201811
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201810
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201809
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201808
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201807
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201806
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201805
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201804
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201803
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201802
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201801
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201712
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201711
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201710
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201709
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201708
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201707
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201706
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201705
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201704
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201703
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201702
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201701
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2017mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201612
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201611
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201610
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201609
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201608
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201607
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201606
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201605
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201604
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201603
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201602
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201601
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201512
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201511
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201510
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2016mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201509
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201508
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201507
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2015tmsd
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201506
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201505
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201504
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201503
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201502
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201501
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201412
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201411
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2015mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201410
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201409
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201408
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201407
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014petrochemicalprocesses_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014petrochemicalprocesses
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201406
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201405
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201404
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201403
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014calendar
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201402
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201401
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201312
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201311
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201310
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201309
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201308
https://www.nxtbook.com/nxtbooks/gulfpub/hp_srsguide2013
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201307
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201306
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201305
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201304
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201303
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201302
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201301
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201212
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201211
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201210
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201209
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201208
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201207
https://www.nxtbook.com/nxtbooks/gulfpub/hp_srsguide2012
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201206
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201205
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201204
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201203
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201202
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201201
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201112
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201111
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201110
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201109
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201108
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201107_srsguide
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201107
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201106
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201105
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201104
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201103
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201102
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201101
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201012
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201011
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201010
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201009
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201008
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201007
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201006
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201005
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201004
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201003
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201002
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201001
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200912
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200911
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200910
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200909
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200908
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200907
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200906
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200905
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200904
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200903
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200902
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200901
https://www.nxtbookmedia.com