Iraqi Journal of Chemical and Petroleum Engineering

The inhibitive action of polyvinyl alcohol –sodium nitrite (PVASN) composite on
the corrosion of mild steel in simulated cooling water (SCW) has been investigated by
weight loss and potentiodynamic polarization. The effect of composite concentration
(PVA/SN) , pH, and exposure time on corrosion rate of mild steel were verified using
2 levels factorial design and surface response analysis through weight loss approach,
while the electrochemical measurements were used to study the behavior of mild steel
in (SCW) with pH between 6 and 8 and in absence and presence of (PVA) in solution
containing different concentration of NaNO2. It was verified that all three main
variables studied were statistically significant while their interaction is less
pronounced.

Several correlations have been proposed for bubble point pressure, however, the
correlations could not predict bubble point pressure accurately over the wide range of
operating conditions. This study presents Artificial Neural Network (ANN) model for
predicting the bubble point pressure especially for oil fields in Iraq. The most
affecting parameters were used as the input layer to the network. Those were reservoir
temperature, oil gravity, solution gas-oil ratio and gas relative density. The model
was developed using 104 real data points collected from Iraqi reservoirs. The data was
divided into two groups: the first was used to train the ANN model, and the second
was used to test the model to evaluate their accuracy and trend stability. Trend test
was performed to ensure that the developed model would follow the physical laws.
Results show that the developed model outperforms the published correlations in term
of absolute average percent relative error of 6.5%, and correlation coefficient of 96%.

Water flooding is one of the most important methods used in enhanced production; it
was a pioneer method in use, but the development of technology within the oil
industry, takes this subject toward another form in the oil production and application
in oil fields with all types of oils and oil reservoirs. Now days most of the injection
wells directed from the vertical to re-entry of full horizontal wells in order to get full
of horizontal wells advantages.
This paper describes the potential benefits for using of re-entry horizontal injection
wells as well as combination of re –entry horizontal injection and production wells. Al
Qurainat productive sector was selected for study, which is one of the four main
productive sectors of South Rumaila oil field. A simulation model – named as SRFQ
was used in the present work to predict the re-entry horizontal wells performance.
Four scenarios were suggested to cover the full scope of the study; those scenarios are
different in manner of wells combinations. Cumulative oil production, ultimate
recovery percentage are two criteria were used to predict the performance and
comparison of scenarios.
Results from simulation model (SRFQ) runs revealed that the productive sector can be
continue to gain 1564.331 MMSTB till 2020, without changing to any existing
injection and production wells status, which is called the base scenario. While
scenario no.1 needs some of work over and remedies jobs, which gives more
cumulative oil production reaches to 1698.481 MMSTB till 2020.
On another side, scenarios no. 2 and 4 are the most important scenarios because reentry horizontal injection wells were implemented. Very good and encourage results
were gained over the bas scenario from the sector under study.
At last, scenario no.3 was suggested just to predict the production capacity of the Al
Qurainat sector with re-entry horizontal production wells and existing vertical
injection and production wells, while the cumulative oil production reaches
3398.481MMSTB.

In all process industries, the process variables like flow, pressure, level, concentration
and temperature are the main parameters that need to be controlled in both set point
and load changes.
A control system of propylene glycol production in a non isothermal (CSTR) was
developed in this work where the dynamic and control system based on basic mass
and energy balance were carried out.
Inlet concentration and temperature are the two disturbances, while the inlet
volumetric flow rate and the coolant temperature are the two manipulations. The
objective is to maintain constant temperature and concentration within the CSTR.
A dynamic model for non isothermal CSTR is described by a first order plus dead
time (FOPDT).
The conventional PI and PID control were studied and the tuning of control
parameters was found by Ziegler-Nichols reaction curve tuning method to find the
best values of proportional gain (Kc), integral time (

I) and derivative time (

D).
The conventional controller tuning is compared with IMC techniques in this work and
it was found that the Ziegler –Nichols controller provides the best control for the
disturbance and the worst for the set-point change, while the IMC controller results
show satisfactory set-point responses but sluggish disturbance responses because the
approximate FOPTD model has relatively small time delay.
Feedforward and feedforward combined with feedback control systems were used as
another strategy to compare with above strategies. Feedforward control provides a
better response to disturbance rejection than feedback control with a steady state
deviation (offset). Thus, a combined feedforward-feedback control system is preferred
in practice where feedforward control is used to reduce the effects of measurable
disturbances, while feedback trim compensates for inaccuracies in the process model,
measurement error, and unmeasured disturbances. Also the deviation (offset) in
feedforward control was eliminated.