liquid loading is a problem associated with in gas wells , this presentation is a part of out graduation project

1. UOT- OIL& GAS ENGINEERING DEPARTMENT
Presented By :
Kadhim Adnan Atiyah
Mohamed Sami Kadhim
Abbas Ghanim Khazal
Supervised by: Asst. Lect. Ali Anwar Ali
PREDICTING THE PROBLEM OF
LIQUID LOADING IN GAS
WELLS

2. Motivations
the extraction of natural gas has challenges. One of the most significant issues is
liquid loading, a phenomenon that occurs when liquids accumulate in a gas well,
hindering its performance and, in severe cases, leading to its premature
abandonment. We focused on this problem for several considerations :
1.The problem liquid loading is serious and could lead to the death of the well if
its occurrence is not predicted and treated
2.Despite the many studies on this problem, we did not find any Iraqi research
that addresses the problem or even some of it.
3.Our desire to make a sensitivity analysis on how to control or reduce the
problem if it occurs.
4.This is the first study applied to gas wells in Iraq using real field data of a gas
field using prosper software

3. Introduction
Gas wells usually create condensate, or water or both. In the early phases of
production, the gas flow rate is adequate to raise the produced liquids to the
surface. The produced gas flow rate decreases as the reservoir pressure decreases
up until the gas hits a critical state, which lowers the gas's capacity to carry liquids
[1]. The liquid loading then begins. When liquid loading happens, liquids start to
accumulate at the bottom of the well because the gas flow rate isn't high enough
to carry the liquid to the surface[2][3]
The primary limiting element preventing liquid loading is this critical gas velocity
(gas flow rate)[4][5]. The liquid will then eventually rise to the surface as a result
of the growing back pressure and the elevated reservoir pressure. The gas forces
the liquid slug out of the well, allowing the liquid to refill it. Up until the well is
eventually completely filled and gas production stops, this process is repeated.

4. Introduction
Over time, this buildup of liquid may generate enough hydrostatic pressure in the
wellbore to significantly reduce or perhaps stop gas production altogether. The
liquid in low pressure wells may totally destroy or kill the well[6][7][8][9]. In
higher-pressure wells, there may eventually be a variable degree of slugging or
churning of the liquids if solutions like velocity string, gas lift, soap injection, or
plunger lift are not used to remove the liquids promptly[5][10]. This could have an
impact on calculations used in routine well tests[7].
As a gas well ages and reservoir pressure decreases, liquid loading is typically
seen in the latter stages of the well's life [2][11][8].

5. Fig 1 : Life history of a gas well.( Lea et al 2003)

6. Gas velocity theories
A number of authors have proposed techniques for figuring out whether a well's
flow rate is adequate to remove particles in the liquid phase. Wellhead velocities
recorded in the field, according to Vitter and Duggan [12], should be sufficient to
maintain wells unloaded. Jones and Dukler gave analytical procedures that
produced formulas for figuring out the minimal required flow rate based on
physical characteristics
Two physical models have been presented to explain the evacuation of gas well
liquids, according to an examination of these studies:
(1) liquid droplets entrained in the high velocity gas core, and
(2) (2) liquid film migration along the pipe walls.

7. Literature Survey
van et al (2007)
clarified the process that causes liquid loading
to begin. They observed the phenomena that
happens when gas velocity is reduced in a
flow-tube experiment and conducted
multiphase flow studies. Liquid loading is
associated with film-flow reversal, they
determined based on droplet size and velocity
data. Furthermore, the change from annular
to churn flow occurs at the same time as the
film-flow-reversal phenomena.

8. Literature Survey
Alamu et al (2012)
After conducting laboratory studies Alamu
came to the conclusion that during cocurrent
annular flow, the film-flow reversal happens
at the transition between mist and annular
flows

9. Literature Survey
Yuan et al (2013)
in their multiphase-flow studies for deviated
and vertical pipes. They came to the
conclusion that, for vertical and deviated
wellbores, the flow-pattern change from
totally cocurrent annular flow to partially
cocurrent annular flow initiates the
commencement of film-flow reversal.
Consequently, rather than droplet-flow
reversal, the research conducted by these
authors suggests that liquid loading is related
to film-flow reversal.

10. Literature Survey
Ikpeka et al
(2019)
developed a new and improved model to
predict liquid loading in gas wells. This model
was then included into the Ms-Excel
application. The new model adds a
deformation coefficient, represented by "C,"
to account for the liquid droplet's deformation
along the wellbore and precisely predict the
critical rate when the droplet changes from a
spherical to a flat shape. the new model had a
20 percent error rate

11. methodology
In this project, liquid loading analysis will be carried out on a field data by suing
the turner method. As well as carrying out a sensitivity analysis by using PROSPER
software. The following stages will be carried out in this study:
1. Well data collection:
a. Reservoir data: reservoir pressure, reservoir temperature, reservoir
thickness, permeability, reservoir porosity, reservoir area.
b. Fluid data: Water cut, physical properties of fluid, fluid composition.
c. Well data: depth, perforation interval. Tubing ID, completion
d. Production data: production rate, PI, Pwf, Pwh, WGR.
2. Identify liquid loading with critical velocity using the turner method to determine
if the well is experiencing liquid loading problems.
3. Create a well model using PROSPER software.
4. Create sensitivity scenarios.
5. Evaluate the production rate with several assumptions regarding critical velocity.

12. methodology
The flow diagram for this study is shown in figure below
Start
Problem
Identification
Data collection:
1. Well profile data
2. Formation data and
reservoir characteristics
Data processing :
1.Input well data
2. Identify liquid loading
problems
3. Create a sensitivity
scenario
Data
analysis

13. References
[1] R. Ming, H. He, and Q. Hu, “A new model for improving the prediction of liquid loading in horizontal gas wells,” 2018, doi:
10.1016/j.jngse.2018.06.003.
[2] D. Zhou and H. Yuan, “A new model for predicting gas-well liquid loading,” SPE Prod. Oper., vol. 25, no. 2, pp. 172–181, 2010, doi:
10.2118/120580-PA.
[3] H. V. Lea, James F.; Nickens, “Solving Gas-Well Liquid-Loading Problems,” J. Pet. Technol., 2004, doi: 10.2118/72092-jpt.
[4] A. Banafi, M. R. Talaei, and M. J. Ghafoori, “A comprehensive comparison of the performance of several popular models to predict
pressure drop in stratified gas-liquid flow with low liquid loading,” J. Nat. Gas Sci. Eng., vol. 21, pp. 433–441, Nov. 2014, doi:
10.1016/j.jngse.2014.09.009.
[5] G. Li, Y. Yao, and R. Zhang, “An improved model for the prediction of liquid loading in gas wells,” J. Nat. Gas Sci. Eng., vol. 32, pp.
198–204, 2016, doi: 10.1016/j.jngse.2016.03.083.
[6] F. A. Spe, F.-O. Damilola, and F. Olugbenga, “An Improved Predictive Tool for Liquid Loading in a Gas Well.”
[7] A. E. Turner, R. G., Hubbard, M. G., & Dukler, “Analysis and prediction of minimum flow rate for the continuous removal of liquids
from gas wells.,” J. Pet. Technol., 1969, doi: 10.2118/2198-PA.
[8] M. F. Riza, A. R. Hasan, and C. S. Kabir, “A pragmatic approach to understanding liquid loading in gas wells,” SPE Prod. Oper., vol. 31,
no. 3, pp. 185–196, 2016, doi: 10.2118/170583-PA.
[9] S. B. Coleman, H. B. Clay, D. G. McCurdy, and H. L. Norris, “New look at predicting gas-well load-up,” JPT, J. Pet. Technol., vol. 43,
no. 3, pp. 329–333, 1991, doi: 10.2118/20280-pa.
[10] M. A. Nosseir, T. A. Darwich, M. H. Sayyouh, and M. El Sallaly, “A new approach for accurate prediction of loading in gas wells under
different flowing conditions,” SPE Prod. Facil., vol. 15, no. 4, pp. 241–246, 2000, doi: 10.2118/66540-PA.
[11] K. E. Abhulimen, K. E. Abhulimen, and A. D. Oladipupo, “Modelling of liquid loading in gas wells using a software-based approach,”
J. Pet. Explor. Prod. Technol., vol. 13, no. 1, pp. 1–17, 2023, doi: 10.1007/s13202-022-01525-x.
[12] M. Liao et al., “On the development of a model for the prediction of liquid loading in gas wells with an inclined section,” Fluid Dyn.
Mater. Process., vol. 15, no. 5, pp. 527–544, 2019, doi: 10.32604/fdmp.2019.07903.