Ogai Vladislav Scientific adviser : Yushkov Anton, PhD Industrial University of

922 004 0842
ogayvlad@mail.ru
The XV International Forum-Contest
of Students and Young

Researchers.
TOPICAL ISSUES OF RATIONAL USE OF NATURAL RESOURCES

RESEARCH STAND FOR
SIMULATION OF GAS-LIQUID FLOWS

for 64% of the Russian oil production and 91% of

the Russian gas production.
The map shows the fields of natural gas and gas condensates, which have the problem of fluid accumulation in wells.

Tyumen Region

Moscow

Tyumen Area

Figure 1.Geography of the Russian market of the product

σ – surface tension, n/m; ρl – liquid density, kg/m3;

ρg – gas density, kg/m3.

Figure 2. Liquid loading process by decreasing gas rate

The problem of liquid accumulation inside gas and gas condensate wells occurs at a low velocity flow of the gas-liquid mixture in the Production tubing. It should be noted that the problem occurs in almost all wells completed as high-permeability and low permeability reservoirs [1,2].

of the Russian Federation, PJSC Gazprom, on fields which provide

50% of gas production of the company more than 20% of fund make problem wells, every year their number increases [5].
For example, at the Yamburg field 344 wells are operated in the "self-kill" mode, at Medvezhye 198, according to forecasts of by 2030 on the Urengoy field there will be about 500 wells working in the “self-kill” mode [6,11].
Large residual reserves of Cenomanian gas field of depleted field increase the level of relevance of the issue (table 1)

Table 1. Residual reserves of Cenomanian gas field

tubing
Figure 4. Solid soap sticks
The technology of introducing foaming surfactants

into the well is widespread in the world, which is characterized by a relatively low level of capital investments and a high level of efficiency, including economic efficiency [7, 8, 9,10]
In the Russian Federation considerable experience of application surfactant (in most cases solid soap) in various regions is accumulated: on fields of the North Caucasus, Krasnodar Krai, the Orenburg region, Far North (Yamburg, Urengoy, Medvezhye, etc.) [11].
One of the most effective ways to production conditioning of well operating in liquid loading mode is to periodically or continuously inject liquid foaming surfactants into the well. In Russia, the technology is gaining popularity.

well fluid and the gas upflow to form a foam.

The foam formation reduce the density of the gas-liquid mixture and the surface tension between liquid and gas. Thereby reducing the critical speed required to remove the liquid.

Liquid level

Vt – critical velocity to lift a liquid, m/s;
σ – surface tension, n/m;
ρl – liquid density, kg/m3;
ρg – gas density, kg/m3.

Figure 5. Liquid level changing after surfactant treatment

Before

After

water the technology of injection of liquid surfactant was tested

in three Cenomanian wells of the field "M" in the winter 2015-2016
Pneumatic pumping units (figure 6) were used for injection of foam additives for constant dosed supply into wells.
Works on surfactant testing were carried out in several stages:
Stage I - impact treatment of surfactant wells (40-60 liters), exposure to the response time, work wells (gas production) to well flare stack to remove the accumulated liquid and sand from the bottom hole of the wells.
Stage II - work wells (gas production) to the gas gathering line with a constant dosed supply of liquid surfactant in the annular space was (18-20 l/day. surfactant solution at 200-250 l/day. waters)

Figure 6. Pneumatic pumping units

rate without the use of surfactants for the removal of

liquid from the bottom hole of wells with a production tubing with a diameter of 168 mm and bottom-hole pressures varying within 0.7-1.2 MPa is from 94 to 101 thousand m3/day. The use of surfactants reduced the critical flow rate to 50-60 thousand m3/day. As a result of the application of the technology in the wells decreased sand ingress, increased well flow rate to 90 – 100 thousand m3/day without restrictions on the removal of mechanical impurities, the average increase in the operating flow rate was about 40 thousand m3/day.

Figure 7.Field data after use surfactant

the lack of multiparameter models (functional relations) describing the multi-phase

foamed flow in gas well with surfactants. These models represent multidimensional arrays (VFP-tables) and characterize drop pressures between the bottom and the top of well.
In Russia, the stands for research of multi-phase flow are not adapted for qualitative studies of foaming flow.
The few computational models obtained by foreign groups have drawbacks and require adaptation at the fields in the Russian Federation, including for the developed Cenomanian fields, due to specific conditions of development (low liquid content in the flow, low formation pressure, large diameters of production tubing, etc.).

THE LACK OF MODELS OF MULTI-PHASE FOAM FLOW

TNO
Film liquid content:
with
Film viscosity:
Interfacial friction:
with
Γf – mean film

quality
Гf,max – maximum foam quality
f – film thickness
D – pipe diameter
K1 to K8 – general constants
C – surfactant concentration
C* – surfactant specific concentration
, , 0 – modelling variables
Resg – gas phase superficial Reynolds number

By DUT

By TU

with

Film liquid content:

Lubrication layer:

fs – surfactant specific scaling factor for the surfactant concentration
E1 to Е5 – constants
Usg – shear breaking down the foam
UTurner – estimate of the critical velocity using the Turner relation
lub – lubrication layer thickness
l, g, foam – liquid, gas and foam densities
 – surface tension
CD – drag coefficient of a sphere

Interfacial friction:

with

Film viscosity:

Interfacial friction:

Film liquid content:

Foam holdup:

Total liquid holdup:

G1 to G10 – constants
Usl – superficial liquid velocity
 - – unloading potential

mm/s, l =1000 kg/m3,
l = 1∙10-3 Pas, g =

1.2 kg/m3, and g = 1.8∙10-5 Pas
The anionic surfactant (TU) at 1000 wppm
The surfactant ‘Trifoam’ (DUT) at 3000 wppm
The surfactant ‘Foamatron’ (TNO) at 2000 wppm
Concentration scaling factors: fs.anionic =3fs.Trifoam fs,Foamatron=1,5fs,Trifoam

Case 2
Input: D = 100 mm, Usl = 10 mm/s, l = 1000 kg/m3,
l = 1∙10-3 Pas, g = 1.2 kg/m3, and g = 1.8∙10-5 Pas
The anionic surfactant (TU) at 1000 wppm
The surfactant ‘Trifoam’ (DUT) at 3000 wppm
The surfactant ‘Foamatron’ (TNO) at 2000 wppm
The concentration scaling does not seem to hold here.

Prediction Models COMPARISON versus experiments

Figure 9. ptot (a) and αl (b) as a function of Usg for an air/water/foam flow in a D = 100 mm pipe.

The models of TNO and DUT agree reasonably well with the experimental data for ~5 m/s < Usg < ~25 m/s.
The deviation of the model of TU with the experimental data is significant for the pressure gradient.
The deviation for the model of TU is small for the liquid holdup.

All models have more difficulty in predicting the flow in the D = 100 mm pipe.
The models of DUT and TNO seem to deviate least from the experimental data for the pressure gradient, while the results with the model of TU are closest to the experimental data for the liquid holdup.
The results with the models of TU and TNO are similar in shape, but differ by a factor of about 1,5.

Figure 8. ptot (a) and αl (b) as a function of Usg for an air/water/foam flow in a D = 50 mm pipe

conduct the experiments related to the dynamic processes occurring in

a gas well, working with liquids (with surfactants and other non-aggressive chemicals), and to obtain digital data using the installation.

Figure 10. Photo and 3D installation

and the tubing length.
**For the base diameter of tubing
TECHNICAL SPECIFICATIONS

OF RESEARCH STAND

Table 2. Technical specifications

diagnosis;
data output;
safety precautions at workplace;
video recording of

the experiments.

INSTRUMENTATION AND CONTROLS

Figure 20. Operation panel

of the foam, depending on the demulsifiers and the thermobaric

conditions.

Figure 21. Foam Analysis Instruments TU BAF

CONNECTION BETWEEN TU BAF AND IUT

and meant for optimization of gas wells working in liquid

accumulation regime. Removal of liquid is made by well-timed and dosed injection of foaming agent in a well. Analyzing data coming from transducers and exposure to down hole equipment, the system allows you to identify the characteristics of well performance (including: liquid rate, stored height of water) predict its working regime with foaming agent, foaming agent injection guarantees standard conditions of well performance (e.g. maximize gas production rate and minimize foaming agent delivery). Two patent applications have been filed for the technology.

Figure 22. scheme of collection of information

Table 3. Equipment latching

example it is assumed procurement: a) a surfactant supply unit

(capacity for foam, a pump , supply line, flow meter, flow); b) control flow rate of gas; c) pressure sensor and temperature gauge; d)industrial PC, etc) via radio. The volume of additional gas production was estimated taking into account the results of the use of liquid foaming agents at wells 602, 622, 805 of Bear NGKM in the winter of 2016, where foaming agents were used to remove the condensation liquid.

Table 5. Cost structure

solutions to gas well liquid loading problems./ Gulf Professional Publishing

2003. – 314.
2) Lea, J. F., & Nickens, H. V. (2004). Solving Gas-Well Liquid-Loading Problems. Journal of Petroleum Technology, 56 (04), 30–36.
3) Technology of production of low-pressure cenomanian gas/ Sarancha A.V., Sarancha I.S., Mitrofanov D.A., Ovezova S.M.//Modern problems of science and education-2015-№1 (1). – 211.
4) Operation of gas wells in conditions of active water and sand production/ D.V Izyumchenko, E.V Mandrik, S.A Melnikov,A.A Ploskov,V.V. Moiseev, A.N Haritonov, S.G Pamuzhak // Vesti gazovoy nauki.-2018.- № 1 (33). 235–241.
5) Results of the implementation of Сomprehensive program on the reconstruction and technical re-equipment of gas recovery facilities for 2011–2015/V.Z Minlikaev,A.V Kovalenko,N.A Bilalov,A.V Elistratov // Gas Industry.-2017.- № 1 (747). 30–34.
6) Main causes of stopping gas wells at the final stage of development of deposits / Panikarovskii E. V., Panikarovskii V. V. // The journal “Oil and Gas Studies” № 3, 2017: 85–89.
7) Kalwar, S. A., Awan, A. Q., Rehman, A. U., & Abbasi, H. S. (2017). Production Optimization of High Temperature Liquid Hold Up Gas Well Using Capillary Surfactant Injection. SPE Middle East Oil & Gas Show and Conference.
8) O. Rauf, "Gas Well Deliquification–A Brief Comparison between Foam Squeeze and Foam Batch Approach," Journal of Industrial and Intelligent Information, Vol. 3, No. 1, 45–47, March 2015.
9) Sean H. Peyton, Shona L. Neve, C. Krevor, (2013). Investigation of Batch Foamer Efficacy and Optimisation in North Sea Gas Condensate Wells. SPE Candidate Paper.
10) Schinagl, W., Caskie, M., Green, S. R., Docherty, M., & Hodds, A. C. (2007). Most Successful Batch Application of Surfactant in North Sea Gas Wells. Offshore Europe.
11) A.YU Koryakin, Complex solutions of problems of development and operation of wells of the Urengoy producing complex- М., 2016 – 272.
12) Van ’t Westende, J. M. C., Henkes, R. A. W. M., Ajani, A., & Kelkar, M. (2017). The use of surfactants for gas well deliquification: a comparison of research projects and developed models. BHR Group.

922 004 0842
ogayvlad@mail.ru
The XV International Forum-Contest
of Students and Young

Researchers.
TOPICAL ISSUES OF RATIONAL USE OF NATURAL RESOURCES

RESEARCH STAND FOR
SIMULATION OF GAS-LIQUID FLOWS

the foaming agents' influence on the process of reservoir fluids

and condensate recovery from Cenomanian gas wells on a closing stage of development," in Proceedings of International Academic Conference "The state, trends and problems of development of the oil and gas potential of Western Siberia" (Scopus, 2018 ). Publication of an article in the journal Oil. Gas. Novations № 12/2017 "Study of the influence of foaming agents on the process of removal of formation and condensation fluid from Cenomanian wells at a late stage of development" (VAK);
The project attracted more than 5 million state grant funding;
Meeting successfully carried out with Ltd NOVATEK Scientific and Technical Center, Ltd Tyumen Oil Scientific Center and JSC Sibneftegaz ( PJSC Rosneft);
The results are presented at the Colloquium of young scientists ("Russian-German raw materials conference – 2018", Potsdam);
Certificate for state registration of computer programs № 2018615013;
RF patent for the invention № 2654889.

separators
Figure 13. Containers for recycling
PARTS OF RESEARCH STAND

of the tubing
Figure 16. Sampling device and heat-exchanging apparatus
PARTS OF

RESEARCH STAND

Foam suppression system
PARTS OF RESEARCH STAND

process
-
+
-
+
+
Adaptation to change and quick
response
-
-
-
Capital investments, mln. Rub.
5-8
8-10
1-2,5
4,3
1,2
Operat. costs million

rubles / year

0

0,18

0,5-2,5

Additional gas production million
m³ / year

9,3

13,1

10,9

14,2

Digitalization of well operation, rapid adaptation to changes and fast response of the system
According to preliminary estimates, a 30% increase in additional production (7.4 million rubles / year * well, cost recovery in the first year) and a reduction in surfactant costs by 25%
Capital investments are 2 times less than competing technologies
The ability to simultaneously manage tens / hundreds of wells
Limitations: gas-liquid factor more than 0.17 m³ / l, electrification, the content of condensate in the fluid is less than 50%

calculated parameters of the model
Based on the data obtained from

well research (or taken earlier or before technology introduction) in Software computation model are inserted parameters: Тform – formation temperature; Рform – formation pressure in a well; Нwell – well depth up to bottom; НTBG – bottom depth of TBG; dTBG – inside diameter of TBG; dcs – inner diameter of capital string or filter; hг – effective gas height; a0well и b0well – gas flow coefficients; Mw.form – formation water salinity, Н1перф и Н2перф - depth of top elevation and bottom elevation perforation interval or filter in productive formation, etc.  Measuring equipment provides continuous parameters' monitoring: Тbuf, Рbuf – temperature, pressure in well spring; Рann – pressure in inner annulus; Тapron, Рapron – temperature, pressure after gas production rate regulator ( in gas gathering tail); dr.regul. – drift diameter of gas production rate regulator and etc.  Software supplies engineering analysis in time; qc.form. – condensed fossil water discharge; qg. – quantity of gas coming from reservoir ; hw – depth of watercut part of perforated interval, CGR - gas-condensate factor, WGR - water – gas factor, etc.