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The Development of The Development of Puguang Sour Gas Field September,2009 September,2009
The Development ofThe Development of Puguang Sour Gas Field
September,2009September,2009
ContentContent
An overview of Puguang sour gas field
Development of sour gas phase behaviorDevelopment of sour gas phase behavior
Prediction of elemental sulfur deposition & treatment
An overview of Puguang sour gas field
Puguang Gas field located
An overview of Puguang sour gas field
Puguang Gas field, located
at Xuanhan county ，
Sichuan province, is the
l t fi ld ilargest sour gas field in
China at present.
It was discovered in 2003.
The GIIP is more than
300×109m3.
Primary characteristics
◇carbonate reservoir
Primary characteristics
◇carbonate reservoir
◇giant reservoir thickness, good
porosity and permeability but
strong heterogeneity.strong heterogeneity.
◇ high content H2S（ 15.16%）
&CO2（8.64%）
◇f ti d th 5000 5900◇formation depth: 5000～5900m
◇high pressure: 55－60MPa3D model of Puguang
g p
Productivity of Puguang gas fieldProductivity of Puguang gas fieldBecause of large reserve, great thickness, etc, the designed
annual productivity is more than 10×109 m3. The beginning of
product is at the end of year of 2009.
Main strategies to CDMMain strategies to CDM
Made more than 50 companyp y
criterions on Puguang gas field
development;development;
Improve gas field development
design requirement preventingdesign requirement, preventing
corrosion & dangerous gas leakage;
Strengthen tail gas management
profile of tubing corrosion
Strengthen tail gas management,
decreasing tail gas emission;
Synthetically treat industrialSynthetically treat industrial
rubbish, purify produced water and
reinjectreinject.
3D geological model of water reinjection
Development of Puguang sour gas phase behaviorDevelopment of Puguang sour gas phase behavior
Nowadays, some professional
laboratories of sour gas phase
behavior, anticorrosive, ect, are
t bli h d i h i tit testablished in research institutes,
which can satisfy the requirement
of sour gas field experiments.
It, However, is still lack of
correlative experiment experience.
Sour gas PVT experiment equipment
PVT phase behavoir characteristicPVT phase behavoir characteristic
It conducted experiments on sour gas phase behavior and high-pressure
54
60地层条件
physical property parameters.
1 1500
42
48
54
1.0500
1.150060.0℃78.0℃96.0℃114 0℃
30
36
压力，MPa
C iti l0.9500偏
差系数
114.0℃130.0℃
12
18
24压 Critical point
0.8500
0
6
100 50 0 50 100 150
C
4.0*10-78.5*10-7
0.1 0.75000 10 20 30 40 50 60
-100 -50 0 50 100 150
温度，℃Profile of P－T Phase Behavior
压力，MPa
The relationship between change factor and pressure
Experiment results showExperiment results show
No dew point with some dry gas
samples,
liquid drops separate from gasliquid drops separate from gas
when pressure & temperature
decrease with another samples.
The lower P&T, the faster liquidThe lower P&T, the faster liquid
drops precipitate.
Solubility of sulfur in sour gas
2.4000
y g
The solubility of sulfur in sour gas
1.9000
2.4000
60.0℃78.0℃96 0℃
greatly affects on elemental sulfur
deposition while gas wells produced.
1.4000
度，
g/m3
96.0℃114.0℃130.0
p g p
When the content of H2S in gas is
0.9000
含硫
和饱
constant, experiments indicate that :
the solubility of sulfur in natural gas
0.4000increases, while the pressure increases,
the solubility of sulfur in gas raise-0.1000
5 15 25 35 45 55 65
力压 ， MPa
the solubility of sulfur in gas raise
when temperature increases under the
The solubility of sulfur in sour gassame gas components and pressure.
ProblemsProblems
Although the sour gas PVT experiment equipments have already g g p q p y
been established preliminarily, there are some problems as followings:
Wellhead sampling. Because of the strong corrosion and toxicity, it
can't put the sampling devices into well bottom to collect gas samplecan t put the sampling devices into well bottom to collect gas sample.
The compositions of gas sample getting from wellhead ,therefore, many
be very different from that in real reservoir condition.
Th th l l ti th d t b i d ThThe theory calculation methods are necessary to be improved. The
error from sampling may induce the lack of verification of theory models.
Prediction of elemental sulfur deposition & treatmentPrediction of elemental sulfur deposition & treatment
Current research
As mentioned, elemental sulfur separates out from saturated sourgas and may deposited in transporting medias when reservoir’s
Cu e t esea c
gas and may deposited in transporting medias when reservoir stemperature and pressure reduce. It studied on simulation model tocalculate sulfur deposition in porous media, fractured well and tubing.Meanwhile, treatments of preventing & removing elemental sulfur were
developed.
Sulfur plugging of some wells in Sichuan basin (H2S6.87%,CO22.76%)
sulfur deposition prediction in porous mediasulfur deposition prediction in porous media
Gas saturation , power of gas current & size of transporting h l k f t i ti l t l lf d itichannel are key factors impacting on elemental sulfur deposition
in reservoir. the deposition of sulfur in formation is partitioned as four areasfour areas,
Non-sulfur deposited area;
Sulfur particles steadily
deposited area;
Sulfur particles hydrodynamic
carry area;carry area;
Sulfur particles hydrodynamic
erosion area.
On the condition that gas current power is not enough to carry sulfur
separated out from saturated sour gas, simulation shows elemental
sulfur deposits primarily in the area closed to well bore and the
precipitation rate becomes higher and higher while gas well continuously
produced.
0 15
0.2
0.25
（小
数）
50天
100天
天
0 05
0.1
0.15
含硫饱
和度
Ss
500天
1000天
profile of sulfur concentration around
0
0.05
0 0.5 1 1.5 2
径向距离（m）
含
profile of sulfur concentration around well bore
径向距离（m）Sulfur concentration in reservoir
Sulfur deposition prediction in well hole
The main influence factors
Sulfur deposition prediction in well hole
The main influence factors
•Well hole pressure
• Well hole temperature
•Flow rate in tubing
El t l lf t t i t bi
•Roughness of tubing
Elemetal sulfur transport in tubing
Sulfur deposition analysis and prediction in well holeSulfur deposition analysis and prediction in well hole
Pressure model
Temperature model
含硫饱和度（g/m3）
0
0 100 200 300 400 500 600 700
model model
Sulfur solubility
0
1000
2000
（m）
Solubility of sulfur insolubility model
separation of
？Identify sulfur
Y3000
4000
井深
Solubility of sulfur inwell hole
separation of elemental sulfur
sulfur precipitation position
YP ti l
Move N
5000
6000
流速（m/s）Particle
transportation model
Y
upward0
1000
0.12 0.122 0.124 0.126 0.128 0.13 0.132
）
z2
Adsorption model
2000
3000
4000
井深（m）
Current velocity
Critical carryingrate
Deposited Sulfur
4000
5000
6000
z1
Sulfur deposition prevention measuresSulfur deposition prevention measures
Physical measures:
Treatmentsheating, scraping
TreatmentsChemical measures:
dissolution with solvent
Injecting chemical agents is the measure that 。dissolution with solvent
takes in Puguang gas field to prevent and
remove deposited sulfur .
The injection mode is capillary transportationThe injection mode is capillary transportation.
ProblemsProblems
Sulfur concentration or saturation in original reservoir condition
Sulfur deposition identification & monitoring measures
C t f t t tCost of treatment
We sincerely hope we can cooperate and communicate with
relative companies or CCOP MC.
