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International Journal of Petroleum and Geoscience Engineering
Volume 03, Issue 01, Pages 25-40, 2015 ISSN: 2289-4713
Reserve Estimation and Production Facilities: A Case Study on Titas Gas
Field, Bangladesh
Farzana Yeasmin Nipa a, Md. Minhaj Uddin Monir a,*
a Department of Petroleum and Mining Engineering, Jessore University of Science and Technology, Jessore-7408, Bangladesh
*Corresponding author: Tel.: +88 0421 62020 Ext. 240;
E-mail address: [email protected]
A b s t r a c t
Keywords:
Titas Gas Field,
Reserve estimation,
Production facilities,
Volumetric Method,
Material Balance Method.
Titas gas field is one of the largest gas field and most significant commercial energy resource of
Bangladesh. Therefore, future development of the country largely depends on the judicial use of
this valuable resource. The field was discovered in 1963 and put into production in April 28,
1968. Totally, sixteen wells have been drilled in Titas gas field since 2009. Estimation of gas in
place (GIP) and gas reserves are very crucial for the energy planning and natural gas production
facilities. In this study, gas in place values of the Titas gas field has been estimated using
volumetric and material balance method. Geophysical data, fluid properties data and production
data have been analyzed using volumetric analysis as well as material balance to verify initial
gas in place and reserve estimates for the Titas gas field. In volumetric and material balance
analysis, gas initially in place is 7169 Bcf and 7800 Bcf respectively at Titas gas field since
March, 2009. The daily gas production of Titas gas field is about 394.98 mmscfd with 431.94
bpd of condensate and 1801.7 bpd of water. This study estimates gas in place and daily
production of Titas gas field.
Accepted:23 March2015 © Academic Research Online Publisher. All rights reserved.
1. Introduction
The Titas gas field is located 100 Km away to the
direction of northern-east from the capital city of
Bangladesh, Dhaka (Fig.-1) [10]. It lies in the south
central part of the Surma Basin, and on the western
margin of the Tripura high. It is also located at
24014´N 91022ˊE and 24028´N 91010ˊE respectively
[9]. This field accounts for 43% of country’s gas
production. Estimation of gas in place and gas reserve
are very important for the sale of natural gas. The
reservoir sequence in Titas comprises 12 identifiable
sands that for convenience have been divided into
three groups – “A”, “B” and “C” (Fig.-2). The most
prolific of the sands are those of group A which
constitute the main producing horizon in Titas [9].
Quantitative and qualitative data are mainly used in
this study. The production and pressure data (March
and April) are used to calculate gas in place by
reserve estimation methods. Qualitative data was
collected from the secondary sources like books,
journals, articles, websites and reports [11]. The
major part of the qualitative data is used in this study
for showing the relation between volumetric and
material analysis as well as production performance
in the Titas gas field.
The specific objectives of this research are estimated
the gas reserve of Titas reservoir by volumetric and
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material balance method and studied the production
facilities of the Titas gas field. This study estimates
gas in place, recoverable reserves and daily
production of Titas gas field. Maximizing productivity
can be found in future by applying these two methods
for all the gas fields in Bangladesh.
Fig. 1: Location map of Titas Gas Field (modified after Titas geological report 2009 by Petrobangla).
Fig. 2: Sub-surface location of Titas field and gas bearing sands (Source: Petrel software, Petrobangla).
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2. Methodology
A well-arranged methodology is extremely needed for
good accomplishment of any research work. This
study will focus on the reserve estimation and
production facilities of Titas gas field by using reserve
estimation methods.
2.1. Reserve Estimation
Reserve estimation is an essential study in the field of
petroleum engineering. Various methods are used to
estimate the reserves of discovered reservoirs
depending on the availability of data and development
stage of the reservoir. The methods that are used
predominantly are: Volumetric, Material Balance,
Decline Curve, and Reservoir Simulation. Generally,
the range of uncertainty associated with an estimate
decreases and confidence level increases as more
information becomes available and when the estimate
is supported by more than one estimation method.
2.1.1. Reserve Estimation by Volumetric Method
In volumetric method estimated rock volume of the
reservoir is multiplied with porosity and gas saturation
to calculate the gas in place. The volumetric method is
the most commonly used approach to estimating
reserves in the early stages of production from an oil
or gas field. As more data become available mainly no
production data, the estimate may be refined,
sometimes through the use of other reserves
estimation methods. The volumetric method is used
by employing the standard reserves equation with the
appropriate choice of parameters.
General Information:
1. Early stage of reservoir development and
after discovery.
2. Geology, Geophysical, Rock and fluid
properties data.
3. Recovery Factor assigned arbitrarily.
4. No time dependency.
5. No production data.
The equation for calculating gas in place is:
G =Ahϕ(1 − Swi)
Bgi× 𝑅𝐹
Where, A = Productive area: Hydrocarbon bearing
area of the reservoir; acres.
h = Net pay thickness: It is the vertical extent
thickness of the productive portion of a reservoir. It is
the thickness of those intervals in which porosity and
permeability are known or supposed to be high
enough for the interval to be able to produce oil or
gas; ft.
ϕ = Porosity: The ratio of pore volume to bulk volume
of a reservoir rock; fraction.
Swi = Initial Water Saturation: The ratio of volume of
water and pore volume at initial conditions; fraction.
Bgi = Initial Gas Formation Volume Factor: The ratio
of gas volume at reservoir conditions and gas volume
at standard conditions; ft3/SCF.
G = Gas in Place: The total natural gas estimated to
have originally existed in the earth’s crust in naturally
occurring accumulations including both discovered
and undiscovered resources; BCF.
RF = Recovery Factor: It is based on analysis of
production behavior from the reservoir, by analogy
with other producing reservoirs and/or by engineering
analysis.
2.1.2. Reserve Estimation by Material Balance
Method
The material balance method is employed to estimate
the volume of hydrocarbons in place in a reservoir
when appropriate geologic, production and laboratory
data are available. The material balance method is the
most commonly used approach to estimating reserves
in the later stages of production from an oil or gas
field. It is generally accepted that methods based on
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
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production performance data [7] are more accurate
than those based strictly on inference from geological
and engineering data. Some more theoretical
background on following material balance method
about Gas Field is being performed [1] that may affect
the accuracy of the results. When economic
producibility limits are coupled with the material
balance, reserves are determined.
General Information:
1. Later stage of reservoir development.
2. Geophysical, Rock and fluid properties data,
Production data.
3. Recovery Factor is calculated.
4. Time dependent.
The equation for calculating gas in place is:
Z
P=
RFG
GP
Zi
Pi
1
Where, P = Shut in Reservoir Pressure: The
equilibrated reservoir pressure measured when the
entire gas or oil outflow has been shut off; Psi.
Z = Gas Compressibility factor: It is defined as the
ratio of the gas volume at a given temperature and
pressure to the volume the gas would occupy if it
were an ideal gas at the same temperature and
pressure; Dimensionless.
Pi = Initial Shut-in Reservoir Pressure: The
equilibrated reservoir pressure measured when the
entire gas or oil outflow has been shut off at initial
conditions; Psi.
Zi = Initial Gas Compressibility factor: It which is the
change in volume per unit volume per unit change in
pressure at initial conditions; Dimensionless.
GP = Cummutative Production: The total amount of
oil and gas recovered from a reservoir as of a
particular time in the life of the field until a specific
date; SCF.
2.2. Production Facilities
Titas gas field production history dates back to 1962
with the drilling of Titas well no.1 by Shell Oil Co.
(Pak.). The stacked reservoir of Titas was further
penetrated by four additional wells during the period
1962 to 1969. Petrobangla later on completed Titas
well no. 5 to Titas well no. 7. BGFCL drilled Titas
well no. 8, 9, and 10 during 1985. Under Gas Field
Appraisal Project, Titas well no. 11 was drilled during
the year 1990. During the period 2000 to 2006, five
more wells tagged as Titas well no. 12, 13, 14, 15 and
16 were completed and brought on-stream. Last year
(2007) Titas well no. 03 was killed due to wellhead
vicinity seepage and during the same year Titas well
no. 14 had also to be closed because of severe water
loading. First process operation of Titas field occurred
during 1986 via LTX facility based on Titas well no.
8. Titas well no. 9 joined the commercial production
on 1989, and Titas well no.10 during 1990. For the
latter two wells TEG and LTS unit were installed.
3. Results
3.1. Reserve estimation of Titas Gas Field
Estimation of gas in place (GIP) and gas reserves are
very crucial for the energy planning and natural gas
utilization scheme. Estimation of gas in place and gas
reserves is also very important for the sale of natural
gas.
3.1.1. Reserve Estimation by Volumetric Method
The gas reserves are determined by Volumetric
Method on putting the raw data from using equation
no. 1. The Gas Reserves in their calculation which is
shown in Table 1.
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Table 1: Sand Wise Gas Reserve by Volumetric Method in Titas Gas Field (As on March 2009).
Sands GIIP Bcf (Volumetric Calculation)
A1 1151
A2 3376
A2b 768
A3 1089
A4 Upper (A4U) 172
A4 Lower (A4L) 75
A Sand Total 6631
B1 23
B2 0.0
B3a 127
B3b 147
B Sand Total 297
C1 143
C2 98
C Sand Total 241
B and C Sand Total 538
Total 7169
3.1.2. Reserve Estimation by Material Balance
The gas reserves are determined by Material Balance
on putting the raw data from using equation no. 2. The
Gas Reserves in their calculation which is shown in
Table 2.
Table 2: Sand Wise Gas Reserve by Material Balance in Titas Gas Field (As on March 2009).
Sands GIIP Bcf ( Material Balance )
A Sand Total 6650
B Sand Total 635
C Sand Total 515
B and C Sand Total 1150
Total 7800
3.2. Production Facilities of Titas Gas Field
The daily production of Titas gas field is given below
incorporating different types of wells and sand
formation (1st April, 2009) which is shown in Table
3.
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Table 3: Daily Production of Titas Gas field (1st April, 2009) (Source: Titas Production Facilities Engineering Report, 2009).
Wells Formation Production Period Average Daily Production Average Wellhead
Pressure (psig) Gas (mmscfd) Cond. (bpd) Water
(bpd)
Titas 1 A Sand April 68 - Mar 09 31.27 32.62 26.59 1885
Titas 2 A Sand May 68 - Mar 09 33.06 34.49 28.12 1900
Titas 3 A Sand July 85 - Jan 08 0.0 0.0 0.0 0
Titas 4 A Sand Oct. 69 - Jan 08 32.33 33.73 27.50 1860
Titas 5 A Sand Jan 81 - Mar 09 33.38 34.82 28.39 1850
Titas 6 A Sand Feb 84 - Mar 09 35.00 36.48 29.77 1830
Titas 7 A Sand Jul 85 - Mar 09 32.99 34.43 28.07 1910
Titas 8 B and C Sand April 68 - Mar 09 22.13 23.09 18.81 1550
Titas 9 B and C Sand March 89 - Mar 09 31.37 33.16 26.68 1600
Titas 10 B and C Sand Sept 90 - Mar 09 14.84 15.49 12.58 1460
Titas 11 A Sand Jun 91 - Mar 09 25.93 27.06 22.06 2015
Titas 12 A Sand Jul 02 - Mar 09 21.37 31.79 1286.44 1725
Titas 13 A Sand Jun 00 - Mar 09 21.36 32.22 215.70 2100
Titas 14 A Sand Jun 00 - Nov 06 0.0 0.0 0.0 0
Titas 15 A Sand May 06 - Mar 09 29.99 31.30 25.51 1966
Titas 16 A Sand Dec 05 - Mar 09 29.96 31.26 25.48 1968
Total 394.98 431.94 1801.7
4. Discussions
4.1 Reserve Estimation of Titas Gas Field
The reservoir sands in the Titas field are composed of
stacked sands that are divided into three main layers:
‘A’, ‘B’ and ‘C’ Sands. The A Sand has a further six
sand members, A1, A2, A2B, A3, A4U and A4L.
Similarly, B and C Sands have another six gas bearing
sands: B1, B2, B3a, B3b, C1 and C2. The most
prolific are those of the Group ‘A’ Sands, which
constitute the main producing reservoirs in the Titas
gas field. Almost 85 percent of initial gas in place
(GIIP) is in the A sand which is similar in case of
petro-physical analysis of shaly sand reservoir of
Bengal Basin, Bangladesh [4-6]. From Titas Well
(‘‘A’’ Gas Sand), Gas initially in place is 6631 Bcf (as
on March, 2009) of the volumetric analysis. Where,
Gas initially in place at A1 is 1151 Bcf, A2 is 3376
Bcf, A2b is 768 Bcf, A3 is 1089 Bcf, A4 Upper
(A4U) is 172 Bcf and A4 Lower (A4L) is 75 Bcf. And
from Titas Well (‘‘B’’ & ‘‘C’’ Gas Sand), Gas
initially in place is 538 Bcf of the volumetric analysis
which is nearly comprehensive last Rashidpur gas
field reserve estimation [3]. In ‘‘B’’ Sand, Gas
initially in place is 297 Bcf of the volumetric analysis.
Where, Gas initially in place at B1 is 23 Bcf, B3a is
127 Bcf and B3b is 147 Bcf. And from “C’’ Sand,
Gas initially in place is 241 Bcf of the volumetric
analysis. Where, Gas initially in place at C1 is 143
Bcf and C2 is 98 Bcf. The sand wise gas reserve by
volumetric method in their calculation which is shown
in Figure 3 and Figure 4.
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
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Fig. 3: Sand layers wise gas reserve by Volumetric Method in Titas Gas Field since on 2009.
Fig. 4: Sand groups-wise gas reserve by Volumetric Method in Titas Gas Field since on 2009.
From Titas Well (‘‘A’’ Gas Sand), Gas initially in
place is 6650 Bcf (as on March, 2009) of the material
balance analysis and it has shown that there is no
aquifer support in the sand A [2]. And from Titas
Well (‘‘B’’ & ‘‘C’’ Gas Sand), in the material balance
analysis, Gas initially in place is 1150 Bcf. Where,
Gas initially in place at ‘‘B’’ Gas Sand is 635 Bcf and
at ‘‘C’’ Gas Sand is 515 Bcf The sand wise gas
reserve by material balance method in their
calculation which is shown in Figure 5.
Fig. 5: Sand wise gas reserve by Material Balance Method in Titas Gas Field since on 2009.
1151
3376
7681089
172 75 23 0 127 147 143 98
0
1000
2000
3000
4000
A1 A2 A2b A3 A4U A4L B1 B2 B3a B3b C1 C2
Ga
s R
eser
ve
(Bcf
)
Sand Layers
Sand Layers Wise Gas Reserve by Volumetric
Method A1A2A2bA3A4UA4LB1B2B3aB3bC1C2
6631 Bcf
297 Bcf 241 Bcf
Sand Groups Wise Gas Reserve by Volumetric
Method
A Sand
B Sand
C Sand
6650 Bcf
635 Bcf515 Bcf
Sand Groups Wise Gas Reserve by Material
Balance Method
A Sand
B Sand
C Sand
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Here, the reality is that the field has not been fully
appraised. These are the limitations in the volumetric
estimation. A2 sand is more dominant sand than any
other sands in volumetric calculation and B2 sand is
contains less GIIP Bcf in volumetric calculation than
other sands. The estimation of sand wise gas reserve
in Titas gas field by volumetric and material balance
methods are nearly close. They differ from each other
in their calculation which is shown in Figure 6.
Fig. 6: Gas reserves various by volumetric and material balance method in Titas Gas Field since on 2009.
The material balance method is simple, but effective
means for estimating not only original gas in place but
also gas reserves at different stages of reservoir
depletion. Material balance methods also provide a
check for the gas in place estimates of the volumetric
method.
4.2 Production Facilities of Titas Gas Field
The field was discovered in 1963 and was put into
production in 1968. Current daily gas production of
Titas field is about 394.98 mmscfd with 431.94 bpd of
condensate and 1801.7 bpd of water since on 2009.
The Titas gas field production which is shown in Fig.
7.
Fig. 7: Total production of Titas Gas Field since on 2009.
The Titas No. 1 Well (“A” Sand) was drilled as a
vertical well in 1962 to 13,235 ft MD. Earliest
reported production was in April, 1968 at 4.7 mmscfd
at 3,300 psig wellhead pressure with no reported
water and a condensate gas ratio of 2.27 bpd.
Reported production in March of 2009 is 31.27
6631
538
6650
1150
0
1000
2000
3000
4000
5000
6000
7000
A Sand B & C Sand
Ga
s R
eser
ve
(Bcf
)
Sand Groups
Gas Reserve Varioous by Volumetric & Material
Balance Method
Volumetric
Calculation
Material
Balance
394.98
mmscfd
431.94 bpd
1801.7 bpd
Total Production of Titas Gas Field Since on 2009
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
33 | P a g e
mmscfd of gas with 32.62 bpd of condensate and
26.59 bpd of water at a wellhead operating pressure of
1885 psig. The Titas No. 1 well gas production is
shown in Figure 8.
Fig. 8: Titas Well 1 Gas production history since on 2009.
The Titas No. 2 Well (“A” Sand) was spud in
February, 1963 and was drilled as a vertical well to a
depth of 10,573.5 ft. The well was placed on
production in May, 1968. Early rates averaged 4
mmscfd with 2.18 bpd of condensate. Production rates
from the “A” Sand reported on March, 2009 were
33.06 mmscfd with 34.49 bpd of condensate and
28.12 bpd of water at a wellhead operating pressure of
1900 psig. The Titas No. 2 well gas production is
shown in Figure 9.
Fig. 9: Titas Well 2 Gas production history since on 2009.
In our study, the Titas No. 3 Well (“A” Sand) was
spud as a deviated well on August 3, 1969. The well
was completed in the “A” Sands and was placed on
production in July, 1985. Production from the well
continued until January, 2008. The well was
abandoned in February, 2008. Titas No. 3 well
suffered from vicinity seepage and uncontrollable
casing leakage which made its operation impossible.
The Titas No. 4 Well (“A” Sand) was spud as a
vertical well 1969 and was drilled to a depth of 9,350
ft. The “A” Gas sand was first put on production in
October, 1969 at 12.45 mmscfd. In March, 2009
reported flows from Titas 4 was 32.33 mmscfd with
27.50 bpd of water and 33.73 bpd of condensate at a
flowing tubing pressure of 1860 psig. The Titas No. 4
well gas production is shown in Figure 10.
4.7
31.27
2.27
32.62
0
26.59
0
5
10
15
20
25
30
35
Jan-6
8
Jan-7
1
Jan-7
4
Jan-7
7
Jan-8
0
Jan-8
3
Jan-8
6
Jan-8
9
Jan-9
2
Jan-9
5
Jan-9
8
Jan-0
1
Jan-0
4
Jan-0
7
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 1 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
4
33.06
2.18
34.49
0
28.12
05
10152025303540
Jan-6
8
Jan-7
1
Jan-7
4
Jan-7
7
Jan-8
0
Jan-8
3
Jan-8
6
Jan-8
9
Jan-9
2
Jan-9
5
Jan-9
8
Jan-0
1
Jan-0
4
Jan-0
7
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 2 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
34 | P a g e
Fig. 10: Titas Well 4 Gas production history since on 2009.
The Titas No. 5 well (“A’’ Sand) was spud as a
deviated well on October 5, 1980 to a depth of 10,802
ft (9,780 ft TVD). The “A” Gas sand was first put on
production in January 1981 at 23 mmscfd with 9.57
bpd of water and 21.8 bpd of condensate. At March,
2009 reported production from the “A” Sand is 33.38
mmscfd of gas, 34.82 bpd of condensate and 28.39
bpd of water production at wellhead operating
pressure of 1850 psig. The Titas No. 5 well gas
production is shown in Figure 11.
Fig. 11: Titas Well 5 Gas production history since on 2009.
In study, the Titas No. 6 Well (“A” Sand) was spud as
a vertical well on May 7th, 1983 to a total depth of
10,072 ft. The well was placed on production in
February, 1984 at 28.6 mmscfd of gas, 38.01 bpd of
condensate and 16.98 bpd of water at 3,086 psig.
March 2009 reported production from the “A” Gas
Sand is 35.00 mmscfd of gas at the wellhead
operating pressure of 1830 psig with 36.48 bpd of
condensate and 29.77 bpd of water production. The
Titas No. 6 well gas production is shown in Figure 12.
12.45
32.33
0
33.73
0
27.5
05
10152025303540
Jan-6
9
Jan-7
2
Jan-7
5
Jan-7
8
Jan-8
1
Jan-8
4
Jan-8
7
Jan-9
0
Jan-9
3
Jan-9
6
Jan-9
9
Jan-0
2
Jan-0
5
Jan-0
8
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 4 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
23
33.38
21.8
34.82
9.57
28.39
05
10152025303540
Jan-8
1
Jan-8
3
Jan-8
5
Jan-8
7
Jan-8
9
Jan-9
1
Jan-9
3
Jan-9
5
Jan-9
7
Jan-9
9
Jan-0
1
Jan-0
3
Jan-0
5
Jan-0
7
Jan-0
9
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 5 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
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35 | P a g e
Fig. 12: Titas Well 6 Gas production history since on 2009.
Titas No. 7 Well (“A” Sand) was spud as a deviated
well on December 1, 1984 and was drilled to a total
depth of 11,006 ft (9,491 ft). The well was placed on
production in July, 1985 at 19.7 mmscfd of gas, 4.5
bpd of condensate, and 2.26 bpd of water at 3,008
psig. March 2009 reported production from the “A”
Gas Sand was 32.99 mmscfd of gas, 34.43 bpd of
condensate and 28.07 bpd of water at the wellhead
operating pressure of 1910 psig. The Titas No. 7 well
gas production is shown in Figure 13.
Fig. 13: Titas Well 7 Gas production history since on 2009.
The Titas No. 8 Well (“B” and “C” Sands) was spud
as a deviated well on May 25, 1985 to a total depth of
11,760 ft. The well was placed on production in April
1968 at 1.12 mmscfd with 0.63 bpd of water and 1.9
bpd of condensate. At March, 2009 reported
production from the “B” and “C” Gas Sands is 22.13
mmscfd of gas, 23.09 bpd of condensate and 18.81
bpd of water production at the wellhead operating
pressure of 1550 psig. The Titas No. 8 well gas
production is shown in Figure 14.
28.6
3538.0136.48
16.98
29.77
05
10152025303540
Jan-8
4
Jan-8
6
Jan-8
8
Jan-9
0
Jan-9
2
Jan-9
4
Jan-9
6
Jan-9
8
Jan-0
0
Jan-0
2
Jan-0
4
Jan-0
6
Jan-0
8
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 6 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
19.7
32.99
4.5
34.43
2.26
28.07
0
5
10
15
20
25
30
35
40
Jan-8
5
Jan-8
7
Jan-8
9
Jan-9
1
Jan-9
3
Jan-9
5
Jan-9
7
Jan-9
9
Jan-0
1
Jan-0
3
Jan-0
5
Jan-0
7
Jan-0
9
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 7 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
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36 | P a g e
Fig. 14: Titas Well 8 Gas production history since on 2009.
In the study, Titas No. 9 Well (“B” and “C” Sands)
was spud as a deviated well on September 11, 1987 to
a total depth of 11,893 ft (10,403 ft). The well was
placed on production in March of 1989 at 25.5
mmscfd of gas, 25.59 bpd of condensate, and 13.36
bpd of water, at 2,990 psig. In March, 2009
production from the “B” and “C” Gas Sand is 31.37
mmscfd of gas, 33.16 bpd of condensate and 26.68
bpd of water production at the wellhead operating
pressure of 1600 psig. The Titas No. 9 well gas
production is shown in Figure 15.
Fig. 15: Titas Well 9 Gas production history since on 2009.
The Titas No. 10 Well (“B” and “C” Sands) was spud
as a deviated well on February 14, 1988 and was
drilled to a total depth of 12,139 ft. The well was
placed on production in September of 1990 at initial
rates of 6.745 mmscfd of gas, 0.44 bpd of condensate,
and 0.14 bpd of water at 3,275 psig. In March, 2009
reported production from the “B” and “C” Gas Sand is
14.84 mmscfd of gas, 15.49 bpd of condensate and
12.58 bpd of water production at the wellhead
operating pressure of 1460 psig. The Titas No. 10 well
gas production is shown in Figure 16.
1.12
22.13
1.9
23.09
0.63
18.81
0
5
10
15
20
25
Jan
-68
Jan
-72
Jan
-76
Jan
-80
Jan
-84
Jan
-88
Jan
-92
Jan
-96
Jan
-00
Jan
-04
Jan
-08
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 8 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
25.5
31.37
25.59
33.16
13.36
26.68
0
5
10
15
20
25
30
35
Jan
-89
Jan
-91
Jan
-93
Jan
-95
Jan
-97
Jan
-99
Jan
-01
Jan
-03
Jan
-05
Jan
-07
Jan
-09
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 9 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
37 | P a g e
Fig. 16: Titas Well 10 Gas production history since on 2009.
Titas No. 11 Well (“A” Sand) was spud as a deviated
well on February 10, 1990 and was drilled to a total
depth of 10,462. The well was placed on production in
June of 1991 at 10.896 mmscfd of gas, 0.54 bpd of
condensate and 0.22 bpd of water at 3,000 psig.
March 2009 reported production from the “A” Gas
Sand is 25.93 mmscfd of gas, 27.06 bpd of condensate
and 22.06 bpd of water production at the wellhead
operating pressure of 2015 psig. The Titas No. 11 well
gas production is shown in Figure 17.
Fig. 17: Titas Well 11 Gas production history since on 2009.
The Titas No. 12 Well (“A” Sand) was spud as a
deviated well on June 17, 1999 to a total depth of
9,875 ft (9,543.7 ft). The well was placed on
production in July of 2002 at 14.53 mmscfd of gas,
4.86 bpd of condensate and 951 bpd of water at 2,225
psig. In March, 2009 reported production from the
“A” Gas Sand is 21.37 mmscfd of gas, 31.79 bpd of
condensate and 1286.44 bpd of water production at
the wellhead operating pressure of 1725 psig. The
Titas No. 12 well gas production is shown in Figure
18.
6.745
14.84
0.44
15.49
0.14
12.58
0
5
10
15
20
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 10 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
10.896
25.93
0.54
27.06
0.22
22.06
0
5
10
15
20
25
30
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 11 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
38 | P a g e
Fig. 18: Titas Well 12 Gas production history since on 2009.
The Titas No. 13 Well (“A” Gas Sand) was spud as a
deviated well on August 27, 1999 and was drilled to a
total depth of 11,489.5 ft. The well was placed on
production in June 2000 at 7 mmscfd of gas with no
reported liquids at 2,700 psig. In March, 2009
production from the “A” Gas Sand was reported to be
21.36 mmscfd of gas, 32.22 bpd of condensate and
215.70 bpd of water production at the wellhead
operating pressure of 2100 psig. The Titas No. 13 well
gas production is shown in Figure 19.
Fig. 19: Titas Well 13 Gas production history since on 2009.
In the study, Titas No. 14 Well (“A” Sand) was spud
as a deviated well on July 12, 1999 and was drilled to
a total depth of 11,007 ft (10,554.5 ft TVD). The well
was placed on production in June 2000 at 2.7 mmscfd
of gas, 3.9 bpd of condensate, and no reported water
at 2,669 psig FWHP. The reported production ended
in November, 2006 at reported rates of 15.8 mmscfd
at 1,775 psig with 21.78 bpd of condensate and 14.92
bpd of water production at the wellhead operating
pressure of 1,775 psig. Titas No. 14 well was
abandoned during the year 2007 due to heavy loading
of encroached water.
The Titas No. 15 Well (“A” Sand) was spud as a
vertical well on February 3, 2006 and was drilled to a
total depth of 10,446.2. The well was placed on
production in May 2006 at 25.0 mmscfd of gas, 13.65
bpd of condensate, and 10.49 bpd of water at 2,185
psig. In March, 2009 reported production from the
“A” Gas Sand is 29.99 mmscfd of gas, 31.30 bpd of
condensate and 25.51bpd of water production at the
wellhead operating pressure of 1966 psig that relevant
14.53 21.374.8631.79
951
1286.44
0
200
400
600
800
1000
1200
1400
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 12 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
7 21.36
32.22
0
215.7
0
50
100
150
200
250
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 13 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
39 | P a g e
to evaluate the reservoir sand of Titas-15 well,
Bangladesh [8]. The Titas No. 15 well gas production
is shown in Figure 20.
Fig. 20: Titas Well 15 Gas production history since on 2009.
The Titas No. 16 Well (“A” Gas Sand) was spud as a
deviated well on August 5, 2005 and was drilled to a
total depth of 11,673.2 ft (10,218.7 ft). The well was
placed on production in December, 2005 at 17
mmscfd of gas, 7.55 bpd of condensate, and 5.98 bpd
of water at 2,040 psig. In March, 2009 reported
production from the “A” Gas Sand was 29.96 mmscfd
of gas, 31.26 bpd of condensate and 25.48 bpd of
water production at the wellhead operating pressure of
1968 psig. The Titas No. 16 well gas production is
shown in Figure 21.
Fig. 21: Titas Well 16 Gas production history since on 2009.
5. Conclusions
Titas gas field is the largest gas producer in
Bangladesh. On the overall study, we have found
three main layers reservoir sands such as A, B and C
Sand. Among the sands the most prolific group of
sand is A which constitute the main producing
reservoirs in the Titas gas field. At the beginning of
the reservoir production, reserves are estimated based
on geological and engineering data but at later stages,
production data and additional well information from
appraisal/development drilling are given more
emphasis in estimating the reserves. The daily current
gas production of Titas field is about 394.98 MMcfd
with 431.94 bpd of condensate and 1801.7 bpd of
25
29.99
13.65
31.3
10.49
25.51
0
5
10
15
20
25
30
35
Jan-06 Jan-07 Jan-08 Jan-09
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 15 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
17
29.96
7.55
31.26
5.98
25.48
0
5
10
15
20
25
30
35
Jan-05 Jan-06 Jan-07 Jan-08 Jan-09
Gas Rate (mmscfd)
Condensate Rate
(bpd)
Water Rate (bpd)
Date
Titas Well 16 Gas Production
Gas Production
(mmscfd)
Condensate
Production (bpd)
Water Production
(bpd)
F. Y. Nipa et al. / International Journal of Petroleum and Geoscience Engineering (IJPGE) 3 (1): 25-40, 2015
40 | P a g e
water since on 2009. Among sixteen wells of Titas
gas field, the no. 6, 12 and 13 wells show the best
performance in their production facilities but the no. 3
and 14 wells show the lowest performance in gas
production. This method seems to be applicable to
most of the gas reservoirs of Bangladesh.
Nomenclatures
Bcf billion(s) of standard Cubic Feet
BGFCL Bangladesh Gas Fields Company Ltd.
Bpd barrels per day
Condensate liquid hydrocarbons which are sometimes
produced with natural gas and liquids
derived from natural gas
ft feet
ft3/Scf cubic feet per standard cubic feet
GIP gas in place
GIIP gas initially in place
Mmscfd millions of standard cubic feet per day
Psi pounds per square inch
Psig pounds per square inch gauge
Scf standard cubic feet
mD permeability in millidarcies
TVD true vertical depth
Acknowledgement
The authors would like to thanks to the authority of
BGFCL for the permission of field work and
department of Petroleum and Mining Engineering
(PME), Jessore University of Science and Technology
(JUST), Bangladesh for providing logistical support.
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