Analysis and Synthesis of Horizontal Wells in Hassi R`Mel Oil Rim

Transcription

Analysis and Synthesis of Horizontal Wells in Hassi R`Mel Oil Rim
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
AAPG ID89989
Analysis and Synthesis of Horizontal Wells in Hassi R’Mel Oil Rim, Algeria
R. Recham
PED/Sonatrach Inc.
Algeria
Z. Nennouche
PED/Sonatrach Inc
Algeria
Abstact
The objective of this study is to analyze the
experience of drilling horizontal wells in Hassi R’Mel oil
rim, Algeria. The excepted results are: higher well
productivity, better oil recovery, lower water and gas
coning, minimum cost of production operations and
maximum profit.
For the Hassi R’Mel oil rim, recovery of the oil
using only vertical wells is difficult because water and
gas coning result in low oil production rate and high cost
of production operations. Then using only vertical wells
exhibit a drilling of a large number of wells which could
affect the profitability of the development project
especially in the presence of thin oil thickness.
A field development of Hassi R’Mel oil rim is
needed, the technique of drilling horizontal wells is
chosen as an alternative to some vertical wells, since
horizontal wells provide options whereby pressure
drawdown can be minimized, coning tendency can be
minimized, high oil production rate can be achieved and
consequently the cost of production operations can be
reduced.
The first horizontal well OWPZ1 in Algeria was
drilled in 1991 in Hassi R’Mel oil rim. Since, many
horizontal wells have been drilled based on the
optimization simulation study of the Hassi R’Mel oil rim
development. Eight horizontal wells were chosen for this
study with the objective to analyze their performance
and assess their profitability.
Introduction
The Hassi R’mel field is located approximately 500
kilometers South of Algiers in the Northern Grand Erg
occidental of the Algerian Sahara. Early evaluations of
the discovery by the drilling of well HR-1 in November
1956 revealed it to be one of the largest gas fields in the
world which has an oil rim existing primarily along the
Eastern and Southern margins of the field.
Hassi R’mel oil rim is a thin oil thickness
reservoir sandwiched between a large gas cap support
and a bottom aquifer throughout the entire oil rim. The
gross thickness of the oil column ranges from 3 to 12
meters with an average permeability of 500 md.
All those factors made the necessity to develop
the Hassi R’mel oil rim by implementing horizontal wells,
in addition to vertical wells (Mixed Development
Strategy), to improve the oil recovery in one hand, and to
reduce water and gas coning problems.
One of the main reasons for coning is pressure
drawdown. A vertical well exhibits a large pressure
drawdown near the wellbore, whereas horizontal well
exhibits minimum pressure drawdown, thus horizontal
wells provide options whereby pressure drawdown can
be minimized, coning tendencies can be minimized, and
high oil production rates can be achieved.
For a vertical well, the majority of the pressure
drawdown is consumed near the wellbore. Therefore,
there is a big drawdown around the wellbore in a vertical
well. In the case of horizontal wells, the pressure drop is
fairly uniform throughout the reservoir near the wellbore,
an extra pressure drop is observed. This pressure drop
is, however, very small as compared to that around a
vertical wellbore. For horizontal wells, due to low
pressure drawdown, one expects a high oil production
rate without water coning.
In a reservoir with bottom water or top gas, rising
water and downward movement of the gas cap can be
controlled to obtain the best possible sweep of the
reservoir. This is also called water cresting. With proper
operating procedure, the bottom water drive for
horizontal wells behaves very similar to a water-flood for
vertical wells, resulting in very high recovery. A
horizontal well provides an option not only to enhance
initial oil-production rates, but also to obtain maximum
possible ultimate reserves in a shorter time than a
vertical well.
The development and application of horizontal
wells drilling technology is causing a revolution in the
petroleum exploration and exploitation industry.
Simulation
studies
were
conducted
to
investigate the feasibility and performances of various
patterns of conventional vertical wells. The effect of
horizontal well length, the optimum perforated drain hole
section, the well’s position relative to the fluids contacts,
the change in production rate and the oil saturation
below the oil-water contact were all investigated.
Many horizontal wells have been drilled in Hassi
R’mel oil rim based on the simulation study and
Copyright © 2004, AAPG
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
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R.Recham and D.Bencherif
economic analysis, which was conducted to investigate
the optimum number of vertical and horizontal wells
(enhance reservoir contact and thereby enhance well
productivity) to be drilled in Hassi R’mel oil rim.
There are some cases where horizontal wells have
not been effective in reducing water and gas coning. The
lack of success is due to operational problems that one
encounters while drilling in a very thin pay zone, where
precise targeting may be difficult. Additionally, in gas
coning, gas break-through in the entry portion of the
wellbore is a common problem.
Statement of the Problem
For Hassi R’mel oil rim recovery of the oil is
difficult because water and gas coning results in low oil
production rate and high cost of production operations.
To overcome reservoir fluid flow problem,
horizontal wells are proposed as an alternative to vertical
wells to reduce excessive water and gas coning, and
capture more oil due to large contact area, low pressure
gradients and low drawdown is minimized while still
maintaining production. Hence, this will lead to increase
in the return on the investment.
Objective of the Study
The predominant objective of this study is to
analyze the experience of drilling horizontal wells in
Hassi R’Mel oil rim, Algeria. The excepted results are:
higher well productivity, better oil recovery, lower water
and gas coning, minimum cost of production operations
and maximum profit.
Horizontal Well Profils
The development and application of horizontal
drilling technology is causing a revolution in the
petroleum exploration and exploitation industry. As a
result of the advances in drilling and completion
technologies in the last two decades, the efficiency and
economy of horizontal well have significantly increased.
The state of Art applications of the horizontal well
technology require better completion designs to optimize
production, long term economics and ultimate
recoverable reserves.
A multi-disciplinary team effort for an
economically successful horizontal technology program
in all phases of planning has been established in order
to obtain pertinent information before the well is drilled.
A pri-drill geological model was derived for
horizontal wells utilizing log data of the surrounding
vertical wells. A profile and trajectory was defined and
used reconstructed log response as the geo-steering
guide to compare with real time log data (LWD) and
identify the geological markers during the drilling.
The petrophysical evaluation and the gas indicators
were used to choose the zones to be perforated in order
to maximize the production of dry oil.
Most of horizontal wells drilled in Hassi R’mel oil
rim were designed to be a medium radius with 500
meters long. Prior to drilling, TDT tests were run in the
surrounding vertical wells in order to locate the expected
fluid contact of horizontal wells.
As the oil rim is thin the plan was to drill an
inclined borehole through the reservoir section and use
LWD Resistivity-Gamma Ray to confirm the true depth of
the reservoir sands and the position of the gas, oil and
water contacts and then to navigate up to the oil zone
and land at 1000 meters drain in the section.
The well was geo-steered through the Tag
formation until the LWD Resistivity indicate water and
then the Density Neutron and MDT pressures, sampling
and live fluid analyzer were run to determine the fluid
contacts.
The target formation (reservoir) was the Trias
gréseux oil bearing sand. The plan was to drill down to
the oil-water contact and then to steer back up and land
in the desired zone and continue laterally through the
reservoir.
Transient Well Test Analysis
Well test analysis of a horizontal well is complex
and on many occasions difficult to interpret, because
most horizontal well mathematical models assume that
horizontal wells are perfectly horizontal and are parallel
to the top and bottom boundaries of the reservoir. In
general, the drilled horizontal wellbores are rarely
horizontal but rather snake-like with many variations in
the vertical plane along the well length.
In general, a well test analysis of a horizontal
well is conducted to meet the following objectives :
- To obtain reservoir properties
- To determine whether all the drilled length of a
horizontal well is also a producing length and
- To estimate mechanical skin factor or drilling
and completion related damage to a horizontal
well. Based on magnitude of the damage a
decision regarding well stimulation can be made.
Horizontal Well Applications
Horizontal Well OWPZ1
The first horizontal well (OWPZ1) in Algeria was
drilled in 1991 and put on production in December 1992.
A pilote hole has been drilled to locate efficiently fluid
contacts.The project was designed to complete a 600
meters horizontal medium radius reservoir drain in the
Triassic Argileux gris ‘A’ formation.
The production begun in December 1992
resulting in 624 cubic meters per day of oil bearing
produced through à 40/64 choke with a gas-oil ratio of
208 m3/m3 and a zero percent of water cut.
Because of the high production rate used, a
severe water and gas coning occurred and it was
decided to produce the well at 200 m3/d through a 32/64
choke.
The plot of historical production of well OWPZ1
(Fig.1) shows that the well is producing at an average oil
rate of 200 m3/d from the period of December 1992 to
March 1998, with a GOR of 2500 m3/m3 and a water cut
of 30%. In April 1998 the oil production rate started
Copyright © 2004, AAPG
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
SPE 86924
decreasing from 200 till 80 m3/d in Septembre 2002, this
is due to the increase of th GOR from 2500 to 6000
m3/m3, with an average water cut of 45 %.
The well resulted in a cumulative oil production
of 593 000 cubic meters in 10-year production with a net
present value of 43.4 MM$.
Horizontal Well OWPZ2
The horizontal well OWPZ2 was drilled in 1998
using a pilote hole to locate efficiently fluid contacts. The
CBL logging tool showed a bad cementing job of 30
meters in the horizontal drain hole section from 2615 to
2325 meters. The production started with 106 m3/d of oil
bearing through 32/64 choke, resulting with a GOR of
408 m3/m3 with no water production. The horizontal well
collapsed in last 300 meters of drain hole length
because of the unconsolidated reservoir.
The historical production of well OWPZ2 (Fig.2)
from April to December 1999 shows that the oil
production keep increasing from 50 to 143 m3/d caused
by the increase of the GOR reaching a value of 3334
m3/m3 playing a role of an auto gas-lift, after this period
of time a severe gas coning occurred resulting in a high
GOR of 6600 m3/m3 causing a decrease of oil
production rate from 143 to 42 m3/d from the period of
January to July 2000. the last period of the historical
production resulted in an average oil rate of 80 m3/d and
a GOR of 5500 m3/m3.
The well resulted in a cumulative oil production
of 116 000 cubic meters in 5-year production with a net
present value of 5.24 MM$.
The drilled horizontal wellbore is rather snakelike with many variations in the vertical plane along the
well length (Fig.3), the bad cementing job and the
collapsed section of the horizontal well could be the
reasons of producing with a high GOR. Production
logging can be used to locate the high gas production
zones to squeeze the zone off using cement to
overcome the gas channeling problems or bridge plug
with cement to isolate a part of the horizontal drain hole .
Horizontal Well OWPZ3
The horizontal well OWPZ3 was drilled in 1999
without using a pilote hole to locate efficiently fluid
contacts. The well was completed with cemented liner
and perforated, resulting in 152 m3/d of oil bearing
produced through 30/64 choke. The CBL logging tool
showed a bad cementing job of 30 to 40 meters in the
horizontal drain hole section from 2205 to 2490 meters.
The plot of historical production of well OWPZ3
(Fig.4) shows a severe water coning occurred very
rapidly during the period of March 1999 and 2000
causing a decrease of oil production from 152 to 75
m3/d, and the gas-oil ratio increased from 990 to 1566
m3/m3.
Very soon the water cut dropped to 36 %
allowing the well to be produced at an average oil rate of
75 m3/d during the period of April 2000 to May 2003, the
water cut and the gas-oil ratio increased from 36 to 48 %
and 1500 to 2500 m3/m3 respectively.
The well resulted in a cumulative oil production
of 126 000 cubic meters in 4-year production with a net
present value of 5.27 MM$.
The bad cementing job in the horizontal well
drain hole section could be the reason of producing with
a high GOR and water-cut. Production logging can be
used to locate the high gas production zones to squeeze
the zone off using cement to overcome the gas and
water channeling problems.
Horizontal Well OWPZ4
The project was designed to complete a 600
meters horizontal medium radius reservoir drain in the
Triassic Argileux Greseux ‘A’ formation, without using a
pilote hole. The horizontal well OWPZ4 was completed
with cimented liner and perforated in 1999 resulting in
178 m3/d of oil bearing produced through 20/64 choke.
The CBL logging tool showed a bad cementing job of 30
to 40 meters in the horizontal drain hole section from the
top liner 1828 to 3092 meters
The plot of historical production of well OWPZ4
(Fig.5) shows that the well was producing at an average
oil rate and a gas-oil ratio of 155 m3/d and 500 m3/m3
respectively from the period of July 1999 to September
2001 without water production.
In the second period from Octobre 2001 to May
2003, the plot shows that the gas-oil ratio decreases
very rapidly to 100 m3/m3 causing a decrease of oil rate
till 70 m3/d. this could be explained by the shut-in of the
injection well adjacent to the horizontal well OWPZ4.
The well resulted in a cumulative oil production
of 154 000 cubic meters in 4-year production with a net
present value of 8.14 MM$.
Although the CBL showed a bad cementing job
in a part of the horizontal drain hole section, the
horizontal well still produce with low GOR and water-cut
which could explained by a horizontal barriers since the
type of the reservoir is shaly laminated reservoir
intercepted by clean sands.
Gas-lift Optimization of Well OWPZ4
The end of the historical production of well
OWPZ4 shows that the well is producing at low oil rate
(77 m3/d) and a GOR of 143 m3/m3 with 4% of water
cut. Since the horizontal has a significant potential of oil
production, gas-lift application is suitable for production
optimization for this well.
Because of lack of energy the well cannot
produce oil with water-cut higher than 20%.
To overcome this problem the well is subjected
to gas-lift application, the simulation results (Fig.6)
shows that by injecting 8000 m3/d of gas with 20% of
water-cut, the well can produce at a rate of 160 m3/d.
Many sensitivity runs have been done with different
water cut to optimize gas injection rater and oil
production rate.
Copyright © 2004, AAPG
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
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R.Recham and D.Bencherif
Table 1 Simulation Results of Gas Lift Application
Gas Lift Application Results of Well OWPZ4
Water cut (%)
Gas Injection
Oil Production
Rate (m3/d)
Rate (m3/d)
20
0
0
20
8000
160
40
10000
80
60
15000
50
80
20000
22
From the results we can say that gas-lift application is
suitable for production optimization of well OWPZ4.
Horizontal Well OWPZ5
The drilling of the horizontal well OWPZ5 was
not effective. The lack of success is due to operational
problems encountered while drilling in a very thin pay
zone. The precise targeting was difficult resulting in a
wrong pay zone level toward the water zone. Then it was
decided to plug the horizontal drain hole and to perforate
the inclined section of the well in the oil pay zone.
After the perforation the well resulted in 88 m3/d
of oil bearing produced through 32/64 choke.
The plot of historical production of well OWPZ5
(Fig.7) shows that the oil production rate increases from
30 to 127 m3/d and suddenly the well is shut-in. The
average gas-oil ratio and water cut are 180 m3/m3 and
10 % respectively.
Gas-lift Optimization of Well OWPZ5
The well is shut-in and can not produce oil
because of lack of energy. To overcome this problem
the well is subjected to gas-lift application for production
optimization, the simulation results (Fig.8) shows that by
injecting 6000 m3/d of gas with 15% of water-cut, the
well can produce at a rate of 180 m3/d. many sensitivity
runs have been performed with different water cut to
optimize gas injection rater and oil production rate.
Table 2 Simulation Results of Gas Lift Application
Gas Lift Application Results of Well OWPZ5
Water cut (%)
Gas Injection
Oil Production
Rate (m3/d)
Rate (m3/d)
25
0
0
25
6000
180
40
15000
140
60
20000
75
80
30000
35
From the results we can say that gas-lift application is
suitable for production optimization of well OWPZ5.
Horizontal Well OWPZ7
The horizontal well OWPZ7 is the first well to be
drilled perpendicular to the flank of an anticlinal to the
southwest of the rig location, with an azimuth on 110°
North and the length of 500 meters. The well was
completed with cemented liner and perforated and the
CBL tool showed a very good cementing job. The well
resulted in 678 m3/d of oil bearing produced through a
32/64 choke with a gas-oil ratio of 102 m3/m3.
The plot of historical production of well OWPZ7
(Fig.9) shows that the well is producing during the period
of January to September 2001 with an average oil rate
and gas-oil ratio of 180 m3/d and 130 m3/m3
respectively. The oil production rate decreases
dramatically from 180 till 50 m3/d because of the shut in
of the injection wells adjacent to OWPZ7 and OWPZ4
from the period of Octobre 2001 to May 2003.
The well resulted in a cumulative oil production
of 98 000 cubic meters in 2-year production with a net
present value of 3.18 MM$.
Transient Well Test Analysis of Well OWPZ7
The horizontal well OWPZ7 is the first horizontal
well to be subjected to a measurement and analysis of
drillstem test (DST) pressure, which a practical and
economical means for estimating important formation
parameters prior to well completion.
The interpretation using the software SAPHIR
for the pressure and pressure derivative analysis,
matched very well a model (Fig.10) with boundary of
parallel faults (channel) with a homogeneous reservoir,
where the results of reservoir and well characteristics
are as follows:
- Reservoir pressure : 3064.41 psia
- Productivity index : 59.37 STB/d/psia
- Reservoir conductivity (kh) : 57200 md-ft
- Reservoir permeability (k) : 2180 md
- Vertical anisotropy ratio (kz/kv) : 0.238
- Wellbore damage (skin) : +7.5
- Delta p skin : 49.43 psi
The wellbore damage with a positive skin of 7.5 tell
us that a part of the horizontal well is unproductive,
where stimulation of the well is needed.
Gas-lift Optimization of Well OWPZ7
The end of the historical production of well
OWPZ7 shows that the well is producing at very low oil
rate (51 m3/d) and a GOR of 135 m3/m3 with no water
production. Since the horizontal has a significant
potential of oil production, gas-lift application is suitable
for production optimization for this well.
Many sensitivity runs have been done to match
pressure and production data using the Sotware
PERFORM. The results show that the well can not
produce oil with water-cut higher than 25%.
To overcome this problem the well is subjected
to gas-lift application, the simulation results (Fig.11)
shows that by injecting 15000 m3/d of gas for 25% of
water-cut the well can produce with an optimum oil rate
of 175 m3/d. many sensitivity runs have been done with
different water cut to optimize gas injection rater and oil
production rate.
Copyright © 2004, AAPG
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
SPE 86924
Table 3 Simulation Results of Gas Lift Application
Gas Lift Application Results of Well OWPZ7
Water cut (%)
Gas Injection
Oil Production
Rate 5m3/d°
Rate (m3/d)
25
0
0
25
15000
175
40
15000
122
60
20000
85
80
20000
33
From the results we can say that gas-lift application is
suitable for production optimization of well OWPZ7.
Horizontal Well OWPZ8
The horizontal well OWPZ8 was placed on the
East Hassi R’mel anticline flank in the level ‘A’
sandstone, going 110° direction fairly perpendicular to
this flank, almost parallel to bed Azimuth. The well was
drilled in 2001, completed with cimented liner and
perforated resulting in 379 m3/d and a gas-oil ratio of
105 m3/m3. The CBL logging tool showed a bad
cementing job of 20 to 50 meters in the horizontal drain
hole section from the 2685 to 3015 meters.
The plot of historical production of well OWPZ8
(Fig.12) shows that the oil production rate drop
continuously from 107 to 45 m3/d because of a high
increase of the GOR from 575 till 4240 m3/d, with an
average water cut of 10 %.
The bad cementing job of the horizontal well
drain hole section could be the reason of producing with
a high GOR. Production logging can be used to locate
the high gas production zones to squeeze the zone off
using cement to overcome the gas channeling problems.
Transient Well Test Analysis of Well OWPZ8
The interpretation for the pressure and pressure
derivative analysis, matched very well a linear composite
model with infinite boundary for a homogeneous
reservoir (Fig.13). The results of reservoir and well
characteristics data are as follows:
- Reservoir pressure : 2943.21 psia
- Productivity index : 41.53 STB/d/psia
- Reservoir conductivity (kh) : 22100 md-ft
- Reservoir permeability (k) : 709 md
- Wellbore damage (skin) : -3.14
- Delta p skin : 35.52 psi
Horizontal Well OWPZ9
The horizontal well OWPZ9 was drilled in 2002,
completed with cemented liner and perforated resulting in
332.5 m3/d and a gas-oil ratio of 108 m3/m3. The CBL
tool showed a good cementing job.
The plot of historical production of well OWPZ9
(Fig.14) shows that the oil production rate drop
continuously from 127 to 45 m3/d, the gas-oil ratio and
water cut increase from 130 to 370 m3/m3 and from 5 to
20 % respectively.
Transient Well Test Analysis of Well OWPZ9
The interpretation for the pressure and pressure
derivative analysis, matched very well a model with
boundary of one fault with a homogeneous reservoir
(Fig.15). The results of reservoir and well characteristics
data are as follows :
- Reservoir pressure : 3051.16 psia
- Productivity index : 36.34 STB/d/psia
- Reservoir conductivity (kh) : 19200 md-ft
- Reservoir permeability (k) : 586 md
- Vertical anisotropy ratio (kz/kv) : 0.175
- Wellbore damage (skin) : 3.7
- Delta p skin : 32.82 psi
We can say that a part of the horizontal well is
unproductive since the wellbore is damaged with a
positive skin of 3.7 and a stimulation of the well is
recommended.
Gas-lift Optimization of Well OWPZ9
The end of the historical production of well
OWPZ9 shows that the well is producing at very low oil
rate (45 m3/d) and a GOR of 260 m3/m3 with 19% of
water cut. Since the horizontal has a significant potential
of oil production, gas-lift application is suitable for
production optimization for this well.
Because of lack of energy the well cannot
produce oil with water-cut higher than 15%.
To overcome this problem the well is subjected
to gas-lift application, the simulation results (Fig.16)
shows that by injecting 4000 m3/d of gas with 15% of
water-cut, the well can produce at a rate of 180 m3/d.
many sensitivity runs have been done with different
water cut to optimize gas injection rater and oil
production rate.
Table 4 Simulation Results of Gas Lift Application
Gas Lift Application Results of Well OWPZ9
Water cut (%)
Gas Injection
Oil Production
Rate (m3/d)
Rate (m3/d)
15
0
0
15
4000
180
25
6000
160
40
8000
125
60
10000
100
80
12000
90
From the results we can say that gas-lift application is
suitable for production optimization of well OWPZ9.
Summary
As more wells are drilled, more experience
(learning curve) will become available which will further
enhance the outlined concepts leading to more efficient,
economical, and safer horizontal drilling operations.
Horizontal wells were drilled in Hassi R’Mel oil
rim to improve oil recovery by repressing the coning
problem experienced in conventional wells. Steps taken
to facilitate an optimum completion in the geologically
heterogeneous reservoir included petrophysical logging,
Copyright © 2004, AAPG
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
6
R.Recham and D.Bencherif
cementing the liner to avoid collapse and to provide
isolation, and selective perforating. Disappointing early
gas and water breakthrough in some horizontal wells
resulted in lower than expected oil recoveries.
4.
5.
Conclusions and Recommendations
Proper planning and economic evaluation of a
proposed horizontal well requires an accurate geological
model and reservoir data sufficiently accurate to conduct
a reliable simulation study. Without such an approach
the economic success of a horizontal well should be
considered of high risk.
The measurement and analysis of drillstem test
(DST) pressure behavior affords a practical and
economical means for estimating important formation
parameters prior to well completion.
- The horizontal wells drilled parallel to bedding
plan North 110° present 80% of perforable
cleaned sand of the total horizontal drain hole
section whereas, the horizontal wells drilled
perpendicular to bedding plan North 200°
present 60%.
- The advantage also of drilling horizontal wells
parallel to bedding plan allows to plug the end of
the horizontal drain hole section if water breaks
through since the horizontal drain hole is
perpendicular to the flank.
- The high inverted angle technique has been
successfully applied in Hassi R’Mel oil Rim
instead of expensive pilote hole.
- A very good cementing job has to be done using
a completion with cemented liner and perforated
to avoid collapse and minimize water and gas
channeling.
- The drilled horizontal wellbore are rarely
horizontal but rather snake like many variations
in the vertical plane along the well length and
this could result in a severe water and gas
coning.
- The simulation study using gas-lift optimization
is suitable for the horizontal wells OWPZ4,
OWPZ5, OWPZ7 and OWPZ9 to improve oil
recovery.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
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Acknowledgement
The author would like to thank the manager of
the PED division of Sonatrach Inc (Algeria), for
encouragement, all the means provided for the success
of this work, and permission to publish this paper.
References
1. Chaperon, I.: “Theoritical study of coning toward
horizontal and vertical wells in anisotropic formations:
Subcritical and critical rates”, paper SPE 15377, pp.1-12,
(1986).
2. Yang, W., Wattenbarger, R.A.: “Water coning
calculations for vertical and horizontal wells”, paper SPE
22931, pp.459-470, (1991).
3. Guo, B., Molinard, J.E., Lee, R.L.: “A general solution
of gas/water coning problem for horizontal wells”, paper
Copyright © 2004, AAPG
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
SPE 86924
Figure 3 Horizontal profile of well OWPZ2
600
Oil Production Rate (m3/d)
250
500
200
400
150
300
100
200
50
Cumulative Oil Production (10^3m3)
Figure 1
Historical Production Rate ad its Cumulat ive of Wel
OWPZ1
OWPZ2
MEASURED DEPTH -M2200 2280 2360 2440 2520 2600 2680 2760 2840 2920 3000
2190
100
0
0
2200
Qb
Npb
Historical Gas Oil Ratio and Wate r Cut
OWPZ1
7000
6000
Water Cut (fraction)
0,80
5000
0,60
4000
GOR (m3/m3)
1,00
TRUE VERTICAL DEPTH -M-
Time
2210
2220
3000
0,40
2000
0,20
2230
1000
0,00
0
Time
Figure 4
Historical Production Rate and its Cumulative of We ll
OWPZ3
120
100
160
80
120
60
80
40
40
20
120
160
100
120
60
40
40
20
0
0
se
pt
-9
8
ja
nv
-9
9
m
ai
-9
9
se
pt
-9
9
ja
nv
-0
0
m
ai
-0
0
se
pt
-0
0
ja
nv
-0
1
m
ai
-0
1
se
pt
-0
1
ja
nv
-0
2
m
ai
-0
2
se
pt
-0
2
Time
Time
Qb
Npb
Npb
Historical Gas Oil Ratio and Wate r Cut
OWPZ3
Historical Gas Oil Ratio and W ater Cut
Puits OWPZ2
0,80
6000
0,60
4500
0,40
3000
1,00
Water Cut (fraction)
7500
GOR (m3/m3)
1,00
3000
2500
0,80
2000
0,60
1500
0,40
1000
0,20
0,20
1500
0,00
0
500
0
m
ar
s99
ju
il99
no
v99
m
ar
s00
ju
il00
no
v00
m
ar
s01
ju
il01
no
v01
m
ar
s02
ju
il02
no
v02
m
ar
s03
ju
il03
0,00
se
pt
-9
8
ja
nv
-9
9
m
ai
-9
9
se
pt
-9
9
ja
nv
-0
0
m
ai
-0
0
se
pt
-0
0
ja
nv
-0
1
m
ai
-0
1
se
pt
-0
1
ja
nv
-0
2
m
ai
-0
2
se
pt
-0
2
Water Cut (fraction)
80
80
0
Qb
140
m
ar
s99
ju
il99
no
v99
m
ar
s00
ju
il00
no
v00
m
ar
s01
ju
il01
no
v01
m
ar
s02
ju
il02
no
v02
m
ar
s03
ju
il03
0
200
Oil Production Rate (m3/d)
Oil Production Rate (m3/d)
200
Cumulative Oil Production (10^3m3)
Figure 2
Historical Production Rate and its Cumulative of W ell
OWPZ2
Time
Time
Wcut
Wcut
Cumulative Oil Production (10^3m3)
GOR
GOR
Copyright © 2004, AAPG
GOR
GOR (m3/m3)
W-cut
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
R.Recham and D.Bencherif
180
150
120
120
90
80
60
30
40
120
30
80
20
40
10
0
0
no
v01
ju
il9
oc 9
t-9
ja 9
nv
-0
0
av
r-0
0
ju
il00
oc
t-0
ja 0
nv
-0
1
av
r-0
1
ju
il01
oc
t-0
ja 1
nv
-0
2
av
r-0
ju 2
il02
oc
t-0
ja 2
nv
-0
3
av
r-0
3
0
160
0
Time
Time
Npb
Qb
Historical Gas Oil Ratio and W ater Cut
OWP Z4
Historical Gas Oil Ratio and W ater Cut
OWP Z5
600
0,80
500
0,60
400
300
0,40
200
Water Cut (fraction)
700
GOR (m3/m3)
1,00
Water Cut (fraction)
Np
0,20
1,00
250
0,80
200
0,60
150
0,40
100
0,20
50
0,00
0
GOR (m3/m3)
Qb
se
pt
-0
2
oc
t-0
2
no
v02
40
50
m
ar
s02
av
r-0
2
m
ai
-0
2
ju
in
-0
2
ju
il02
160
200
ja
nv
-0
2
Oil Production Rate (m3/d)
200
Oil Production Rate (m3/d)
Figure 7
Historical P roduction Rate and i ts Cumulative of Well
OWP Z5
Cumulative Oil Production (10^3m3)
Figure 5
Historical Production Rate a nd its Cumulative of We ll
OWPZ4
Cumulative Oil Production (10^3m3)
8
Time
Time
Wcut
se
pt
-0
2
oc
t-0
2
no
v02
no
v01
m
ar
s02
av
r-0
m 2
ai
-0
2
ju
in
-0
2
ju
il02
0
ju
il9
oc 9
t-9
ja 9
nv
-0
0
av
r-0
0
ju
il00
oc
t-0
ja 0
nv
-0
1
av
r-0
1
ju
il01
oc
t-0
ja 1
nv
-0
2
av
r-0
2
ju
il02
oc
t-0
ja 2
nv
-0
3
av
r-0
3
0,00
ja
nv
-0
2
100
GOR
Wcut
Figure 6 Simulation Results of gas-lift well OWPZ4
250
GOR
Figure 8 Simulation Results of gas-lift well OWPZ5
250
B
C
D
E
A
A
B
C
D
E
200
150
1
100
Pressure, kg/cm²
Pressure, kg/cm²
200
1
150
100
50
50
0
0
0
100
200
Inflow @ Sandface
Not(1)
Used
Inflow (1)
Outflow (A)
Case 2 (2)
Case 2 (B)
Case 3 (3)
Case 3 (C)
Case 4 (4)
Case 4 (D)
Case 5 (5)
Case 5 (E)
Not Used
Not Used
Not Used
300
400
500
600
700
Oil Rate, m³/d
Outflow
Injection Rate, m³/d
Reg: Authorized User - Sonatrach - PED
800
Outflow
(A) 1000.0
(B) 3000.0
(C) 5000.0
(D) 8000.0
(E) 10000.0
0
100
Inflow @ SandfaceNot
(1)Used
Inflow (1)
Outflow (A)
Case 2 (2)
Case 2 (B)
Case 3 (3)
Case 3 (C)
Case 4 (4)
Case 4 (D)
Case 5 (5)
Case 5 (E)
Not Used
Not Used
Not Used
Copyright © 2004, AAPG
200
300
400
Oil Rate, m³/d
Outflow
Injection Rate, m³/d
Reg: Authorized User - Sonatrach - PED
500
Outflow
(A) 1000.0
(B) 3000.0
(C) 6000.0
(D) 8000.0
(E) 10000.0
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
SPE 86924
Figure 9
Figure 11 Simulation Results of gas-lift well OWPZ7
100
160
80
120
60
80
40
40
20
A
B
C
D
E
200
150
ju
il03
oc
t-0
2
ja
nv
-0
3
av
r-0
3
ju
il02
oc
t-0
1
ja
nv
-0
2
av
r-0
2
0
ju
il01
ja
nv
-0
1
av
r-0
1
0
250
Pressure, kg/cm²
200
Cumulative Oil Production (10^3m3)
Oil Production Rate (m3/d)
Historical P roduction Rate and its Cumulative of Wel l
OWP Z7
100
Time
Qb
Npb
50
Historical Gas Oil Ratio and W ater Cut
OWPZ7
1200
1,00
0,60
600
0,40
400
0,20
200
0
200
300
400
500
Oil Rate, m³/d
600
Outflow
(A) 1000.0
(B) 5000.0
(C) 10000.0
(D) 15000.0
(E) 20000.0
Outflow
Injection Rate, m³/d
Reg: Authorized User - Sonatrach - PED
ju
il03
ja
nv
-0
3
av
r-0
3
ju
il02
oc
t-0
2
ja
nv
-0
2
av
r-0
2
ju
il01
oc
t-0
1
ja
nv
-0
1
av
r-0
1
0,00
100
Inflow @ Sandface
Not Used
(1)
Inflow (1) Outflow (A)
Case 2 (2) Case 2 (B)
Case 3 (3) Case 3 (C)
Case 4 (4) Case 4 (D)
Case 5 (5) Case 5 (E)
Not Used Not Used
Not Used
GOR (m3/m3)
Water Cut (fraction)
800
1
0
0
1000
0,80
Time
Wcut
GOR
Figure 12
Figure 10 Transient well test analysis well OWPZ7
100
160
70
140
60
120
50
100
40
80
30
60
20
40
10
20
oc
t-0
3
ju
in
-0
3
oc
t-0
2
10
av
r-0
3
0
av
r-0
2
ju
in
-0
2
0
Cumulative Oil Production (10^3m3)
Oil Production Rate (m3/d)
Historical Production Rate and i ts Cumula tive of Wel l
OWPZ8
Time
Qb
Npb
100
0,60
3000
0,40
2000
0,20
1000
0,00
0
Time
Wcut
Copyright © 2004, AAPG
GOR
oc
t-0
3
Log-Lo g plot: dp and dp' [psi] vs dt [hr]
10
av
r-0
3
ju
in
-0
3
1
4000
oc
t-0
2
0 .1
0,80
ju
in
-0
2
0.0 1
5000
av
r-0
2
1 E -3
Water Cut (fraction)
0.1
1,00
GOR (m3/m3)
Historical Gas Oil Rati o and Wate r Cut
OWPZ8
1
AAPG International Conference: October 24-27, 2004; Cancun, Mexico
10
R.Recham and D.Bencherif
Figure 13 Transient well test analysis well OWPZ8
Figure 15 Transient well test analysis well OWPZ9
100
100
10
10
1
1
0.1
0 .1
1 E -3
0 .0 1
0 .1
1
10
1 E -3
100
0.01
0.1
1
10
100
Log-Log plot: dp and dp' [psi] vs dt [hr]
Log-Log p lot: dp and dp' [psi] vs dt [hr]
Figure14
Historical P roduction Rate and its Cumulative of We ll
OWPZ9
Figure 16 Simulation Results of gas-lift well OWPZ9
70
50
120
40
30
80
20
40
10
ju
in
-0
3
av
r-0
3
oc
t-0
2
A
B
C
D
E
250
200
1
150
0
ju
in
-0
2
av
r-0
2
0
300
Pressure, kg/cm²
Oil Production Rate (m3/d)
60
160
Cumulative Oil Production (10^3m3)
200
100
Time
Qb
Npb
50
Historical Ga s Oil Ratio and Wa ter Cut
OWPZ9
1,00
300
0,40
200
0,20
GOR (m3/m3)
400
0,60
ju
in
-0
3
av
r-0
3
oc
t-0
2
ju
in
-0
2
0
Time
Wcut
100
200
300
Inflow @ Sandface
Not Used
(1)
Inflow (1) Outflow (A)
Case 2 (2) Case 2 (B)
Case 3 (3) Case 3 (C)
Case 4 (4) Case 4 (D)
Case 5 (5) Case 5 (E)
Not Used Not Used
Not Used
100
0,00
av
r-0
2
0
500
0,80
Water Cut (fraction)
0
600
GOR
Copyright © 2004, AAPG
400
500
600
700
800
Liquid Rate, m³/d
Outflow
Injection Rate, m³/d
900 1000
Outflow
(A) 1000.0
(B) 2000.0
(C) 4000.0
(D) 6000.0
(E) 8000.0
Reg: Authorized User - Sonatrach - PED