Petroleum Engineering Assignment 2012 13
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Transcript of Petroleum Engineering Assignment 2012 13
Petroleum Engineering Assignment 1
Due Date: 15th of April 2013
Lateef Akanji (Ph.D., D.I.C.)
Petroleum and Gas Engineering
University of Salford
October 14, 2012
UoS Well Test Equations
∆Pskin = (Pwf)measured − (Pwf)calculated
s =∆Pskin
qµB2πκh
Jmeasured
Jcalculated=
P − Pwf + ∆Pskin
P − Pwf
∆P = −70.6µB
kh
[q1Ei
(−948φµctr
2
κt
)+ (q2 − q1)Ei
(−948φµctr
2
κ(t− t1)
)]∆G = VuLco∆Pρo
C = VuLco
tp =Np
q
m =∆P
Cycle
tpDA =κtp
φµctA
PDMBH = 2.3026(P ∗ −P )/m
κ = 0.183qµB
mh
κ = 162.6qµB
mh
s = 1.1513
[(P1hr − Pwf)
m− log
κ
φµctr2w
+ 3.2255
]s = −1.1513
[(Pi − Pwf(t1))
m+ logt1 + log
κ
φµctr2w
+ 0.35173
]
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UoS Well Test Equations
κ =
qµB
[∆PD
(tL∆tc
)2]
Fig
2πh∆P(
tL∆tc
)2
κ =qµB
2πh
(PD)M∆PM
φct =κ
µr2
tM(tDr2D
)M
or in field unit
κ = 141.2
qµB
[∆PD
(tL∆tc
)2]
Fig
h∆P(
tL∆tc
)2
κ = 141.2qµB
h
(PD)M∆PM
φct =2.64e−4κ
µr2
tM(tDr2D
)M
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UoS Petroleum Geology :Geologic Features
Figure 1: Geologic feature
Question 1
1. Determine the relative ages in Figure 1
2. Name the features marked A, B, C and D
3. Describe the sequence of events that resulted in the formation of
the geological features observed in Figure 1
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UoS Petroleum Geology :Geological Map Interpretation Question 1
Figure 2: Geological map
Question 2
1. Identify the rock types in the area shown Figure 2
2. Determine the relative ages of the rocks
3. Name the geological structures that you are able to identify (in
the case of folds, draw their axes)
4. Describe the geological history of the area
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UoS Exploration : Exploration techniques Question 2
Question 3
1. State and define the principle methods of exploration and reser-
voir prediction
2. What are the two methods commonly used in seismic prospect-
ing?
(a) Which is most often used?
(b) Which gives the most information?
3. Describe hydrocarbon indicators on a seismic section
4. What sources of energy are most often used in seismic explo-
ration?
5. What are the principal uses of seismic data
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UoS Petroleum Geology (Case-studies GP1 ):UK North Sea Question 3
Question 4
1. Using a simplified map, describe the major subdivisions and brief
geological history of the North Sea
2. Describe the major distributions of oil and gas fields in the South-
ern North Sea (SNS) basin and adjacent onshore UK areas
3. Using a simplified stratigraphic column describe the oil and gas
fields found in the Northern North Sea (NNS)
4. Describe the diffferent kinds of sedimentary rock and fluid types
found in the North Sea and relate them to the depositional pro-
cesses that led to their formation
5. Discuss the historical oil and gas production profile from the UK
North Sea and the future direction
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UoS Petroleum Geology (Case-studies GP2 ):Nigerian Niger Delta Question 4
Question 5
1. Using a simplified map, describe the major subdivisions and brief
geological history of the Nigerian Niger Delta basin
2. Describe the major distributions of oil and gas fields in the Niger
Delta basin
3. Using a simplified stratigraphic column describe the oil and gas
fields found in the Nigerian Niger Delta basin
4. Describe the diffferent kinds of sedimentary rock and fluid types
found in the Niger Delta and relate them to the depositional
processes that led to their formation
5. Discuss the historical oil and gas production profile from the Niger
Delta and the potentials for future exploitation
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UoS Petroleum Geology (Case-studies GP3 ):Arabian Gulf Question 5
Question 6
1. Using a simplified map, describe the major subdivisions and brief
geological history of the Arabian Gulf basin
2. Describe the major distributions of oil and gas fields the Arabian
Gulf basin
3. Using a simplified stratigraphic column describe the oil and gas
fields found in the Arabian Gulf basin
4. Describe the diffferent kinds of sedimentary rock and fluid types
found in the Arabian Gulf and relate them to the depositional
processes that led to their formation
5. Discuss the historical oil and gas production profile from the Ara-
bian Gulf and the potentials for future exploitation
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UoS Petroleum Geology (Case-studies GP4 ):Gulf of Mexico Basin Question 6
Question 7
1. Using a simplified map, describe the major subdivisions and brief
geological history of the Gulf of Mexico basin
2. Describe the major distributions of oil and gas fields in the Gulf
of Mexico
3. Using a simplified stratigraphic column describe the oil and gas
fields found in the Gulf of Mexico
4. Describe the diffferent kinds of sedimentary rock and fluid types
found in the Gulf of Mexico and relate them to the depositional
processes that led to their formation
5. Discuss the historical oil and gas production profile from the Gulf
of Mexico and the potentials for future exploitation
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UoS Drilling (Ass ): Drilling Engineering Question 7
Question 8
1. The target and the rig coordinates of a well are given in Table 1.
Determine the relative position of the rig and target
(a) rectangular coordinates
(b) polar coordinates
Table 1: Coordinates of rig and target
Target Rig
NS(meters) 964 1334EW (meters) −144 653
2. Using Figure 3 and the information provided in Table 2, design
a build and hold trajectory
Table 2: Build and hold trajectory design
Vertical depth 3, 218.688 meters [10, 560 ft.]Horizontal displacement 1, 333.5 meters [4, 375 ft.]
Kick-off depth 457.2 meters [1, 500 ft.]Build rate 2o per 30.48 meters [2o per 100ft.]
3. From your design, determine the following:
(a) radius of curvature of the build section
(b) hold angle
(c) measured depth (MD) at start of Hold section (MDhold)
(d) measured depth (MD) at total depth (MDTD)
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UoS Drilling (Ass ): Drilling Engineering Question 8
Figure 3: A build and hold trajectory
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UoS Production & Well-Test :Well-Test Objectives Question 8
Question 9
1. Explain the following production related terms, stating all related
equations
(a) Productivity index
(b) Vertical lift performance
(c) Inflow performance relationship
(d) Gas reservoir deliverability
2. Describe the following well-test methods and state the main ob-
jectives of conducting each
(a) Injectivity test
(b) Fall-off test
(c) Interference test
(d) Drill-stem test
(e) Pulse test
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UoS Production & Well-Test : Pressure Drawdown Question 9
Question 10
Table 3 is a pressure drawdown test data from a well in an undersat-
urated reservoir with the following properties:
Pi = 20.7 MPa[3002.3 psi]
Boi = 1.32
µo = 9.2× 10−3 Pa− s[9.2 cp]
h = 21 m[68.9ft.]
φ = 0.17
Swi = 0.26
ct = 1.2× 10−9 Pa−1[8.27× 10−61/psi]
rw = 0.1m [0.328 ft.]
q = −17.2 m3/d[108.2 bbl/d]
1. Plot Pwf versus time on a semilog coordinate sheet (Sheet A)
2. From your plot and using appropriate equations, determine:
(a) the gradient, m
(b) the pressure at t = 10 hrs
(c) the permeability, κ
(d) the skin effect, s
(e) whether the system is damaged or stimulated
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UoS Production & Well-Test : Pressure Drawdown Question 10
Table 3: Pressure drawdown test data
Time(hours) Pwf (MPa)
32 18.4143 18.3853 18.3564 18.3272 18.3081 18.29110 18.25
Figure 4: Sheet A
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UoS Production & Well-Test : Build-up & reservoir pressure Question 10
Question 11
1. Figure 5 is a pressure build-up curve from a reservoir with a
limited drainage area.
(a) Determine the production time tp
(b) Estimate the slope, m
(c) From the graph, estimate the Pws(1hour) and the correspond-
ing Pwf
(d) Why is the Pws(1hour) different from the corresponding Pwf?
Figure 5: Pressure build-up curve with a limited drainage area
2. Using the Matthews-Brons-Hazenbroek (MBH) method, deter-
mine the mean pressure of the drainage area of a well in the
above reservoir which is placed at the center of a square with a
surface A = 0.42 × 106 m2 (103.8 acre). Use Figure 6 and the
following additional data.
Question 11 continued on next page. . . [email protected] Page 15 of 25
UoS Production & Well-Test : Build-up & reservoir pressure Question 11 (continued)
Figure 6: MBH dimensionless pressure for different well locations in a square drainage area (after Matthews-Brons-Hazenbroek)
Additional pressure build-up data
Np = 21409 m3 [134648bbl], cumulative production
q = 38.3 m3/d [241bbl/d], production rate before shut-in
Boi = 1.52 (rb/stb)
Pi = 20.7 MPa [3002.3 psi]
µo = 9.2× 10−3 Pa-s [9.2 cp]
h = 21 m [68.9 ft]
φ = 0.17 [ ]
Swi = 0.25 [ ]
ct = 1.2× 10−9Pa−1 [8.27× 10−61/psi]
rw = 0.1 m [0.328 ft]
Question 11 continued on next page. . . [email protected] Page 16 of 25
UoS Production & Well-Test : Interference and Diagnostics Question 11 (continued)
Question 12
1. During an interference test, water was injected in the active well
for 22 days. The distance to the observation well is 112.4 m
[368.8ft]. The measured pressure changes are drawn on a trans-
parent sheet versus t (hour), and matched by parallel shifting in
Figure 7 with the type curve. In the match point:
(a) tM = 100hours
(b) (tD/r2D)M = 50
(c) ∆PM = 105 Pa [= 14.5psi]
(d) PDM = 0.8
Additional data
q = 300 m3/d [= 1887bbl/d]
µ = 0.82× 10−3 Pa-s [0.82cp]
Bw = 1.0
h = 12 m [39.4ft]
r = 112.4 m [368.8ft]
(a) Determine the permeability, κ and
(b) φct
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UoS Production & Well-Test : Interference and Diagnostics Question 12
Figure 7: Illustration of type curve matching for an interference test
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UoS Production & Well-Test : Interference and Diagnostics Question 12
Question 13
Figure 8 is a well test interpretation models for wells near a single
fault, channel system and wedge systems. The corresponding pres-
sure change and derivative plots are also shown on a log-log plot.
Analyze each of the plots.
Figure 8: Well test interpretation models
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UoS Reservoir Performance : Reservoir Engineering Question 13
Question 14
Consider a reservoir that is shaped like a circular disk, 10 m thick,
and with a 5 km radius in the horizontal plane. The mean porosity of
the reservoir is 15%, the water saturation is 0.3, and the oil saturation
is 0.7.
1. Ignoring the expansion of the oil that would occur when it is
produced from the reservoir, how many barrels of oil are in this
reservoir? (One barrel = 0.1589 m3).
2. If the density of the oil is 900 kg/m3, how much oil (in kg) is
contained in the reservoir?
Question 15
With the aid of annotated phase envelope diagrams, describe the
following
1. cricondenbar and cricondentherm
2. retrograde condensation, dry-gas and wet gas
3. light, intermediate and heavy crude systems
Question 16
Given the gas production data shown in Table 4. Determine:
1. the total volume (at standard conditions) of gas initially in place
(GIIP)
Question 16 continued on next page. . . [email protected] Page 20 of 25
UoS Reservoir Performance : Reservoir Engineering Question 16 (continued)
Table 4: Data from a gas reservoir
Pressure(MPa) Z Gp(108 m3)
25 0.85 024 0.86 6.0923 0.87 11.822 0.88 17.121 0.89 23.1
2. the volume of gas (Gp) that will be produced at the abandonment
pressure of 3 MPa when Z = 0.95
3. Explain why the abandonment pressure is not 0.1 MPa (1 atm)
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UoS Reservoir Rock : Rock properties Question 16
Question 17
In a laboratory experiment, a pressure drop of 100 kPa is imposed
along a core that has length of 10 cm, and a radius of 2 cm. The
permeability of the core is 200 mD, its porosity is 15%, and the
viscosity of water is 0.001 Pa− s.
1. What will be the volumetric flowrate Q of the water, in m3/s?
2. What is the numerical value of q = Q/A, in m/s?
Question 18
Consider a layered reservoir consisting of alternating layers, 1 m
thick, of rock 1, rock 2 and rock 3, where k1 = 1000 mD, k2 =
100 mD, and k3 = 10 mD.
1. What is the effective permeability of this rock, if fluid is flowing
parallel to the layering?
2. What is the effective permeability of this rock, if fluid is flowing
perpendicular to the layering?
3. Imagine that the reservoir consists of these three rock types, in
equal volumetric proportions, but occurring in a ’random’ spatial
distribution. Estimate the effective permeability in this case.
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UoS Reservoir Rock : Rock properties Question 18
Question 19
Consider a small blob of oil surrounded by water. The surface tension
between the oil and water is 0.02 Nm. If the radius of the blob is
0.05 mm
1. What is the value of the capillary pressure?
2. Is the pressure higher in the oil or the water?
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UoS Reservoir Fluid : Fluid properties Question 19
Question 20
Table 5 is the fluid compositional data of a gas reservoir. Compute
1. the apparent molecular weight (AMW)
2. the specific gravity γ
3. the composition in weight fraction
4. the composition in volume fraction
Table 5: Data from a gas reservoir
Component Composition, mole fraction
Methane 0.820Ethane 0.059Propane 0.046Isobutane 0.035n-butane 0.030
1.000
Question 21
An oil reservoir has the compositional data given in Table 6
1. What is the API gravity of the oil? Use ideal-solution principles
Table 6: Data from a gas reservoir
Component Mole fraction
n-butane 0.29n-pentane 0.40n-hexane 0.31
1.00
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UoS Reservoir Fluid : Fluid properties Question 21
Question 22
1. The analysis of a formation water is given in Table 7. Convert
the concentrations of solids for the brine to
(a) milligrams per liter
(b) percent solids
(c) milliequivalents per liter
2. Draw a pattern of the brine
Table 7: Data from a gas reservoir
Component Mole fraction
Na 7, 365Ca 1, 582Mg 305S04 521Cl 14, 162C03 705
HC03 0
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