Petroleum Engineering Assignment 1Due Date: 15th of April 2013

Lateef Akanji (Ph.D., D.I.C.) Petroleum and Gas Engineering University of Salford l.t.akanji@salford.ac.uk October 14, 2012

UoS

Well Test Equations

Pskin = (Pwf )measured (Pwf )calculated Pskin s = qB2h

Jmeasured P Pwf + Pskin = Jcalculated P Pwf 70.6B 948ctr2 P = q1Ei kh t G = VuLcoP o

+ (q2 q1)Ei

948ctr2 (t t1)

C = VuLco Np tp = q P m = Cycle tp tpDA = ctA PDM BH = 2.3026(P P )/m qB = 0.183 mh qB = 162.6 mh (P1hr Pwf ) s = 1.1513 log + 3.2255 2 m ctrw (Pi Pwf (t1)) s = 1.1513 + logt1 + log + 0.35173 2 m ctrw

l.t.akanji@salford.ac.uk

Page 1 of 25

UoS

Well Test Equations

qB PD = 2hP =

tL tc tL tc

2 F ig 2

qB (PD )M 2h PM tM ct = 2 r tD2 rD

M

or in eld unit qB PD = 141.2 hP = 141.2tL tc tL tc 2 2 F ig

qB (PD )M h P M 4 2.64e tM ct = tD r22 rD

M

l.t.akanji@salford.ac.uk

Page 2 of 25

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

l.t.akanji@salford.ac.uk

Page 3 of 25

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

l.t.akanji@salford.ac.uk

Page 4 of 25

UoS

Exploration : Exploration techniques

Question 2

Question 3

1. State and dene the principle methods of exploration and reservoir prediction 2. What are the two methods commonly used in seismic prospecting? (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 exploration? 5. What are the principal uses of seismic data

l.t.akanji@salford.ac.uk

Page 5 of 25

UoS

Petroleum Geology (Case-studies GP1 ):UK North Sea

Question 3

Question 4

1. Using a simplied map, describe the major subdivisions and brief geological history of the North Sea 2. Describe the major distributions of oil and gas elds in the Southern North Sea (SNS) basin and adjacent onshore UK areas 3. Using a simplied stratigraphic column describe the oil and gas elds found in the Northern North Sea (NNS) 4. Describe the diferent kinds of sedimentary rock and uid types found in the North Sea and relate them to the depositional processes that led to their formation 5. Discuss the historical oil and gas production prole from the UK North Sea and the future direction

l.t.akanji@salford.ac.uk

Page 6 of 25

UoS

Petroleum Geology (Case-studies GP2 ):Nigerian Niger Delta

Question 4

Question 5

1. Using a simplied map, describe the major subdivisions and brief geological history of the Nigerian Niger Delta basin 2. Describe the major distributions of oil and gas elds in the Niger Delta basin 3. Using a simplied stratigraphic column describe the oil and gas elds found in the Nigerian Niger Delta basin 4. Describe the diferent kinds of sedimentary rock and uid 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 prole from the Niger Delta and the potentials for future exploitation

l.t.akanji@salford.ac.uk

Page 7 of 25

UoS

Petroleum Geology (Case-studies GP3 ):Arabian Gulf

Question 5

Question 6

1. Using a simplied map, describe the major subdivisions and brief geological history of the Arabian Gulf basin 2. Describe the major distributions of oil and gas elds the Arabian Gulf basin 3. Using a simplied stratigraphic column describe the oil and gas elds found in the Arabian Gulf basin 4. Describe the diferent kinds of sedimentary rock and uid 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 prole from the Arabian Gulf and the potentials for future exploitation

l.t.akanji@salford.ac.uk

Page 8 of 25

UoS

Petroleum Geology (Case-studies GP4 ):Gulf of Mexico Basin

Question 6

Question 7

1. Using a simplied map, describe the major subdivisions and brief geological history of the Gulf of Mexico basin 2. Describe the major distributions of oil and gas elds in the Gulf of Mexico 3. Using a simplied stratigraphic column describe the oil and gas elds found in the Gulf of Mexico 4. Describe the diferent kinds of sedimentary rock and uid 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 prole from the Gulf of Mexico and the potentials for future exploitation

l.t.akanji@salford.ac.uk

Page 9 of 25

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 coordinatesTable 1: Coordinates of rig and target T arget N S (meters) EW (meters) 964 144 Rig 1334 653

2. Using Figure 3 and the information provided in Table 2, design a build and hold trajectoryTable 2: Build and hold trajectory design Vertical depth Horizontal displacement Kick-o depth Build rate 3, 218.688 meters [10, 560 f t.] 1, 333.5 meters [4, 375 f t.] 457.2 meters [1, 500 f t.] 2o per 30.48 meters [2o per 100f t.]

3. From your design, determine the following: (a) radius of curvature of the build section (b) hold angle (c) measured depth (M D) at start of Hold section (M Dhold) (d) measured depth (M D) at total depth (M DT D )

l.t.akanji@salford.ac.uk

Page 10 of 25

UoS

Drilling (Ass ): Drilling Engineering

Question 8

Figure 3: A build and hold trajectory

l.t.akanji@salford.ac.uk

Page 11 of 25

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) Inow performance relationship (d) Gas reservoir deliverability 2. Describe the following well-test methods and state the main objectives of conducting each (a) Injectivity test (b) Fall-o test (c) Interference test (d) Drill-stem test (e) Pulse test

l.t.akanji@salford.ac.uk

Page 12 of 25

UoS

Production & Well-Test : Pressure Drawdown

Question 9

Question 10

Table 3 is a pressure drawdown test data from a well in an undersaturated reservoir with the following properties:

Pi = 20.7 M P a[3002.3 psi] Boi = 1.32 o = 9.2 103 P a s[9.2 cp] h = 21 m[68.9f t.] = 0.17 Swi = 0.26 ct = 1.2 109 P a1[8.27 1061/psi] rw = 0.1m [0.328 f t.] 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, (d) the skin eect, s (e) whether the system is damaged or stimulatedl.t.akanji@salford.ac.uk Page 13 of 25

UoS

Production & Well-Test : Pressure Drawdown

Question 10

Table 3: Pressure drawdown test data T ime(hours) 32 43 53 64 72 81 110 Pwf (M P a) 18.41 18.38 18.35 18.32 18.30 18.29 18.25

Figure 4: Sheet A

l.t.akanji@salford.ac.uk

Page 14 of 25

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 corresponding Pwf (d) Why is the Pws(1hour) dierent from the corresponding Pwf ?

Figure 5: Pressure build-up curve with a limited drainage area

2. Using the Matthews-Brons-Hazenbroek (MBH) method, determine 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. . . l.t.akanji@salford.ac.uk Page 15 of 25

UoS

Production & Well-Test : Build-up & reservoir pressure Question 11 (continued)

Figure 6: MBH dimensionless pressure for dierent well locations in a square drainage area (after MatthewsBrons-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 M P a [3002.3 psi] o = 9.2 103 Pa-s [9.2 cp] h = 21 m [68.9 ft] = 0.17 [ ] Swi = 0.25 [ ] ct = 1.2 109P a1 [8.27 1061/psi] rw = 0.1 m [0.328 f t]Question 11 continued on next page. . . l.t.akanji@salford.ac.uk 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 [368.8f t]. The m