1. Recent Advances in Oil & Gas Production Engineering
Professor Ma, Xianlin
Nov. 2016

2. Professional Experience
Instructor
Ma, Xianlin Phone:
About Me
Professor, College of Petroleum Engineering, Xi’an Shiyou University
Education
Postdoc Stanford University
Ph.D Texas A&M University
Ph.D   Institute of Computing Technology, Chinese Academy of Sciences
M.S China University of Petroleum, Beijing
B.S China University of Geosciences, Wuhan
Professional Experience
, (Senior) Reservoir Engineering, Chevron, Houston, US
, Lecturer, China University of Petroleum, Dongying, China
Research Interests
Reservoir Simulation and Applications
Inverse Modeling and Data Integration
Modeling and Scaling-up of Enhanced Oil Recovery
Stochastic Reservoir Characterization

3. Grading System
Attendance 10 % Homework 20 % Final Exam 70 %

4. Course Outline
Chapter 1: Introduction Chapter 2: Gas Well Unloading Technologies Chapter 3: Advanced Hydraulic Fracturing Technologies Chapter 4: Horizontal Well Fracturing Chapter 5: Coiled tubing operations and Intelligent Well Chapter 6: Unconventional Oil and Gas Production Chapter 7: Shale Gas Development

5. International Energy Outlook-1
EIA: Energy Information Administration

6. International Energy Outlook-2

7. International Energy Outlook-3

8. International Energy Outlook-4
OPEC (Organization of the Petroleum Exporting Countries) 

9. International Energy Outlook-4
Organization for Economic Co-operation and Development (OECD) 
Non-OPEC petroleum supply growth is concentrated in five countries

10. Natural Gas Markets-1

11. Natural Gas Markets-2

17. What is Production Engineering?
A branch of Petroleum Engineering
Deals with hydrocarbon fluid flow from the sand face through wellbore to surface
Maximizes production (or injection) of fluids from (or into) wells in a manner that optimizes the economic values of the resource
Other branches are :
Reservoir Engineering
Drilling and Completions
Facilities Engineering
Operations Engineering

18. Responsibilities of Production Engineer
Work closely with reservoir, facilities, drilling and operations engineers
Design workover to change downhole equipment
Evaluation of well performance and recommend remedial action
Design and complete well stimulation treatments

19. Production System -1

20. Production System -2

21. Production System –Pressure lose

22. Sources of pressure loss in a production system

23. Production System –Pressure lose
Location

24. Production engineering-wellbore performance

25. Wellbore performance-introduction

26. Wellbore performance-IPR/VLP

27. Wellbore performance-VLP

28. Pressure lose: Single phase flow, liquid

29. Laminar flow vs. Turbulent flow
Re < 2000
Transitional flow:
2000 < Re < 4000
Turbulent flow:
Re > 4000
Laminar flow
a fluid flows in parallel layers, with no disruption between the layers
Reynolds (1880s) number:
 ρ = density,  v = mean velocity, 
d = diameter and µ = viscosity

30. Pressure lose: Single phase flow, liquid

31. Pressure lose: Single phase flow, liquid

32. Pressure lose: Single phase flow, liquid

33. Pressure lose: Single phase flow, liquid

34. Two-phase flow

35. Phase Diagram for hydrocarbon matrix
CP: Cricondenbar – a pressure point, above which a liquid can not be vaporized.
CT: Cricondentherm – a temperature point, above which a gas can not be condensed.
C: Critical Point – a pressure and temperature point, at which two phases become identical

36. Two-phase, flow regimes

37. VLP models

38. Total System analysis-nodal analysis
Nodal point

39. Total System analysis-nodal analysis

40. VLP curve

41. Oil & Gas Production System
Overall flow system
Inflow Performance
Vertical Flow performance
Horizontal flow performance
Surface Choke Performance
Multiphase flow
Pressure loss

42. Well Inflow Performance Relationship(IPR)

43. Well Inflow Performance Relationship(IPR)
Well production are related to reservoir driving force by inflow performance relationship
Mathematical equation that is designed to describe the flow behavior of fluids varies depending on the reservoir characteristics
The primary reservoir characteristics （油藏特性） include:
Types of fluids
Flow regimes
Reservoir flow geometry
Number of flowing fluids

44. Introduction
Mathematical relationship that is designed to describe the flow behavior of fluids varies depending on the reservoir characteristics
The primary reservoir characteristics include:
Types of fluids
Flow regimes
Reservoir geometry
Number of flowing fluids

45. Types of Fluids
The isothermal compressibility coefficient is essentially the controlling factor in identifying the type of the reservoir fluid.
Reservoir fluids are classified into three groups:
(1) incompressible fluids
(2) slightly compressible fluids;
(3) compressible fluids.

46. Volume and density change as a function of pressure for three types of fluids
Pressure-volume relationship
Fluid density versus pressure for different fluid types

47. Flow Regimes
There are basically three types of flow regimes that must be recognized in order to describe the fluid flow behavior and reservoir pressure distribution as a function of time.
These three flow regimes are:
(1) Steady state flow（稳定流）;
(2) Unsteady state (transient) flow;
(3) Pseudosteady(semi-steady) state flow.

48. Flow Regimes

49. Flow Geometry
The flow geometry may be represented by one of the following flow geometries:
radial flow（径向流）
linear flow（线性流）
spherical and hemispherical flow（球形流和半球形流）

50. Radial Flow
Plane View

51. Linear Flow

52. Spherical and Hemispherical Flow
Spherical flow due to limited entry.
Hemispherical flow in a partially penetrating well

53. Number of flowing fluids
The mathematical expressions that are used to predict the volumetric performance and pressure behavior of a reservoir vary in form and complexity depending upon the number of mobile fluids in the reservoir.
There are generally three cases of flowing system:
single-phase flow (oil, water, or gas)
two-phase flow (oil–water, oil–gas, or gas–water)
three-phase flow (oil, water, and gas)
The description of fluid flow and subsequent analysis of pressure data becomes more difficult as the number of mobile fluids increases.

54. SPE unit system q stb/d k mD A ft2 μ cP B bbl/stb p psia l ft
Types of fluids: incompressible
Flow regimes: steady-state
Flow geometry: linear
Number of flowing fluids: single-phase q
stb/d k mD A
ft2 μ cP B
bbl/stb p
psia l ft
SPE unit system

55. Skin Factor(表皮系数） Types of fluids: incompressible
Flow regimes: steady-state
Flow geometry: radial
Number of flowing fluids: single-phase h
Skin Factor(表皮系数）

56. Pressure Profile
(1) S > 0: damaged zone (mud filtrate, cement slurry,
or clay particles to enter the formation) near the wellbore exists, causing permeability kskin < k
(2) S<0: kskin > k, This negative factor indicates an improved wellbore condition (acid treatment （酸化处理）or hydraulic fracturing（水力压裂）)
(3) S = 0: kskin = k

57. Productivity Index (PI)
(stb/d/psi)
q = JΔp
Direct measure of well potential or ability to produce
Well property

58. IPR Curve
qmax: absolute open-flow potential (AOF)

59. IPR for Single Phase (oil)
Vertical well production
Steady-state
Constant pressure support
Pseudosteady-state
Closed boundary
Unsteady-state
Radial diffusivity equation

60. Example of Steady-state IPR

61. Example of Steady-state IPR various skin factors

62. Example of pseudosteady-state IPR

63. Example of transient IPR
Well testing relies on the transient flow

64. IPR for two-phase flow Vogel correlation
AOFP is the absolute open-flow potential of single-phase oil flow.

65. Wellbore Flow Performance (Vertical Lift Performance, VLP)
 Estimating the pressure-rate relationship in the wellbore as the reservoir fluids move to the surface through the tubulars
Pressure loss
hydrostatic and friction pressure drops
Several correlations for wellbore flow performance are used (Beggs and Brill, 1973; Hagedorn and Brown, 1965)

66. Wellbore Flow Performance
Liquid holdup, hydrostatic pressure
higher friction pressures

67. Well Deliverability

68. Artificial Lift
Used to lower the producing bottomhole pressure on the formation to obtain a higher production rate from the well.
Most oil wells require artificial lift at some point in the life of the field

69. Types of Artificial Lift
Gas Lift
DuraLift
PC Pumps
HydroLift
Hydraulic Pumps
Beam pump
ESP (Electrical Submersible Pumping)

70. Summary of Advantages and Disadvantages