Introduction to Oil Gas MBALLM Oil Gas Patrick
Introduction to Oil & Gas MBA/LLM Oil & Gas Patrick Ruharuza BSc, MSc. Oil & Gas Management
In this lecture • About the Lecturer • Definition of key terms • Basic Geological concepts (Occurrence of Hydrocarbons) • Petroleum System Mapping • Introduction to Exploration • Conventional & Nonconventional Petroleum resources
About the Lecturer Patrick Ruharuza MSc. Oil & Gas Management CEO Quest Energy Almost Nice guy
Definition of key terms • A Barrel (bbl. ) of crude contains 42 gallons or 158. 8 liters • Hydrocarbons are chemical compounds made mainly of carbon and hydrogen • Fossil fuels are fuels formed by natural processes such as anaerobic composition of buried dead organisms • An oil reservoir is merely a solid sand formation in which oil has accumulated. If you covered a sand beach with tons of sediments, you would have a potential sand reservoir. The only difference is that the loose sand grains would consolidate into a hard sandstone rock. • An "oil field" or "oilfield" is a region with an abundance of oil wells extracting petroleum (crude oil) from below ground.
Petroleum • Crude Oil (or Petroleum) • Petroleum (Latin for: Petra = Rock; Oleum = Oil). • Crude oil is a naturally occurring, toxic, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other organic compounds that are found in geologic formations beneath the earth’s surface.
Occurrence & Formation of Petroleum
The Petroleum (Charge) System • Source Rock – a rock with abundant hydrocarbonprone organic matter. • Reservoir Rock – a rock in which oil and gas accumulates: • Porosity – space between rock grains in which oil accumulates. • Permeability – passage ways between pores through which oil and gas moves. • Seal Rock – a rock through which oil and gas cannot move effectively (such as mudstone and claystone). • Migration Route – avenues in rock through which oil and gas moves from source rock to trap. • Trap – the structural and stratigraphic configuration
Porosity. • To function as a reservoir rock, a rock must have some open space within its structure to contain the oil or gas. This is called porosity, and is expressed as a percent of the open space to the overall rock volume. That is, a rock with 25% porosity is composed of 75% rock and 25% open space.
Porosity
High Porosity sand stone
Petroleum System
Petroleum Systems Elements • A petroleum system is said to exist in a particular sedimentary basin IF: • There is a source rock that is mature – effective source rock. • The source rock has expelled hydrocarbons – hydrocarbon generation. • The hydrocarbons have migrated – hydrocarbon migration. • The migrated hydrocarbons have formed an accumulation – reservoir rock. • The accumulation has been trapped by a sealing mechanism – a cap rock.
Petroleum Systems Mapping • Identification of a working petroleum system is the cardinal role of oil and gas explorationists. • Petroleum exploration involves: • Reconnaissance surveys – geological mapping, geophysical (gravity and magnetic) surveys, surface geochemical surveys, shallow well drilling and seismic surveys. • Exploration drilling • Appraisal drilling if exploration wells have encountered oil and/or gas.
Lecture 2 • Exploration and Appraisal Drilling • Drilling operation • Field Development Processes • A chat about the assignment
Exploration and Appraisal Drilling • Exploration drilling • Drilling with the aim of discovering previously undiscovered petroleum • Can be a success or failure • Appraisal drilling • Drilling with the aim of quantifying the discovered petroleum to establish its commercial viability • Helps to delineate the extent of a discovery and contributes to the establishment of volumes • 3 D seismic data can also be part of the appraisal activities
The Drilling Operation 1 • The main operation at the well site. • Undertaken in accordance with an approved well proposal and drilling program. • Program outlines following essentials: well prognosis, logging program, casing and cementing, suspension or abandonment. • In the case of suspension or abandonment, a separate program is submitted for approval. • Involves either vertical or deviated drilling • Undertaken using a drilling rig, whose size depends on the complexity of the structure
THE RIG
The Drilling Operation 3 • Drilling is facilitated by drilling mud which is a mixture of some chemicals with either water (for a water based mud, WBM) or oil (for an oil based mud, OBM). • OBM’s are discouraged because of environmental concerns since oil is a pollutant. • The mode of flow of mud can be followed at the rig or on • the schematic shown on the next slide but one.
- Slides: 35