GEOLOGY - GEOPHYSICS
All ABOUT THE ROCK
Oil is a rather elusive thing. We won’t ﬁnd pools of it waiting for extraction under the surface of the Earth. It’s all about rock, and even then, it is not visible to the human eye. So what do we look for in a precious rock?
First of all, we look for pores.
conventional vs. UnconventionaL WISDOM
- The difference between conventional and unconventional oil and gas is simply a difference between the geological characteristics of the reservoir rock that contains them.
- Unconventional oil and gas includes shale oil and gas, tight oil and gas and coalbed methane, or coal seam gas. The key difference between conventional and unconventional is the method by which they are extracted and the cost of extraction, with conventional being considerably cheaper and easier to extract.
- Conventional oil and gas is usually trapped in small, porous zones in natural occurring rock formations such as sandstones and carbonates. For 100 years, until the advent of directional drilling and hydraulic fracturing that led to the shale boom, exploration and production were all about the conventional. The technological revolution made it possible to access commercially viable volumes of tight oil and gas and shale oil and gas. These are resources that are trapped in very low-permeability rock and ultra-compact structures that limit the ability of the hydrocarbons to migrate upwards.
- The revolution turned the unconventional into the conventional—but in times of falling oil and gas prices, the conventional again becomes attractive.
Geologists & GEOPHYSICISTS
Geological FACT sheet - What we are targeting
Geologists examine what rocks are made of - what class and type of formations they have created in the Earth.
Geophysicists use physical characteristics to determine the type and shape of rocks beneath the Earth's surface. Those physical characteristics would include gravitational and magnetic properties, among other things.
Both are vital to the exploration process.
There are ﬁve key things that we will want to consider in terms of the geology of a prospect in question. If any one of these elements is missing, we will be unsuccessful:
1. Source Rock
We need source rock. There are no hydrocarbons without source rock. Source rock is what you get when organic-rich rock (oil shale or coal, for instance) undergo natural high pressure and temperatures over a long period of time, in the process forming hydrocarbons. In other words, source rock is a rock with organic materials that if heated sufﬁciently will produce hydrocarbons.
2. A Permeable Reservoir
The source rock will be contained within a reservoir, typically of porous sandstone or limestone. Thus, a reservoir is a subsurface body of rock that has sufﬁcient porosity and permeability to store and transmit ﬂuids. In other words, the reservoir must have a high enough permeability for the oil and gas to ﬂow to the surface.
The oil and gas has to be able migrate out of the source rock and into the reservoir rock, towards the surface. The right geological conditions must exist for this to happen. This means it has to be able to be lured out of the source rock. Either they migrate as oil seeps or they get trapped somewhere along the way.
The oil and gas have to be trapped within a structural or stratigraphic trap in order, otherwise they can never be pinned down and found or extracted.
5. Cap Rock (Seal)
There has to be a layer of cap rock covering the trap. Cap rock is naturally impenetrable for the oil and gas—meaning that it cannot escape the trap.
If any one of these geological conditions is missing, we won’t ﬁnd any oil or gas and our exploration efforts will fall ﬂat. While we don't expect an investor or a client to be an expert geologist, these top 5 geological preconditions provide an idea of what we are looking for and our investors and clients should feel free to ask management before you invest or hire us.
© Copyright 2009-2020.