There are many different types of wells when it comes to oil and gas. One of those is exploratory well or exploratory oil well. This particular well is part of the exploration stage of oil and gas wells, as the name indicates.
In this post, we’ll focus solely on exploratory well and answer questions like what it is, how it works, and what benefits it can offer in oil and gas exploration and extraction.
Exploratory Well Definition
An exploratory well is a test well or hole drilled in the ground to locate and test oil and gas resources, both on the ground and under the sea.
The exploratory well is typically the second part of the exploration of proven reserves. First, the engineers look for resources and identify their location underground through seismic data. Then, exploratory wells are dug to access the formations with the oil or gas to get more data.
These are technically wells but not fully prepared for production. In fact, these are rudimentary wells dug for the sole purpose of getting more information and accessing the potential of the oil or gas field in a particular location.
Exploratory well holes are normally not that deep or difficult to drill as compared with injection or production wells.
Why is an Exploratory Well Used in the Oil and Gas Industry?
In the discovery of oil and gas under the surface of the Earth, scientists and engineers gather data through seismic testing.
Seismic testing basically collects information through shock waves and creates an image of the subsurface. This allows exploration companies to find whether a particular stretch of land, both onshore and offshore, has oil or gas reserves underneath it.
Seismic testing has typically two types: dynamite or thumper trucks. Regardless of the type, the goal is to determine whether there’s any oil or gas underneath.
However, this data can only tell so much about the formation underneath. It doesn’t tell much about how much oil or gas reserves there may be or how difficult it may be to extract them.
To be more certain of all this, exploratory and production companies have to dig in to get the actual formation and collect rocks and samples to make further decisions.
Further Importance of Exploratory Wells
This is why exploratory wells are important for oil and gas exploration companies because digging a well and actually assessing the rock formation gives them a better idea about the production potential of the well. They can get rock samples and fluid samples to make important measurements and assessments before going forward.
Digging a proper well with completion based on just seismic data can be risky. Some rock formations are difficult to fracture or may not have a profitable yield despite having ample reserves.
Companies can clear up all those doubts and reservations by simply digging an exploratory well.
It is also somewhat cost-effective for the drilling and exploration companies as drilling an exploratory well is much cheaper than drilling a production well and its completion.
They usually only go forward with more drilling and completion of the production well once they determine the well will be viable enough to be profitable.
Exploratory Wells vs Developmental Well
In comparison with an exploratory well, a developmental well is drilled for production purposes. In essence, a development well depends on the results from the exploratory well. If the data and sample from the exploratory oil well indicate profitable production, the companies go ahead and dig a developmental well.
In contrast to an exploratory well, a developmental well is much deeper and wider. They also cost significantly more too.
You may find a dry developmental well but not a dry exploratory well. If there’s any oil or gas, it is turned into a developmental well.
Developmental well is only drilled after the exploratory well. It can take several years for well completion and to start production.
While exploratory wells only really have two types, there are many different types of developmental wells.
Wildcat Drilling: A Type of Exploratory Well
There’s a relatively newer form of exploratory drilling on the rise today, and it’s wildcat drilling. Wildcat drilling involves drilling wells in already exploited or unexploited fields with no historic production or perhaps even proven reserves. It is also common for places that have been fully exhaustion for minerals.
This is more of experimental drilling to explore the resources underneath. It’s a typical high risk, high reward strategy with many such these welles proving unsuccessful.
Since it’s more experimental and high-risk, this kind of digging requires a very high level of expertise on board. That’s because drillers will have to use different parameters of the well while digging to assess whether it has any resources worth extracting.
One of the main reasons why this kind of drilling is on the rise is that there are many developmental wells that haven’t yet produced 100 per cent of the minerals they hold. In many cases, the extraction is only 75 per cent of the total reserves.
Exploratory Wells Today
The number of these wells dipped in the early 21st century. However, the numbers are rising again, especially with newer techniques and better technology. The wildcat drilling, in particular, is rising pretty fast, with smaller companies trying to tap already explored and exploited fields.
Oil and gas exploration companies are also moving into remote areas and previously unknown locations with high potential for mineral wealth.
As the world’s known oil and gas resources are slowly depleting, the need for more of these wells will only increase.
Exploratory wells are extremely important in the exploration and extraction of oil and gas. An exploratory oil well can give the company all the information they need before proceeding with completion and production.
This helps reduce the risk of failure and increases the potential of yield. Nowadays, companies are using advanced technologies like the Internet of Things to get direct data from the these wells. Companies have better equipment now to test such wells than they had a few decades ago.
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