ASSOCIATED NATURAL GAS

 What happens to the associated natural gas produced from oil wells in the Bakken and DJ Basins?  

Many of you know that much of this associated natural gas, especially in the Bakken Shale play, is being flared into the atmosphere due to the abundance in the marketable gas supply. Flaring the natural gas is detrimental to our environment. Why do we flare the gas, why not treat it and process it?  Much of the answer lies in the operational cost and the challenges in treating and processing the natural gas.     

In the production of oil, the process is very simple.  Drill for the oil, separate the water and associated natural gas from the oil at the wellhead, and then move the oil either by pipeline or truck to a collection facility. The oil is then transported via pipeline, rail, or truck to refineries for processing into products such as gasoline, diesel, jet fuel, motor oil, and asphalt. Natural gas production however, is a bit more complicated and requires much more treating and processing in order to be sold in the market. 

When the associated natural gas is separated at the wellhead, it is  full of all types of petroleum products that are useful in so many different areas.  The first product trapped in the natural gas stream, is methane.  Methane is the most common gas that is used by all of us for heating and cooking and electrical power generation.  But did you also know that common products like propane and butane are also gases that are trapped in the natural gas stream?  Often items that are trapped in the gas are typically water, C02, and other inert (non flammable) gases, and some very highly flammable elements.  All of these items have to be removed, which is commonly called “treating the gas”. 

First, water must be removed from the gas stream, which is accomplished by a dehydration process. Other products like C02 must also be removed which depending on where the facility is located can be sold and transported via pipeline. Natural gas can also contain H2S (hydrogen sulfide), which is extremely deadly and must be extracted and separated from the gas stream.  H2S is then typically re-injected back into the ground or incinerated.   

Using cryogenic process methods, products like ethane, methane, propane, and butane are separated from the gas stream.  Continuing in this process, other products such as hydrogen, nitrogen, oxygen, sulfur, and selenium, hexane, pentane, octane and so forth.  These complex products are then marketed and used to manufacture and create all types of useful products that we consumers use daily.  The simple graphic illustration below gives just a snapshot of how natural gas (and oil) are processed for products to be used by consumers.

A small list of end products that start from natural gas;

• pharmaceuticals
• plastics
• paints
• cellphones
• surgical equipment
• car parts
• garbage bags
• home parts
• electronic parts
• fertilizers
•  cameras
• cosmetics
• diapers
• glue, and a whole lot more.

 The production, gathering, treating, processing, and delivery of natural gas is very complex and can be very expensive depending on location and delivery points for the products.  That is why much of the associated natural gas being produced in fields like the Bakken, are currently begin flared and not processed.  Of course, companies will continue to work to find ways to gather, treat, and process the natural gas in the region in the best economic manner possible, which will help to reduce flaring and is overall very good for the industry.

 

 

Creg Hughes

President