Final answer:
The key differences in natural gas supply include the types of natural gas (biogenic and thermogenic) and the depths at which they are found. Biogenic gas is formed through anaerobic decay of organic matter at shallow depths, while thermogenic gas is formed through the compression of organic matter and deep heat underground.
Step-by-step explanation:
Natural gas supply is obtained from various sources and different geographic areas. The key differences include the types of natural gas (biogenic and thermogenic) and the locations where they are found. Biogenic gas is found at shallow depths and arises from anaerobic decay of organic matter by bacteria, while thermogenic gas comes from the compression of organic matter and deep heat underground. They are found with petroleum in reservoir rocks and with coal deposits.