Why are there large reserves of oil and gas on the shelf?
The shelf is called the coastal area of the sea or ocean. In the shelf zone, the depth is usually much less than in the rest of the sea.
There are several reasons why large reserves of oil and gas are found in these zones than on land.
The reasons:
Under water, almost all dead living organisms were without oxygen access. This means that the process of decay was slowed down;
Salt water is conducive to long-term preservation of organic matter without decomposition, which made it possible for more active chemical reactions to create saturated and aromatic hydrocarbons (the main constituent part of oil and natural gas);
Millions of years ago, life existed to a greater extent in water, so there were more dead particles;
During the Ice Age, most of the land was covered with ice, which in the process of melting carried away hundreds of thousands of cubic meters of sedimentary ball from the surface of the earth;
During periods of storms, hurricanes, tsunamis and other natural disasters, the raging water carried away the upper layers of sedimentary rocks that had accumulated in the shelf zones for millennia.
Conclusion: On the offshore shelves, conditions for the creation of oil and natural gas have been more favorable for many centuries.
In addition, fossils are easier to mine on land, so their development began in the middle of the twentieth century. By the present time, industrial reserves on land are being depleted, and there is still quite a lot of oil and gas left on the sea shelves.
