Offshore Drilling In Detailed

Offshore drilling refers to the act of extracting crude oil which lie underwater near the shoreline in the oilfield . Offshore drilling is used to describe oil extraction off the coasts of continents.

The first offshore drilling was done at the end of the 19th century in Baku at the Bibi-Eibat field.[citation needed] In 1896 oil companies began drilling from wharves built out over the Pacific Ocean at Summerland field, California.

This is how offshore drilling done in detail preparation:

The crew makes the rig ready and starts the drilling perations. From the first hole, they drill a surface hole down to a pre-set depth, which is above where the oil trap is placed. There are five sequences to drilling the well:

1. Put the drill bit, collar and drill pipe in the hole.
2. Mount the kelly and turntable and begin drilling.
3. As drilling runs, circulate mud through the pipe and out of the bit to float the rock cuttings out of the hole.
4. Add new sections (joints) of drill pipes as the hole gets deeper.
5. Remove (trip out) the drill pipe, collar and bit when the pre-set depth (anywhere from a few hundred to a couple-thousand feet) is reached.

when they reach the depth they are expected, they operate and cement the casing -- put casing-pipe sections into the hole to avoid it from collapsing in on itself. The casing pipe has spacers around the outside to make the pipe keep staying in the center of the hole.

The crew installes the casing pipe in the hole. The cement crew pumps cement down the casing pipe using a bottom plug, a cement slurry, a top plug and drill mud. The pressure from the drill mud causes the cement slurry to flow through the casing and fill the space between the outside of the casing and the hole.



You might interested to read about the types to do offshore drilling and where is it done??