Oil--A Beginner's Guide by Vaclav Smil

Author:Vaclav Smil [Smil, Vaclav]
Language: eng
Format: epub
ISBN: 9781786072870
Publisher: Oneworld Publications

OFFSHORE DRILLING

In 1949 John Hayward combined a submersible barge and a piled platform to build the first submersible rig, Breton Rig 20; he devised a way to stabilize a ballasted barge on the seafloor so that only the columns (connected to the barge and supporting the rig’s working deck) were exposed to waves. Kerr-McGee bought the rig in 1950, after it had drilled nineteen wells. A better version, Mr. Charlie, was built in 1953 by Alden J. Laborde who founded the Ocean Drilling & Exploration Company (ODECO). That company eventually combined with three other pioneers of marine drilling to form Transocean, the world’s leader in offshore engineering.

The first self-elevating (jack-up) drilling rig, Offshore Rig 51, began working in 1954. Its ten legs (1.8m in diameter and 48m long) ended in large spud cans to minimize the pressure of the ocean floor. A prototype of modern jack-ups – a triangular platform with three legs and pinions driven by electric motors – was built by Le Tourneau Company in 1956. Jack-ups were not suitable for deeper waters and in 1961 Shell Oil was the first company to deploy a semisubmersible rig, Bluewater I, in the Gulf of Mexico. Different designs followed in rapid succession – and a decade after the first model there were thirty semisubmersibles at work.

During the 1970s Transocean introduced the Discoverer-class drill ships whose operations proceeded to set repeated drilling records: by the year 2000 the fifth generation of these ships could drill in waters 3km deep. A new chapter of offshore drilling began with operations in very deep water. The industry defines work at a depth of 1,500m as ultra deep drilling, and the Gulf of Mexico has the world’s highest concentration of such projects and associated records, including an exploratory well drilled in 2003 by Discoverer Deep Seas in more than 3,000m of water. In early 2016 the Maersk Venturer, a drillship working for a consortium of Total and ExxonMobil, set a new record by drilling in water depth of 3,400m offshore Uruguay. These efforts have been rewarded with regular new major deepwater finds in the Gulf of Mexico (both in US and Mexican waters), offshore Brazil (in fields lying beneath salt and rock deposits up to 5km thick 2km below the sea level) and Guyana, West Africa and Angola and, most recently, in South-East Asia. By the middle of 2017 there were about 820 mobile offshore rigs (jack-ups, semisubmersibles and drill ships) marketed worldwide, with about 11% of them in US waters.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.