Read the text. In small groups, match these descriptions of oil platforms to the correct illustration. Be prepared to justify you answers.

 

 

 

1. Gravity or fixed platforms

 

Gravity or fixed platforms sit on the seabed. They often have a concrete base with three or four hollow columns acting as legs with a steel deck built on top. Used in water to 520 m. gravity rigs are often built in sheltered waters, then floated out to sea and sunk in position. The hollow legs and base can be used for storing oil. They cannot easily be moved when their useful life is over, so disposal can be a problem.

 

2. Jack-up

 

These platforms sit on steel legs. The legs can be lowered to raise the platform above the sea (like a car jack). They are used in shallow waters up to about 100 m. They are cheap, and are reusable, as they can be moved to other locations. However, there are towing problems with the rigs and their safety record is poorer than that of other types.

 

3. Semi-submersible

 

Semi-submersible platform stands on columns which sit on pontoons below the level of the sea. These provide enough lift to float the platform and enough weight to keep it upright. By altering the amount of water in the pontoons, the platforms can be moved up and down. They are used in water of 600 – 1800 m in depth. They are very stable, even in rough seas. They can be easily moved to new locations. They need more support vessels because they have limited storage.

 

4. Spar

 

Spars are floating platforms moored to the seabed. They come in three forms: a cell spar that has a body composed of a number of vertical columns, a conventional spar that has one column, and a truss spar which has a floating hard tank at the top linked to a soft tank at the bottom, which is weighted to provide stability to the structure. Spars are cheaper and more stable than tension leg platforms. They are suitable to depth up to 1800 m. They can be moved horizontally.

 

5. Tension leg

 

These are floating platforms where the mooring system prevents vertical movement. This means that the well can be tapped directly from the platform. They can be useful in depth of 200 – 1100 m. They are inexpensive to make compared with other platform types, and can be moved to new locations, but are less stable than fixed platforms.

 

Complete the table for each type of platform described above.

 

Type	Depth of water	Advantages	Disadvantages

Text D

Improving Production Results in Monobore,

Deepwater and Extended Reach Wells

Read the abstract of an article, pay attention to its structure.

 

Authors: Almond, Ken; Coull, Craig; Knowles, Peter; Smith, James; Smith, Michael V.; Mowbraw, Kyle
Source: Proceedings - SPE Annual Technical Conference and Exhibition, 2002, p 1615-1629
Conference: Proceedings of the 2002 SPE Annual Technical Conference and Exhibition, Sep 29-Oct 2 2002, San Antonio, TX, United States
Sponsor: SPE
Publisher: Society of Petroleum Engineers (SPE)

 

Keywords: Well Production, Petroleum Reservoirs, Well Completion, Fields, Turbulence, Packers, Flow Control, Well Drilling, Tubing, Pressure Effects.

 

Abstract: Big bore completions (i.e., those using 6-5/8-inches and larger production tubulars) are required for economical production and injection in prolific reservoirs. A variety of completion configurations exist, though only the most traditional schemes have been discussed. This paper will present the results of a study that analyzed and evaluated more than 350 large bore completions over a 20-year span to determine best practices. The study formed the basis for a new approach to well design that merges wellbore construction with the completion. The paper will discuss this approach, which includes a classification system to help operators choose the optimum design to match their completion objective. This paper will begin by reviewing the big monobore concept, discuss various enabling technologies and their opportunity to increase production while reducing costs, review configuration choices with case histories and conclude with a case history that illustrates how the big monobore concept is evolving in the world's largest gas field.

 

Read some tips and warnings about writing abstracts.

a. Embed keywords into the first 20 words of your abstract. This will make it visible to the major internet search engines if you publish online.

b. Emphasize the information, not the author, unless the author has noteworthy credentials.

c. Never introduce new information in the abstract. Reveal what’s in the article.

d. Read it aloud to yourself or to your friend. Make sure it sounds natural and coherent.

e. Keep it short-stick to one or two solid paragraphs.