Christmas tree

LESSON 3.

WELL

UNIT 1

WELL DESIGN

Terminologу

casing – обсадные трубы

contamination – загрязнение

conductor – направляющая колонна

surface casing – кондуктор

intermediate casing – техническая (промежуточная) обсадная колонна; буфер

well head – устье скважины

choke – штуцер; дроссельная катушка; воздушная заслонка; дроссель; заглушка

seal – герметизировать

drive pipe – обсадная труба

hammer -driven – молотковый привод

circulating fluid – буровой раствор

washout - размыв

seal off – заделывать

withstand – противостоять

return -выход

BOP(blowout preventer) – противовыбросовый превентор

leak-off - пропускной

packers - сальник

slip – скользящая клиновая плашка

“tie-back” string – колонна надставка

emergency shut- down system – система аварийного отключения

pressure gauge - манометр

annulus – затрубное устройство

Х-mas tree – фонтанная арматура

fluid access – доступ жидкости

adaptor flange - переводный фланец

flanged cross, flow tee –фланцевый блок-крестовина

secondary master valve –второстепенная ствольная задвижка

wing valve – боковая задвижка

top adaptor – колпак фонтанной арматуры

Translate the text.

Well design can be described as pipeline from the ground surface to the oil bearing for­mation. Oil comes to the surface through this pipeline. Such pipeline includes a number of special pipes connected between each other and called a casing string.

Casing has several important functions during the drilling and completing of a well. It is used to prevent the borehole from caving in during the drilling of the well, to provide a means of controlling fluids encountered while drilling, to prevent contamination of fluids to be produced, and to protect or isolate certain formations during the course of a well. Casing is also one of the most expensive parts of a well, around 20% of the cost of a completed well. Casing is usually divided into five basic types:conductor casing, surface casing, intermediate casing, production casing, liner.

Conductor pipe or drive pipe if it is hammer-driven to depth, is the first string of casing to be used. The setting depth can vary from 10 ft to around 300 ft. The normal size range for conductor pipe is from 16 to 36 inches (outside diameter). The conductor pipe must be large enough to allow the other casing strings to be run through it. Purposes of conductor pipe are:

1) to raise the level of circulating fluid so that fluid returns are possible; 2)to prevent washouts in the near surface, normally unconsolidated formations

The amount of surface casing used will depend on the depth of the unconsolidated formations. Surface casing is usually set in the first competent formation. Normal size for surface casing is between 20 inch and 13-3/8 inch (outside diameter). Since temperature, pressure and corrosive fluids tend to increase with depth, different grades of casing will be required to handle the different well conditions. Purposes of surface casing are to:

1) protect fresh water formations; 2)seal off unconsolidated formations and lost circulation zones; 4) provide a place to install the B.O.P.'s; 5) protect “build” sections on deviated well; 6) provide for a sufficient “bottomhole ” test to be conducted

Intermediate casing is set after surface casing, normally to seal off a problem formation. The size of intermediate casing, will depend on the size of the surface casing and the grade required to withstand the subsurface conditions. Normal sizes are between 9 5/8 and 13 3/8 inch (outside diameter).

Production casing is usually the last full string of pipe set in a well. These strings are run to isolate producing formations and provide for selective production in multi-zone production areas. The size of production casing will depend on the expected production rate, the higher the barrel per day production rate, the larger the inside diameter of the pipe. Common sizes are between 3 and 7 inch (outside diameter).

A liner is a string of casing that does not reach the surface. They are usually “hung” (attached to the intermediate casing using an arrangement of packers and slips) from the base of the intermediate casing and reach to the bottom of the hole. The major advantage of a liner is the cost of the string is reduced, as are running and cementing times. During the course of the well, if the liner has to be extended to the surface (making it another string of casing), the string attaching the liner to the surface is known as a “tie-back” string.

Well equipment required for field operations includes: wellhead, valves and chokes, emergency shut down systems, blowout preventer, fluid tanks, separators, line heaters, dehydration equipment, gas sweetening equipment, compressors.

Christmas tree is the main component of wellhead equipment. Christmas tree is attached to casing. It is designed to hold casing and tubing strings, isolate or seal annulus between these strings, provide fluid access to all strings, control processes of fluid and gas injection and production by means of valves.

Standard Christmas tree assembly includes adaptor flange, master valve, flanged cross, top adaptor, secondary master valve, wing valve, and a choke.

Pressure gauges are installed on Christmas tree to measure pressure in annulus and tub­ing. When pressure values under different working conditions are known the well can be con­trolled much easier.

Answer the questions.

1. What functions does casing have?

2. What types of casing do you know?

3. What are purposes of conductor pipe?

4. What does the size of intermediate casing depend on?

5. Why are the strings of production casing run?

6. What is the major advantage of a liner?

7. What is a “tie-back” string?

8. What is Christmas tree designed for?

9. What equipment does typical Christmas trее include?

10. What are pressure gauges installed for?

Find the pairs of equivalents

drive pipe колонна надставки

casing strings искривленная скважина

“tie-back” string. загрязнение бурового раствора

сasing обсадная колонна

contamination of fluids обсадная труба

deviated well разрушение

Fill in the blanks using the following words

Liner surface casing hammer-driven competent formation washouts pressure gauges

Tto prevent … in the near surface, normally unconsolidated formations

The amount of used … will depend on the depth of the unconsolidated formations.

… are installed on Christmas tree to measure pressure in annulus and tub­ing.

… is a string of casing that does not reach the surface.

Conductor pipe or drive pipe if it is … to depth, is the first string of casing to be used.

Surface casing is usually set in the first …

Translate into English.

Предотвратить от разрушения, последняя колонна труб, рыхлое (несцементированное) образование, уровень бурового раствора, выход бурового раствора на поверхность, параллельное образование, герметизировать затрубное устройство.

Christmas tree

Рис.6

Дата добавления: 2015-10-28