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
Фонтанная арматура
1-манометр (pressure gauge)
2-трехходовой кран (three-way cock)
3-буфер (tubing)
4,9-задвижки (valves)
5-крестовик елки (flanged cross)
6-переводная катушка (adaptor spool)
7-переводная втулка (adaptor bushing)
8-крестовик трубной головки (tubing cross)
10-штуцер (choke)
11-фланец колонны (tubing flange)
12-буфер (tubing)
Pigging
1.Underline the word that is the odd one out in each row.
1 steel rubber plastic seal foam
2 fluid plug liquid solution water
3 friction by-pass lubrication elevation pressure
4 damaged dry worn wide debris
2.Look at the diagram of a pig and answer the questions.
Рис. 7
1 What does this device do?
2 Are these devices always the same size?
3 What is it made of?
4 Is it used in gas or oil pipelines?
3.Read the texts about pigs and pigging and check your answers.
pig (n): a device that moves through the inside of a pipeline in order to clean or inspect or give information about the pipeline. |
Pigging Pigs (Pipeline Inspection Gauges) are pieces of equipment used to clean pipelines. The pig is propelled down the pipeline by compressed gas or fluid. Pigging systems and equipment are also used in smaller-diameter pipes in continuous and batch process plants. |
PIPEFLOW SERVICES cleans pipelines by propelling a series of flexible foam PRO-PIGS (cleaners) through them. Where there are heavy build-ups, the PRO-PIGS are introduced into the system in a progressive manner. We start with smaller and softer cleaning units, and gradually work up to full-sized cleaners with more abrasive qualities. This PRO-PIG cleaning method has proven to be the safest, fastest and most economical way to clean most pipelines. |
4.Read some more information about pigging. Decide whether the statements below are true (t) or false (f).
A pig generally has a steel body fitted with rubber or plastic cups at both ends. The cups are wider in diameter than the internal diameter of the pipeline to ensure a tight seal. Through use, the cups can become worn and need to be replaced, as pigs are less effective and allow more blow-by (fluid passing the pig) if the seal is not good.
Pigs are used to clear debris and excess liquid from the inside of pipelines. They are forced through the pipeline by the pressure of the flow. Several factors affect the force required to move the pig: elevation of the pipeline, friction and lubrication. A pig moves more easily through a crude oil pipeline than a dry gas pipeline due to better lubrication and greater flow pressure, but crude oil pipelines also contain much more debris than gas pipelines.
The pig contains by-pass holes which allow more fluid to flow past the pig, decreasing the speed. If all the by-pass holes are plugged, the pig moves more slowly, as the pressure forcing it through the pipeline is lower than when some of the by-pass holes are unplugged.
1 Pigs are usually made of foam or plastic.
2 Pigs are very durable.
3 It is possible to replace the rubber sections of the pig.
4 They need an electric motor to propel them through the pipe.
5 Pigs move faster through gas pipelines because there is less resistance. □
6 Pigs move faster through oil pipelines because there is higher pressure and less friction.
7 Pigs do not move as fast when the by-pass holes are plugged.