Drilling Fluid Functions

Drilling fluid functions describe tasks which the drilling fluid is capable of performing, although some may not be essential on every well. Removing cuttings from the well and controlling formation pressures are of primary importance on every well. Though the order of importance is determined by well conditions and current operations, the most common drilling fluid functions are:

1. Remove cuttings from the well.

2. Control formation pressures.

3. Suspend and release cuttings.

4. Seal permeable formations.

5. Maintain wellbore stability.

6. Minimize reservoir damage.

7. Cool, lubricate and support the bit and drilling assembly.

8. Transmit hydraulic energy to tools and bit.

9. Ensure adequate formation evaluation.

10. Control corrosion.

11. Facilitate cementing and completion.

12. Minimize impact on the environment.

As drilled cuttings are generated by the bit, they must be removed from the well. To do so, drilling fluid is circulated down the drillstring and through the bit, entraining the cuttings and carrying them up the annulus to the surface. Cuttings removal (hole cleaning) is a function of cuttings size, shape and density combined with Rate of Penetration (ROP); drillstring rotation; and the viscosity, density and annular velocity of the drilling fluid.

Viscosity. The viscosity and rheological properties of drilling fluids have a significant effect on hole cleaning. Cuttings settle rapidly in low-viscosity fluids (water, for example) and are difficult to circulate out of the well. Generally, higher-viscosity fluids improve cuttings transport.

Послетекстовые упражнения

Подберите из списков А и Б близкие по значению слова.

1) to drill 2) mud 3) well 4) formation 5) cuttings 6) to conduct 7) tools

a) drilling fluid b) borehole c) bed (seam) d) drilled rocks e) to make a hole f) instrument g) to perform

Переведите следующие сочетания слов, пользуясь правилом ряда.

wellbore stability, reservoir damage, formation evaluation, control corrosion, drilling operation, rig crew, mud engineer

3. Ответьте на вопросы по тексту.

1) What is the objective of drilling operation?

2) Who is responsible for performing drilling fluid function?

3) What is the chief duty of the mud engineer?

4) What are the most common drilling fluid functions?

Соотнесите термины с их сокращениями. Расшифруйте сокращения и выучите их.

1) ROP 2) BOP 3) RIH 4) POOH 5) BHA 6) ID 7) OD 8) Csg 9) TD 10) PT 11) RO (RU) 12) SIW 13) WO 14) ESP 15) w / h

a) blowout prevent for b) bottom hole assembly c) inside diameter d) casing e) pull out of the hole f) tubing depth g) electrical submersible pump h) rate of penetration i) outward diameter j) run in the hole k) pressure test l) rig up (out) m) shut in well n) work over o) well head

а) спускать скважину (трубы, инструменты) б) поднимать из скважины в) внешний диаметр г) КРС д) обсадная колонна е) компановка инструмента ж) скорость проходки з) опрессовка и) внутренний диаметр к) (де) монтировать л) противовыбросовое оборудование м) электро центробежный насос н) глубина спуска о) устье скважины п) закрытая скважина

5. Представьте, что вы - специалист по буровым растворам. Ознакомьте членов буровой бригады с предназначением бурового раствора.

Lesson 9

Предтекстовые упражнения

Прочитайте следующие слова и постарайтесь их запомнить.

rigger – строгальщик

rig up – монтировать

rig out – демонтировать

to hook (up) to smth – подключать к чему-либо

tank – резервуар (емкость), цистерна

drilling mast – буровая мачта

mast – буровая вышка

derrick substructure – подвышечное основание

rest – держать(ся), лежать (на), опираться (на)

rig floor – пол (вышки, буровой установки)

cellar – подвал, погреб

stack – мачта, дымовая труба

slingshot – строн, грузоподъемная петля, строна

drawworks – лебедка (буровая)

a spool – катушка

drilling line –

hooking – зацепление

hoisting hook – подъемный крюк

rotary hook – подъемный крюк

drilling mud – буровой раствор

slingshot – рогатка

to sling – поднимать с помощью каната, ремня, подвешивать

Определите, какой частью речи является следующие слова.

rig – rigger – rigging

consider – considering – consideration

science – scientific – scientist

equip – equipment

drill – driller – drilling

usual – usually

act – active – activate

transport – transportation – transporter

Переведите следующие сочетания слова.

the water’s surface; crew members; to get the land rig to the site; too much heavy equipment; to drill a hole; to hook up the engine; to get power; rest directly over the hole; one the level ground; to achieve the desired height; to house a drum; a steel and wood rig floor

4. Прочитайте текст и ответьте на вопросы.

1) What does “rigging up” mean?

2) When do crew members position the rig’s structure?

3) What does a substructure look like?

4) How high does the substructure raise the rig floor above the ground?

5) What types of substructure do you know?

6) What are the functions of the substructure?

7) What equipment may be installed on the rig floor?

8) What kind of equipment supports everything that goes in or comes out of the hole?

Rigging Up

Rigging up an offshore drilling rig is usually not as complicated as rigging up a land rig. Most offshore rigs can be moved across the water’s surface with virtually no disassembly of major parts. To move most land rigs, on the other hand, crew members must dissemble many of its components. Disassembly is required so they can load the, parts on tricks, planes, or helicopters for transportation to the next location. Once the contractor gets the land rig to the site, the next step is for the drilling crew to put the rig together, or to rig up. For safety’s sake, rig up usually occurs only during daylight hours. A rig usually has too much heavy equipment moving around rig up for it to be safe in the dark, even with lights.

For most land rigs, rigging up means to put the rig parts back together so that the rig can drill a hole. It involves unloading and hooking up the rig engines, the mud tanks and pumps, and other equipment of the site. One the last steps, and one of the most dramatic, is raising the mast from horizontal – the position it was transported in – to vertical to ready it for drilling. After unloading and hooking up the engines to get power, crew members position the rig’s substructure, which is its base, or foundation.

SUBTRUCTURES

A substructure is a framework that rests directly over the hole and is the foundation of the rig. The bottom of the substructure rests on level ground. Crew members place a work platform on top of the substructure that they term the “rig floor”. The substructure raises the rig floor about to 40 feet (3 to 12 meters) above the ground. Elevating the rig floor makes room under the rig for the special high-pressure valves and other equipment that the crew connects to the top of the well’s casing. The exact height of a substructure depends on the space needed to clear this equipment. Remember, too, that, in some cases, a cellar provides more space for the equipment.

One type of substructure is the box-on-box. Using trucks or portable cranes, the crew stacks one steel-frame box on top of another to achieve the desired height. Another, more modern substructure is the self-elevating, or slingshot, type. Crew members place it on the site in a folded position. They then activate winches to unfold and raise the substructure to full height. Slingshot substructures go up much faster than the box-on-box type. Whether box on box or slingshot, the substructure is rugged because it not only supports the weight of the drilling equipment that the crew assembles on top of it, but also the weight of the entire drill string.

RIG FLOOR

Crew members set many pieces of equipment on the substructure, including a steel-and-wood rig floor on which to work. An important piece of equipment that the rig floor may support is the drawworks. (Some rig designs call for the drawworks to be installed below the rig floor.) Whether at floor level or below, the drawworks is a large hoist. It houses a spool, or a drum, on which the crew wraps braided steel cable called “drilling line”. The drilling line is large-diameter wire rope, which ranges in size from 7/8 to 1 ½ inches (22,23 to 38,1 millimeters). It has to be big because it carries and moves an incredible amount of weight as the well is drilled. The drawworks, the drilling line, and the mast or derrick support practically everything that goes in or comes out of the hole.