Drilling ppt

Drilling and Completions Spectrum of D&C activity

DRILLING & COMPLETIONS BASICS

Main Components of a Drilling Rig All drilling rigs have the following basic systems • • • • •

Hoisting Rotating Circulating & Solids Control Power Blowout Prevention

Hoisting System Used for raising and lowering the drilling assembly, and for running casing, completion equipment and other tools in and out of the hole.

Rotating System A hexagonal or square pipe is connected to the topmost joint of the drill string. The rotary table and kelly drive bushing impart rotation to the drill string while allowing it to be moved up or down.

As an alternative to the kelly and rotary table, most modern rigs employ a Top Drive system for rotating the drill string. A powerful electric or hydraulic motor is suspended from the traveling block.

Circulating System During drilling, fluid is continuously pumped down the drill string, through the bit, and up the annular space between the hole and the drill string. Its main purpose is to bring up the cuttings, cool the bit, maintain hole stability, and prevent formation fluids from entering the wellbore.

Circulating System & Solids Control

Types of Drilling Fluids Water-based

Oil-based

Pneumatic

Non-dispersed Dispersed Calcium treated Saltwater based Low solids Polymer

Diesel based Mineral Oil based Synthetic: Esters Ethers Olefins

Dry air/gas Mist Foam Aerated mud

Selection of the type of drilling fluid systems for a well is based on: PERFORMANCE, ECONOMICS, and ENVIRONMENTAL CONSIDERATIONS More than one system may be used in the same well.

Power System Most modern rigs are electric. Generally, large diesel engines are the primary source of power. Electric power generated by the engines is first converted from AC to DC in the SCR unit. DC motors supply power to the drawworks, rotary, and pumps. AC power is still used for auxiliary equipment.

Diesel Electric

Drill String & Bit Hole is made by turning a bit connected to the bottom of the drill string and applying weight at the same time. The bit is turned either entirely by drill pipe rotation from surface or with the help of a downhole motor which rotates when drilling fluid is pumped through it.

Drill pipe

Drill collars Measurement tools Downhole motor Bit

Bottom Hole Assembly

Bit Types Roller Cone Steel tooth

Tungsten Carbide Insert

Diamond PDC

Diamond Natural & Synthetic

Fixed Cutter

Well Control Primary control of wellbore pressures is maintained by ensuring that the hydrostatic pressure of the drilling fluid in the well is always slightly higher than the highest formation pressure exposed to the open wellbore. Primary control is lost if a kick is taken due to imbalance of pressures.

RIG TYPES

Inland Barge

Land

Jackup Semisubmersible Drillship Types of Drilling Rigs

Platform Land Rig

Semi-Submersible Jack-up

T.L.P. Drill Ship

Offshore Drilling Rigs  SUBMERSIBLE (35 – 50 world wide)  INLAND BARGES (POSTED) - Very Shallow Water (up to 20 –22ft)  SUBMERSIBLE RIG / BARGE - Shallow Water (up to 70 – 100ft)

 PLATFORM

Intermediate Water (Petronius US GOM= 1800ft+)

 JACK-UP (+/-400 worldwide)

Shallow to Intermediate Water (20 – 400ft, very few >300ft)

 SEMI-SUBMERSIBLE (+/– 180 world wide)

Intermediate – Deep Water (300 – 7500+ft)

 DRILL SHIP (+/- 50 world wide)

Intermediate – Deep Water (200 – 10,000ft)

SHALLOW-WATER BARGE RIG

PLATFORM RIG

JACK-UP RIG

Derrick cantilevered over stern of hull.

Well conductor

SEMI-SUBMERSIBLE RIG “Ocean America” (on tow)

Semi-Submersible Generations Year

Rated Water

Deck

Mud

BOP

Built

Depth (ft)

Load (tons)

Capacity (bbls) (Mpsi)

5th

97+

5000-10000

6000+

6000+

15

4th

86+

2000-5000

4000-5000

4000+

15

3rd

81-85

1200-2500

2500-3500

2000-3000

15

2nd

73-80

600-1500

1500-2500

1500-2500

10

1st

pre-73 600