Drilling and CompletionsSpectrum of D&C activity

DRILLING & COMPLETIONS BASICS

Main Components of a Drilling RigAll drilling rigs have the following basic systems Hoisting Rotating Circulating & Solids Control Power Blowout Prevention

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

Rotating SystemA 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 SystemDuring 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 FluidsWater-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 SystemMost 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 & BitHole 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 TypesRoller ConeSteel tooth Tungsten Carbide Insert

Fixed Cutter

Diamond PDC

Diamond Natural & Synthetic

Well ControlPrimary 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 Jack-up

Semi-Submersible Drill Ship

T.L.P.

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) SEMI-SUBMERSIBLE (+/ 180 world wide) DRILL SHIP (+/- 50 world wide)

Shallow to Intermediate Water (20 400ft, very few >300ft)Intermediate Deep Water (300 7500+ft) 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 RIGOcean America (on tow)

Semi-Submersible GenerationsYear Built 5th 4th 3rd 2nd 1st 97+ 86+ 81-85 73-80 Rated Water Depth (ft) 5000-10000 2000-5000 1200-2500 600-1500 Deck Load (tons) 6000+ 4000-5000 2500-3500 1500-2500