rig components

Drilling Engineering

Drilling Rigs, Components And Rig Operations

Copyright ©2001-2011 NExT. All rights reserved

Drilling Rigs

2


Drilling Rigs

Nearly all of today’s rigs are of the rotary type (other type is percussion

or “cable tool” type – used only for shallow wells)

Rigs may be marine or land (offshore or onshore)

Marine (swamp)/offshore/deepwater rigs

Bottom supported - for water depth (WD) of ~350 ft

Platform, barge (20 - 40 ft WD), and jackup up to 350 ft WD)

Platform rigs may be self contained or tendered, water depth limited by

platform design, may be >1500 ft WD

Floating - semi-submersible (up to ~6000+ ft WD) and drillship (up to

13,000+ ft WD)

Land rigs - conventional or mobile

Mobile rig may be jacknife (cantilever) or portable mast

3


Classification of Rigs Based on Location

In general, there are three locations: onshore, swamp

(inland) or offshore

Onshore: mast or mobile (generally of the cantilever type)

Swamp: tender barge or jack-up (they are bottom-supported)

Offshore: tender barge, jack-up, semi-submersible, drill ship

4


Drilling Rigs Land

5


Land Rigs (light land rig)

Capable of drilling up to 10,000’

Typical derrick load < 750,000

lbf

BOP rating 5,000 psi

Cost around $20,000/day

6


Land Rig : Mast Type (light land rig)

Description:

Portable Truck Mounted,

Telescopic Mast.

Lower Lift Capacity

Quick mobilization and rig up/ rig

down

Used for:

Shallower onshore wells

(<3650 m).

Mobilization time is crucial.

Location or road capacity size is

limited

7


Land Rig : Mast Type

Description:

Transported by dismantling /

Reassembling in several parts.

When greater lift capacity is

needed.

Longer moving time.

Used for:

Deeper wells (>2500 m) on land.

Transporting time is not a

concern.

8


9

9

Example rig footprint 240 ft x 145 ft


Some Rig Requirements

Determine derrick load from heaviest casing string plus overpull requirement (with floating rig this may be riser weight)

Determine substructure requirements from drillstring stand back load plus heaviest casing load

Determine pump requirement from annular velocity requirements (look at all hole sizes) and horsepower requirements (motors, bit hydraulics, cuttings removal)

Determine drill string requirements (drill pipe strength, drill collar size)

Determine mud system requirements from hole volume and other factors (e.g. lost circulation reserves, mud change out, mud cleaning requirements)

Continued

10


Some Rig Requirements

Determine total rig power requirements – drawworks, pumps, electrical

generation

Power type – SCR, direct drive, diesel electric

Determine storage and work area requirements – fuel, water, supplies,

pipe storage, well testing, etc.

Determine drilling fluid treatment requirements

Identify well control equipment requirements

11


Some Rig Requirements Special Requirements

Onland

Road load limits

Noise and illumination pollution

Cuttings and mud disposal requirements

Location size constraints

Rig floor to ground clearance for wellhead and well control equipment

12


Marine Rigs Selection

Many designs criteria are used in selecting the proper marine rig. Major criteria are as follows:

Water depth rating (first evaluation tool)

Derrick and substructure capacity

Physical rig size and weight

Deck load capacity

Stability in rough weather (wind)

Duration of drilling program

Rig rating features such as horsepower, pipe handling and mud mixing capabilities

Exploratory versus development drilling

Availability and cost.

Rig mobilization costs must be considered when selecting marine rigs and this is a function of number of wells to be drilled.

13


Offshore/Bottom Supported: Submersible /Barge

Description:

Transported by floating, submerged on location for drilling.

Used for:

Shallow Waters ( < 30 m) – rivers, swamps, coastal regions, and inland

bays.

14


Marine rigs – floating – drilling barge

Floating rectangular barge with

self contained rig on board

Sheltered inland waters

Can drill to 20,000 +ft

15


Offshore/Supported : Jack-Ups

Description:

Mobile offshore drilling structure with tubular or derrick legs that can be ‘jacked up’ and positioned on location to support the deck and hull. Used for:

Offshore drilling with water depths 100-130 mts

16


Marine rigs – bottom supported - jack up

Usually 3 legs which stand on

the seabed

Hull is lowered and legs raised

for rig moves

Can drill in shallow waters (to

~450 ft)

Can cost between $45,000-

90,000+/day

BOP’s are below the derrick

cantilever

Accommodation for up to 100

persons

17


Another Jack-up – Cantilever Over Platform.

18


Offshore/Supported : Platform

Description:

Self-contained rigid, immobile structure from which development wells are drilled and produced. Used for:

Offshore drilling on existing platforms essentially unlimited water depths, limited by platform design which may be floating and tethered.

19


Offshore/Supported : Tender

Description: Drilling mast and drawworks

and a limited amount of drilling support equipment is placed on the platform.

The rest of the drilling equipment (pumps, generators, storage, and living accommodations, etc.) are on a barge like vessel moored adjacent to the platform.

Used for: Platforms with limited size of

weight bearing capacity or working area.

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Marine Rigs – Bottom Supported – Other Platform Types

21

Tension Leg Platform (TLP) Concrete Gravity Platform (CGP) Guyed Tower Platform


Tension Leg Platform (TLP)

22


Marine rigs (floating – semi-submersible)

Rig towed on to location, then

either anchors or uses dynamic

positioning

Can move off location fast if

problems arise.

Usually uses BOPs located at

the seabed.

Accommodation for up to 100+

persons. High cost;

$150,000/day up.

23


Marine Rigs – (Floating – Drill Ship)

Ship shaped hull, usually self-propelled for rig moves

Often uses dynamic positioning but may be anchored

High storage capacity; 1 or 2 wells without re-supply

High cost, can be well over $500,000/day

24


Let’s Take a Break

Coming up will be a discussion of selected rig components.

25


At the end of this module, YOU should be able to;

1. Name or describe the rig components.

2. Explain the functions of the major components of a rig.

3. Understand fundamental rig operations.

4. Understand the well control systems especially BOP functions and arrangements.

5. Know well monitoring systems.

6. Understand some safety requirements on the rig.

26


Basic Rig Components and Operations

Whether offshore or land based all rotary rigs have the same

basic drilling equipment, with the following major components

or systems:

Power system

Hoisting system

Fluid-circulating system

Rotary system

Well control system

Well monitoring system

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Major Common Rig Components - Overview

28


Rig Power Systems

Most rig power is consumed by the hoisting and fluid circulation systems.

Usually both systems are not used at the same time

Power requirements: 500 - 3,000+ HP (horse power)

Types of power prime movers

Steam engine (obsolete)

Internal combustion diesel engine

Diesel-electric

Direct-drive – (uses gears, chains, belts etc.)

Mechanical HP requirement for prime movers must be modified for harsh temperature environment & altitude

Power-system performance characterized by output HP, torque, fuel consumption, and efficiency

29


Comparison of Rig Power Systems

Comparison is based on transmission methods

Mechanical drive - uses gears, chains, and belts

Direct-current (DC) generators and motors: use power cords

instead of chains; decreased rig noise level; can be positioned

away from the rig, and increase efficiency

Alternating current (AC)-silicon controlled rectifier (SCR)

combined with motors: most widely used; offers longer life,

lighter weight; and less maintenance, and lower cost than DC

systems

30


Hoisting System

Function: To provide a means of lowering and raising

equipment into or out of the hole

Principal components Drawworks

Derrick & substructure

Block & tackle pulley arrangements and drill line

Major routine operations

Making connection

Making a trip

Slip and cut program

31


Major Rig Components - Drawworks

32

The drawworks controls the

movement of the travelling

block up and down the derrick.

Drawworks unit showing sand line sheave on top,

eddy current brake, main brake, gear handles

View across drill floor to the drawworks

Driller’s console with weight

indicator and main brake


Drawworks

The drawworks is the control center of the rig and it houses the drum

which spools the drilling line

Principal parts are: drum, brakes, the transmission, and the catheads

Its design depends on prime mover type and power transmission type

Rated by horse power & depth

Drawworks HP = (W x Vh)/(33000 x E); W is lbf and Vh is in ft/min, E is traveling

assembly (block and tackle) efficiency

33


Major Rig Components – Mast or Derrick

34

The mast provides the range of movement of the travelling block. It allows pipe “stands” to be racked or stood back during trips.

Derrickman on monkey board adding stands to the string

Derrick showing monkey board,

crown block, block guides

Crown block at top of mast with fast line sheave to the right


Major Rig Components – Drill Line and Travelling Blocks

35

Deadline anchor with sensator shown

Changing the drill line with a snakeskin

View of the travelling block from above


Rig Fluid Circulating System

Function is to remove rock cuttings out of the hole as drilling

progresses

Principal components are

Pumps

Pits and or tanks

Mixing devices

Contaminants removal equipment, and

Flow conduits

36


Conventional Fluid Flow Conduits

These are components through which the fluid moves from the pump to the rig floor

Surge chamber - located in the high pressure discharge line from the pump to reduce vibration

4 - 6” heavy-walled pipe from pump to base of rig substructure

Stand pipe, attached to one of the legs

Flexible rotary hose

Swivel - rotates and allows fluid circulation under pressure

Kelly or Top drive (connects to drill string)

37


Rig Fluid Circulating System

38


Mud Pumps

The function of the mud pump is to circulate fluid at desired pressures and flow rates.

Mud pumps are generally reciprocating types: two general types - double-acting (duplex) and single-acting (triplex)

Pumps are denoted by the stroke, bore and rod diameters (for duplex only)

Commonly rated by horse power (HP), maximum pressure and maximum stroke rate (which controls the maximum output volume rate)

Two or three pumps are generally installed on a rig One pump may be used as a standby; two or three may be used when drilling

surface holes; one often is all that is needed at deeper depth

Overall pump efficiency = mechanical efficiency x volumetric efficiency (Em x Ev)

39


Major Rig Components – Mud Pumps

40

Mud pumps provide fluids at desired pressures and flow

rates to the drill string for circulation into and out of the well.

3 Triplex mud pumps


Mud Pumps

41

Discharge Pulsation Damper

Pump Suction Line (from mud tank)

Flexible High Pressure Discharge Hose

Fluid End of Pump

Pressure Relief Valve

Suction Charging Pump

Drilling Rig Substructure

Well with BOPS


Advantages and Disadvantages of Reciprocating Pumps

Advantages

Ability to move fluids with high solids content

Ability to pump large particles, for example, lost circulation materials,

(LCM)

Ability to operate over a wide range of pressures and volumes by

using different liners and pistons

Ease of operations and maintenance; and very reliable

Disadvantages

Discharge flow is pulsating and hence causes vibration on discharge

lines

42


Mud Pump Exercises:

Use the formula:

HHP= DF x [(P)(Q)/1714]/efficiency

To calculate the horsepower needed for the following situations:

Surface hole drilling: 1200 gpm at 2500 psi

Intermediate hole drilling: 400 gpm at 3000 psi

Deep hole drilling: 275 gpm at 3700 psi

Use an efficiency factor of 0.9 and a design factor (DF) of 1.1

43


Single-Acting Triplex Pump

Has three pistons and it sucks and discharges on every two strokes

Pump factor, Fp = pump displacement per complete cycle (or stroke)

Fp = (/4)(3)(Ls)(DL2)Ev

DL = liner diameter

Ls = stroke length

Ev = pump volumetric efficiency

Note: there is no Dr = rod diameter

This pump is light, more compact, cheaper to operate and very useful offshore where space is limited

Parts are smaller and easier to maintain

44


Mud Pits or Mud Tanks

Mud pits may be pits in the ground lined with an impermeable liner or

may be steel tanks. Offshore they of course are steel tanks.

Three basic types of mud tanks: settling, suction, and reserve

Settling: allows time for setting of cuttings and release of entrained gas

Suction: the pump sucks cleaned fluid from it

Reserve: to contain contaminated fluid, cuttings, and any sometimes

produced formation fluid

Tanks are usually equipped with motor-driven agitators (mixers)

45


Contaminants (Solids) Removal Equipment

Shale shaker - a vibrating screen that removes coarse rock

cuttings/caving such as shales

Desander - removes sand or larger particles not caught by the shale

shaker screen

Desilter - removes very fine particles and silt

Hydrocyclone/decanting centrifuge - removes finely grounded solids

Mud cleaner - a combination of a hydrocyclone and a shaker screen,

and use only for moderately high-density fluid

Degasser - removes entrained gas from the fluid

Except for the shale shaker all devices separate fluids by density

differences or settling

46


Solids Control

Solids control equipment will be covered in detail when we

discuss drilling fluids.

47


Conventional Rig Rotary System

Rig rotary system includes all the equipment used to achieve bit rotation. Can be conventional or top drive type

Conventional rotary system is made up of - swivel, kelly, kelly bushing, rotary drive, rotary table, and the drill string (i.e. drill pipe and drill collars)

More common offshore and on large land rigs is a top drive system, which may also be called a power swivel

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The kelly and swivel may be replaced with a top drive


Swivel

First connection to the hoisting system

Mud entry point under high pressure

2000 – 7500 psi

Top does not rotate

Bottom free to rotate

Top connects to a flexible hose which

in turn connects to a fixed steel high

pressure standpipe

Bottom connects to Kelly or Top Drive

49


Kelly, Rotary Kelly Bushing and Rotary Table

Square or Hexagonal drive

shaft

Passes through Kelly

Bushings

Bushings have drive pins to

locate into the master

bushings of the rotary table.

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Top Drive

51

Top drive, also may be called a power swivel. In this system the regular swivel, kelly, and kelly bushing are eliminated.

Image from Tesco


Rig Rotary System Top Drive

Top drive

Has built-in tongs to make and breakout pipes.

Uses a hydraulic or electric motor to achieve rotation.

Safer and easier for crew members to handle the drill pipe.

Saves time as connections are made very fast and safer. The crew uses the unit’s built-in tongs.

Connections only need to be made every ~90 feet or every 3 joints of pipe improving drilling efficiency.

Provides other operational advantages.

52 Images from Tesco


Well Control System

One of the most important systems on the rig. Its functions are: To detect a kick and to close the well on surface

To circulate well under pressure and permit increasing the fluid density at the same time

To move pipe under pressure

To divert flow from the rig

“Kick” is the uncontrolled flow of formation fluid into the well and occurs when hydrostatic pressure (Ph) is less than the formation pressure (Pf)

If the well control system fails, a BLOWOUT occurs - this is perhaps the worst disaster while drilling. A blowout is an uncontrolled flow of fluid from a well

Effects of blowouts may cause: loss of life, loss of equipment, loss of the well, loss of natural resources, and damage to the environment.

53


Kick Detection During Drilling Operation

Kick detection while drilling

usually achieved by use of a pit

volume indicator or mud flow

indicator.

Both devices can detect an

increase in the flow of mud

returning from the well over that

which is being circulated by the

pump.

Mud flow indicator can detect a

kick more quickly. Used in

conjunction with pump strokes.

54


Blowout Preventer Accessories

These are accumulators, casing head, control panel, kelly cock, inside BOP, and high pressure circulation device

Accumulator

Used to close hydraulically the BOP and located away from the rig

Its characteristics: most be able to close all the BOP units at least once; has its own power source; it’s oil must be compatible with elastomers used in the BOP.

Casing head - connects BOP stack to top of casing.

Control panel - on the rig floor and easily accessible to the driller.

Kelly cock/inside BOP - stop flows from inside the drill pipe.

High pressure circulating device (pump) - used to circulate the kick out of the hole.

Back pressure device – used to maintain additional pressure on the well while circulating drilling fluid. This is done with an adjustable choke (an adjustable valve or throttling device suitable for high velocity solids laden fluid).

55


Blowout Preventers

These are special pack-off devices used to stop fluid flow from a well. A

multiple of the pack-of devices is called BOP stack. Stack arrangement

is dependent on many factors including formation pressure & operator

policies

Purpose of BOP

Stops flow from the annulus with or without the drill string in the hole

To determine if flow from the well may occur

To allow pipe movement under pressure

To allow fluid circulation

To control pressure in the well

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Blowout Preventer Stack

57


Typical Arrangements of Blowout Preventers

The arrangement of the BOP stack varies considerably. The arrangement used depends on the magnitude of formation pressure in a particular area and on the type of well control procedures used by the operating company.

API suggests several arrangements of BOP stacks. This figure shows typical arrangements for 10K and 15Kpsi working pressure service.

A = annular preventer,

R = ram preventer,

S = drilling spool

G = rotating head

58


Remote Control Panel for Operating Blowout Preventers

The control panel for operating the

BOP stack usually is placed on the

derrick floor for easy access by the

driller.

The controls are marked (and should

be marked) clearly and identifiably

with the BOP stack arrangement

used.

In general, the control panel is located

away from the rotary area.

Another remote panel may be located

on the ground or at a remote location

for use if the primary operating panel

is in a hazardous area.

59


Well Monitoring Systems

A well must be monitored for safety, operational efficiency, and to detect

drilling problems

Different devices are used to achieve these objectives

Parameter Measured Device Used

Depth Geolograph

Rate of Penetration (ROP) Geolograph (by deduction)

Hook load Weight indicator

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Well Monitoring Systems

Parameter Measured Device Used

Rotary speed Tachometer on weight indicator

Torque Torque indicator

Pump pressure Pressure gauge on stand pipe

Flow rate Stroke counter

Fluid density Mud balance

Mud temperature Flow line thermometer

Pit level Pit volume indicator

61


Major Rig Components – Marine BOP’s

62

BOPs allow the top of the well to be sealed

against very high pressures and allow fluid to

be pumped into the well.

Views of a blowout preventer underneath a jackup cantilever


Marine Rigs – Specialist Equipment – Slip Joint and Riser Tensioners

63

Slip joint allows relative movement

between the rig and the well (heave,

tide).

Tensioners supports the weight of

the riser and keep the riser top in

tension.

The hole through the deck

is called the “Moonpool.”


Marine Rigs – Specialist Equipment – Riser Joints And Flex Joint

1. Riser joints contain buoyancy chambers

(reduce load), kill & choke lines and boost

line.

2. Flex joint at seabed allows lateral movement

of rig.

64


Marine Rigs – Specialist Equipment – Subsea BOP

Subsea BOP is positioned on the wellhead at the seabed.

Remote controls from the surface.

Accumulator bottles on the stack allow operation, even if disconnected from the rig, by sonic signals

65


Tubular Specifications

All tubular (drill pipe, drill collar, casing, and tubing) are specified by the following:

Range (length): 3 ranges - R1 (18 – 22 ft, uncommon), R2 (27 - 30 ft), R3 (>38-45 ft)

Nominal weight per foot

Outside diameter, OD

Steel grade (drill pipe is E75, X95, G105, S135, and Z140)

Essentials of drill string design

Tally - each joint must be measured carefully and recorded

Capacity and displacement volumes must be known

Pipe capacity = (xdid2)/4

Displacement capacity = ( x(dod2 -

did2)/4

API/ISO documents dictate pipe and connection specifications

66


Drill Pipes and Drill Collars

Drill pipes Transmit rotational power to the bit.

Transmit drilling fluid to the bit.

Drill collars Provide weight on bit.

Prevent buckling of the drill string.

Provide pendulum effects to cause the bit to drill a more nearly vertical hole.

Support and stabilize the bit to drill new hole aligned with the already drilled hole.

Drill collars can be round (most), spiral, or square Spiral used in small diameter holes or

deviated wells to prevent or reduce differential pipe sticking.

Square used in straight hole (vertical) drilling.

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Drill pipe Drill collar


How About Taking a Break?

68


Safety Provisions on the Rig

Rig equipment is designed to prevent accidents

Handrails on walkways and stairways

Guards on all moving machinery

Pressure relief devices on mud lines and pumps

Personal Protective Equipment (PPE)

No loose or floppy clothing

Hard hat must be worn to protect the head

Steel-toe shoes must be worn to protect the feet

Safety goggles to prevent eye injuries

Ear muffs or ear plugs to protect hearing

69


Safety Provisions on the Rig

Safety meetings

Must be conducted often to discuss procedures

Must provide manuals for new employees

Must conduct regular drills

Special conditions

Drilling in H2S environment needs special precautions

70


Review

Rig Selection Criteria Review

71


Rig Selection: Major COMPONENTS to be Selected / Sized:

Hoisting System

Rotary System

Circulating System

Well Control System

Power Generator System

Tubular Goods

Derrick and Substructure Capacity

72


Rig Specification: Hoisting System

Specify Hook Load Capacity

Specify Drawworks

Power Delivery (loose guidelines)

Lightweight Rigs : 650 HP

Intermediate Rigs : 1300 HP

Heavyweight Rigs : 2000 HP

Ultraheavy Rigs : 3000 HP or above

Drum Diameter, Groove Sizes etc.

Braking Systems (Operational, Emergency)

Crown Block

Load Cap, Number of Sheaves, Block Type

Drilling Lines

Type, Capacity, Durability

73


Rig Specification: Rotary System

Specify Type of Rotary System

Rotary Table-Kelly System

Top-Drive System

Specify Max. Working Torque

Specify Max. Working RPM

Length, Diameters and Pressure Rating of Rotary Hose

74


Rig Specification: Circulating System

Specify The Pumps

Types (Duplex, Triplex; Single Acting, Double Acting etc)

Capacities (HP, Max Pressure, Max SPM, Max GPM etc)

Stroke Lengths, Liner Sizes etc.

Specify Tanks

Numbers, Purposes, Volumes, Number of Tank Agitators.

Specify The Mud Cleaning Equipment

Shale Shakers, Gas Separators, Degasser, Desanders, Desilters, Centrifuges, Gas Burners, etc.

Specify The Additive Mixing Equipment

Hoppers, pneumatic equipment, etc.

75


Rig Specification: Well Control System

Specify the BOP stack

Individual Components (pipe rams, pipe rams, shear rams, annular preventer and their pressure ratings)

Stack Configuration

Other Components

Chokes, Choke Manifolds, Valves

Kill Line, Choke Line, Secondary Lines

Control System

Reaction Time

Capacity (accumulator capacity, number of bottles or pressure tanks, etc.)

Reliability

Redundancy

76


Rig Specification: Power Generation System

Number of generator sets

Engine specification (fuel used, type of engine, horsepower)

Generator specification (Kilowatts, AC/DC)

SCR specifications

Distribution system

Flexibility to redistribute power

Fuel economy

77


Rig Specification: Tubular Goods Inventory

Drill Collars, HWDP, Drill-Pipe, Cross-Overs, Various Subs, Mills, Jars,

etc.

Sizes

Thread types

Grades

Quantities

Condition (New, Premium, Class 2, etc.)

78


Rig Specification: Derrick/Mast Capacity & Sub-Structure

Derrick/Mast Capacities

Load Capacities

Floor Space

Height

V-door clearance, etc

Rig floor auxiliary hoists

Elevating/Assembling/Transportation Mechanism

Sub-Structure

Load Capacities

Dimensions

KB to Ground Clearance

Assembling / Transportation Mechanism

79


Rig Specification: Miscellaneous

Floor Equipment – power tongs, hydraulic slips, etc.

Automation and instrumentation

Communication systems

Operational water depth, riser specification, etc.

Operating conditions (wind, water currents, temperature, altitude etc.)

Mooring system

Stationing/positioning system

Transportation/propulsion system

Cranes

Cementing unit

Logging unit, etc.

Accommodations

80


Minimum Calculations

1. Derrick Load Calculations

2. Power Requirement Calculations

3. Pump Requirements Calculations

81


Now, YOU should be able to;

1. Name or describe the rig components

2. Explain the functions of the major components of a rig

3. Understand fundamental rig operations

4. Understand fundamental rig calculations such as rig power, derrick load, derrick efficiency, mud pump volume, tubular volumes.

5. Understand the well control systems especially BOP functions and arrangements

6. Know well monitoring systems

7. Understand the safety requirements on the rig

82


Appendix to Rigs and Rig Operations The following slides are relevant to sections covered in this lecture but are left out for brevity, they may be used as deemed appropriate by the instructor

83


Land Rigs (Heavy Land Rig)

Capable of drilling deeper

than 10,000’

Typical derrick load

> 1,000,000 lbs

BOP rating 10,000 psi

Cost around $30,000/day

84


Land Rigs – Helicopter Portable

Breaks down into small packages for moving (~8000 lb for medium lift

choppers to 20,000 lb for military type choppers)

Can deploy in locations not otherwise useable without very high cost

(jungle, mountain tops, inaccessible locations)

85


Marine Rigs – Bottom Supported – Platform

Self contained rig installed

on platform

Once drilling is finished, rig

can be removed or

replaced with smaller

completion or workover

rig.

86


Drilling tender

87


Marine Rigs – (Semi-Submersible)

Another Semi-submersible Drilling Rig

88


Heating Values of Various Fuels

90

Fuel

Type

Density

(lbm/gal)

Heating Value

(Btu/lbm)

Diesel 7.2 19,000

Gasoline 6.6 20,000

Butane 4.7 21,000

Methane --- 24,000


Example: A diesel engine delivers an output torque of 1,740 ft-lbf at 1,200 rpm. If the fuel

consumption rate is 31.5 gal/hr, what is the output power and overall engine efficiency?

Solution:

The angular velocity, ω, is given by min/8.539,7200,12 rad

The power output can be computed using the equation P = T hp

hplbfft

lbfftP

TP

5.397min//000,33

min/740,18.539,7

From the previous table, the density, ρ, for diesel is 7.2 lbm/gal and the heating value, H, is

19,000 Btu/lbm. Thus, the fuel consumption rate wf is:

min/78.360

1/2.7/5.31 lbm

minutes

hourgallbmhrgalw f

The total heat energy consumed by the engine is given as:

%4.23234.04.695,1

5.397or

Q

PE

it

hpQ

hplbfft

BtulbfftlbmBtulbmQ

HwQ

i

i

fi

4.695,1

min//000,33

/779/000,19min/78.3

Thus, the overall efficiency of the engine at

1,200 rpm is calculated as


Rig Power System-Example Problem

Example: A drilling rig is working in an arid climate (85°F) at an elevation of 3,600 ft. During the day, the peak temp. is 105oF. The min. temperature (prior to dawn) is 45°F. The rig has three 1,000 HP prime movers. Determine the min. and max. HP available during the 24-hr period.

Solution

The total available HP from the prime movers is 3 x 1000 HP = 3,000 HP

The loss in HP due to altitude =3% loss/1000 ft x 3600 ft x3000 HP= 324 HP

Hence, available HP at an altitude of 3,600 ft = 3,000 HP-324 HP = 2676 HP

Minimum HP will occur at the max. temp. = 2676 HP - loss to increase in temp.= 2676 HP - 1% loss/10oF x (105-85) °F x 2676

= 2676 HP - 53.5 HP = 2622 HP

Maximum horsepower will occur at the minimum temp.

= 2676 HP + increase due to decrease in temp.

= 2676 HP + 1% gain/10°F x (85-45)°F x 2676 =2676 HP+107 HP

= 2783 HP

92


Example: A rig must hoist a load of 300,000 lbf. The drawworks can provide an input power to the block and tackle system of 500 hp. Eight lines are strung between the crown block and traveling block. Calculate (1) the static tension in the fast line when upward motion is impending, (2) the maximum hook horsepower available, (3) the maximum hoisting speed, (4) the actual derrick load, (5) the maximum equivalent derrick load, and (6) the derrick efficiency factor. Assume that the rig floor is arranged as shown previously.

(1) The power efficiency for n = 8 is given as 0.841.

The tension in the fast line is calculated as follows: lbf

nE

WF f 590,44

8841.0

000,300

(2) The maximum hook horsepower available is hppEP ih 5.420500481.0

(3) The maximum hoisting speed is given by min/3.46

000,300

min/000,335.420

ftlbf

hp

lbffthp

W

Ph

Time to pull a 90-ft stand would require min9.1min/3.46

90

ft

ftt

continued


Example: A rig must hoist a load of 300,000 lbf. The drawworks can provide an input power to the block and tackle system of 500 hp. Eight lines are strung between the crown block and traveling block. Calculate (1) the static tension in the fast line when upward motion is impending, (2) the maximum hook horsepower available, (3) the maximum hoisting speed, (4) the actual derrick load, (5) the maximum equivalent derrick load, and (6) the derrick efficiency factor. Assume that the rig floor is arranged as shown previously.

Solution:

(4) The actual derrick load is calculated as follows:

(5) The maximum equivalent load is calculated as follows:

(6) The derrick efficiency factor is

lbfWnE

nEEFd 090,382000,300

8841.0

8841.0841.011

lbfWn

nFde 000,450000,300

8

484

%9.84849.0000,450

090,382or

F

FE

de

dd

continued


Projection of Drilling Lines on Rig Floor

The drilling lines usually are arranged as in the plan view of the rig floor shown.

For this arrangement:

All legs equally support the load on the traveling block – each having one fourth of the “hook load.”

Derrick legs C and D share the load imposed by the tension in the fast line.

Leg A assumes the full load imposed by the tension in the dead line.

95


Double-Acting Duplex Pump

Has two pistons and it both sucks and discharges on every stroke

Pump factor, Fp = pump displacement per complete cycle (or stroke)

Fp = (/4)(2)(Ls)[(2(DL2)) - Dr2)]Ev

DL = liner diameter

Dr = rod diameter

Ls = stroke length

Ev = pump volumetric efficiency

Hydraulic pump horse power HHP= (P)(Q)/1714

P = differential pressure, psi (Pout - Pinlet)

Q = flow rate, gal/min

96


The following slides may be used to illustrate drill line capacity and contains an exercise

97


Schematic of Block and Tackle

1. Comprised of crown

block, traveling block,

and drilling line.

2. Provides a mechanical

advantage, which

permits easier handling

of large loads.

3. Generally mechanical

advantage is less than

n (i.e. less than 100%)

due to friction.

4. As n increases, the

mechanical advantage

increases.

98


Drilling Line

The drilling line is subjected to fatigue and wear when in service during normal tripping operation.

Failure of the line may result in injury to personnel, damage to the rig, and loss of the drilling string.

Hence, drilling line tension is always maintained less than the yield strength of the line.

The greatest wear occurs at pickup points on the traveling and crown blocks and the drawworks.

These wear locations must be changed regularly by following a preventative maintenance program called a SLIP and CUT Program (similar to oil change for your car).

99


Drilling Line

Steel construction 6x19 6 pieces or strands 19 wires in each piece

Rope lays The lay of a wire rope is the way the

wires and strands are placed during manufacture. Right and Left lay refers to the

direction in which the strands of the rope are wound around the core.

Regular and Langs lay refers to the way the wires in the strand are wound in relation to the strands

Refer to API Spec 9A (ISO 10425) for details as well as API RP9B for recommended practices

100


Slip and Cut Program

Slip and Cut involve:

Suspend the traveling block.

Loosen the dead line at the wire line anchor.

Slip in a few feet of new line into service from the storage reel.

Disconnect the drill line from the drawworks drum.

Cut off a section of the line from the drawworks end, pull through an amount equal to the amount cut off and reconnect the drill line to the drawworks spool.

A Slip and cut program is conducted based on a unit of service called the “ton-mile” method.

Based on the assumption that a line will safely perform so much work (ton-mile).

A line has rendered 1 ton-mile when the traveling block has moved 2,000 lbf a distance of 1 mile.

Must keep a record of ton-miles the drill line has experienced.

Ton-miles vary with drilling conditions.

101


Exercise: Calculate Desired Drawworks Horsepower

Using this equation: Drawworks HP = (W x Vh)/(33000 x E); W is lbf and Vh is in ft/min, E is traveling assembly

(block and tackle) efficiency

Calculate the needed horsepower to move a drillstring weighing

225,000 pounds at a rate of 150 feet per minute, use an

efficiency factor of 0.85.

102


Exercise: Calculate wire rope capacity

Using the previous 2 slides and a design factor of 3.5.

Determine the maximum load that may be supported if a 1-1/2

inch EIP wire rope is used as a drilling line. Use load case A

strung up with 10 lines.

Consider that the tension in the fast line is calculated as follows:

FL Tension = Fast Line Factor x Load

The Fast Line Factor for 10 lines is 0.123

What is the maximum load that can be lifted with this drilling

line?

105


Example: Compute the pump factor in units of barrels per stroke for a duplex pump

having 6.5-in. liners, 2.5-in. rods, 18-in. strokes, and a volumetric efficiency of 90%.

Solution:

The pump factor for a duplex pump can be determined as follows using

the equation for duplex-double-acting pump

strokeinF

ddELF

p

rlsp

/2.991,1

5.25.629.0182

22

3

2222

Recall that there are 231 in3 in a U.S. gallon and 42 U.S. gallons in a U.S.

barrel. Thus, converting to the desired field units yields

strokebblgal

bbl

in

gal

stroke

in/2052.0

423231

32.991,1


The following slides discuss solids control equipment, this is

covered in detail later in the course, however these slides may

be used to illustrate or respond to questions at this time.

Realize though that these same slides will be shown later in the

course.

107


Example Solids Processing Layout

108

Degasser

Centrifuge

To Trip Tank

Gumbo Slide (optional)

Gas

Buster

Removal Section

Hopper

Additions Section

Su

cti

on

& T

es

tin

g S

ec

tio

n

Treated Fluid to Well

Returns from Well

Choke

From Trip Tank

Scalping Shaker (optional)

Desilter or

Mud Cleaner Desander

Sand Trap

Main Shaker

Hopper

Mud Pump(s) Well


Shale Shaker

109


Shale Shaker

110


Components of a Shale Shaker

111


Inside a Hydrocyclone

112


Desander

113

Inside diameter larger

than six inches.


Desilter

114

Inside cone diameter less than 6 inches


Centrifuges

In weighted drilling fluid systems,

decanting centrifuges recover as

much as 95% of barite, which is

returned to the active system, while

also discarding finer, lower-gravity

solids. In chemically enhanced

dewatering systems, centrifuges

significantly reduce liquid

discharge volumes and appreciably

enhance total solids control system

efficiency.

115


Example Solids Processing Layout - Review

116

Degasser

Centrifuge

To Trip Tank

Gumbo Slide (optional)

Gas

Buster

Removal Section

Hopper

Additions Section

Su

cti

on

& T

es

tin

g S

ec

tio

n

Treated Fluid to Well

Returns from Well

Choke

From Trip Tank

Scalping Shaker (optional)

Desilter or

Mud Cleaner Desander

Sand Trap

Main Shaker

Hopper

Mud Pump(s) Well


The following slides may be useful to support your lecture or

respond to questions related to well control topics, well control

is covered in more detail later in this course.

117


Two alternative trip-tank arrangements for kick detection during tripping operations

While making a trip, circulation is stopped and a significant volume of pipe is removed from the hole. Hence, to keep the hole full, mud must be pumped into the hole to replace the volume of pipe removed.

Hole-fill up indicator is used during trip operations. Used to measure accurately the mud volume required to fill hole.

Trip tanks - small tanks holds 10 - 15 gauge makers - provide the best means of monitoring hole fill - up volume.

Pump stroke counters - use if no trip tanks on the rig to determine hole fill - up volume.

Never use active pits as hole fill-up volume indicators because it is too large to provide sufficient accuracy.

118


Components of a Kick Detection System

Mud flow indicator - detects a kick more quickly, sees the kick first

Pit volume indicator - indicates the active pit volume and presets at

high & low levels; an alarm turns a light or a horn on when the levels

are below or above set levels

Gain in pit volume = kick volume !!!

Hole fill-up indicator - used while tripping to measure accurately the

fluid required to fill the hole

Trip tanks - usually very small (10 - 15 bbl capacity) and provide the

best way to monitor hole fill-up volumes

When the trip tanks are not available, use pump strokes

Never use active tanks as hole fill-up volume indicator

119


Blowout Preventers

Types of BOP - ram and annular preventers

Three types of ram: pipe; blind; and shear

Pipe closes against the drill pipe.

Blind closes the well when there is no drill pipe in hole.

Shear, is a special blind ram as it shears the drill pipe.

Usually only used when all pipe ram and annular preventers have failed.

Annular preventer, also called a “bag” preventer uses an

elastomer ring to close against the drill string.

BOP working pressures

2,000, 3,000, 5000, 10,000, 15,000 and 20,000 psi.

120


Annular Blowout Preventer

121


Choke and Kill lines

122


Choke Manifold

123


Typical Arrangements of Blowout Preventers

The arrangement is defined

starting at the casing head and

proceeding up to the bell

nipple.

Thus, arrangement RSRRA

denotes the use of a BOP stack

with a ram preventer, attached

to the casing head, a drilling

spool above the ram preventer,

two ram preventers in series

above the drilling spool and

annular preventer above the

ram preventer

124

rig components

Documents

ft copyright

rig operations copyright

substructure requirements

floating rig

drill string requirements

ft wd land rigs conventional

ft wd platform rigs

mud system requirements