Hoisting System

Drilling Engineering – Fall 2011

Drilling Engineering PE 311

Prepared by: Tan Nguyen


General Information

Instructor: Tan Nguyen

Class: T and TH 11 pm - 12:15 pm Room: Cramer 101 Office: MSEC 372 Office Hours: T and TH 1:00 pm – 3:00 pm or by appointment Phone: 835-5483 E-mail: [email protected]



Required Materials

1.

Applied Drilling Engineering – Adam T. Bourgoyne – SPE

textbook 2.

Drilling Engineering Handbook – Volume II – Robert Mitchell

3.

Class notes

4.

PowerPoint slides



Grading

Homework: 20% Quizzes: 20% Midterm exam: 30% Final: 30%



Movie

http://www.youtube.com/watch?v=DniNIvE69SE&feature=relate d



Main Rig Components



Main Rig Components 1. Power System 2. Hoisting System 3. Fluid Circulating System 4. Rotary System 5. Well Control System 6. Well Monitoring System



Main Topics in Drilling 1.

Rotary drilling

2.

Drilling fluids

3.

Drilling hydraulics

4.

Drilling bits

5.

Directional drilling

6.

Formation and fracture pressure

7.

Cements

8.

Casing design

9.

Tubing design

10.

Other topics: under balance drilling, cutting transport, etc.



Introduction What we want to do is: To make a hole! But we have to make it economically and safely



Steps To Drill an Oil/Gas Well 1. Complete or obtain seismic, log, scouting information or other data. 2. Lease the land or obtain concession. 3. Calculate reserves or estimate from best data available. 4. If reserve estimates show payout, proceed with well. 5. Obtain permits from conservation/national authority. 6. Prepare drilling and completion program. 7. Ask for bids on footage, day work, or combination from selected drilling contractors based on drilling program. 8. If necessary, modify program to fit selected contractor equipment.



Steps To Drill an Oil/Gas Well 9. Construct road, location/platforms and other marine equipment necessary for access to site.

10. Gather all personnel concerned for meeting prior to commencing drilling (prespud meeting) 11. If necessary, further modify program. 12. Drill well. 13. Move off contractor if workover unit is to complete the well. 14. Complete well. 15. Install surface facilities. 16. Analysis of operations with concerned personnel.



Drilling Rig A drilling rig is a machine which creates holes (usually called boreholes) in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas wells, or they can be small enough to be moved manually by one person. They sample sub-surface mineral deposits, test rock, soil and groundwater physical properties, and also can be used to install sub-surface fabrications, such as underground utilities, instrumentation, tunnels or wells. Drilling rigs can be mobile equipment mounted on trucks, tracks or trailers, or more permanent land or marine-based structures (such as oil platforms, commonly called 'offshore oil rigs' even if they don't contain a drilling rig). The term "rig" therefore generally refers to the complex of equipment that is used to penetrate the surface of the Earth's crust.



Drilling Rig

Drilling rig preparing rock blasting

Water well drilling rig Prepared by: Tan Nguyen


Drilling Rig

Oil drilling rig offshore Oil drilling rig onshore



Drilling Rig The most common drill rigs are of the rotary rig type. Today's rotary drill rig consists of multiple engines that supply: (1) power, (2) hoisting equipment that raises and lowers the drill string (drill pipe), and (3) rotating equipment that turns the drill string and the drill bit. These engines also drive the circulating equipment that pumps liquids (mud) down the hole to lubricate the drill string and drill bit which are rotating in the hole. These liquids remove cuttings (loose bits of rock), and controls downhole pressure to prevent blowouts (unexpected pressure, which overcomes the weight of the drilling mud and explodes to the surface).



Drilling Rig While the bit cuts the rock at the bottom of the hole, surface pumps are forcing drilling fluids down the hole through the inside of the drill pipe and out the bit. This fluid lubricates and removes cuttings. The fluid (with the cuttings) then flows out the center of the drill bit and is forced back up the outside of the drill pipe onto the surface of the ground where it is cleaned of debris and pumped back down the hole. This is an endless cycle that is maintained as long as the drill bit is turning in the hole. In generally, there are four main systems of a rotary drilling process including: Rig power system, hoisting system, drill string components, and circulating system.



Rig Power System The power generated by the power system is used principally for five main operations: (1) rotating, (2) hosting, (3) drilling fluid circulation, (4) rig lighting system, and (5) hydraulic systems. However, most of the generated power is consumed by the hoisting and fluid circulation systems. In most cases these two systems are not used simultaneously, so the same engines can perform both functions. Rig power system performance characteristics generally are stated in terms of output hoursepower, torque, and fuel consumption for various engine speeds. The following equations perform various design calculations:



Rig Power System



Rig Power System P – shaft power developed by engine, hp (1)

(2)

Qi – heat energy consumed by the engine, hp

Et – overall power system efficiency w – angular velocity of the shaft, rad/min;

(3)

w = 2pN with N is the shaft speed in RPM

T – output torque, ft-lbf Wf – volumetric fuel consumption, gal/hour H – heating value of diesel, 19,000 BTU/lbm

rd – density of diesel, 7.2 lbm/gal 33,000 – conversion factor, ft-lbf/min/hp Prepared by: Tan Nguyen


Rig Power System


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


Rig Power System Example 1.1. A diesel engine gives an output torque of 1740 ft-lbf at an engine speed of 1,200 rpm. If the fuel consumption rate was 31.5 gal/hr, what is the output power and overall efficiency of the engine. Solution: Angular velocity:

w = 2pN = 2p(1200) = 7,539.84 rad/min

The power output:

Heat energy consumed by the engine:

Overal efficiency:



Hoisting System The function of the hoisting system is to get the necessary equipment in and out of the hole as rapidly as is economically possible. The principal items of equipment that are used in the hole are drillstring, casing, and miscellaneous instruments such as logging and hole deviation instruments. The major components of the hoisting system are: (1) the derrick, (2) the block and tackle system, (3) the drawworks, (4) miscellaneous hoisting equipment such as hooks, elevators, and weight indicator.



Derrick The function of the derrick is to provide the vertical height required to raise sections of pipe from or lower them into the hole. Derricks are rated according to their height and their ability to withstand compressive and wind loads. The greater the height of the derrick, the longer the section of pipe that can be handled. The most commonly used drillpipe is between 27-30 feet. To provide working space below the derrick floor for pressure control valves called blowout preventer, the derrick usually is elevated above the ground level by placement on a substructure.



Making a Trip http://www.youtube.com/watch?v=5f3STxhzICQ http://www.osha.gov/SLTC/etools/oilandgas/drilling/trippingout_in.html#



Making a Trip Tripping In

Tripping Out •Setting Slips

•Elevators raised

•Breaking Out and Setting Back the Kelly

•Tripping In -- Latching Elevators to Top of Stand

•Attaching Elevators to the Elevator Links •Latching Elevators to Pipe •Working on the Monkeyboard •Breaking Out Pipe •Maneuvering Pipe to Racking Area

•Moving pipe to rotary •Pipe is made up •Slips are pulled •Slips are set

•Elevators are unlatched •Process repeated for all stands •Pickup kelly and attach to drill string •Break circulation, and •Resume drilling



Making a Connection / Tripping In

Making a mouse hole connection



Making a Connection / Tripping In

Moving Kelly to Single in Mousehole


Stabbing the Pipe

Single Added. Ready to Drill


Tripping Out

Put Kelly in Rathole


Use Elevators for tripping


Tripping Out



Block and Tackle Block and tackle is comprised of the crown block, the travelling block, and the drilling line. The principal function of the block and tackle is to provide a mechanical advantage which permits easier handling of large loads.



Machenical Advantage

The mechanical advantage M of a block and tackle is defined as the ratio of the

load supported by the traveling block, W, and the load imposed on the drawworks, Ff.

(4)



Pully A pulley transfers a force along a rope without changing its magnitude. In Figure a, there is a force (tension) on the rope that is equal to the weight of the object. This

force or tension is the same all along the rope. For this simple pulley system, the force is equal to the weight, as shown in the picture. The mechanical advantage of this system is 1!. In the Figure b, the pulley is moveable. As the rope is pulled up, it can also move up. Now the weight is supported by both the rope end attached to the upper bar and the end held by the person! Each side of the rope is supporting the weight, so each side carries only half the weight. So the force needed to hold up the pulley in this example

is 1/2 the weight! Now the mechanical advantage of this system is 2.



Pully

a


b

c

d


Block and Tackle Without friction between the block and the tackle, the mechanical advantage is given by (5) Equation (1.5) tells us the ideal mechanical advantage is equal to the number of lines. For frictionless between the block and tackle, the power efficiency is given by

(6) In general, the power efficiency can be calculated (7)



Block and Tackle The load applied to the derrick, Fd, is the sum of the hook load, W, the tension in the dead line, Fs, and the tension in the fast line, Ff: (8)

The total derrick load is not distributed equally over all four derrick legs. Since the

drawworks is located on one side of the derrick floor, the tension in the fast line is distributed over only two of the four legs. Also, the dead line affects only the leg to which it is attached. If E > 0.5, the load on leg A is greatest of all four legs. Since if any leg fails, the entire derrick also fails, it is convenient to define a maximum equivalent derrick load, Fde, which is equal to four times the maximum leg load.



Block and Tackle Maximum equivalent derrick load:

(9)



Drawworks Drawworks is the key operating component of the hoisting system. On most modern rotary drilling rigs, the prime movers either operate the hoisting drum within the

drawworks or operate the rotary table through the transmission within the drawworks. Thus the drawworks is a complicated mechanical system with many functions: Transmit power from the prime movers to its hoisting drum to lift drill string, casing, or tubing string, or to pull in excess of these string loads to free stuck pipe.

Provide the braking systems on the hoist drum for lowering drill string, casing string, or tubing string into the borehole. Transmit power from the prime movers to the rotary drive sprocket to drive the rotary table Transmit power to the catheads for breaking out and making up drill string, casing and tubing string.



Drawworks



Drawworks



Efficiency Factor, E The input power to the drawworks is calculated by taking into account the efficiency of the chain drives and shafts inside the drawworks. The efficiency factor E is given by the following equation:

Where K is sheave and line efficiency per sheave; K = 0.9615 is in common use.



Example Example 1.2: A rig must hoist a load of 300,000 lbf. The drawworks can provide an input power to the block and tackle system as high as 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

6. The derrick efficiency factor



Example 1. The static tension in the fast line when upward motion is impending

2. The maximum hook horsepower available.

Ph = Epi = 0.844 x 500 = 420.5 hp 3. The maximum hoisting speed

4. The actual derrick load

5. The maximum equivalent derrick load

6. The derrick efficiency factor


Hoisting System

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