What is the idea behind a cloverleaf?
Eliminates cross-traffic movements (left turns - most disturbing turn in traffic)
How is the density of roads determined?
Area of roads per square mile
What are the origins of many present roads?
Indian trails, trails made by animals (heavily compacted), and the relevance of roads to water, such as rivers
Why do people chose high roads to travel?
Valleys (low land) are susceptible to flooding/mud
Two major patterns for road design
Grid pattern (##)
Contoured (curved, i.e. cul-de-sac)
Road pattern favored by architects? Why?
Following the natural contour of the land
- Minimizes costs and doesn't require cut and fill of the land
Major purpose of the Land Ordinance Act of 1785
Developed by Thomas Jefferson, it divided a 36 mi^2 plot into 6x6 shape of 1 mi^2 sections to organize the land
- Development of original colonies
How has the Land Ordinance Act helped in creating roads?
33 ft. wide strip dedicated by landowners for public usage - created 66 ft wide right-of-way at one mile intervals, which led to the construction of roads
Why 66 ft for public use by LOA?
66 feet was the length of Gunter's chain, standard measuring device in surveying.
What is the dominant pattern of roads in the Midwest?
Grid-patterned: run straight and parallel to cardinal points of the compass, heedless of hills, valleys and extreme obstacles
Major problem of plotting a north-south grid on the surface of a spherical earth?
Does not fit - Longitude lines converge toward the poles, so north/south roads have deviate left or right
Most common shape of city blocks
easiest to divide into plots and build homes
Major problem with the grid pattern of San Francisco
The grade of sidewalks is so steep they have to be carved into stairways.
Advantages and disadvantages of soft curves, loops, and cul de sacs
A: architecturally free, eliminates congestion, limits slope and grade (conforms to topography to cut costs)
D: Hard to navigate network of streets and lengthens time for emergency response
Who are the builders of El Camino Real? Origin?
the Spanish - joined cities - originated from Mexico City to Sonoma (now coincides with U.S. Highway 101)
Route 40 nicknames
Ocean to Ocean Highway
The Business Route
Factors that affect road design
Design speed (sharpness of curves)
Slope (esp. downhill in snow areas)
Width (# of lanes)
Volume of traffic
Design speed vs. legal speed limit
Engineered based on survey, curves, grades vs. safer, government posted speed to forgive driving errors
Styles of road building
Traditionally straight line sections connected with curves, or curved sections with straight lines (depends on nature of the land)
Purpose of engineering codes
Public Safety and Quality Assurance
Purpose of curves and grades? Are there limits?
Curves help change direction safely
Grades change elevation
There are limits to ensure safety - design speed, sharpness, sight distance, slope, engine of vehicle
Why are long straight sections of road avoided?
Psychological - drivers tend to lose attentiveness on straightaways
Why one mile of every 5-highway miles must be straight and obstruction-free
1/5 miles in Interstate Highway system straight so roads can be used as runways for military aircrafts for emergency landings
Parkways vs. Freeways
Parkways are smaller, lower standards
Freeways can handle more volume
Rules for route numbering
east-west routes get even numbers
north-south roads get odd numbers.
Route numbers higher than 100 are reserved for shorter spurs, loops, and connectors.
When the leading digit is even it means the road is connecting to another main road.
Where the leading digit is off it means the main road is connecting to a minor road. (numbers increase from south to north and from west to east.
Major, long distance roads are assigned numbers less than 100, ending in either 0 or 5).
Purpose of a diamond type interchange
Connects a major highway to a lesser volume road
Allows entrance/exit at proper speeds
Requires ramps and stop lights, and is more compact (cheaper)
How does a traffic circle work?
Organizes traffic from many directions without need for traffic lights
Cloverleaf interchange vs. Directional interchange
Cloverleaf: designed to eliminate left turns, requires sharp turns
Directional: keeps flow of traffic unhindered, dedicated road for every direction (increase cost/design), eliminates sharp curves
What does it take to make a left and U turn on a cloverleaf
Left: three right turns (270)
U: six right turns (540)
Major drawback of a cloverleaf
Loop roads turn sharply, so vehicles have to slow down and it creates an awkward "weaving zone" of vehicles entering/exiting
Flagstone vs. Cobblestone in road building
Flagstone - laid flat
Cobblestone - laid on end (much more resistant)
composed of crushed stone and sand laid on natural roadbed; bound by bitumen (tarry residue); requires compaction
What is traffic calming?
design features to force drivers to slow down - done by weaving roads, narrow roads, island placement, speed bumps
Accessories used in traffic calming
Speed bumps/humps/tables, bulbs, knuckles, islands, chokers, roundabouts, narrowing traffic lanes, diagonal parking, chicanes (slalom course)
Who opposes traffic calming?
Why is asphalt the preferred binder in road construction
Flexible and less expensive
It deforms and yields (flexion/contraction) rather than cracking
Drawbacks of asphalt
Deformation due to temperature flux.
"creep" - shift forward as vehicle applies brakes, due to continuous application in one spot (i.e. bus stops)
Benefits of rigid concrete pavement
Stiff/strong (resists bending)
Does not respond to temperature change
Drawbacks of rigid concrete
Strips of concrete make bumps that are annoying and requires repair
Susceptible to cracks
Difference between expansion and contraction joints in concrete pavement
E: gap between panels of pavement left open during construction, then filled with liquid asphalt
C: one continuous piece of asphalt, cut with saw to increase flexibility; knowing the ground will crack at weaker points, the cracks develop in controlled areas
Solution to eliminate expansion and contraction joints in concrete pavement
Ties (horizontal) and dowels (parallel)
They are coated with grease to slide and deal with exp/cont.
Compared with pre-motor vehicle days, what makes pavement work today
Pneumatic tires - rubber filled with compressed air, spreads the load evenly over the road surface
Road accessories that minimize loss of life in case of accidents
Anything associated with absorbing energy
(guardrails, crash cushions, sign posts, runaway truck ramps, mini billboards, retro-reflective coating to reflect light, Botts dots, rumble strips)
How can road signs and lane marks be seen at night?
Retro reflective coating
Allows light to bounce back only to where it came from due to glass beads/prisms embedded in translucent plastic layer
Traffic jams are analogous to a flooding river. How do they differ?
A flood is faster and can overflow where as traffic is slower and limited in the area it can occupy.
A river can flood its banks, highway traffic can not spill over the median
Function of metered entrance ramps on freeways
Prevent unnecessary traffic jams by dribbling cars onto the highway at a controlled rate
What are Botts dots?
Plastic reflectors embedded in the centerline and edges of roadways
Visible in rain and provide a tactile/auditory warning if cars stray from their lane
Conventional difference between conventional traffic lights and LED's
Instead of using a light bulbs, LED's have a geometric array of small, semiconductor devices that emit various distinct colors
Brighter and consume less energy, but last longer
If one LED burns out, the rest remain lit
How to optimize traffic light times
Motion detectors in the ground and on poles to detect cars presence
What is a big no-no in traffic signals and how can it be avoided
Two green lights in conflicting/perpendicular directions
Avoided by traffic signals being linked in a citywide network controlled from a central point
How can traffic lights be made responsive to emergency vehicles?
Detectors in lights allows fire engines and ambulances to preempt normal signals and turn green as the vehicle approaches.
The strobe light on the vehicle must be a certain frequency.
How many highway and railroad bridges in the US
600,000 highway and 100 railroad track bridges (2001 census)
Principle components of a girder bridge
Stringers, concrete columns and piers.
Basic principle a girder bridge serves
To span a distance
Beams or girders support both sides
Why are fasteners used in bridge building
Bridges must handle other forces in addition to gravity; has to support more than just itself
- "live loads" (actual traffic)
What is a truss
- a sort of lacework girder
- designed to maximize stiffness and minimize material used in construction
- built from beams, bars, or rods connected in triangular arrangements
Major difference between rectangular and triangular truss
Triangular: much more stable (maintains shape)
Rectangular: can squirm into a diamond shape and collapse into a flat line
What forces are top and bottom chords subjected to in a truss bridge
Upper: compression (must be stiff enough to resist bending and usually are beams of substantial cross section)
Lower: tension (can be thin rods or flexible chains/cables where strength matters instead of stiffness)
Give examples of steel sections used in resisting compression and tension forces
Compression: I-beam (bulky)
Tension: thin chains or cables
Material first used in truss construction? Why is its use becoming limited?
Steel and iron becoming economically attractive and longer lasting; wood is subject to rotting, weathering, and disintegration
**Other members used in truss bridge construction - are they subject to tension or compression?
Diagonal pieces and vertical members
Force could be tension or compression, depending on shape of bridge and construction of the pieces
Main purpose of constructing covered bridges
to keep wooden framework out of weather and protect it from rotting
Main idea behind the Pratt Bridge where the middle of the span is thickest and diminishes near the support
Thickest in the middle because that is where the greatest bending develops and thinnest section at the supports because there is no bending
Two major components of the Whipple bowstring truss
Arch and Truss
Upper chord is a curved arch held in compression and prevented from spreading out by tension in the lower chord, which also forms the deck of the bridge
Vertical and diagonal braces connect the deck with the arch, working in tension
Main idea behind Cantilever bridge design
Total fixation at one end, with a thinner section on the beam (in the center) to save material
Like an arm outstretched or a tree branch, it is balanced/anchored to prevent toppling
Difference in profile of a truss bridge and cantilever bridge
Cantilever: thickest at its point of support
Truss: rests at both ends where it is thinnest and thickest in the middle
How to counterbalance the weight acting on a cantilever bridge
add counterweights to the other end or anchor it into the ground
Major construction advantage of cantilever bridges
Self-supporting and stable during construction; trusses are extended from opposite sides and connected in the middle by a short section of truss
Major advantage of stone arch bridges
Bridge acts entirely under compression, while stone and brick are not strong under tension
Two major disadvantages of stone arch bridges
- only stable when finished and will only be stable when the keystone is entered at the end of construction
- outward thrust at the base of the arch needs to be resisted or the arch will spread and collapse
Main advantage of suspension bridges? How does it transmit its loads?
Makes the bridge lighter - can span the bridge longer and limit costs
Transmits loads by having the main cables being in tension everywhere and pulls inward on their anchorages
Name of the mathematical shape of the main cables of a suspension bridge? Origin? What does the shape resemble?
"catena" - Latin - means "chain"
shape resembles a parabola
Factors suspected in the failure of the Tacoma Narrows Bridge
Resonance - small force producing large effects by periodically reinforcing natural vibrational motions of the structure
Flutter - self-reinforcing behavior in which the twisting of the bridge, by altering the wind forces on the deck, causes more twisting
Suspension bridge vs. Cable-stayed bridge
Suspension - relies on two main cables that support vertical suspenders/cables; the deck is suspended (i.e. Golden Gate)
Cable-stayed - supported in segments by individual stays fanning from a main point/tower to the deck (i.e. Sunshine Skyway)
One suspension cable snapping will cause the bridge to fall, but one stay snapping will remain intact
Technical difficulties with increasing the span of a cable-stayed bridge
Must increase height of tower as span increases. Force is exerted away from vertical and becomes more horizontal, which is tougher to support
Is the Brooklyn Bridge suspension type, cable-stayed, or both? Why?
Suspension and Cable-stayed
The weight of the deck is carried by four catenary cables; diagonal stays fan out from the towers to add stability
How can a cable-stayed bridge be made asymmetrical?
The bridge has the same number of cables on either side but one side is bunched more closely together.
Bridge is raised and adjusted using a hydraulic jack; nothing is totally rigid/fixed
Advantages/disadvantages of floating bridges
A: they can carry highways across large bodies of water using less material because they don't require a base structure
D: Steep decline to get to the bridge, vulnerable to currents, tides, floods, ice, and blocks channels for ships until moved.
Main convenience/inconvenience afforded by moveable bridges
+ Resolves the conflict between waterway and road traffic
- Movement by land or water can only be utilized once at a time
Three types of moveable bridges and characteristics
1. Bascule - like a seesaw, part of the deck pivots upward, raising the arm of the bridge. Physical work is reduced using counterweights to balance the weight of the deck
2. Lift - essentially an elevator, lifting the middle of the deck for passing ships
3. Swing - pivots horizontally, like a compass needle, using counterweights to open two channels
Why are moveable bridges presently out of favor?
Cost of operation, which includes maintaining the bridge and workers who need to control it
Accessories found in a bridge's underbelly
Roller support, rubber pads, hinged bars, finger joints, lubricated steel plates - all used to keep the bridge flexible, not rigid
T/F: A bridge is capable of resisting earthquakes is one that can move freely over its foundation
T - the bridge deck must move freely over its foundation. Damage can only occur if the deck is attached to the ground/base
Tunnels require continuous services. Name some.
Describe the cut-and-cover technique used in building tunnels
Requires digging a trench, inserting U-shaped concrete base of the tunnel, putting in the road/rail line, and adding a roof
Name other techniques used in digging tunnels
Tunnel boring machines (TBM)
How is the cut-and-cover technique applied in water
It is applied in water by having a tube assembled on the surface and sunk into a trench dredged into the river bottom, then having it covered for protection from ship anchors.
What is shortening of a mountain tunnel? How can it be achieved? What purpose does it serve?
It means going higher up the mountain, which makes the approach roads longer/steeper.
It is achieved by building a turn into the tunnel with part of the descent parallel to the riverbank.
The purpose is to save money by having to go through less earth and making the tunnel shorter.
Are mountain tunnels or river tunnels more prone to leakage? Why?
Mountain tunnels, because of the rock being fissured and porous. River tunnels are installed far below water, dug and confined in soil, as the strata underlying rivers tend to be naturally waterproof.
Holland Tunnel has a unique fire resistance system. Describe.
The fire resistance system includes a collapsable ceiling so ventilation can suck out the smoke. The hole acts as a duct to clear the tunnel. (smoke is the main killer in fires, not fire)
Heat generation is a problem in tunnels. How is it generated/treated?
High-speed motion in static environments creates friction, causing heat. Chilled water along the length of the tunnel cools it.
Tunnel fires are major concerns even in electrically operated rail tunnels. Name a possible source of fires.
A spark created by a high speed train in a static environment
What are the lighting problems in tunnels?
Ratio of daylight to tunnel light is 4000:1. Tunnels appear black in daytime and the exit is blackened at night.
Name devices used in monitoring tunnel safety.
Sensors (carbon monoxide and visibility)
Monitors (air velocity)
Overhead lane markers
Why traffic jams are easier to develop in tunnels than on the road? How to break a tunnel jam?
Drivers overreact and slow down, becoming cautious in small spaces.
Strategy is to stop traffic completely at the entrance portal, not releasing new groups of cars until the tunnel is cleared.
Name different types of mines
Describe placer mining. What is its major disadvantage?
Recovery of loose flakes of metal from mineral-rich sands by spraying high-velocity water to separate the material.
Disadvantages are incredible use of water and environmental damage as tons of material is deposited downriver, increasing the chance of flooding.
Open-pit mining vs. Underground mining
Open-pit: used when the deposit is near the surface. Can result in significant soil movement, which requires heavy machinery and leaves its effect on the landscape.
Underground: used when deposit is far underground and remains out of sight
What is hydraulicking? Why is it outlawed in the US?
Elaborate form of placer mining. Material is washed over a "sluice box" (sieve) to extract metals.
It is outlawed because it washes the land into rivers, a detriment to both.
What are the sheaves and skips in a head frame mining operation?
Sheaves - large pulleys at the top of a head frame
Skips - ore-carrying buckets of a hoist
Name some of the methods of ore transportation
Trucks or rail carts
Transport systems that look like ski lifts
Conveyer that looks like a carousel
Roller runs in a channel
Describe buffering in mining operations. How well does it serve the mining operation?
Keep a margin for continuous operation of the mine and/or mill by continuing to pile up ore for production.
Name two amenities underground mining cannot operate without. Why are they necessary?
Ventilation - to keep air quality clean/remove all suspended particles of dust, and control temperature
Pumping of water - to prevent buildup of water/flooding and allows them to be dug deeper
How deep can a mine go? What are problems associated with increasing depth?
16,000 feet in South Africa
1-degree increase for every 300 ft depth
Workers have to make the trip in stages, using multiple hoists. Also, no pump exists that can lift water from these depths, maximum pump strength can lift ~3500 feet (1 mile). Transportation of material (i.e. gravel) is ~75% of the cost.
Name/describe the two types of surface mines
Open-pit: works best for mineral veins that dive deep into the earth through hard rock, mostly for iron and copper
Strip-mining (open cast): used for bedded sedimentary deposits that extend horizontally over large areas but not too far under the surface (typically coal)
What are benches and faces in open pit mines?
Benches: architectural formation of terracing that stabilize walls against landslides and provides a work platform
Faces: vertical walls between benches
What is the most challenging task in forming the cascading shape of an open pit mine?
Forming ways for trucks to get in and out of the mines. Spirals are formed to allow trucks to drive in full circles to navigate the mine.
Name three types of explosives used in mining operations.
Ammonium nitrate (blasting powder)
Name and describe three patterns used in building roads in an open pit mine
Spiral (inverted cone clock or counter clock wise)
Ramp (series of terraces)
Zigzag/Switchback (ramp that switches directions)
Although it restores the landscape after the mining operation open cast strip mining is not favored by environmentalists. Why?
It opens up vast areas of countryside, up too 100 times as much as a regular open pit mine. Although the land is reclaimed, it will not be natural again for many years.
The land should be restored to its "approximate original contour" after a strip mining operation. What does this process entail?
Filling up the mine with earth, putting sod/seeds down, and attempting to make the land similar to how it was with vegetation/greenery.
How many tons of 1% ore should be mined to obtain 1 ton of metal? How does the percent of metal in ore impact waste volume?
100 tons, with 99% of it waste.
Higher richness of a mine means more harvest and less waste.
Explain the process of solution mining.
Low-cost and low-labor scheme of recovering metal from low-grade ores.
Heap leaching of copper requires ore to be sprayed with water and sulfuric acid, which creates "pregnant liquor" which is processed in a plant to extract the metal. The operation goes on for years.
What does black lung refer to?
respiratory disease caused by coal dust
Name three methods for cutting stone
Using a wire saw
How is crushed stone produced. How are the dimensions checked?
Like an open pit mine, the face is drilled and blasted, with broken stone mucked out by power shovels and loaders, then carried to a primary crusher.
Secondary crushers reduce the size and a sieve is used to check the dimensions.
Name some uses of crushed stone
Ingredient in asphalt mix
Ingredient in concrete mix
(stone is the most used resource in the world)
Describe the relationship between quarries and urban sprawl.
Starts as a good one as urban sprawl requires stone from quarries, until the city expands beyond its reach. People do not like noise, dust, truck traffic, deterioration of roads from quarries.
- Requires a trade off
How is dimension stone mined?
Stone is wedged in a little hole between pieces of wood. When wood is wet/dry, it expands/contracts until the piece is separated from the quarry.
Dimension stone was humanity's most important building material for centuries. Explain.
Used in building pyramids, skyscrapers, and medieval cathedrals.
Washington Monument made from 1 block from every state in the Union; National Cathedral
How is dimension stone transported out of the mine
Jib cranes or Derricks
Describe the process of brick making
Clay is extracted, dried and ground to powder, blended/kneaded with water, sliced by a fine wire and heated in a kiln.
What is the difference between cement and concrete?
Cement is an ingredient in concrete.
Concrete is mixed with several ingredients
Why do concrete truck driver always seem to be in a hurry?
Concrete will dry/set in ~30-90 mins. Chemical retardants are used to keep concrete fresh for up to 2 hours.
How does a concrete truck work?
Spins clockwise rapidly to mix the concrete, slowly to keep agitated once mixed and counterclockwise to deliver the concrete.
The helix shape and spin determine whether mixing or delivering.
What are the ingredients of concrete? What happens to the water used in the mixture?
Cement, Water, Aggregate, Sand
Water hydrates the cement that turns it to a binder. Once hydration is complete, the concrete hardens
water does not evaporate
Ingredients used in mixing hot asphalt. Why is it necessary to heat the ingredients?
Aggregate (crushed stone and gravel) and Bitumen (course, medium, or fine black, tarry goo).
Heat is required to completely coat the aggregate and so it does not harden.
What is a concentrator? Describe the process of benefication.
Also known as a mill that concentrates the material into a richer ore.
Benefication is the consolidation of mine ore to enrich concentration.
Froth flotation is the most popular method of ore milling. Describe.
Pine oil is added to create little air bubbles to attach to the material, flor to the surface and the material is skimmed from the container.
Name an additive that helps ore grain float in a water tank
Milling is a mechanical process whereas smelting is a chemical one. Describe both.
Milling: material is ground or crushed
Smelting: state of the material is transformed, using a "flux agent" to chase out sulfur and clean the ore.
Name an undesired byproduct of the smelting operation and why.
As sulfur mixes with moisture in the air, it creates more waste, hurts the environment and can cause metals to rust.
Describe the "make-lemonade" strategy in smelting
If the producers cannot help but produce sulfuric acid, why not capture it and sell it as a by-product because sulfuric acid does have value
Where are North American iron sources clustered
North Minnesota, along the flanks of the Great Lakes and eastward through OH and PA
Taconite is an iron ore that is too hard to mine and enrich. How were the problems solved?
Jet-piercing torch (like a channeling machine) solved this problem.
Enrichment is done using magnets to consolidate a portion of ore
What is the rough recipe for making iron
3 cups Taconite
1 cup Coke
1/2 cup limestone
Oxygen plays two conflicting roles in smelting copper and iron. Explain.
Iron oxide, prevalent in nature, requires a seducer (carbon) to remove the oxygen and for CO2 or CO (which must be captured to reduce pollution). Limestone may also be used to remove the impurities in the iron, which results in the formation of a residue called slag (oxygen in ore + limestone). Limestone vs. carbon depends on the quality of the ore, with high impurites using limestone as acceptable.
What is the difference between iron and steel?
Carbon exists in iron and is brittle.
Steel is iron with carbon removed and is ductile.
The steel recycling operation in minimills does not require coke or limestone. Why?
New steel is being formed out of a material with no impurities (old steel), which is simply melted and rerolled, as it has already been treated.
What is the ore from which aluminum is produced? What is the major source of power needed for aluminum production? What is the key operation necessary in aluminum production?
Aluminum comes from the separation of aluminum oxide. It requires incredible amounts of heat derived from electricity.
Pacific Northwest is perfect because of hydroelectric power and prevalence of bauxite.
What can be mined from air?
few other gases
To mine air, refrigeration to 300-320 degrees F below zero is required. Why?
Refrigeration is needed to keep these elements at their boiling point and compress the air to be condensed.
Air cannot be refined as a gas.
When a gas is _____ it heats up; when the same gas is allowed to _____, it cools.
What is the function of drilling mud?
1. carry away the cuttings from the drilling hole
2. lubricate the system, which also cools the system
3. seal the joints of the drill string to prevent ground pollution
What are the functions of the drill string and kelly?
Drill string: connects the drilling bit to the drilling table to apply torque down to the bottom
Kelly: top section of the string that acts as a socket/fitting to transmit the torque. It is square or hexagonal to lock tight to the round string
Despite the application of a pushing down vertical force, the string does not buckle. How is this achieved?
We apply the force by collars just above the bit with just the right amount of force to advance on revolution per pitch.
One full revolution advances the screw a distance equal to the pitch by rotating the screw.
Describe the process of tripping in
Consists of putting the drill back in the ground piece by piece.
A new bit is required per about 2000 ft. of drilling.
Tripping out is the process of removing the drill in three or four segments.
Describe the difference between top-drive motor and down-hole motor in drilling operation.
Top-drive: exists on the top of the platform that runs on mud. It requires an electric motor mounted on vertical rails and both a rotary table and kelly. Allows the crew to drill faster but requires a stronger derrick that takes longer to set up and break down.
Down-hole: motor exists directly on top of the bit and is operated by the stream of mud. An advantage is that it can facilitate steering and is more precise and easier.
How can drilling mud be densified?
Adding barite - a mineral rich in the heavy metal barium
What is the purpose of the doghouse on the main deck of the rig?
Office space, lunch room, gathering space, and houses controls for the rig
What is a gusher?
Demonstrated in Hollywood movies, it is when large amounts of oil are released from the ground.
*Describe the lines of defense against blowouts.*
At the mouth of the well there is a cluster of valves (each serving specific functions). During a "kick out" (rise in pressure inside the well), the string of pipes may become damaged and oil will want to surge. We rely on valves during these kick outs to shut off both the mud and oil pipes in the string. If this fails, the string will be sheared/cut and patched with "heavy mud" and cement to cut the flow - this damages the pipe and is costly, but can preserve the oil supply.
The lines of defense against a blowout include the blowout preventer, which is a series of valves mounted at the wellhead under the deck of the drilling rig. If the valves fail, the pipe can always be crushed.
Average production rate of an oil well in the US
11 barrels a day
(many only produce one)
1 barrel = 42 gallons
Why is well stimulation/fracking sometimes needed?
Pockets of oil are forced out by squeezing that oil into the well
name the methods used to open up the passages through rock formations to facilitate oil extraction? How are they help open?
Explosives (very small charges)
Acid (to disintegrate and open a passage)
High-pressure water (only if the passage is closed by soft spongy rock)
Spherules are synthetic spheres sent down the tube and solidify against the walls to allow room for oil to escape. Their shape maintains a 33% void along the gap.
What does a Christmas tree in the oil industry refer to?
Free-flowing well, one with enough pressure underground to push the oil or gas to the surface, that is fitted with a tall stack of valves and gauges. Valves serve various functions - taking samples, regulating flow and pressure, providing an emergency shutoff - but there is deliberate redundancy in the event that a valve needs to be replaced.
Offshore drilling platforms may be floated to the drilling site. How are they mounted where drilling is to take place?
Mounted by being lowered down. The rig is floated to the site with legs raised and then lowered to the sea floor and the hull is jacked up above water level.
How are floating barges and semisubmersible rigs kept in position while drilling in the sea?
Anchored in place or held on station by a dynamic positioning system that uses computer controlled thrusters to correct any drift.
What is the function of a sucker-rod pump?
To suck oil out when there is not enough pressure to force the oil out itself.
What is the main function of the nodding horse-like head of the sucker-rod pump?
It converts the rotary motion from a motor to a vertical/linear motion at the horses head.
Most sucker-rod pumps run intermittently. Why?
To avoid distorting the distribution of oil, water, and gas in underground formations. Over pumping can permanently impair well production and affect neighboring wells.
What does field processing entail? How is it achieved?
Separating oil, gas, and salt water that inevitably come up out of the well. Gravity separators are used to separate the water into gas, oil, saltwater (in that order).
Heavy, light, sweet and sour are crude oil varieties. What do these names refer to?
They are grades of the oil. Heavy means the oil is more viscous, tarry, and dense because of concentration of "bottoms." Heavy is not as pure as light.
Difference between sweet and sour is the amount of sulfur, sour having more.
Best kind of oil is light sweet.
What is the average parcel of land size per oil well in the US? What is the purpose of maintaining this area?
Purpose is so the field does not get overtaxed
The Alaska pipeline was very controversial. Why?
Failure of the pipeline would be dangerous to the environment, pollution, migration paths were cut (moose/caribou), and heats the ground melting permafrost.
How many barrels of oil are in transport through the AK pipeline? What is the average speed of oil through the line and why is the speed used?
9 million barrels
3-5 mph in order to control oil through the pipeline
AK pipeline is ~800 miles in length
Pipeline is also mounted on rail tracks to deal with lateral movement and massive expansion/contraction rates.
Pumping of oil through the pipeline would have thawed permafrost soil. Why? How was the soil kept frozen along the path of the pipeline?
Soil is kept frozen by elevating the pipe with the use of posts (50 ft. depth) holding liquid ammonia, which absorbs heat discharged from the pipe and vented out by fans.
What is a pig in the pipeline trade?
Big brush, scraper, or squeegee that get pushed through pipeline to clean inner surfaces.
It makes a squealing noise.
If the cross-section becomes narrower, you lose capacity.
What are the functions of smart pigs?
To carry instruments through pipeline to check for corrosion and other flaws, saving time, money, and destruction of pipes.
Why do storage tanks get shallower as they get longer?
Storage tanks get shallower in that the internal pressure at the base of the tank depends on the height of the fluid inside, not the total volume. Higher pressures call for stronger and more expensive walls.