Advanced Technology

This teaching guide is designed to complement the 20-minute video, Crude Energy. Click here to request the video. Please note that video supplies are limited and may no longer be available.

From the first official oil well drilled in Titusville, Pa., in 1859 to today’s wells drilled on land, in oceans and beneath lakes, oil exploration and gathering have changed a lot.

Today’s oil and gas industry workers, including geologists who find crude oil and natural gas deposits; site supervisors who oversee field operations; and refiners, use computers and other technology to make their work easier, more efficient and less costly.

In the words of David Pletcher, an independent geologist, he and others want more than anything to “find oil cheaper and more effectively.” And doing that is becoming easier as technology comes into play -- especially in the last decade, when using computers for everything from finding gas and oil deposits to testing the purity of such finds became common.

Innovations in Drilling
“Large operations have a definite advantage when it comes to using technology, since advanced technology costs more than small outfits can afford or justify for limited use. A lot of the technological innovations are not feasible except for big oil companies,” Pletcher said.

But some pieces of technology are available to all, and even the “little guys” have latched onto them. Some of the top technologies in drilling include logging while drilling, horizontal drilling, “smart” drill bits, and miscible methods for recovering oil.

Logging while Drilling
Basic forms of logging while drilling, where a driller views the inside of the hole being drilled in one way or another, have been around for some time.

The word logging may bring visions of big burly men yelling “Timber!” as a tree falls in a forest. But logging is used here in the sense that you log, or check and write up, what is happening as it occurs. Keeping track of what you are hitting or missing helps in future drilling.

Logging while drilling includes visual wall-logging, in which a geologist physically inspects the wall of a hole being drilled. In this field technique, an area being drilled is sampled as progress is made.

In core logging, samples are drawn from the hole to determine what is being drilled. These samples, once brought to the surface, are tested both physically and chemically to confirm findings.

With borehole camera logging, after a hole is drilled, a still or broadcast camera is put into the hole, which allows drillers to photograph or film what they are drilling.

Radioactivity logging involves measuring radioactivity beneath the ground, which can help determine what type of substance is being drilled, be it rock, shale, natural gas or crude oil.

A recent innovation allows what is called open-hole logging. With this technique, a magnetic resolution induction log, working on the same premise as a medical MRI, uses two magnets to determine substances being drilled. One continually fixed magnet reflects intermittent pulses from an electromagnet. The pulsing changes rates of speed with varying substances, giving off one rate for shale and another for oil and yet another for natural gas.

Such techniques make drilling more efficient, meaning less money is spent on getting to crude oil, which eventually could lower consumer prices for oil-related products, such as gasoline.

Horizontal Directional Drilling
Not all oil deposits are readily accessible to a traditional vertical well. In fact, in recent years many oil wells have been dug beginning on one piece of land and crossing underneath a body of water to another piece of land to reach the deposit.

The record is 10 miles for BP Amoco wells on the southern coast of England. These start onshore and penetrate an offshore field. The main reason for doing this is to minimize environmental impact in an area of great natural beauty.

At one U.S. site, a pipe stretches about two miles. Drilling on solid ground is much easier than doing so in a swamp or in water, which is why some wells are dug horizontally. Occasionally, a potential oil deposit is found beneath a town, which is another reason for getting at it from afar.

Here’s how it works. Surface drilling equipment is offset from the oil deposit. At the start of the drill process, the well is drilled vertically, then a few degrees at a time it turns whichever direction is needed to hit the deposit. Sometimes the arc of the well is great, other times less, depending on how sharp a turn has to be made.

Horizontal drilling itself has been around for some time, but about 10 years ago it regained notoriety in its use to increase production from narrow, fractured formations, said Joe Hurt, director of land operations for the International Association of Drilling Contractors.

“When a vertical well is drilled through a narrow formation, its exposure to the formation is limited,” he said. “But if the well is turned and follows the formation for a distance, the well bore to formation surface is greatly increased.”

Drill Bits
The drilling part that actually tears or chips away at soil, rock and other materials as a well is dug, called a drill bit, is an essential tool to drilling a well. In recent years, technology advancements have made such tools more capable, longer lasting and less expensive.

Ten years ago, when Allen King and his two brothers formed Bear Production, a small drilling outfit based in Kinta, Okla., the brothers poured money into drill bits. Each tricone bit, known as a button bit, cost about $3,000.[FrontPage Image Map Component] These bits are named for the three roller cones, which roll and gouge out material as they rotate. After digging about 2,000 feet, the bit would break, he said.

King now drills using an air hammer, which costs about $5,000, and flat-bottom bits, which cost only a few hundred dollars each and have a much longer life. These bits, which have carbide teeth and are specially designed for different types of material, can go between 30,000 and 40,000 feet before needing to be replaced.

Each of these bits is used with a drill using rotary, or rotating, motion to do the work. Beginning in the mid-1950s, rotary drilling gained popularity over cable tooling, in which a much more crude, chisel-shaped bit was attached to a cable then pounded into the earth. Intermittent stops were needed to remove the chipped-away rock and other material.

Rotary drilling allows the use of fluids or drilling mud as rock is chipped away. The fluid washes out the drill hole as it goes, making the process more efficient. The fluid also stops an oil well from bursting forth unexpectedly (known as a “gusher”).

Around for many years, diamond drill bits were once used to drill, but their weak planes caused them to break easily. The individual diamond pieces are tough, and industry now makes a similar synthetic diamond powder used to coat carbide bits, making one tough bit.

Oil Extraction
In the best conditions, nature helps oilfield workers bring their find to the surface after a well is drilled. But after an initial surge, either large or small, pressure in the reserve decreases, meaning human creativity must be used to get the rest.

This is when artificial lift enters the scene. With this method, a pump sucks oil into tubing which then feeds into a storage container on ground level. Several years back, walking beams—arms which pump back and forth like a teeter-totter to suck the oil upward—were a common site in Oklahoma, Texas, Louisiana, California and other oil-producing states.

Another form of artificial lift involves pumping gas bubbles into oil to decrease its density, making it lighter and thereby allowing reservoir pressure to pump it out.

Both of these methods leave much oil in the reservoir, meaning other methods must be employed to get the rest.

Enter water or gas. With gas injection into the top of the reservoir, a gas cap forms, forcing oil to the bottom and then pressuring it out. To use water flooding, water must be entered into another well site connected to the well being worked on. The water floods into all wells, forcing oil to the top, since oil floats on water. To see this, take any common oil, such as the kind found in most kitchens, and pour some into a cup of water. The two fluids stay separate with the oil on top even after vigorous mixing.

Still more oil can be pulled from many reservoirs after other means are exhausted.

Natural gas can be pumped into a reservoir to mix with the oil, making it light enough to flow. The mixing is why the term miscible, meaning to be mixed, is used.

Another option is to use a surfactant or soap-like substance ahead of water and behind the oil. The substance forms a barrier around the oil, and water behind the substance pushes the oil to the surface. The soapy substance also ensures a thorough gathering of oil.

Heat also can be used to get oil flowing. Up to a million times thicker than water, oil can be thinned by blasting steam into the reservoir. Water is first pumped off, then oil is gathered.

Summary
From day to day, oilfield workers and their bosses are seeing oil drilling improvements. These improvements could lower the cost of many petroleum-related products. In another 10 to 20 years, who knows what will be out there? We shall see.

1.	What kinds of advances have been made in oil drilling and retrieval?
2.	How can consumers like you benefit from these advances?
3.	What ideas do you have to make drilling easier? (These can be creative and wacky.)

Classroom Discussion...
One of the largest oil fields in the world is found in Saudi Arabia. It measures 149 miles long and 22 miles wide. Can you think of anything that would have similar measurements?

Note: For easy-to-understand and readily accessible information on petroleum and the gathering process, see Encyclopedia Britannica online at www.britannica.com.

Sources
Ardley, Neil. How We Build Oil Rigs. Garrett Educational Corporation. 1990.
Hurt, Joe. Director of land operations for Independent Association of Drilling Contractors. Telephone interview. 8 June 2000.
King, Allen. Independent driller. Personal interview. 9 June 2000.
“Our Activities.” Horizontal Drilling International, Inc. 1999. www.hdi.fr/emain.htm“Petroleum Production” and “Well Logging.” Encyclopedia Britannica online. 1999-2000. www.britannica.com
Pletcher, David. Independent geologist. Personal interview. 12 June 2000.

Last Updated: 02/16/03
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