I've been looking for a good website that explains the basics of oil wells that the average person might be able to understand. Finally, I stumbled across a US Department of Energy Website for school kids that actually will help adults to better understand a few of the dynamics involved in an oil well. Here are the follwing links. I recommend that everyone take a few minutes to visit the DOE site. It will really help you see the dynamics and understand better why Pressure is so critical. Once a well is capped it loses that pressure. Thus a new well has to be drilled. Here's the links

http://www.fe.doe.gov/education/index.html Click on "Looking Down an Oil Well"

Here's the text below...but go to the site to see the pictures and graphics displays.

http://www.fe.doe.gov/oil_gas/drilling/adv_drilling.html

Drilling a well involves much more than making a hole. It entails the integration of complex technologies, requiring the producer to make individual decisions related to unexpected pressure regimes, practices, and rock formations. The resulting well is the sole conduit to move fluids from a reservoir to the surface  a conduit that must last at least 50 years and be flexible enough in design to allow for application of future technologies.

Drilling operators must confront and solve extremely difficult technical, safety, and control problems as they bore through layers of subsurface rock to access oil- or gas-bearing strata. Furthermore, drilling must be done in a way that protects the geologic formation, the ultimate productive capacity of the well, and the surface environment. Drilling problems must first be diagnosed using the information or data that is transmitted from the bottom of the well to the surface, where the information is collected on the rig floor.

An example of DOE's R&D: Microdrilling Technology - Drill bit attached to thin steel coil could be a major advancement in underground oil and gas exploration. [Details] Depending on the depth of the well, this time lag can consume valuable time needed to address the problem  either technical or geological  before it becomes worse and/or causes drilling operations to stop. Drilling a well involves all types of technical, geological, and economic risks. The greatest economic risk occurs when drilling operations must be halted after time and cost has been invested. This is the nature of the challenge faced during the drilling process, and the primary reason for developing advanced drilling technologies.

When a well has been drilled and lined with pipe, the connection between the geological formation and the well must be established. Completion includes installing suitable tubing or casing, cementing this casing using rock section isolation devices, and perforating the casing to access the producing zones. In some reservoirs, the geological conditions dictate that stimulation processes be applied to improve reservoir permeability or flow conductivity, facilitating production through the wellbore. Therefore, there are many technologies involved with minimizing complications during the drilling process.

To facilitate exploration and production, DOE invests in research to develop new technologies. In partnership with industry, National Laboratories, and universities, DOE develops tools and techniques that reduce the costs and risks of drilling and support services. DOE also develops methods to reduce potential damage to the geologic formation, and to enhance environmental protection. Drilling technologies that are under development consist of non-damaging fluids and advanced hardware for high-efficiency directional drilling, offering faster rock penetration rates and reduced costs.

DOE's Program - Leading the Way Toward Faster, Deeper, Cheaper, and Cleaner Drilling Systems

DOE has a long history of investment in drilling research. For example, since DOE supported pioneering efforts on measurement-while-drilling (MWD) in the 1970s, this technology has revolutionized drilling operations. The first system to transmit drill bit location by sending pressure pulses through drilling mud was developed by DOE and Teleco, Inc. Today, this mud pulse telemetry has become standard in the industry, saving hundreds of millions of dollars in time and labor.

In 1992, the Department reorganized the oil and gas program to make it more accessible to its stakeholders and to stimulate more joint projects with them. Since then, a number of notable contributions have been made, contributions that would not have been possible without the support of DOE. Examples are:

the near-bit sensor, which has made it possible to acquire data from immediately behind the drill bit;

carbon dioxide/sand fracturing stimulation, making it possible to stimulate the formation using the liquid phase of the gas as a carrier fluid, and then recovering it in the gaseous phase; and

air motors, based on DOE horizontal drilling technology, that are now being used for most new wells drilled in eastern U.S. gas formations.

In the next millennium, the program will continue to make strategic investments in a portfolio of projects that are focused on problems and challenges associated with the wellbore and the near-wellbore region. The Department will focus on making the strategic investments needed to enhance U.S. leadership in the development of "smart wells," such as:

"zero footprint" drilling technologies,

"rig-less" drilling,

"self-drilling" well technology,

"designer" stimulation technology, and

"single well drainage" capabilities. Drilling Faster... This program element addresses the need for increased efficiency during the drilling phase of energy production. Recognizing that drilling rig time is the most expensive part of operation (30 to 35 percent), the objective then becomes to increase the efficiency with which the well is drilled. This can involve reductions in equipment failure, extension of drill bit life, and reaching the target zone with the fewest number of course corrections possible. This can also involve efficiencies related to production equipment and waste management.

Drilling Deeper...This aspect of the program addresses the varied and complex geologic environments that exist and affect the drilling phase. Drilling into these environments requires unique drilling strategies that use the specific characteristics of the geologic formation itself to assist in generating a hole. An example of this is the deeper, harder rock formations that contain natural gas. For those formations, the most efficient strategy is to focus on the brittle nature of the rock itself. When hit or hammered, this rock will break into large chips. This is a more effective drilling strategy than to crush and grind the rock into powder, as would be done using conventional roller cone bits. Other formations are sensitive to the type of drilling fluid used. In these cases, the best strategy is to use air as the drilling medium.

Drilling Cheaper...There is still no substitute for drilling, at least, not yet. The goal, therefore, is to develop technology that will allow the most "cost-effective" drilling. Costs are measured in terms of the least impact on the environment, the longevity of the wellbore and all its components, and the long-term productivity of the wellbore. This means drilling a well with mechanical longevity that does not inhibit the entry of fluids from the reservoir, and that is placed at the precise location needed to achieve the ultimate recovery of oil and gas from a particular type of reservoir.

Drilling Cleaner... Another special focus of the program is minimizing the environmental impact of drilling activities. This can range from reducing the amount of surface disturbance that results from the drilling phase of energy production, to dealing with the final disposition of used drilling fluids, drill cuttings, and other waste generated by drilling activities. The use of small bore "slimhole" wells has led to a 75 percent reduction in the amount of surface disturbed and the amount of waste generated. Operating costs are also reduced by up to 50 percent. Furthermore, reduced volume and weight of equipment favors slimhole drilling use in sensitive environments, such as wetlands.

The goal is to develop drilling technologies that are environmentally "neutral," or even "friendly." After all, the drilling cuttings that are excavated from the well are natural materials, and the fluids used in the drilling process must be compatible with the rock to result in a productive well with a long life. Therefore, the basic elements for environmentally benign drilling technologies already are present.

Drilling for the 21st Century... Finally, there is a need for highly futuristic technologies that would enable drilling without drilling rigs  systems that would have no "footprint." Also, there is a need for drilling systems that anticipate problems and apply the self-correcting adjustments needed to precisely place the wellbore, and that would enable the drilling process to be conducted from an office setting, instead of from a wellsite operation. Recently, the National Aeronautical and Space Administration, has expressed interest in exploring if a habitable zone for micro-organisms exists under the surface of Mars. To answer this and other questions will require advanced drilling technologies that must withstand the extreme temperatures and remote location, be cost-efficient, and not impact the surface of the planet. Advanced technology that addresses these issues on Mars will also benefit drilling on Earth.

Laser drilling is another possible area of interest. Currently, the Gas Research Institute is studying the feasibility of adapting high-power laser technology, developed by the military for national defense, to drilling for oil and gas. GRIs initial goals are to establish a scientific basis for developing a commercial laser drilling system, and to determine the level of industry interest in pursuing future research. If sufficient industry interest is demonstrated, DOE also will consider a strategic investment in this emerging area.

AND NOW... here's another page from the DOE website for kids...

http://www.fe.doe.gov/oil_gas/res_efficiency/res_efficiency.html

For every barrel of crude oil produced in the United States, two barrels are left in the ground. Average oil recovery from U.S. reservoirs is only about 32 percent. Although it is physically impossible to recover all of the oil that is discovered, the potential for improvement with the use of technology is very large indeed.

Today, the United States is considered a mature oil and gas province. Production of easily-accessible oil peaked in 1970 and has declined since then. Advanced technologies, often based on sophisticated computer modeling, hold great promise for additional oil and gas production from the Nation's remaining hydrocarbon resources.

Using tomorrow's advanced technologies, our Nation will be able to slow down, even stabilize, the currently declining oil production rate and increase the gas production rate. More importantly, it is imperative that we reduce the rate at which domestic oil and gas fields are being abandoned. Once shut-in or abandoned, oil and gas reservoirs cannot be economically restored to the production status due to the high costs associated with developing the field.

The U.S. Department of Energy, in partnership with the oil and gas industry, academia, and the National Laboratories, supports basic and applied research of physical and chemical processes that govern fluid flow in porous media. This combination of the best public and private research capabilities has already produced remarkable results. Our goal is to accelerate the creation and implementation of promising, innovative approaches to increase recovery efficiency processes.

The Reservoir Efficiency Processes Program addresses all aspects of upstream petroleum research, but focuses on improved, less expensive, and less risky oil recovery technologies. These technologies are known as enhanced oil recovery (EOR) processes. In general, EOR technologies fall into one of the following four categories: thermal, gas-miscible and -immiscible, chemical, and microbial. New or improved technologies often combine elements from more than one category.

Methods of the future include unconventional approaches, such as field-wide development of strategically-placed horizontal wells, gravity drainage enhancement, microbial EOR, and radio frequency heating.

The United States leads the world in EOR technology. Already, 12 percent of U.S. oil production is from EOR applications, and that fraction is growing steadily. The world's EOR production is about three percent and also growing.

The Need for Research In Reservoir Efficiency Processes

Changes in technology, competition, resource base, and politics have transformed the petroleum industry. Some of the most significant changes include:

The decline of U.S. oil production and reserves since 1970, with decreased hope for the reversal of this trend.

Increase of oil and gas well abandonments, due to insufficient productivity and low oil prices. Once abandoned, redevelopment cannot be justified and future access to reservoirs is foreclosed, even with improved technologies.

Concern for improving the environment has led to new regulations imposed on industry by State and Federal agencies, which add costs to operations. This particularly affects the independent producers operating marginal wells. Increasing cost of complying with regulations is often the reason for many companies to move overseas.

Downsizing in the petroleum industry and reduction of basic and applied research. Independents, in particular, drill 85 percent of all U.S. wells, produce 66 percent of natural gas and 40 percent of crude oil, but do not conduct their own research.

As a consequence, more than 15,000 to 22,000 marginal oil and gas wells are abandoned every year, and about 220,000 wells are idled (not producing). Use of advanced technology enables reduced production costs during times of depressed prices. Advanced technology can uniquely access the already discovered but unrecovered resource; on average, two-thirds of the discovered resource is currently unrecoverable.

Hope this gives you some insight as the subject of OIL and Oil wells continues to come up in discussions. Hopefully, you'll be able to come back to this thread and use it to stop a false assertion that oil wells can be capped and reopened.

-- R.C. (racambab@mailcity.com), December 10, 1999

Answers

Thanks RC. Very informative.

-- Andy (2000EOD@prodigy.net), December 10, 1999.