Advanced Oil & Gas Drilling Technology - a PDH Online Course for Engineers, Architects and Surveyors

Advanced Oil & Gas Drilling Technology

Course Outline

This three-hour online course summarizes basic information and issues for advancements made in oil and gas drilling and exploration technology. The advantages and limitations of the methods conventionally used for offshore well drilling are discussed and compared with advanced methods. Economic and environmental benefits are presented. Also addressed are drilling safety issues and the means used to provide reliable undersea operations, which protect coastal environments from leakage and spills. The functions of various methods and procedures are described to give an understanding of typical problems encountered in the field. Fact sheets, case studies and reading sources for drilling and exploration are included.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will:

Be aware of economic and environmental benefits and how impacts to environmentally sensitive areas are reduced. Sensitive areas such as wetlands, beaches, and agricultural land can be better protected;
Have an understanding of the basic terminology and history of conventional undersea drilling versus the newer drilling technologies such as measurement-while-drilling;
Be familiar with the basics of horizontal, directional, and multilateral drilling techniques and comparisons with conventional vertical drilling;
Have an understanding of devices and methods used to maintain wells, to protect from storm damage and to prevent spills and leaks into undersea environments;
Consider the economic and environmental advantages of coiled tubing and microhole drilling technology;
Understand the advancements in drilling bits and drilling fluids and mud;
Understand the principles and benefits of subsurface formation fracturing techniques used to stimulate production of declining reservoirs, including CO2-sand fracturing and hydraulic fracturing;
Consider safety issues and potential undersea hazards typically encountered during drilling operations; and
Consider the advancements in drilling technology, which have made deeper exploration and production drilling possible while retrieving additional oil from reservoirs that was not feasible before or had been considered as depleted.

Intended Audience

This course is intended for civil engineers, environmentalists, and contractors.

Benefit to Attendees

The student will gain an understanding of the methods and recent advancements used for exploration and production drilling in offshore coastal areas. The advantages, limitations and comparisons of the oil and gas drilling methods are considered. Safety considerations and potential hazards to safeguard against during drilling operations to prevent petroleum releases into the environment during drilling or storms are discussed.

Course Introduction

This course provides general guidance for the impacts of measures used for offshore oil and gas drilling. As oil and gas reservoirs are discovered in deep offshore sites, oil and gas exploration and development have been gradually moving farther offshore and into still deeper and colder water with production wells in water exceeding depths of 10,000 feet. Among the topics covered are horizontal, directional, coiled tubing, microhole drilling, latest drilling bits and fluids, subsurface formation fracturing and measurement-while-drilling. These advancements when properly selected and combined together have permitted deeper offshore exploration and production of oil and gas wells. Necessary measures to reliably operate wells and other equipment as well as any unsound conditions or potential problems are considered in the course.

After oil and gas fields are discovered the next challenge is to start production of the oil and gas and to move the product to onshore refining or processing facilities. The locations of mooring lines for drill rigs, operating barges and pipelines in deeper water are difficult because of uncertainties of the sea floor. Many methods such as 2-D and now 3-D seismic surveys, satellite sensors and surface-towed sonar have mapped sea bottoms with varying degrees of resolution. Sea floor maps have shown furrows, which indicate sea bottom currents are present but for how long they've occurred is uncertain. Recent mapping has shown unanticipated furrows in the Gulf of Mexico further out from the continental shelf. Furrows however are another factor with impacts for drilling operations and must be considered because of abrupt changes in seafloor topography. Additional and better survey data over time will clear up those uncertainties and indicate any ongoing patterns or changes in the seafloor.

Drilling mud and fluids are an expensive part of oil exploration and production. Advancements in drilling mud allow the best "fit" for the drilling conditions and the environment. Drilling mud is used to bore the wells and to clean and cool the drill bits. Mud is pumped from mud pits through the drill string, sprayed out the drill bit and then used to carry the drilling cuttings, oil soaked soil, waste soil and rock pieces, back up to the surface. If the viscosity is too low, the cuttings will settle down the well instead. However if the reservoir has a low formation pressure, the mud may be too heavy in the fluid column and the oil will not flow. Mud with higher viscosity is used for borehole cleaning. The types of drilling fluid include water based, oil based, synthetic based and gaseous or pneumatic. Drilling mud has these main functions:

a. Remove cuttings from the borehole.
b. Suspend the cuttings for removal to the surface.
c. Cool and lubricate the drill bit.
d. Control formation pressures.
e. Seal and stabilize the well bore and reduce damage to the formation.

Mud storage is expensive and can be environmentally unfriendly especially if stored in unlined open-air pits. Such storage will contaminate groundwater and surface waters. The returning mud may contain flammable material or natural gas, which can collect around shale shakers and are potential fire or explosion risks if ignited. The equipment, wiring and panels must be explosion proof and require sensors for safe operations.

As water depths have become progressively deeper, cable-mooring lines typically made from steel cables would have become too heavy and too costly. A concern for using synthetic ropes stems from potential failure from wear and tear while moored, from repetitive redeployment during rig and barges advance to new stations and from rope fatigue caused by repetitive movements. The ropes are subjected to great stresses at the anchor and barge points of connection. Department of the Interior, Minerals Management Service (MMS) has funded research for mooring lines and special synthetic ropes have been tested in such locations as the Gulf of Mexico and offshore of Brazil. The weight saving become very large as production heads farther offshore and into deeper waters. Just reducing the number of support barges required for mooring lines can result in big cost saving.

Many advances have been made in mechanical equipment such as remote spillage or leakage detectors, monitoring systems and alarms that safeguard against the threat of petroleum releases. Periodic inspections, knowing when a component of a system is defective or improperly maintained and understanding what is necessary to correct observed problems are important to continue proper operations of a well and pipelines. The course covers the basic features and factors that can adversely effect oil and gas well operations.

Recently developed alternatives to offshore pipelines are floating production, storage, and offloading vessels (FPSO) which look like oil tankers but are used to store oil and load tankers out at sea. They can hold up to 2 million barrels and eliminate pumping the crude through pipelines from the wellheads. The vessels can be advantageous where extremely long pipeline are needed and/or where political instability with acts of sabotage would cause costly repairs and setbacks in oil production. Long offshore pipelines are very expensive and take years of construction time.

FPSO have been used along the coast of Brazil, W. Africa and Southeast Asia but not in the Gulf of Mexico (GOM) which has an existing and extensive system of pipelines. An advantage for FPSO in GOM would be the ability of disconnecting from undersea wells before hurricanes and towing them out of severe storms until the storm have passed. Many GOM pipelines, wellheads and risers were severely damaged by the 2005 hurricanes. These floating production vessels are very expensive and whether they are cost effective would have to be based on case by case economical analysis.

Course Content

This course is based primarily on the US Department of Energy publication, "Environmental Benefits of Advanced Oil and Gas Exploration and Production",(2001 Edition, 11 pages), PDF file. The course is also based on the US Department of Energy "Drilling and Completion" fact sheets from the above DOE publication, (2001 publication, 22 pages), PDF file.

The links to the parts of both documents are as follows:

"Environmental Benefits of Advanced Oil and Gas Exploration and Production",(2001 Edition, 11 pages)

"Drilling and Completion" fact sheets from the above DOE publication, (2001 publication, 22 pages)

A brief list of "Terms and Definitions" shown in the text material has been included as a study aid for the course:

Terms and Definitions

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

This course serves as a guide for the methods and advancements of offshore oil and gas drilling. The means necessary to prevent or warn of any leakage of the products into the undersea environment are explained. Also described are the main equipment, materials and devises used for drilling operations and the problems that are commonly encountered during operations. The environment and other sensitive areas potentially impacted by drilling operations are addressed.

Related Links

For additional technical information related to this subject, please refer to:

http://www.mms.gov/tarprojectcategories/pipeline.htm
The US Department of the Interior, Minerals Management Service (MMS) has publications and data sheets on oil and gas well drilling, pipeline installation and regulation in Outer Continental Shelf (OCS) areas of the United States. The Technical Assessment & Research (TAR) program of MMS assesses the design and installation of future wells and pipelines as well as mitigation for the existing ones.

http://www.worldoil.com
Onshore technical data and offshore pipeline oil and gas projects are discussed. The site also offers guidance on systems and methods of hydrocarbon exploration.

http://www.fe.doe.gov/programs/oilgas/microhole/index.html
US Department of Energy has publications and information on microhole drilling for oil and gas.

http://www.ees11.lanl.gov/EES11/Programs/drilling.html
Los Alamos National Laboratory research on microbore and other advancements in the oil drilling industry.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.