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.
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.
Advanced Drilling, Completion & Stimulation
Microdrilling Technology
Los Alamos National Laboratory researchers are currently testing new micro-drilling technology that may revolutionize the way underground resource exploration is conducted in the 21st century. Several major oil companies are also contributing financial or technical support for this technology development.
The technology consists of a standard mining drill bit and oil field drillout turbine attached to a steel coil that is 1 inch in diameter. Conventional production well drills used today can be anywhere from 6 inches to more than a foot in diameter.
Microdrilling systems will occupy a space roughly one-twentieth that of a typical rig and will cost about 90 percent less. Microdrilling realizes additional savings because it requires only about a barrel of fluid per 1,000 feet of drilling to lubricate the bit and motor and remove dirt, whereas conventional drilling requires about 40 barrels of fluid per 1,000 feet.
The microdrilling technology is currently undergoing the first phase of testing at Fenton Hill, a site located about 40 miles northwest of Los Alamos.
Thus far, the results have been encouraging. Los Alamos researchers hope to be able to drill down to a target depth of 6,000 feet within the next three to five years.
Source:United States Energy Information Administration.
