Smart Drilling System
SMART DRILLING SYSTEM There are both short- and long-term benefits from this research aimed at developing advanced drilling systems. Improvements in individual system components could be incorporated into conventional drilling systems almost immediately, providing short-term (less than five-year) payoffs. Long-term payoffs will come from advances in basic research to assemble these individual components into a smart drilling system; a system capable of sensing and adapting to conditions around and ahead of the drill bit. PROPOSED RESEARCH 1. Research in advanced drilling technology is needed to improve the drilling system. This research should result in reduced costs and drilling times to more effectively achieve various drilling goals. Drilling involves a complex set of mutually interacting, consecutive component operations (mechanical, hydraulic, and electrical) that must function in unison. An integrated systems approach is needed to ensure that these component operations function near peak performance with a minimum of discontinuities (failures in components that lead to system breakdowns). A long-term R&D effort could provide significant improvements in drilling technology through advances in understanding basic physical and chemical processes related to rock breaking and rock removal, and particularly through the development of flexible smart drilling systems incorporating improvements in sensing and guidance of autonomously advancing drilling units. Significant improvements in drilling technology could also be realized over the short term (less than five years) through incremental R&D on many of the rate-limiting processes and critical components of current drilling systems. A well-coordinated, incremental research effort could accelerate attainment of the primary goal of development of the smart drilling system. 2. The principal thrust of this proposal is on the development of the smart drilling system. A smart drilling system is one that is capable of sensing and adapting to conditions around and ahead of the drill bit in real time (i.e., while drilling), with minimal operator intervention. Such a system must be capable of assessing the mechanical properties of rock through measurement of physical and chemical (e.g., mineralogical) properties concurrent with drilling. The development of a smart system will require concerted technological advances in several areas, including the following: • Development of precise connections between measurable properties and local drilling resistance: Such connections must be established based on the existing understanding of the connection between rock constitution and commination mechanisms. Many physical and microstructural properties such as porosity, elastic properties, and wave attenuation can readily be measured locally. These must be associated more precisely with factors that govern the drilling resistance of rock through directed mechanistic studies and modeling to develop automated response characteristics of a smart system. • Development of sensors for the smart drilling system: The smart drilling system requires sensors that are capable of detecting and measuring the following: a. Conditions at the drill bit: Sensors are needed for in situ measurement of pressure (including pore pressure), temperature, permeability, mineralogic and chemical composition of the rock and heterogeneities, borehole fluid composition (at the part-per-million level for environmental applications), stress state, and rock strength. b. Conditions ahead of the drill bit: Sensors are needed that measure rock properties (such as porosity, elastic properties, and wave attenuation) ahead of the drill bit to adjust drilling parameters, such as the weight on the drill bit and the rotary speed, and to avoid potential problems (e.g., blowouts or loss of circulation) while drilling. c. Spatial position of the drill bit: Sensors are needed that are capable of detecting the position of the drill bit in space in order to steer the bit around undesirable zones and reach desired targets. • Development of control systems for accurate positioning and steering of the drill bit and for automatically adjusting drill parameters (e.g., load and torque on the drill string, flow rates of drilling muds and fluids), according to local conditions, is necessary to optimize rock breakage and rock removal. This will require precise information at the bit-rock interface of the rock breaking mechanism, rock strength, pressure, temperature, and stress state. • Development of improved methods for steering the drill bit: A number of mechanical methods for steering are currently available, but large turning radii often preclude their application in a smart drilling system. To enhance steering capabilities, Reseach is needed to develop downhole motors, flexible drill strings, and guidance techniques for smart drilling systems. • Continuous monitoring of the state of the entire drilling unit, including wear of tools, state of other mechanical components, flow of coolant, and the like, is required to anticipate the occurrence of possible discontinuities. • Development of improved telemetry methods for transmitting real-time borehole data to the surface: The use of advanced sensors for real-time, downhole measurements will require significant improvements in data telemetry. Such telemetry is essential for monitoring the smart system from the surface. At present, the most advanced telemetry systems utilize mud-pulse technology and are capable of transmitting data at only a few bits per second. Rates on the order of kilobits per second or higher will be required for advanced smart drilling systems. Telemetry is a rate-limiting step in present drilling systems, and it will become more so as smart drilling systems are developed. • Development of means for continuous and instantaneous support of the rock around the borehole: The support provided by the rock itself should be used, where possible, in lieu of casing the hole as a separate operation. Although the principal thrust of the proposed PhD should be on the smart system, the research would also facilitate incremental improvements in all consequential aspects of present drilling technology. This should result in more immediate attainment of greater efficiencies and cost savings. Such additional research will focus on the following problems: • Novel drilling technology; with a focus on the physics of rock removal to reduce energy requirements for drilling: Hybrid systems that combine novel technologies to lower the drilling resistance of the rock and mechanical methods (e.g., fluid jets coupled with conventional rotary technologies) to break and remove the rock are especially promising. Initial attempts to develop combined novel-mechanical cutters should be conducted with mining or oil field bits because of their smaller size and lower cost. Once this technology is developed in drilling applications, the transfer to tunneling and excavating applications should be attempted. • Improved cutter materials and bearings: Conventional drill bits have steel, diamond, or carbide cutters that remove rock by impact or shearing processes. New wear-resistant, diamond-coated cutters are finding increased use in hard, abrasive rocks. Advances in new wear-resistant materials are rapidly applied to cutters and high-speed bearings; as such, additional R&D on hard materials and their applications is encouraged. • Improved bits for drilling in heterogeneous materials: Bits with polycrystalline or natural diamond cutters have the potential to drill much faster than conventional steel or carbide bits because they can operate at much higher rotary speeds and weight-on-bit loads. R&D is needed to utilize these wear-resistant cutter materials in multipurpose bits that can effectively drill through alternating layers of soft and hard rock. • Development of environmentally friendly drilling fluids: Research is needed on the design of nontoxic drilling fluids and foams as alternatives to oil-base fluids, which may be both toxic and difficult to remove from the drillhole. These new drilling fluids must have (1) filtration control to minimize fluid invasion and damage to permeable zones and (2) lubrication to prevent differential-pressure sticking of the drill pipe against the borehole wall. They also must provide adequate hole-cleaning capabilities in horizontal and high-angle wells. Improvements in understanding the fundamentals of cutting transport, flow visualization, air/foam behavior, and fluid viscoelastic behavior will aid the development of such fluids. • Development of durable, compact, high-power downhole motors for directional and extended reach drilling: Technology now exists to build downhole motors to increase drilling rates by factors of two to four by increasing the power delivered to the drill bit; the development of such motors would be a short-term improvement. Additional areas for R&D include improved air-drilling motors and higher-power motors for hard-rock drilling. The smart drilling system does not currently exist, but it is presaged by recent dramatic advancements in directional drilling and in technologies of measurement while drilling. Rapid innovation in microelectronics and other fields of computer science and miniaturization technology holds the prospect for greater improvements, even revolutionary breakthroughs in these systems.The development of smart drilling systems has the potential to revolutionize drilling. Research in this area will have a significant impact on drilling success and overall cost reduction. Such ''smart" systems are increasingly needed to overcome the drilling challenges posed by small, elusive, easily damaged subsurface targets. This is particularly true in applications where the identification of small or difficult-to-predict drilling targets and formation damage are key issues in drilling success. In the development of smart drilling systems, the required improvements in the sensing elements of the system will have an impact on other processes such as rock breaking, debris removal, and borehole stabilization. Revolutionary advances in these fundamental processes might be possible as information about the subsurface environment becomes available in real time. In the integrated systems approach, all component parts and processes are designed to function in unison at an optimum level of performance without excessive redundancies and without overloading any of the interdependent component parts and processes. At present, this is rarely the case in drilling. The driller must adjust drilling parameters to changing conditions based on very limited information with some modifications guided primarily by experience and intuition. Further, a host of discontinuities can and do interrupt these processes. These discontinuities include: • Tool-bit wear • Degradation and loss of effectiveness of the drilling fluid • Damage to the wellbore (e.g., borehole breakouts) • Time out for well testing and wireline geophysical logging Discontinuities are costly and time consuming and, in the worst case, catastrophic (e.g., lost circulation, borehole collapse). Adherence to a systems approach in all instances should reduce costly discontinuities to acceptable levels. This research focuses on the development of a Smart Drilling System; a self-guided drilling system that has the potential to operate with optimized selection of drill bits in a way that permits rapid, efficient, and damage-free detection and acquisition of targets without costly breakdowns and discontinuities.
01 Jan 2019
31 Jan 2021
17000 Dollar / annum or exempt for first year
Strategic Research Theme
Environment, Energy and Natural Resources