A seal assembly for use in a pressure containment device for containing a fluid pressure in an annular space around a drill string whilst allowing the drill string to rotate in the pressure containment device. The seal assembly includes a seal with an inner surface and a tubular body, and a wear sensor embedded in the tubular body of the seal. The wear sensor emits an alert signal when the inner surface of the seal has been worn away by a first preset amount. The alert signal includes a pressure signal and/or a chemical signal.

A mining system with an inertial guidance system configured to enable precise excavation of geological material without a need to advance a survey line over a long distance and/or nonlinear excavation path, thereby maximizing productivity of the mind by minimizing a width of un-mined material necessary for support between adjacent excavation paths and minimizing equipment downtime.

A mining system with an inertial guidance system configured to enable precise excavation of geological material without a need to advance a survey line over a long distance and/or nonlinear excavation path, thereby maximizing productivity of the mind by minimizing a width of un-mined material necessary for support between adjacent excavation paths and minimizing equipment downtime.

A drill string for rotary drilling of underground mining machines includes a first elongate drill string member and a second elongate drill string member. The first member has a main section and a male end, and the second member has a main section and a female end. The male and female ends each have respective threads to provide a thread coupling between the male and female ends, the thread coupling enabling the male end to be secured inside the female end such that the male and female ends overlap axially. A thread lead of the respective threads of the male and the female ends are greater than a diameter of the male end and the female end.

A drill string for rotary drilling of underground mining machines includes a first elongate drill string member and a second elongate drill string member. The first member has a main section and a male end, and the second member has a main section and a female end. The male and female ends each have respective threads to provide a thread coupling between the male and female ends, the thread coupling enabling the male end to be secured inside the female end such that the male and female ends overlap axially. A thread lead of the respective threads of the male and the female ends are greater than a diameter of the male end and the female end.

Methods and apparatus are described to drill and complete wellbores. Such wellbores include extended reach horizontal wellbores, for example in shales, deep subsea extended reach wellbores, and multilateral wellbores. Specifically, the invention provides simple threaded subassemblies that are added to existing threaded tubular drilling and completion equipment which are used to dramatically increase the lateral reach using that existing on-site equipment. These subassemblies extract power from downward flowing clean mud, or other fluids, in an annulus to provide additional force or torque on tubular elements within the wellbore, while maintaining circulation, to extend the lateral reach of the drilling equipment and completion equipment. These added elements include combinations of The Leaky Seal, a Cross-Over, The Force Sub and The Torque Sub. The use of such additional simple elements allow lighter drilling equipment to be used to reach a given lateral distance, therefore reducing drilling costs.

Methods and apparatus are described to drill and complete wellbores. Such wellbores include extended reach horizontal wellbores, for example in shales, deep subsea extended reach wellbores, and multilateral wellbores. Specifically, the invention provides simple threaded subassemblies that are added to existing threaded tubular drilling and completion equipment which are used to dramatically increase the lateral reach using that existing on-site equipment. These subassemblies extract power from downward flowing clean mud, or other fluids, in an annulus to provide additional force or torque on tubular elements within the wellbore, while maintaining circulation, to extend the lateral reach of the drilling equipment and completion equipment. These added elements include combinations of The Leaky Seal, a Cross-Over, The Force Sub and The Torque Sub. The use of such additional simple elements allow lighter drilling equipment to be used to reach a given lateral distance, therefore reducing drilling costs.

The invention relates to powdered lubricants for water based drilling fluids. Conventional liquid lubricants containing particularly divalent ions have the tendency to grease out. The powdered lubricants have excellent dispersion properties and hence do not grease out, when added to the drilling mud in the concentrations, preferably of the order of about 3% or less. The powdered lubricant is a combination of inert fillers with fatty acids that are essentially free from fatty acid esters and metal soaps and have organic acids containing C10-C24 alkyl groups fatty acids. The improved lubricating properties of the drilling muds result in greatly increased life of the rotary drilling bits and marked reduction in torque required to rotate the bit. Solid powdered additives compositions greatly reduce transportation costs and simplify the logistics and environmental concerns associated with shipping large volumes of liquids and overcome the pour point issues associated with liquid additives.

A mine control system for monitoring mine operations includes a plurality of mine vehicles provided with on-board monitoring means. Monitoring data is transmitted from the mine vehicle to the mine control system, which is provided with a mine plan. The mine control unit is configured to compare the received monitoring data with the mine plan and to determine the current state of the mine relative to the mine plan on the basis of the monitoring data.

A mine control system for monitoring mine operations includes a plurality of mine vehicles provided with on-board monitoring means. Monitoring data is transmitted from the mine vehicle to the mine control system, which is provided with a mine plan. The mine control unit is configured to compare the received monitoring data with the mine plan and to determine the current state of the mine relative to the mine plan on the basis of the monitoring data.