A spallation drill head can include a drill head body having a primary face substantially oriented facing in a primary drilling direction along a longitudinal axis of the drill head body. A liquid inlet can be on the drill head body. The liquid inlet can be connected or connectable to a liquid supply line. An internal liquid connection can be oriented within the drill head body and fluidly connected to the liquid inlet. A plurality of liquid jets can be oriented on the primary face of the drill head. The liquid jets can be fed by the liquid inlet through the internal liquid connection. A mass flow controller can be associated with the liquid jets to control delivery of liquid by the liquid jet, and flowrates to at least two of the liquid jets can be independently controllable.

Systems and methods for controlling geysering in mining operations.

The present disclosure describes electro-hydrofracturing (E-HF) using electrically conductive proppants and methods for hydraulic fracturing using electrically conductive proppants.

Disclosed is a lens driving apparatus. The lens driving apparatus includes a base formed at a center thereof with a first opening; a housing coupled with the base and having a second opening corresponding to the first opening; a yoke installed on the base and including a horizontal plate having a third opening corresponding to the first opening and a vertical plate protruding upward from the horizontal plate; a bobbin movably installed in the yoke and coupled with a lens module; a coil fixedly disposed around the bobbin; a plurality of magnets provided at the vertical plate of the yoke to face the coil; and a spring installed on at least one of upper and lower portions of the yoke to return the bobbin, which has moved up due to interaction between the magnet and the coil, to its initial position.

Disclosed are systems and methods for thermal management of subsea conduits such as jumpers that provide the ability to alternate between cooling and heat retention of production fluids within the conduit as needed depending on the phase of operation. Adjustable insulation elements are provided on the conduits so that convective heat transfer between surrounding seawater and the conduit can be allowed or reduced. A control system can activate an alarm indicating the need to adjust the insulation depending on the temperature and/or flow rate of fluids in the conduit. Conventional conduits can be retrofitted by adding adjustable insulation elements to enable thermal management.

A passive cooling system for wellbore operations fluids includes a wellbore operations fluid reservoir including an inlet, an outlet, and a fluid containment area. At least one heat pipe is arranged in the wellbore operations fluid reservoir. The at least one heat pipe includes a first end arranged in the fluid containment area, a second end that extends outwardly of the fluid containment area, and a hollow interior containing a working fluid.

Methods for drilling in higher temperature rock formations such as geothermal formations with phase change material augmented drilling fluid include observing flow rate of the augmented fluid. Heat exchange between the annulus returning fluid and tubular fluid can be minimized thereby facilitating a cooler fluid for contact with a rock face being drilled. The cooling assists in pre-fracturing the rock face prior to destruction by the drill bit.

A method of increasing hydrocarbon recovery from a wellbore in a tight formation with greater breakdown pressures, the method including using hydro-jetting to effect a plurality of oriented cavities or discoidal grooves in the horizontal portion of the wellbore to overcome near-wellbore stresses, injecting a thermally controlled fluid into the wellbore to alter the temperature of the formation and lower stresses, and then fracturing the formation to generate a series of fractures that can be formed in a planar formation.

A Drill-To-The-Limit (DTTL) drilling method variant to Managed Pressure Drilling (MPD) applies constant surface backpressure, whether the mud is circulating (choke valve open) or not (choke valve closed). Because of the constant application of surface backpressure, the DTTL method can use lighter mud weight that still has the cutting carrying ability to keep the borehole clean. The DTTL method identifies the weakest component of the pressure containment system, such as the fracture pressure of the formation or the casing shoe leak off test (LOT). With a higher pressure rated RCD, such as 5,000 psi (34,474 kPa) dynamic or working pressure and 10,000 psi (68,948 kPa) static pressure, the limitation will generally be the fracture pressure of the formation or the LOT. In the DTTL method, since surface backpressure is constantly applied, the pore pressure limitation of the conventional drilling window can be disregarded in developing the fluid and drilling programs.

The present invention relates to a closed loop subsea cooling system with a subsea cooler. A coolant pump assembly is located in a dedicated, sealed, gas filled, coolant pump housing in coolant fluid connection with the at least one subsea cooler. A heat sink in a dedicated sealed, gas filled, electronics housing is in coolant fluid connection with the subsea cooler. An accumulator is in coolant fluid connection with the subsea cooler, whereby the electric coolant pump is adapted to pump coolant through the at least one subsea cooler, the at least one heat sink and back to the at least one electric coolant pump assembly, forming a closed loop subsea cooling circuit.