A method of clearing well casing (3) or tubing from a target region of an oil/gas well (1) borehole is provided. The clearance of the oil/gas well bore hole being achieved by employing chemical agents (9) that consume, weaken or melt the well casing/tubing. In some aspects of the method the well casing is cleared to expose the rock formation within which the well borehole is formed so that the rock formation can be accessed from within the well casing/tubing. In other aspects of the method the removal of inner tubing structures is used to facilitate the unimpaired deployment of repair tools down the well borehole.

Insulating fluids for use in drilling, production, and other applications are provided, the insulating fluids containing a porous medium (such as a sponge or foam) to limit the mobility of the liquid phase of the insulating fluid. The porous medium in the insulating fluid provides a mechanical means for reducing convective heat transfer, as the small pore spaces within the porous media create tortuous paths for the liquid moving therethrough. Methods include introducing the insulating fluid into an annulus of a drilling, riser, production, packer, or pipeline assembly to reduce heat transfer therethrough.

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 method for forming a sleeve for wrapping around and insulating a joint of a downhole tubing string is provided. The method includes the steps of providing a mold, applying insulation around the mold, winding an interfacing material around the insulation; and applying a polymer onto the interfacing material to bind to the interfacing material to form the sleeve.

A geothermal well is provided including a first tube including at least one opening in a first depth; a second tube having a closed bottom in a second depth; and a third tube having a closed bottom in a third depth. The first tube is inside the second tube, which is inside the third tube, wherein the first tube has at least one opening in fluid communication with a first interspace between the first tube and the second tube; wherein the third depth and the first depth are smaller than the second depth. Through-holes are formed in the second tube above the bottom of the third tube, which allow fluid communication between the first interspace and a second interspace between the second tube and the third tube. A first sealing element and a heat insulating material are disposed in the first interspace above the through-holes.

Subsea acoustic insulation is used to mitigate noise associated with any one or a combination of a deep-water production tree, a deep-water manifold or structure, subsea pumping equipment, or subsea compression equipment. A subsea oil and gas facility includes subsea equipment having one or more devices that generate noise during operation, and subsea acoustic insulation surrounds at least a portion of the subsea equipment and is configured to attenuate the generated noise.

A method and system are shown that conditions an underground reservoir by flooding the reservoir with a heated fluid to transfer heat to the underground reservoir and cause oil and gas to increase flow during recovery from the underground reservoir, wherein the fluid is heated by heat from a geothermal well, or heated by heat generated by burning gas recovered from the underground reservoir, or heated by heat from both a geothermal well and heat generated by burning gas recovered from the underground reservoir, and recovering the oil and gas with the increased flow.

A system and method for enhanced hydrocarbon recovery utilizing steam. The system may include a high pressure water pump supplying pressurized water to a heat exchanger within a combustion heater to form supercritical steam that is provided to a reservoir. The combustion heater may be a surface mounted heater or a downhole steam generator.

Embodiments relate to cementing operations and, in certain embodiments, to passivated cement accelerators and methods of using passivated cement accelerators in subterranean formations. An embodiment may comprise a method of cementing comprising: providing a cement composition comprising cement, water, and a passivated cement accelerator; and allowing the cement composition to set.

An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.