What is provided is a method and apparatus which can be detachably connected to an annular blowout preventer thereby separating the drilling fluid or mud into upper and lower sections and allowing the fluid to be displaced in two stages, such as while the drill string is being rotated and/or reciprocated. In one embodiment the sleeve can be rotatably and sealably connected to a mandrel. The swivel can be incorporated into a drill or well string and enabling string sections both above and below the sleeve to be rotated in relation to the sleeve. In one embodiment the drill or well string does not move in a longitudinal direction relative to the swivel. In one embodiment, the drill or well string does move longitudinally relative to the sleeve of the swivel.

Embodiments of the disclosure provide an unfoldable device for controlling lost circulation in a target lost circulation zone in a borehole. The unfoldable device includes a sheet, a backbone, and a shell. The sheet has an unfolded state and a folded state. The backbone reinforces the sheet. The backbone includes a shape-memory material having an original state and a deformed state. The shell encapsulates the sheet in the folded state and the backbone in the deformed state. In some embodiments, the shell includes a degradable polymer that degrades in the borehole upon contact with a drilling fluid such that the sheet transitions to the unfolded state and the backbone transitions to the original state. The sheet in the unfolded state accumulates on a borehole wall at least partially covering an entrance to a macrochannel of the target lost circulation zone.

Methods and apparatuses for determining surface wetting of metallic materials at downhole wellbore condition with fixed or changing well fluids are disclosed. In general, the methods according to the disclosure include carrying out an electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface by simultaneously dynamically moving electrodes exposed to the well fluid while measuring the changes in electrical characteristics between the electrodes.

Methods and apparatuses for determining surface wetting of metallic materials at downhole wellbore condition with fixed or changing well fluids are disclosed. In general, the methods according to the disclosure include carrying out an electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface by simultaneously dynamically moving electrodes exposed to the well fluid while measuring the changes in electrical characteristics between the electrodes.

Modified Drilling fluid compositions, lost circulation material compositions and methods for using drilling fluid compositions are provided with enhanced loss control properties where the modified drilling fluid may include a carrier fluid, one or more drilling fluid additives, and a lost circulation shape-adaptable material. The loss lost circulation shape-adaptable material may include a plurality of oval shaped composite particles, wherein the plurality of oval shaped composite particles comprise a first component, a second component, and a high temperature, high pressure (HTHP) binding adhesive. Methods to control lost circulation in a lost circulation zone in a wellbore may include introducing a modified drilling fluid into the wellbore such that the modified drilling fluid contacts the lost circulation zone.

A method of extracting the underground resources by pressurizing a fluid filled in an ore chute in which cracks are formed and by, further, forming or growing the cracks, the underground resources being extracted through the cracks, wherein a hydrolysis-blocking agent is introduced with pressure into the fluid to block a diverting agent that works to temporarily close the cracks.

Drill-in fluids disclosed herein comprise an aqueous base fluid, a viscosifier, a fluid loss control additive, and a degradable bridging agent comprising a degradable high strength polymetaphosphate material capable of undergoing an irreversible degradation downhole. The present disclosure further relates to a method for controlling fluid loss through a subterranean surface by using the drill-in fluid for form a filter cake on the subterranean surface. Also provided is a method of degrading a filter cake with an aqueous fluid or aqueous acidic fluid, wherein the filter cake is produced from the drill-in fluid. Further provided is a specific order of addition of constituents of the drill-in fluid, which results in improved filter cake performance and/or filter cake removal.

Compositions for stimulating hydrocarbon production from a subterranean formation are generally disclosed. In some embodiments, such compositions include olefinic ester compounds, such as alkyl esters of C10-18 unsaturated fatty acids. In some embodiments, the olefinic ester compounds are derived from a natural oil or a natural oil derivative, for example, by catalytic olefin metathesis. Uses of such compounds, such as in oil- and gas-production methods are also generally disclosed.

This disclosure includes flow spool riser segment assemblies that are suitable for managed pressure drilling (MPD) and that can be lowered (e.g., when connected to other riser segment assemblies) through a rotary of a drilling rig. Some embodiments are configured to have portions of the flow spool connected (e.g., without welding) below the rotary.

An air/water separator including a first hollow member configured to receive a flow including an air and water mixture and a second hollow member configured to receive the flow from the first hollow member. An exit of the first hollow member extends into an opening of the second hollow member such that the exit of the first hollow member axially overlaps the opening of the second hollow member, thereby creating a first flow path from the interior of the first hollow member to the outside of the second hollow member including two turns about the exit of the first hollow member and opening of the second hollow member, and a second flow path from the first hollow member through the second hollow member.