A treatment fluid can include: a base fluid, wherein the base fluid comprises water; and a lost-circulation material, wherein the lost-circulation material comprises a polymer network having at least one branching point formed with a monomer and a cross-linking agent that comprises at least three active functional groups. The treatment fluid can maintain a pressure differential of at least 1 psi when tested with a cylindrical void that has a diameter of 0.02 inches. The monomer can be a vinyl ester-based monomer that is polymerized with the cross-linking agent to form the polymer network. The treatment fluid can be used in an oil and gas operation.

A lost circulation material (LCM) having flakes formed from waste vehicle tires. The LCM includes flakes produced from waste vehicle tires processed to remove steel components of the tires and produce flakes having a specific size. Also, methods of lost circulation control and manufacture of the waste vehicle tire LCM.

A circulating downhole tool utilising a variable fluid pressure regulated cycle valve device that can be attached to the borehole assembly BHA of a coiled tubing and used down an offshore or onshore wellbore is disclosed. The circulating downhole tool utilising a variable fluid pressure regulated cycle valve device can be remotely operated by an operator on the surface as many times as required in either the through-flow, intermediary or circulatory modes-of-operation, by simply varying the drilling fluid flow rate and pressure being supplied from the pump located on the surface and interconnected to the coiled tubing and the BHA that will include the circulating downhole tool utilising a variable fluid pressure regulated cycle valve device.

Branched and crosslinked polymeric fluid loss control agents and methods are provided that have at least one acrylamide-based monomer, at least one sulfonated anionic monomer, and at least one crosslinking monomer. The at least one acrylamide-based monomer and the at least one sulfonated anionic monomer are crosslinked. The branched and crosslinked polymeric fluid loss control agents have between 50 and 99 mol % of the at least one acrylamide-based monomer, between 1 and 30 mol % of the at least one sulfonated anionic monomer, and between 0.1 and 10 mol % of the at least one crosslinking monomer.

A method of operating an actuator in mud having debris and lost circulation material is described. The method includes closing a servo valve positioned within a valve housing. The valve housing has a plurality of fluid vents positioned downstream of the servo valve and a plurality of debris vents positioned upstream of the servo valve. Dimensions of the plurality of fluid vents are less than dimensions of the plurality of debris vents. Closing of the servo valve creates a first fluid path such that fluid flows from a mud pump at a surface into the plurality of debris vents and out of the plurality of fluid vents shielding the servo valve from debris and lost circulation material.

Compressed lost circulation materials for use in subterranean formations are provided. In some embodiments, the methods include: introducing a treatment fluid that includes a base fluid and a compressed lost circulation material into a wellbore penetrating at least a portion of a subterranean formation including a loss zone, the compressed lost circulation material including a binding material and a compressed material; allowing the binding material to at least partially degrade or dissolve; and allowing the compressed lost circulation material to at least partially expand in the subterranean formation.

A measurement tool may be positioned downhole in a wellbore for measuring formation properties and drilling mud properties during a drilling operation. The measurement tool may include a body and an antenna. The body may include magnets for generating a magnetic field and a transmitter for transmitting a radiofrequency pulse. The antenna may be positioned proximate to the body to measure properties using nuclear magnetic resonant frequencies. The antenna may measure formation properties in a first volume of a formation using a first frequency. The antenna may measure drilling mud properties in a second volume in a borehole using a second frequency.

A method of drilling a subterranean geological formation is described. The method includes driving a drill bit to form a wellbore into the subterranean geological formation thereby producing a formation fluid including hydrogen sulfide (H.sub.2S). The method includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid composition includes 0.25 to 2 wt.% of a primary H.sub.2S scavenger which is potassium permanganate. The drilling fluid composition includes an invert emulsion includes a continuous phase including palm oil and a dispersive phase including water. The potassium permanganate present in the drilling fluid composition reacts with the H.sub.2S present in the formation fluid to produce a dispersion of manganese-containing particles which are at least one selected from the group consisting of manganese sulfide and manganese sulfate.

A multi-impeller passive-rotating-stirring-type rotary drilling rig for open caissons includes a hollow main drill pipe, a drill bit, four cutting edges, four impeller shafts, four passive impellers and a rotation bracket. Through being uniformly distributed at a peripheral of the drilling rig, four passive impellers contact with a hole wall of a borehole during the drilling process for passively generating relative rotation opposite to the rotation direction of the drill bit, so as to accelerate sufficient mixing of silt and water for forming mud during the drilling process, thus enhancing the stirring effect of the drill bit on the mud. The present invention is able to improve the mud discharge efficiency without adding additional power, thus avoiding the blockage of the mud suction pipe and blockage or even breakage of the drill bit due to poor mud discharge during the drilling process.

A multi-impeller passive-rotating-stirring-type rotary drilling rig for open caissons includes a hollow main drill pipe, a drill bit, four cutting edges, four impeller shafts, four passive impellers and a rotation bracket. Through being uniformly distributed at a peripheral of the drilling rig, four passive impellers contact with a hole wall of a borehole during the drilling process for passively generating relative rotation opposite to the rotation direction of the drill bit, so as to accelerate sufficient mixing of silt and water for forming mud during the drilling process, thus enhancing the stirring effect of the drill bit on the mud. The present invention is able to improve the mud discharge efficiency without adding additional power, thus avoiding the blockage of the mud suction pipe and blockage or even breakage of the drill bit due to poor mud discharge during the drilling process.