A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilization in forming the barrier is provided.

A while drilling mud loss treatment method includes providing a drilling tool main body with a through bore connected to an above arranged wired drill pipe string with a communication line to a topsides monitoring and control system, the drilling tool main body connected to a below arranged one or more drill collar sections with a lower of said drill collar sections connected to a drill bit, and drilling in a well. The main body is provided with an annular tank with a swellable sealant and the annular tank has a valve to an outlet to the through bore. A control system in the main body receives MWD sensor signals from an MWD sensor system and controls the valve having a valve actuator. The control system is, during drilling, running a monitoring and control algorithm using the signals as input for detecting an undesired mud loss state during drilling, and, if a mud loss state is detected, to command said valve actuator to open said valve upon detecting an undesired mud loss state, so as for ejecting said swellable sealant to said through bore.

A drilling fluid and method for drilling in a coal containing formation. The method includes: providing a mixed metal-viscosified drilling fluid including at least 1% potassium salt; circulating the drilling fluid through the well; and drilling into a coal seam.

An aqueous suspension of polymer bodies is made by coalescing polymer from a flowing aqueous solution. These suspended bodies may be fibrous in appearance. However, the coalescence of the polymer bodies may be controlled to produce shapes. The coalesced polymer bodies are used for treating a downhole location within or accessed by a borehole. The bodies may be formed by coalescence at the surface and then pumped downhole or may be formed by coalescence downhole. Coalescence of polymer may result from crosslinking, complexing with material of opposite charge, or change in the polymer solution temperature, pH, solute concentration or solvent. The coalesced polymer bodies are maintained in aqueous solution after coalescence, and are not removed from solution for strengthening.

A testing apparatus for testing a fluid and a loss control material (LCM) is provided. The testing apparatus includes a testing chamber having an upstream end, a downstream end, a device central axis, and a general flow direction. The testing chamber includes a chamber body having an upstream cap, a downstream cap, a first chamber wall, and a second chamber wall. The first chamber wall has a first diameter and in part defines a first chamber interior, the second chamber wall has a second diameter, the first diameter is less than the second diameter, and both the first chamber wall and the second chamber wall are positioned relative to one another such that an annulus is defined in part in between. The traversal of the fluid and the LCM along the fluid flow path is restricted by a flow restriction.

A communication unit is situated in or on a casing collar. The casing collar has two threaded ends for joining casing joints to construct a well casing, and a communication unit is disposed in or on a central region of the tube between the two threaded ends. In an example, the communication unit has a transmitter for transmitting sensor data uphole from a sensor sensing a well bore condition. For example, the communication unit has a receiver for receiving sensor data from Micro-Electro-Mechanical Systems (MEMS) sensors, a transceiver for interrogating RFID tags, an acoustic transceiver for sensing wellbore conditions, a pressure sensor, a temperature sensor, and batteries for powering the communication unit.

Systems and methods for drilling in a subterranean formation are disclosed. A method comprises providing a drilling fluid, wherein the drilling fluid comprises an aqueous fluid; a first polymer comprising 2-acrylamido-2-methylpropane sulfonic acid, vinylpyrrolidinone, pentaerythritol allyl ether, and methylenebisacrylamide; and a second polymer comprising acrylate. 2-acrylamido-2-methylpropane sulfonic acid, methacrylic acid, and allyloxy 2-hydroxy propane sulfonic acid. The method further comprises placing the drilling fluid into the subterranean formation and drilling a wellbore in the subterranean formation.

On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (α) from the bitstream, where 1≤m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.

A plugging assembly includes a plug and a setting tool attached directly to the plug, wherein the plug includes an elongate core with an uphole end and a downhole end opposite the uphole end, and a sealing element disposed fully around the core to seal against the casing. The plug additionally includes an anchoring system for anchoring the plug to the casing in a fixed position, a compression fitting disposed around the core at or near the uphole end of the core, and a nose at the downhole end of the core. The setting tool includes an elongate housing extending between an uphole end and a downhole end opposite the uphole end, an open passageway extending from the uphole end to the downhole end of the housing, and the downhole end of the housing is aligned to directly engage the compression fitting of the plug.

A two-component lost circulation material (LCM) is provided having a polymer component and a sodium hydroxide component. The polymer component may include a carrier fluid such as water, a particulate material such as fly ash, a fibrous material such as polypropylene fibers, and an acrylic polymer. The sodium hydroxide component may include water and sodium hydroxide. The sodium hydroxide component is introduced to contact the polymer component to form the two-component LCM. Methods of lost circulation control and manufacture of a two-component LCM are also provided.