Abstract: A flow splitting device for gas reverse circulation drilling, including: an upper joint for connecting with a double-wall drill pipe; an inner tube which is arranged in the upper joint and defines a first passageway in communication with an inner chamber of the double-wall drill pipe, a second passageway in communication with an annular space in the double-wall drill pipe formed between the inner tube and the upper joint; a lower joint, having an upper end fixedly connected with the upper joint and a lower end for connecting with a drill tool; and a flow guiding member provided between the upper joint and the lower joint. A flexible sealing mechanism is provided outside the upper joint. The flexible sealing mechanism extends radially outward relative to the upper joint and the lower joint to form a sealing contact with a wellbore wall.

Abstract: A flow splitting device for gas reverse circulation drilling, including: an upper joint for connecting with a double-wall drill pipe; an inner tube which is arranged in the upper joint and defines a first passageway in communication with an inner chamber of the double-wall drill pipe, a second passageway in communication with an annular space in the double-wall drill pipe formed between the inner tube and the upper joint; a lower joint, having an upper end fixedly connected with the upper joint and a lower end for connecting with a drill tool; and a flow guiding member provided between the upper joint and the lower joint. A flexible sealing mechanism is provided outside the upper joint. The flexible sealing mechanism extends radially outward relative to the upper joint and the lower joint to form a sealing contact with a wellbore wall.

Abstract: A method is provided for removing silver mirroring from the surface of a black-and-white negative film by: mixing 80-100 parts by mass of triethanolamine, 0-10 parts by mass of glycerol and 0-10 parts by mass of a surfactant uniformly under stirring to produce a silver mirroring remover, where the surfactant is one or more of isomeric tridecanol polyoxyethylene (8) ether, polyethylene glycol 200, polyethylene glycol 400 or alkylphenol polyoxyethylene (10) ether; applying the silver mirroring remover onto the region of the surface of the negative film, where the silver mirroring occurs, allowing the film to stand for at least 30 minutes, and then blotting up the residual solution on the negative film; and soaking the negative film in n-butanol and cleaning it, and then blotting the residual solvent on the negative film, followed by air drying, to complete the removal of silver mirroring on the surface of the negative film.

Abstract: Various methods and systems for providing query result titles using a problem-solution search engine in a search system are provided. A query is received; the query is identified as a free-text query. Problem description features are identified from the free-text query. The problem description features characterize an issue described in the free-text query. Solution description features associated with product titles are accessed, where solution description features characterize a resolved issue described in a product review. A product associated with the product review is the product that resolved the resolved issue in the product review. The problem description features are compared to the solution description features. A product title is identified as a query result title. The product title is selected based on solution description features of the product title corresponding to the problem description features of the free-text query. The query result title is communicated.

Abstract: A push-the-bit rotary guiding device includes a mandrel having a central passage, a sleeve rotatably sleeved outside the mandrel, a plurality of swing ribs circumferentially arranged in an outer wall of the sleeve with an interval, an actuation mechanism for controlling each swing rib to swing respectively, a plurality of detectors for detecting a distance to a well wall in real-time, and a controller for determining whether the actuation mechanism is required to actuate the swing ribs to swing according to the detected distance. Through a real-time detection of the detectors of the push-the-bit rotary guiding device, a well section having an expanded or reduced diameter is detected in time and guiding of the rotary guiding device herein is avoided. The rotary guiding device has advantages of a simple and compact structure, convenient machining, easy assembling, and a safe and highly-efficient operation, and is easy to be popularized and applied.

Abstract: A static push-the-bit rotary guiding device includes: a mandrel having a central passage, wherein a circumferential groove is provided on an outer wall of the mandrel; a sleeve, which is sleeved in the circumferential groove and able to rotate independently; and a clutch, for cutting off or transferring a power from the mandrel to the sleeve. When it is unnecessary for the static push-the-bit rotary guiding device to provide a deviating force in a steady inclined section, a vertical section and a horizontal section, a rotational inertia and an interior energy storage of the rotary guiding device are not decreased, which is beneficial to highly-efficient and stable drilling of a downstream drill bit.

Abstract: The present disclosure discloses a comb polymer or a salt thereof, wherein the structural formula of the comb polymer containing the following constitutional units. When the comb polymer provided in the present disclosure is used in a water-based drilling fluid as a filtration control agent, it can eliminate the defects of conventional filtration control agents which would be subject to ineffectiveness under high temperature and high salinity conditions. The comb polymer has high temperature and salt resistance, and can be produced through simple processes at comparatively low costs. When the comb polymer provided by the present disclosure is used as a filtration control agent, even being added into the drilling fluid at a comparatively low amount, it can still present rather good effects in lowering the amount of filter loss.

Abstract: A push-the-bit rotary guiding device includes a mandrel having a central passage; a sleeve which is rotatably sleeved outside the mandrel; a plurality of swing ribs which are circumferentially arranged in an outer wall of the sleeve with an interval; an actuation mechanism, for controlling each swing rib to swing respectively; a plurality of detectors, which are circumferentially arranged in the outer wall of the sleeve with an interval, for detecting a distance to a well wall in real-time; and a controller, for determining whether the actuation mechanism is required to actuate the swing ribs to swing according to the detected distance. An application method of the push-the-bit rotary guiding device is provided. According to the push-the-bit rotary guiding device, through a real-time detection of the detectors, a well section having an expanded or reduced diameter is detected in time and guiding of the rotary guiding device herein is avoided.

Abstract: The present disclosure discloses a comb polymer or a salt thereof, wherein the structural formula of the comb polymer containing the following constitutional units. When the comb polymer provided in the present disclosure is used in a water-based drilling fluid as a filtration control agent, it can eliminate the defects of conventional filtration control agents which would be subject to ineffectiveness under high temperature and high salinity conditions. The comb polymer has high temperature and salt resistance, and can be produced through simple processes at comparatively low costs. When the comb polymer provided by the present disclosure is used as a filtration control agent, even being added into the drilling fluid at a comparatively low amount, it can still present rather good effects in lowering the amount of filter loss.