Abstract: Disclosed are a method, device and system for sending a virtual card and a readable storage medium, which are configured to receive at least one audio-video stream data of a plurality of participant terminals in communication connection with a server side; determine target audio-video stream data corresponding to at least one speaker from the at least one audio-video stream data; obtain biological characteristic information for identifying the at least one speaker from the target audio-video stream data, the biological characteristic information includes face characteristic information and/or voiceprint characteristic information; generate a virtual card according to the biological characteristic information; overlay the virtual card to the target audio-video stream data, and synthesize the target audio-video stream data with other audio-video stream data in response to there being a plurality of audio-video stream data into a to-be-sent audio-video stream data; send the to-be-sent audio-video stream data to

Abstract: An electropositive and water-based production well treating fluid system exhibits electropositivity by using a cationic viscosifier meanwhile matched with a cationic fluid loss additive and, optionally, contains a mud-building agent, an electrical stabilizing agent, a colloid-stabilizing agent, lubricant, an oil layer protective agent and/or a weighting agent. The electropositive production well treating fluid can beffer solve the contradiction of technical requirements between “treating fluid stability” and “bore hole stability”, and features a strong ability to inhibit the dispersion of clay, a good effect of protecting oil-gas reservoirs, fast drilling speeds, regular shape of bore holes and good resistance to salt.

Abstract: The present invention provides an electropositive and water-based production well treating fluid system. The production well treating fluid system can be made to exhibit electropositivity by using a cationic viscosifier meanwhile matched with a cationic fluid loss additive and optionally matched with a mud-building agent, electrical stabilizing agent, colloid-stabilizing agent, lubricant, oil layer protective agent and/or weighting agent. Such kind of electropositive production well treating fluid can solve better the contradiction between “treating fluid stability” and “bore hole stability”, and has features in strong ability of inhibiting the dispersion of clay, good effect of protecting oil-gas reservoir, fast drilling speed, regular shape of bore hole and good resistance to salt. The present invention relates further to a method of preparing said production well treating fluid system and use of the drilling fluid and well completion fluid in petroleum drilling and well completion.