To monitor corrosion in multiphase fluids pipelines, a first pipe is fluidically coupled to extend perpendicularly away from a bottom portion of a multiphase hydrocarbons pipeline. The multiphase hydrocarbons include oil, gas and water. The first pipe is fluidically coupled to a T-shaped pipe subassembly including a second pipe and a third pipe attached to the second pipe to form a T-shape. A hydrocarbon sample of the multiphase hydrocarbons is drawn into the first pipe. Gas in the hydrocarbon sample separates gravimetrically from oil and water in the hydrocarbon sample. The hydrocarbon sample is flowed from the first pipe through the T-shaped pipe subassembly. The hydrocarbon sample is analyzed using a corrosion coupon attached to one end of the third pipe and a corrosion probe attached to another end of the third pipe. A level of corrosion of the pipeline is determined based on results of analyzing the hydrocarbon sample.

Systems and methods for recovering hydrocarbon liquids from oil and gas pipelines are provided that include a tap provided in a section of pipe within a pipeline, wherein the tap includes a straw arranged to extend within the section of the pipe to a low point of the section of pipe; and a pump or compressor arranged to be fluidically coupled to the tap via a first conduit, wherein the pump or compressor is arranged to: draw liquid from the low point of the section of pipe via the tap and the conduit until a pressure within the section of pipe drops to a predetermined pressure; cross-compress the liquid, to raise the pressure from a first pressure to a second pressure that is higher than the first pressure; and inject the liquid at the second pressure back into the pipeline at a location downstream of the tap or into another adjoining pipeline or into a customer asset or into a storage container via a second conduit.