Abstract: A transportable well capping system, kit, and methods are provided. The transportable well capping system can include a plurality of modular subsystems capable of fitting within a bed of a standard full-sized pickup truck. The modular subsystems can include a sealing mechanism subassembly including a plurality of different sized seals for securing to a range of diameters of well casings, a gas flow meter subassembly, a hydrogen sulfide scrubber subassembly, a compressor and storage subassembly capable of storing the scrubbed methane in a storage tank, and a methane destruction subassembly capable of igniting the scrubbed methane gas and converting it to carbon dioxide. The subassemblies are sized to be capable of fitting within the bed of a standard full-sized pickup truck and can be driven to a location of an abandoned well and fluidically interconnected in a manner to cap the abandoned well.