An apparatus, system, and method are disclosed for in-situ extraction of hydrocarbons from a hydrocarbon-bearing formation. The system includes a well drilled through a hydrocarbon-bearing formation, and a completion unit that places an injection tube near a fluid injection point near the bottom of a target zone and a production tube near a fluid production point near the top of the target zone. An isolation unit isolates the fluid injection point from the fluid production point such that injected fluid flows through the target zone. The system further includes a heat source, and a fluid that delivers thermal energy from the heat source to the hydrocarbons in the target zone to entrain the hydrocarbons in the fluid. The resulting production fluid is heated, free hydrogen is added, and the production fluid is treated on a catalytic reactor to reduce the size of the hydrocarbon chains.