A system for accessing a well, comprising: a spool comprising a longitudinal passage and a longitudinal upper end, the spool further comprising a spool hub connection and a spool lateral flow passage extending through the spool from the spool longitudinal passage to the spool hub connection, said spool hub connection being configured to interface with a mating hub connection of a horizontal tree, said spool hub connection being configured to establish a flow path from the spool lateral flow passage and into the horizontal tree when the spool hub connection being is coupled with the mating hub connection; a tubing hanger installed and supported in the spool longitudinal passage and comprising a hanger longitudinal passage through the tubing hanger, the tubing hanger including a lateral flow passage extending through the tubing hanger and in fluid communication with the hanger longitudinal passage, the hanger lateral flow passage being configured to transfer a product from the hanger longitudinal passage to the spool lateral passage, an upper end of the hanger longitudinal passage being in fluid communication with the spool longitudinal passage; fluid barriers within the hanger longitudinal passage to control access to the well, at least one of the fluid barriers comprising an adjustable barrier, wherein the adjustable barrier comprises an actuatable valve; a cap configured to be disposed in the spool longitudinal passage between the tubing hanger and the upper longitudinal end, the cap comprising a cap longitudinal passage through the cap, an upper end and a lower end of the cap longitudinal passage being in fluid communication with the spool longitudinal passage; and an adjustable barrier located in the cap longitudinal passage to control access to the well, characterized in the cap further comprising an actuatable valve in an annulus access passage extending through the cap along the cap longitudinal passage and separate from the cap longitudinal passage, an upper end and a lower end of the cap annulus access passage being in fluid communication with the spool longitudinal passage, wherein, when the actuatable valve in the cap annulus passage is open, a fluid can be pumped from above the cap and down through the cap to above the tubing hanger. a spool comprising a longitudinal passage and a longitudinal upper end, the spool further comprising a spool hub connection and a spool lateral flow passage extending through the spool from the spool longitudinal passage to the spool hub connection, said spool hub connection being configured to interface with a mating hub connection of a horizontal tree, said spool hub connection being configured to establish a flow path from the spool lateral flow passage and into the horizontal tree when the spool hub connection being is coupled with the mating hub connection; a tubing hanger installed and supported in the spool longitudinal passage and comprising a hanger longitudinal passage through the tubing hanger, the tubing hanger including a lateral flow passage extending through the tubing hanger and in fluid communication with the hanger longitudinal passage, the hanger lateral flow passage being configured to transfer a product from the hanger longitudinal passage to the spool lateral passage, an upper end of the hanger longitudinal passage being in fluid communication with the spool longitudinal passage; fluid barriers within the hanger longitudinal passage to control access to the well, at least one of the fluid barriers comprising an adjustable barrier, wherein the adjustable barrier comprises an actuatable valve; a cap configured to be disposed in the spool longitudinal passage between the tubing hanger and the upper longitudinal end, the cap comprising a cap longitudinal passage through the cap, an upper end and a lower end of the cap longitudinal passage being in fluid communication with the spool longitudinal passage; and an adjustable barrier located in the cap longitudinal passage to control access to the well, characterized in the cap further comprising an actuatable valve in an annulus access passage extending through the cap along the cap longitudinal passage and separate from the cap longitudinal passage, an upper end and a lower end of the cap annulus access passage being in fluid communication with the spool longitudinal passage, wherein, when the actuatable valve in the cap annulus passage is open, a fluid can be pumped from above the cap and down through the cap to above the tubing hanger.