a high pressure seal adapter for a conductor housing of a wellhead , the high pressure seal adapter having a unitary body comprising : a first circular bore extending through said unitary body ; and a second circular bore adjacent said first circular bore and extending through said unitary body ; wherein said seal adapter is capable of being installed in said conductor housing . the high pressure seal adapter may further include at least one seal extending around a perimeter of said unitary body , said at least one seal contacting said conductor housing . the adapter may receive a high pressure riser in said first circular bore when said seal adapter is installed in said conductor housing , said high pressure riser having a lower surface that contacts said flange and at least one seal extending around an outside perimeter of said riser .