METHOD AND DEVICE FOR RISERLESS DRILLING FLUID RECOVERY

摘要

A method and a device for enabling the use of riserless drilling fluid recovery from a seabed-based borehole (1) which is to be drilled by means of a casing (26), the casing (26) being provided with a drill bit (28) at its lower portion and with an inner wellhead (30) at its upper portion, and there being a conductor casing (6), which has an outer wellhead (8), in the seabed (2), the method including:—providing a suction module (12) with a dividable adapter (16) which fits complementarily in the outer wellhead (8);—drilling a length of the borehole (1) by means of the casing (26) extending through the suction module (12), while, at the same time, drilling fluid is flowing via the suction module (12) from the borehole (1);—subsequently pulling the adapter (16) up from the outer wellhead (8) and dividing the adapter (16); and—lowering the casing (26) with the inner wellhead (30) through the suction module (12) and the adapter (16) to its position in the outer wellhead (8).

主权项

1. A method for riserless drilling fluid recovery from a seabed-based borehole configured to be drilled by a casing comprising a drill bit at its lower portion and an inner wellhead at its upper portion, and a conductor casing comprising an outer wellhead placed on the seabed, the method comprising:
providing a suction module with a dividable adapter fit complementarily in the outer wellhead; drilling a length of the borehole with the casing extending through the suction module, while drilling fluid simultaneously flows from the borehole via the suction module; subsequently pulling the dividable adapter up and out of the outer wellhead and dividing the dividable adapter; and lowering the casing with the inner wellhead through the suction module and the dividable adapter into a position in the outer wellhead.