Well control analysis in conventional and riserless reelwell method

Abstract

The oil industry is nowadays facing several problems as hydrocarbon reserves are declining and challenging areas are forced to explore. Deepwater drilling is one of these challenging areas as increased target depth results in narrower working window between pore pressure and fracture pressure. Reelwell Riserless Drilling Method can solve these problems.

This thesis is written in cooperation with Reelwell AS. The unique technology developed by Reelwell is based on drilling with a dual bore string which provides optimum well control, resulting in long reach wells without the use of riser in deepwater environment. This thesis will focus on a well “Well A-1” which is regarded as typical for presalt reservoirs in the Atlantics. Both RDM-R and conventional drilling approaches are based on this well. The well control aspects described focus on kick causes, kick detection and the kill procedures.

Well Plan in Landmark simulator has been used to calculate kick tolerance and choke pressure behavior during kick circulation with given inputs from well A-1.

A well control comparison between RDM-R and Conventional Method, both riserless and with riser was made. The results showed that with riserless drilling approach a lot of time will be saved in order to circulate the kick out of the well. RDM-R further shows many beneficial advantages as listed in the summary, table 4-26.