Well Control Aspects Regarding Slender Well Drilling With Surface and Subsea BOP

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe 2003 Brazilian deepwater drilling record (4 th in the world) was achieved with a slender well in a 2887-meter water depth in Campos Basin (block BMC-10), Rio de Janeiro. Uncommon to the drilling practices throughout the world and, particularly, in the Brazilian coast, the well was safely drilled with a surface blowout preventer system (SBOP). Beyond the importance of a world record class, the result points out to an important paradigm shift in the current technical culture throughout the country, considering safety (human, environmental and material), economical and regulatory issues which surrounds such decision taking task. This work presents two discussions: the first one concerns the technical issues considering well control operations performed on the drilled well and on a hypothetical conventional well that could also be drilled under the same conditions. This discussion involves the calculation of pressures at the choke, at the casing and liner shoes, pit gain and produced gas rates at the surface using the driller's method. The results were obtained with an existing well control simulator for deep and ultradeep water drilling. The second discussion concerns important aspects of the surface BOP technology mainly related to well control. Thus, the main objective of the present work is to bring to light a broad discussion regarding the potential application of the SBOP concept to explore and develop deep and ultradeepwater reserves in Brazil, with emphasis on well control.

Development of the artificial seabed technology and implementation pretrial well in the South China Sea

“…The ABS provides a buoyancy assisted stable semi-submersible 200 m to 400 m below the sea surface using a tieback of 22-in casing string from the first casing in the well as an anchoring system [4] . This means that the BOP and riser do not have to run to the seabed in deepwater.…”