... being employed to redefine interval limitations in deepwater operations. This discussion includes limitations of conventional methods, types of riserless fluids in use today as well as future considerations, the benefit of new hardware designed to optimize the process, challenges accompanying this new...

...Abstract Abstract Drilling hazards in deepwater riserless intervals include shallow water and gas flows, disassociating gas hydrates, lost circulation and formation instability all which are particularly challenging without a proper mitigation strategy. Unmitigated, these hazards can result...

... Abstract The operator and co-venturers are developing several Angola Block 15 fields in water depths of up to 1400m. To date, 83 development wells and 33 exploration / appraisal wells have been drilled in the Block. Most have experienced hole quality issues in the riserless interval...

... shallow water flow zones and a narrow pore pressure to fracture gradient margin requiring a very aggressive top hole casing program, including the drilling of two riserless intervals prior to running the 20-inch conductor casing. Riserless drilling of the upper intervals of subsea wells has been standard...

... with a shallow flow zone can ultimately prevent deepwater wells from reaching projected casing points and even total well depths.1 The technical challenges commonly encountered when drilling riserless intervals are: Logistics - being able to supply enough weighted fluid at the wellsite to drill the interval...

... Artificial Intelligence drilling fluid chemistry planning & scheduling drilling fluid formulation riserless interval drilling fluid selection and formulation drilling fluids and materials LMP offshore supply base bulk facility requirement drilling fluid property Upstream Oil...

...-diameter deepwater intervals can cause bit balling, especially with water-based fluids. The dynamic elements of the hybrid drill bit, namely the rolling cones, lead to better bit cleaning and lower balling potential. The riserless intervals of deepwater wells are drilled with fluid pumped down through...

.... These challenges have resulted in new technologies and methods to exploit more resevoirs coupled with new and complex well designs. Riserless drilling has been used for years to construct the shallow intervals of deep water wells due to the low facture gradients in the shallow sediments. However increases in pore...